What Is Hearing Impairment?

Hearing impairment occurs when there's a problem with or damage to one or more parts of the ear.

Conductive hearing loss results from a problem with the outer or middle ear, including the ear canal, eardrum, or ossicles. A blockage or other structural problem interferes with how

sound gets conducted through the ear, making sound levels seem lower. In many cases, conductive hearing loss can be corrected with medications or surgery.

Sensorineural (pronounced: sen-so-ree-nyour-ul) hearing loss results from damage to the inner ear (cochlea) or the auditory nerve. The most common type is caused by the outer hair

cells not functioning correctly. The person has trouble hearing clearly, understanding speech, and interpreting various sounds. This type of hearing loss is permanent. It may be

treated with hearing aids.

In most severe cases, both outer and inner hair cells aren't working correctly. This is also a type of permanent hearing loss and can be treated with a cochlear implant. In some other

cases, the outer hair cells work correctly, but the inner hair cells or the nerve are damaged. This type of hearing loss is called auditory neuropathy spectrum disorder. The transmission

of sound from the inner ear to the brain is then disorganized.

Children with auditory neuropathy spectrum disorder can develop strong language and communication skills with the help of medical devices, therapy, and visual communication

techniques.

Mixed hearing loss happens when someone has both conductive and sensorineural hearing problems.

Central hearing loss happens when the cochlea is working properly, but other parts of the brain are not. This is a less frequent type of hearing loss and is more difficult to treat.

Auditory processing disorders (APD). This is not exactly a type of hearing loss because someone with APD can usually hear well in a quiet environment. But most people with APD have difficulty hearing in a noisy environment, which is the usual environment we live in. In

most cases, APD can be treated with proper therapy.

The degree of hearing impairment can vary widely from person to person. Some people have partial hearing loss, meaning that the ear can pick up some sounds; others have complete hearing loss, meaning that the ear cannot hear at all (people with complete

hearing loss are considered deaf). In some types of hearing loss, a person can have much more trouble when there is background noise. One or both ears may be affected, and the

impairment may be worse in one ear than in the other.

1

The timing of the hearing loss can vary, too. Congenital hearing loss is present at birth. Acquired hearing loss happens later in life — during childhood, the teen years, or in

adulthood — and it can be sudden or progressive (happening slowly over time).

According to the National Institute on Deafness and Other Communication Disorders, about 28 million Americans are deaf or hearing impaired. That's about 1 out of every 10 people. Another 30 million are exposed to hazardous noise levels on a regular basis. Hearing loss is also the most common birth anomaly

r genes"? They were probably talking about a physical characteristic, personality trait, or talent that you share with other members of your family.

We know that genes play an important role in shaping how we look and act and even whether we get sick. Now scientists are trying to use that knowledge in exciting new ways,

such as treating health problems.

What Is a Gene?

To understand how genes work, let's review some biology basics. Most living organisms are made up of cells that contain a substance called deoxyribonucleic (pronounced: dee-AHK-

see-rye-bow-noo-klee-ik) acid (DNA).

DNA contains four chemicals (adenine, thymine, cytosine, and guanine — called A, T, C, and G for short) that are strung in patterns on extremely thin, coiled strands in the cell. How

thin? Cells are tiny — invisible to the naked eye — and each cell in your body contains about 6 feet of DNA thread, for a total of about 3 billion miles of DNA inside you!

So where do genes come in? Genes are made of DNA, and different patterns of A, T, G, and C code for the instructions for making things your body needs to function (like the enzymes to

digest food or the pigment that gives your eyes their color). As your cells duplicate, they pass this genetic information to the new cells.

DNA is wrapped together to form structures called chromosomes. Most cells in the human body have 23 pairs of chromosomes, making a total of 46. Individual sperm and egg cells,

however, have just 23 unpaired chromosomes. You received half of your chromosomes from your mother's egg and the other half from your father's sperm cell. A male child receives an

2

X chromosome from his mother and a Y chromosome from his father; females get an X chromosome from each parent.

Genes are sections or segments of DNA that are carried on the chromosomes and determine specific human characteristics, such as height or hair color. Because you have a pair of each

chromosome, you have two copies of every gene (except for some of the genes on the X and Y chromosomes in boys, because boys have only one of each).

Some characteristics come from a single gene, whereas others come from gene combinations. Because every person has about 25,000 different genes, there is an almost endless number of possible combinations

how Is It Treated?

Treatment for hearing loss varies depending upon the cause of the hearing impairment

Treatment may involve removing wax or dirt from the ear or treating an underlying infection. If there is damage or a structural problem with the eardrum or ossicles, surgery may help to repair it. If the problem is with the cochlea or hearing nerve, a hearing aid or

cochlear implant may be recommended.

Hearing aids come in various forms that fit inside or behind the ear and make sounds louder. They are adjusted by the audiologist so that the sound coming in is amplified enough to

allow the person with a hearing impairment to hear it clearly.

Sometimes, the hearing loss is so severe that the most powerful hearing aids can't amplify the sound enough. In those cases, a cochlear implant may be recommended.

Cochlear implants are surgically implanted devices that bypass the damaged inner ear and send signals directly to the auditory nerve. A small microphone behind the ear picks up

sound waves and sends them to a receiver that has been placed under the scalp. This receiver then transmits impulses directly to the auditory nerve. These signals are perceived

as sound and allow the person to hear.

Depending upon whether someone is born without hearing (congenital deafness) or loses hearing later in life (after learning to hear and speak, which is known as post-lingual

deafness), medical professionals will determine how much therapy the person needs to

3

learn to use an implant effectively. Many people with implants learn to hear sounds effectively and even use the telephone.

More than 200,000 people around the world have received cochlear implants and about one third of them are children.

Some patients with hearing loss and their families may decide not to restore hearing. This is particularly true of children whose parents are hearing impaired and want their children to be able to function in the deaf community. The language of the deaf community is American Sign Language (ASL). ASL is a system of gestures many deaf and hearing-impaired people use to communicate

Description:

A hearing impairment is a hearing loss that prevents a person from totally receiving sounds through the ear. If the loss is mild, the person has difficulty hearing faint or distant speech. A

person with this degree of hearing impairment may use a hearing aid to amplify sounds. If the hearing loss is severe, the person may not be able to distinguish any sounds. There are

four types of hearing loss:

Conductive: caused by diseases or obstructions in the outer or middle ear that usually affect all frequencies of hearing. A hearing aid generally helps a person with a conductive hearing

loss.

Sensorineural: results from damage to the inner ear. This loss can range from mild to profound and often affects certain frequencies more than others. Sounds are often

distorted, even with a hearing aid.

Mixed: occurs in both the inner and outer or middle ear.

Central: results from damage to the central nervous system.

People with hearing impairment can communicate using numerous methods of communication, such as:

American Sign Language (ASL): This is the primary language of people who are deaf. It consists of a combination of hand movements and positions to express thoughts and

phrases.

Finger spelling: This is a manual form of communication in which the hand and fingers spell out letters of the alphabet to form words.

4

Lipreading: This is a difficult skill used only by about 10% of people with hearing impairments. Therefore, don't assume that a deaf person to whom you are speaking can lip

read. Even if a person cannot lip read, however, being allowed to see the speaker's mouth provides helpful visual cues.

Written communication ("Pad and Pencil"): This is a fairly simple way to communicate with a person who is deaf. Remember, however, that sign language is the primary language for

most persons who are deaf; English is a second language, so keep your words simple.

Oral communication

(From: "Those of Us DisLabeled: A Guide to Awareness and Understanding", University of Kentucky Human Development Institute, Cooperative Extension Service)

Adaptations/Accommodations:

Smile and maintain eye contact during the time you are talking to a person who is hearing impaired. The person always needs to be able to see your lips if he has learned to read lips. If

a sign language interpreter is present, talk directly to the person who is deaf, not the interpreter.

If at all feasible, use complete sentences, especially when communicating with children. Good language development is dependent upon correct use of verbs, adjectives, adverbs,

nouns, etc. Restricting communication to a single word or short phrase deprives this population of opportunities to master the English language, thus limiting their academic

development.

Speak slowly and clearly, but do not exaggerate. Be expressive, but not overly so.

If a word is not understood, try another word. Demonstrate if possible.

Use sign language only if you're qualified. Otherwise, incorrect information may be conveyed.

Do not shout. Hearing aids make sounds louder, but they do not clarify the person's reception or understanding of the sound. The presence of a hearing aid does not mean that

the person can hear normally.

If all else fails, use a pad and pencil to communicate. Since this often isolates the person with a hearing impairment from the group, try to use writing only if oral speech, lip reading, sign

language, gestures, and finger spelling have failed.

During group gatherings, seat the person with a hearing impairment so s/he can see others in the group. Try a semi-circle arrangement. If possible, arrange to have an interpreter or

note-taker. Use visual aids whenever possible.

5

Watch the person who is deaf or hearing impaired carefully for facial expressions and body language that will help you determine the success of your communication.

If you have trouble understanding the speech of a person who is deaf, don't hesitate to ask him to repeat what he said. Your willingness and desire to communicate is what is most important, not the ease with which you understand

. Visual Impairment 

Definition

Total blindness is the inability to tell light from dark, or the total inability to see. Visual impairment or low vision is a severe reduction in vision that cannot be corrected with

standard glasses or contact lenses and reduces a person's ability to function at certain or all tasks. Legal blindness (which is actually a severe visual impairment) refers to a best-

corrected central vision of 20/200 or worse in the better eye or a visual acuity of better than 20/200 but with a visual field no greater than 20° (e.g., side vision that is so reduced that it

appears as if the person is looking through a tunnel).

Description

Vision is normally measured using a Snellen chart. A Snellen chart has letters of different sizes that are read, one eye at a time, from a distance of 20 ft. People with normal vision are

able to read the 20 ft line at 20 ft-20/20 vision—or the 40 ft line at 40 ft, the 100 ft line at 100 ft, and so forth. If at 20 ft the smallest readable letter is larger, vision is designated as

the distance from the chart over the size of the smallest letter that can be read.

Eye care professionals measure vision in many ways. Clarity (sharpness) of vision indicates how well a person's central visual status is. The diopter is the unit of measure for refractive errors such as nearsightedness, farsightedness, and astigmatism and indicates the strength of corrective lenses needed. People do not just see straight ahead; the entire area of vision is called the visual field. Some people have good vision (e.g., see clearly) but have areas of

reduced or no vision (blind spots) in parts of their visual field. Others have good vision in the center but poor vision around the edges (peripheral visual field). People with very poor

vision may be able only to count fingers at a given distance from their eyes. This distance becomes the measure of their ability to see.

The World Health Organization (WHO) defines impaired vision in five categories:

Low vision 1 is a best corrected visual acuity of 20/70.

Low vision 2 starts at 20/200.

Blindness 3 is below 20/400.

Blindness 4 is worse than 5/300

6

Blindness 5 is no light perception at all.

A visual field between 5° and 10° (compared with a normal visual field of about 120°) goes into category 3; less than 5° into category 4, even if the tiny spot of central vision is perfect.

Color blindness is the reduced ability to perceive certain colors, usually red and green. It is a hereditary defect and affects very few tasks. Contrast sensitivity describes the ability to

distinguish one object from another. A person with reduced contrast sensitivity may have problems seeing things in the fog because of the decrease in contrast between the object

and the fog.

According to the WHO there are over forty million people worldwide whose vision is category 3 or worse, 80% of whom live in developing countries. Half of the blind population

in the United States is over 65 years of age.

Causes and symptoms

The leading causes of blindness include:

macular degeneration

glaucoma

cataracts

diabetes mellitus

Other possible causes include infections, injury, or nutrition.

Infections

Most infectious eye diseases have been eliminated in the industrialized nations by sanitation, medication, and public health measures. Viral infections are the main exception

to this statement. Some infections that may lead to visual impairment include:

Herpes simplex keratitis. A viral infection of the cornea. Repeated occurrences may lead to corneal scarring.

Trachoma. This disease is responsible for six to nine million cases of blindness around the world, of the third of a billion who have the disease. Trachoma is caused by an incomplete

bacterium, Chlamydia trachomatis, that is easily treated with standard antibiotics. It is transmitted directly from eye to eye, mostly by flies. The chlamydia gradually destroy the

cornea.

Leprosy (Hansen's disease). This is another bacterial disease that has a high affinity for the eyes. It, too, can be effectively treated with medicines.

River blindness. Much of the tropics of the Eastern Hemisphere are infested with Onchocerca volvulus, a worm that causes "river blindness." This worm is transmitted by fly

7

bites and can be treated with a drug called ivermectin. Nevertheless, twenty-eight million people have the disease, and 40% of them are blind from it.

Other causes

Exposure of a pregnant woman to certain diseases (e.g., rubella or toxoplasmosis) can cause congenital eye problems. Injuries to the eyes can result in blindness. Very little blindness is

due to disease in the brain or the optic nerves. Multiple sclerosis and similar nervous system diseases, brain tumors, diseases of the eye sockets, and head injuries are rare causes of

blindness.

Nutrition

Vitamin A deficiency is a widespread cause of corneal degeneration in children in developing nations. As many as five million children develop xerophthalmia from this deficiency each

year. Five percent end up blind.

Diagnosis

A low vision exam is slightly different from a general exam. While a case history, visual status, and eye health evaluation are common to both exams, some things do differ. Eye

charts other than a Snellen eye chart will be used. Testing distance will vary. A trial frame worn by the patient is usually used instead of the instrument containing the lenses the

patient sits behind (phoropter). Because the low vision exam is slightly more goal oriented than a general exam, for example, what specifically is the patient having trouble with

(reading, seeing street signs, etc.) different optical and nonoptical aids will generally be tried. Eye health is the last thing to be checked so that the lights necessary to examine the eyes

will not interfere with the rest of the testing.

Treatment

There are many options for patients with visual impairment. There are optical and nonoptical aids. Optical aids include:

Telescopes. May be used to read street signs.

Hand magnifiers. May be used to read labels on things at the store.

Stand magnifiers. May be used to read.

Prisms. May be used to move the image onto a healthy part of the retina in some eye diseases.

Closed circuit television (CCTV). For large magnification (e.g., for reading).

Nonoptical aids can include large print books and magazines, check-writing guides, large print dials on the telephone, and more.

For those who are blind, there are enormous resources available to improve the quality of life. For the legally blind, financial assistance for help may be possible. Braille and audio

8

books are increasingly available. Guide dogs provide well-trained eyes and independence. Orientation and mobility training is available. There are special schools for blind children and

access to disability support through Social Security and private institutions.

Prognosis

The prognosis generally relates to the severity of the impairment and the ability of the aids to correct it. A good low vision exam is important to be aware of the latest low vision aids.

Prevention

Regular eye exams are important to detect silent eye problems (e.g., glaucoma). Left untreated, glaucoma can result in blindness.

Corneal infections can be treated with effective antibiotics. When a cornea has become opaque beyond recovery it must be transplanted. Good hygiene (e.g., washing hands

frequently) to prevent infection, proper use of contact lenses, and not sharing makeup are just some ways to guard against corneal infections.

Cataracts should be removed when they interfere with a person's quality of life.

Primary prevention addresses the causes before they ever begin. Fly control can be accomplished by simple sanitation methods. Public health measures can reduce the

incidence of many infectious diseases. Vitamin A supplementation (when appropriate) will eliminate xerophthalmia completely. It is possible that protecting the eyes against ultraviolet

(UV) light will reduce the incidence of cataracts, macular degeneration, and some other eye diseases. UV coatings can be placed on regular glasses, sunglasses, and ski goggles. Patients should ask their eye care professional about UV coatings. Protective goggles should also be

worn in certain situations (e.g., certain jobs, sports, even mowing the lawn).

Secondary prevention addresses treating established diseases before they cause irreversible eye damage. Having general physical checkups can also detect systemic diseases such as diabetes or high blood pressure. Control of diabetes is very important in preserving sight.

Resources

Organizations

American Academy of Ophthalmology. 655 Beach Street, P.O. Box 7424, San Francisco, CA 94120-7424. http://www.eyenet.org.

American Foundation for the Blind. 11 Penn Plaza, Suite 300, New York, NY 10001. (800) 232-5463.

Guide Dogs for the Blind. P.O. Box 1200, San Rafael, CA 94915. (415) 499-4000.

International Eye Foundation. 7801 Norfolk Ave., Bethesda, MD 20814. (301) 986-1830.

Lighthouse National Center for Education. 111 E. 59th Street. New York, NY 10022. (800) 334-5497. http://www.lighthouse.org.

9

National Association for the Visually Handicapped. 22 West 21st St., New York, NY 10010. (212) 889-3141.

National Center for Sight. (800) 221-3004.

National Children's Eye Care Foundation. One Clinic Center, A3-108, Cleveland, OH 44195. (216) 444-0488.

National Eye Institute. 2020 Vision Place, Bethesda, MD 20892-3655. (301) 496-5248. http://www.nei.nih.gov.

National Federation of the Blind. 1800 Johnson St., Baltimore, MD 21230. (301) 569-9314.

Prevent Blindness America. 500 East Remington Road, Schaumburg, IL 60173. (800) 331-2020. http://www.preventblindness.org.

Research to Prevent Blindness. 598 Madison Ave., New York, NY 10022. (212) 363-3911.

the human eye is like a camera that collects, focuses, and transmits light through a lens to create an image of its surroundings. In a camera, the image is created on film or an image

sensor. In the eye, the image is created on the retina, a thin layer of light-sensitive tissue at the back of the eye.

Like a camera, the human eye controls the amount of light that enters the eye. The iris (the colored circular part of the eye) controls the amount of light passing through the pupil. It

closes up the pupil in bright light and opens it wider in dim light. The cornea is the transparent, protective surface of the eye. It helps focus light, as does the lens, which sits

just behind the iris.

When light enters the eye, the retina changes the light into nerve signals. The retina then sends these signals along the optic nerve (a cable of more than 1,000,000 nerve fibers) to

the brain. Without a retina or optic nerve, the eye can't communicate with the brain, making vision impossible.

What Is Visual Impairment?

Many people have some type of visual problem at some point in their lives. Some can no longer see objects far away. Others have problems reading small print. These types of

conditions are often easily treated with eyeglasses or contact lenses.

10

But when one or more parts of the eye or brain that are needed to process images become diseased or damaged, severe or total loss of vision can occur. In these cases, vision can't be fully restored with medical treatment, surgery, or corrective lenses like glasses or contacts.

The American Foundation for the Blind estimates that 10 million people in the United States are visually impaired. Visual impairment is a term experts use to describe any kind of vision

loss, whether it's someone who cannot see at all or someone who has partial vision loss.

Some people are completely blind, but many others have what's called legal blindness. They haven't lost their sight completely but have lost enough vision that they'd have to stand 20

feet from an object to see it as well as someone with perfect vision could from 200 feet away

what Causes Visual Impairment?

People rarely lose their eyesight during their teen years. When they do, it's usually caused by an injury like getting hit in the eye or head with a baseball or having an automobile or

motorcycle accident.

Some babies have congenital blindness, which means they are visually impaired at birth. Congenital blindness can be caused by a number of things — it can be inherited, for

instance, or caused by an infection (like German measles) that's transmitted from the mother to the developing fetus during pregnancy.

Conditions that may cause vision loss after birth include:

Amblyopia (pronounced: am-blee-OH-pee-uh) is reduced vision in an eye caused by lack of use of that eye in early childhood. Some conditions cause a child's eyes to send different

messages to the brain (for example, one eye might focus better than the other). The brain may then turn off or suppress images from the weaker eye and vision from that eye then

stops developing normally. This is also known as a "lazy eye." Strabismus (misaligned or crossed eyes) is a common cause of amblyopia, since the brain will start to ignore messages

sent by one of the misaligned eyes.

Cataracts are cloudy areas in part or all of the lens of the eye. In people without cataracts, the lens is crystal clear and allows light to pass through and focus on the retina. Cataracts prevent light from easily passing through the lens, and this causes loss of vision. Cataracts

often form slowly and usually affect people in their 60s and 70s, but sometimes babies are

11

born with congenital cataracts. Symptoms include double vision, cloudy or blurry vision, difficulty seeing in poorly lit spaces, and colors that seem faded.

Diabetic retinopathy (pronounced: reh-ton-AH-pa-thee) occurs when the tiny blood vessels in the retina are damaged due to diabetes. People with retinopathy may not have any

problems seeing at first. But if the condition gets worse, they can become blind. Teens who have diabetes should be sure to get regular eye exams because there are no early warning

signs for this condition. To help prevent retinopathy, people with diabetes should also avoid smoking, keep their blood pressure under control, and keep their blood sugar at an even

level.

Glaucoma is an increase in pressure inside the eye. The increased pressure impairs vision by damaging the optic nerve. Glaucoma is mostly seen in older adults, although babies may be

born with the condition and children and teens can sometimes develop it as well.

Macular (pronounced: MAH-kyoo-lur) degeneration is a gradual and progressive deterioration of the macula, the most sensitive region of the retina. The condition leads to

progressive loss of central vision (the ability to see fine details directly in front). Macular degeneration is often age related (it occurs in older people, especially older than 60), but

sometimes it can occur in younger people. Excessive exposure to sunlight and smoking can increase the risk for age-related macular degeneration. Symptoms may include increased

difficulty reading or watching TV, or distorted vision in which straight lines appear wavy or objects look larger or smaller than normal.

Trachoma (pronounced: truh-KO-muh) occurs when a very contagious microorganism called Chlamydia trachomatis causes inflammation in the eye. It's often found in poor rural countries that have overcrowded living conditions and limited access to water and sanitation. Blindness due to trachoma has been virtually eliminated from the USA

What Do Doctors Do?

If you, your parent, or your doctor suspects a visual problem, you'll probably pay a visit to an ophthalmologist (pronounced: af-thal-MAH-luh-jist), a medical doctor who specializes in

examining, diagnosing, and treating eyes and eye diseases. When someone goes for an examination, the ophthalmologist will look at the structure of that person's eye.

Other simple tests an ophthalmologist may perform include:

Visual acuity test. A person reads an eye chart to measure how well he or she sees at various distances.

Visual field test. Ophthalmologists use this test to measure side, or peripheral, vision.

Tonometry test. This test determines the fluid pressure inside the eye to evaluate for glaucoma.

12

If your doctor determines that you have an eye condition that is likely to cause visual impairment, many treatments are available. Options may include eyeglasses, contact lenses,

and eye drops or other medicines.

In some cases, surgery may be required. For instance, cataracts are often treated by removing the clouded lens and replacing it with an intraocular lens (an artificial plastic lens

that requires no special care and restores vision).

Other methods can compensate for vision loss. Guide dogs can help people get from place to place independently. Braille allows those with visual impairment to read and write. Special equipment such as microscopic and telescopic glasses and voice-recognition software can

make school and homework easier.

What's It Like to Be Visually Impaired?

Just as you don't think about your eye color every day, people with visual impairment don't always think about their condition every day either.

Someone with sight problems can become isolated from others more easily, though. If a visually impaired person asks for assistance, don't hesitate to help. But someone who uses a

cane or a guide dog is probably self-sufficient and may not need help.

Reviewed by: Jonathan H. Salvin, MD

Visual impairment and blindness

Fact Sheet N°282

Updated August 2014

Key facts

285 million people are estimated to be visually impaired worldwide: 39 million are blind and 246 have low vision.

About 90% of the world's visually impaired live in low-income settings.

13

82% of people living with blindness are aged 50 and above.

Globally, uncorrected refractive errors are the main cause of moderate and severe visual impairment; cataracts remain the leading cause of blindness in middle- and low-income

countries.

The number of people visually impaired from infectious diseases has reduced in the last 20 years according to global estimates work.

80% of all visual impairment can be prevented or cured.

Definitions

There are 4 levels of visual function, according to the International Classification of Diseases -10 (Update and Revision 2006):

normal vision

moderate visual impairment

severe visual impairment

blindness.

Moderate visual impairment combined with severe visual impairment are grouped under the term “low vision”: low vision taken together with blindness represents all visual

impairment.

The causes of visual impairment

Globally the major causes of visual impairment are:

uncorrected refractive errors (myopia, hyperopia or astigmatism), 43%

unoperated cataract, 33%

glaucoma, 2%.

Who is at risk?

Approximately 90% of visually impaired people live in developing countries.

14

People aged 50 and over

About 65 % of all people who are visually impaired are aged 50 and older, while this age group comprises about 20 % of the world's population. With an increasing elderly population

in many countries, more people will be at risk of visual impairment due to chronic eye diseases and ageing processes.

Children below age 15

An estimated 19 million children are visually impaired. Of these, 12 million children are visually impaired due to refractive errors, a condition that could be easily diagnosed and

corrected. 1.4 million are irreversibly blind for the rest of their lives and need visual rehabilitation interventions for a full psychological and personal development.

Changes over the last twenty years

Overall, visual impairment worldwide has decreased since the early estimates in 1990s. This is despite an ageing global elderly population. This decrease is principally the result of a

reduction in visual impairment from infectious diseases through:

overall socioeconomic development;

concerted public health action;

increased availability of eye care services;

awareness of the general population about solutions to the problems related to visual impairment (surgery, refraction devices, etc.).

The global response to prevent blindness

Globally, 80% of all visual impairment can be prevented or cured. Areas of progress over the last 20 years include:

governments established national programmes and regulations to prevent and control visual impairment;

15

eye care services increasingly available and progressively integrated into primary and secondary health care systems, with a focus on the provision of services that are high

quality, available and affordable;

campaigns to educate about visual function importance and raise awareness, including school-based education; and

stronger government leadership on international partnerships, with increasing engagement of the private sector.

Data over the last 20 years shows that there has been significant progress in preventing and curing visual impairment in many countries. Furthermore, the massive reduction in

onchocerciasis- and trachoma-related blindness is part of a significant reduction in the disease distribution and has substantially reduced the burden resulting from these infectious diseases. This has been achieved through a number of successful international public-private

partnerships.

Specific achievements include:

Brazil which in the last decade has been providing eye care services through the national social security system;

Morocoo which has launched a public effort to control glaucoma;

China which has invested over 100 million dollars in cataract surgeries since 2009;

Oman has completely integrated eye care service provision in the primary health care framework over the last decade; and

India since 1995 has made available funds for eye care service provision for the poorest at district level.

The largest civil society effort to prevent and cure blinding disease and rehabilitate people whose irreversibly visually impaired or blind is the SightFirst programme of the International

Association of the Lions Club (LIONS). Among others, this programme supports the largest initiative to develop child eye care centres (45 national reference paediatric centres

established in 35 countries so far), implemented in partnership with WHO.

WHO response

WHO coordinates the international efforts to reduce visual impairments.

16

It's role is to:

monitor the worldwide trends of visual impairment by country and by region;

develop policies and strategies to prevent blindness appropriate for various development settings;

to give technical assistance to Member States and partners;

to plan, monitor and evaluate programmes; and

to coordinate effective international partnerships in support of national efforts.

In 2013, the World Health Assembly approved the 2014-19 Action Plan for the universal access to eye health, a roadmap for Member States, WHO Secretariat and international

partners with the aim of achieving a measurable reduction of 25% of avoidable visual impairments by 2019.

WHO works to strengthen national and country-level efforts to eliminate avoidable blindness, help national health care providers treat eye diseases, expand access to eye

health services, and increase rehabilitation for people with residual visual impairment or who are blind. Building accessible and comprehensive health systems is the focus of this

decade.

WHO leads several international alliances of governments, private sector and civil society organizations aiming at contributing to the elimination of blinding diseases. It also provides

technical leadership to specific disease efforts which are deployed by its partners or the private sector to eliminate trachoma from the world by the year 2020.

For the last two decades WHO has worked with a network of international partners and private sector to ensure that appropriate, updated, good quality eye care solutions were

made available to the people in need.

Since 2004, WHO in partnership with Lions Clubs International has established a global network of 45 childhood blindness centres in 35 countries for the preservation, restoration

or rehabilitation of sight in children. This unique and innovative global project has served so far more than 150 million children and will open 10 additional eye care service centres for

the children in 10 new countries in 2014. The centres will help combat to fight avoidable childhood blindness and help securing a future with full visual function for the children in

need of care.

17

In response to the increasing burden of chronic eye disease WHO is coordinating a global research effort to map services and policies for controlling diabetic retinopathy, glaucoma,

age-related macular degeneration and refractive errors.

Finally, to support comprehensive eye care systems, WHO continues to provide epidemiologic and public health technical support to its Member States

The definition of vision impairment by the Centers for Disease Control and Prevention (CDC) says a visually impaired person’s eyesight cannot be corrected to a “normal level.”

It may be said that visual impairment is the functional limitation of the eye or eyes or the vision system. This leads to (1-5)–

Loss of visual acuity and inability of the person to see objects as clearly as a healthy person

Loss of visual field meaning inability of an individual to see as wide an area as the average person without moving the eyes or turning the head.

Photophobia – inability to look at light

Diplopia – double vision

Visual distortion or distortion of images

Visual perceptual difficulties or difficulties of perception

Or any combination of the above features

Low visual acuity

The CDC and the World Health Organization suggest that low visual acuity means vision between 20/70 and 20/400 with the best possible correction, or a visual field of 20 degrees

or less.

Blindness

Blindness is defined as a visual acuity worse than 20/400 with the best possible correction, or a visual field of 10 degrees or less.

18

Legal blindness in the US means visual acuity of 20/200 or worse with the best possible correction, or a visual field of 20 degrees or less. (1)

Measuring visual acuity

Visual acuity is measured by use of a Snellen’s chart.

The chart consists of random letters and numbers of various sizes set at a distance of 6 feet.

The best possible vision if 6/6. Visual field is the width of the vision without moving or turning the head. It is measured in degrees.

Causes of vision impairment

Vision may be impaired due to multiple reasons. These could be due to eye damage, failure of the brain to receive and read the visual cues sent by the eyes etc.

Underlying diseases may also cause visual impairment. The commonest cause is diabetic retinopathy, age-related macular degeneration, formation of cataracts and raised pressure

within the eyes leading to glaucoma.

Who does visual impairment affect?

Although impairment of vision can occur at any point in life, it is more common among the elderly.

Sometimes visual impairment may be inherited. It manifests at birth or in childhood in such cases.

Common conditions are retinitis pigmentosa, genetic or developmental abnormalities etc.

These children with partial or complete impairment are often developmentally delayed especially in gross and fine motor skills. Visually impaired adults struggle with gainful

employment and day to day activities. (1-5)

19

How many people are visually impaired?

Some estimates suggest the approximately 10 million people in the United States are blind or visually impaired.

Some sources suggest that one million adults over the age of 40 are blind, and 2.4 million are visually impaired.

It is estimated that as the elderly population swells over the years, the number of adults with vision impairments is expected to double.

Figures also show that only 46% of working-age adults have vision impairments and 32% of legally blind adults of working age are gainfully employed. (1-5

Educating Students With Visual Impairments for Inclusion in Society

A Paper On The Inclusion Of Students With Visual Impairments

Executive Summary

"Inclusion," "full inclusion" and "inclusive education" are terms which recently have been narrowly defined by some (primarily educators of students with severe disabilities) to

espouse the philosophy that ALL students with disabilities, regardless of the nature or the severity of their disability, receive their TOTAL education within the regular education environment. This philosophy is based on the relatively recent placement of a limited

number of students with severe disabilities in regular classrooms. Research conducted by proponents of this philosophy lacks empirical evidence that this practice results in programs

which are better able to prepare ALL students with visual impairments to be more fully included in society than the current practice, required by federal law, of providing a full

range of program options.

Educators and parents of students with visual impairments have pioneered special education and inclusive program options, for over 164 years. It is significant that the field of education

of visually impaired students was the first to develop a range of special education program options, beginning with specialized schools in 1829 and extending to inclusive (including "full

inclusion") public school program options since 1900.

20

Experience and research clearly support the following three position statements outlining the essential elements which must be in place in order to provide an appropriate education

in the least restrictive environment for students with visual impairments. This document also contains papers which provide additional information supporting each of these position

statements and a list of selected readings on inclusion for students with visual impairments.

I. Students with visual impairments have unique educational needs which are most effectively met using a team approach of professionals, parents and students. In order to meet their unique needs, students must have specialized services, books and materials in appropriate media (including braille), as well as specialized equipment and technology to

assure equal access to the core and specialized curricula, and to enable them to most effectively compete with their peers in school and ultimately in society.

II. There must be a full range of program options and support services so that the Individualized Education Program (IEP) team can select the most appropriate placement in

the least restrictive environment for each individual student with a visual impairment.

III. There must be adequate personnel preparation programs to train staff to provide specialized services which address the unique academic and non-academic curriculum needs

of students with visual impairments. There must also be ongoing specialized personnel development opportunities for all staff working with these students as well as specialized

parent education.

Providing equal access to all individuals with disabilities is the key element of the Rehabilitation Act of 1973 and the Americans with Disabilities Act of 1992. Access involves

much more than providing ramps. Access is also the key element of inclusion, which involves much more than placement in a particular setting. The relationship of access and inclusion

may not be obvious to individuals who are not familiar with the educational and social impact of a vision loss. Placing a student with a visual impairment in a regular classroom

does not, necessarily, provide access and the student is not, necessarily, included. A student with a visual impairment who does not have access to social and physical information

because of the visual impairment, is not included, regardless of the physical setting. Students with visual impairments will not be included unless their unique educational needs for

access are addressed by specially trained personnel in appropriate environments and unless these students are provided with equal access to core and specialized curricula through

appropriate specialized books, materials and equipment.

21

Conclusion: Students with visual impairments need an educational system that meets the individual needs of ALL students, fosters independence, and is measured by the success of

each individual in the school and community. Vision is fundamental to the learning process and is the primary basis upon which most traditional education strategies are based.

Students who are visually impaired are most likely to succeed in educational systems where appropriate instruction and services provided in a full array of program options by qualified

staff to address each student's unique educational needs, as required by Public Law 101-476, The Individuals with Disabilities Education Act (IDEA).

The Unique Educational Needs Of Students With Visual Impairments

Position Statement I:

Students with visual impairments have unique educational needs which are most effectively met using a team approach of professionals, parents and students. In order to meet their

unique needs, students must have specialized services, books and instructional materials in appropriate media (including braille), as well as specialized equipment and technology so

they can have equal access to the core and specialized curricula, and to enable them to most effectively compete with their peers in school and ultimately in society.

The majority of learning in infants and young children occurs through vision. Soon after the birth of an infant who is visually impaired, families may become aware that their child does

not respond to them in the same way as an infant who is sighted. In order to ensure a healthy bonding process and emotional growth, early intervention is essential for both the

child and the family.

Vision is the primary sense upon which most traditional education strategies are based. These strategies must be modified to reflect the child's visual, auditory and tactile/vision

capabilities. A child with a severe visual loss can directly experience only what is within arm's reach and can be safely touched, and in most cases, what can be heard. To ensure an

appropriate education, families and staff with special training must work together to bring the world of experiences to the child in a meaningful manner.

As the child grows, the absence or reduction of vision dramatically limits understanding of the world. No other sense can stimulate curiosity, combine information, or invite exploration

in the same way, or as efficiently and fully as vision. Students with visual impairments can and do succeed, but at different rates and often in different sequences. There must be

significant intervention, coordinated by an educational team to ensure that appropriate development does occur.

22

It is important to remember that education goals for students with visual impairments are essentially the same as those for all students. The goals are: effective communication, social competence, employability, and personal independence. In order to accomplish these goals, however, students with visual impairments require specific interventions and modifications

of their educational programs. An appropriate assessment of these unique educational needs in all areas related to the disability and instruction adapted to meet these needs is

essential to ensure appropriate educational programming.

Clearly, the lack of vision significantly affects learning. The unique educational needs created by a visual impairment may be summarized as follows:

Vision loss can result in delayed concept development which, without effective intervention, severely impacts the student's social, emotional, academic, and vocational development.

Students with visual impairments often must learn through alternate mediums, using their other senses.

Students with visual impairments often require individualized instruction since group instruction for learning specialized skills may not be provided in a meaningful manner.

Students with visual impairments often need specialized skills as well as specialized books, materials and equipment for learning through alternate modes.

Students with visual impairments are limited in acquiring information through incidental learning since they are often unaware of subtle activities in their environment.

Curriculum areas that require unique strategies or adaptations for students with visual impairments include concept development, academic functioning,communication skills,

sensory/motor skills, social/emotional skills, orientation and mobility, daily living skills, career/vocational skills and utilization of low vision.

The more intensive and unique needs associated with visual impairment must also be addressed in educating students who are visually impaired and have one or more additional disabilities, including specialized health care needs. The education of students with multiple disabilities or other special needs must involve a team approach, combining the expertise of

specialists to competently address the complex needs of these students. Educators of students with visual impairments possess unique competencies needed by the team.

Therefore, to achieve quality education for students with multiple disabilities or other special needs, services must be provided using a team approach, including members with

disability-specific expertise in educating students with visual impairments.

Conclusion: The unique educational needs of all students with visual impairments cannot be met in a single environment, even with unlimited funding. It is critical that a team approach

23

be used in identifying and meeting these needs and that the team must include staff who have specific expertise in educating students with visual impairments. The proposal that ALL of the needs of ALL students can be met in one environment, the regular classroom, violates

the spirit as well as the letter of the law - IDEA.

The Full Range Of Program Options And Support Services For Students With Visual Impairments

Position Statement II:

There must be a full range of program options and support services so that the Individualized Education Program (IEP) team can select the most appropriate placement in

the least restrictive environment for each individual student with a visual impairment.

In order to meet the individual and disability-specific needs of students with visual impairments, there must be a full array of program options and services. Educational needs

that are specific to these students must be addressed throughout their school experience. Educators of students who are visually impaired recognized long ago that the only manner in

which the unique, individual needs of students could be met was to provide choices for delivering specialized services.

Efforts throughout the history of education for students with visual impairments have been focused on the right of these persons to full participation in an inclusive society. Quality

education was acknowledged as the first step toward that goal. In the early 1800s, schools for the blind were founded in the United States, in recognition of the fact that children who were blind had the capability of learning and becoming independent. In 1900, the first class for blind students in a regular day school was established in Chicago, to meet the individual

needs of these students. By 1950, about 15 urban areas were serving students with visual impairments in their local schools. The decades of the 1950s and 1960s marked a period of

time when parents and educators first became aware of the need for an array of service options for students with visual impairments, and efforts to provide services based on the

assessed needs of individual students began.

Currently most students with visual impairments are served in their home schools by itinerant personnel. There is increasing concern, however, that students are not receiving

the intensity of services needed, particularly in the primary grades, to provide them with the skills (including braille, daily living, and social skills) necessary to be successfully integrated in

school. Because students are expected to learn the core curriculum and meet graduation requirements, it is very difficult to provide these additional specialized skills when the

student is fully included, particularly in a time when specialized support services have been reduced because of funding cuts and teacher shortages. In addition, funds are often not

24

available to provide the specialized books, materials and technology required by students. Students cannot be successfully included without the necessary support.

The Pinebrook Report (American Foundation for the Blind, 1953) provided the first written definition of local school service delivery systems for students with visual impairments.

Clearly described in this booklet are itinerant services, resource room services, and cooperative efforts between classroom teachers and teachers of students with visual

impairments. This landmark publication appeared long before IDEA, but its content clearly reflects the intent of federal legislation. In the years since The Pinebrook Report, educators of students with visual impairments and their parents have expanded the appropriate array

of service options.

Selection from this array must be driven by the assessed needs of each individual student; no delivery option within the array of services has more or less value. Each option may be

the best for different periods of a student's schooling. The array that should be available to students with visual impairments includes, but is not limited to, the following:

The educational needs of students with visual impairments will vary, depending on the age and development of the student. Therefore, services needed will vary. There will be periods

of time for most students when time outside the regular classroom will be extensive, such as beginning braille reading, expansion of orientation and mobility skills, career education,

social skills, or times when independent living skills need to be emphasized. Such opportunities for learning may require pull-out time, or a special class placement, or a

residential school placement for a period of time.

IDEA requires a "continuum" of placement options. This is often interpreted as a hierarchy of options from most desirable (least restrictive) to least desirable (most restrictive). Students

who are visually impaired require an "array" of service delivery systems, which means a choice of the best option to meet each student's needs. The appropriate placement for each individual student is determined by educational goals and objectives, based on assessment,

that are identified in the IEP, and is thus the most desirable (and least restrictive) for the student at that time.

Conclusion: The right of every student with a visual impairment to an appropriate placement in the least restrictive environment, selected by the IEP team from a full range of program

options and based upon each student's needs, is nothing more or less than is mandated by federal law.

25

Personnel Development For Staff And Parents Of Students With Visual Impairments

Position Statement III:

There must be adequate personnel preparation programs to train staff to provide specialized services which address the unique academic and non-academic curriculum needs of students with visual impairments. There must also be ongoing specialized personnel

development opportunities for all staff working with students with visual impairments as well as specialized parent education.

Preparation Of Specially Trained Staff

Instruction, regardless of setting, must be provided by professionals thoroughly prepared and qualified to teach students with visual impairments. The skills and knowledge needed by

these staff can be defined with three classifications. First, the teacher must have a foundation in regular education, including methodology in teaching reading, mathematics,

and other areas of subject matter. Second, the teacher must learn the techniques for curriculum adaptation for visual learning experiences so that the concepts taught remain the same with adapted teaching methodology and materials. Third, the teacher must know how

to assess skills and deliver instruction in the specialized areas of independent living skills, social skills, career education, and specific areas of academics.

The combination of knowledge and skills needed in order to provide appropriate educational services to students who are visually impaired requires intensive preparation in a teacher

training program. Most often, these programs are offered at colleges and universities, either at the undergraduate or graduate level. Experience has shown that at least one school year

of preparation is necessary in order to possess entry level skills as a teacher of students with visual impairments.

Programs that prepare teachers of students with visual impairments contain curricula that is not found in general teacher preparation or generic programs in special education.

Competencies for special teachers of students who are visually impaired include:

Development patterns in students with visual impairments

Comprehensive assessments of the students with visual impairment in all areas related to the disability

Ability to design and modify core and specialized curricula for the student with visual impairment

Knowledge of specialized technology

Special instructional strategies for the student with a visual impairment

26

Specialized books, materials and equipment used by the student with a visual impairment

Appropriate specialized counseling and guidance services

Knowledge of specific local, state and national legal requirements, policies and specialized resources

Knowledge of and need for research in the field

Understanding vision loss and other related impairments

Collaboration with families and other professionals

Another important unique need area is orientation and mobility which must be provided by trained and qualified orientation and mobility specialists. The teacher of students with visual

impairments may share in the responsibility for reinforcing learned skills in orientation and mobility, but educational programs must offer instructional services of appropriate

frequency and duration from both a specially trained teacher and an orientation and mobility specialist.

Staff Development, Including Parent Education

Because of the low incidence of visual impairments, many students and adults have never been exposed to individuals who function without vision or with limited vision. Therefore,

although individuals often want to be helpful to the student with a visual impairment, they often do not know what to do. Some do nothing at all. Others use a trial and error strategy,

sometimes being helpful and, other times failing to accomplish much that is productive. Still others do too much, creating a debilitating dependence. In order for professionals, peers, or

parents to assist a student who is visually impaired, they must have a realistic picture of what the student can do and of those situations in which help is really needed. Then they

must be provided with guidance and special techniques for providing appropriate assistance.

For example, it is important to realize that the student who is visually impaired must accomplish the same work as his sighted peers using disability-specific skills which generally

require greater time to master and, often, more time to use in completing the same tasks. Both the reading and writing of braille, even by a proficient braille user, requires more time.

In an integrated setting, the vision teacher often has limited time that can be spent with a student who is visually impaired. This necessitates the development of a support team which

includes professionals, paraprofessionals, peers, and parents with a unified philosophy and strategies for assisting the student to learn and develop.

27

Therefore, it is important that all individuals who will be interacting with the student who is visually impaired receive specialized in-service training:

Specialist staff serving visually impaired students with a wide range of cognitive abilities and, perhaps, additional disabilities and special needs will need opportunities to sharpen skills

that may not be used for significant periods of time. For example for the vision teacher, advanced braille math (Nemeth Code) skills may be called upon only when a particular

student required assistance with higher level mathematics courses. Specialist staff, including the orientation and mobility specialist, will also need to develop skills to remain current with

advances in the field, such as the rapid advances in technology that are critical to the student with a visual impairment.

Regular educators and other special educators, who may not have had any prior training or experience in teaching students with visual impairments, will need in-service regarding the

impact of visual impairment on learning and development. They will also need to be assisted in applying strategies for teaching that address the unique educational needs of the student

with limited or no vision.

Paraprofessionals, including transcribers, readers and aides, who facilitate the education of students who are visually impaired within the regular classroom will need training to assist

the student to develop skills for independence rather than dependence.

Administrators who are responsible for providing appropriate facilities, technical assistance, and educational service delivery to students with visual impairments, need training related

to the specific needs and essential interventions associated with blindness and visual impairment. They also need assistance in locating the resources needed to implement high

quality programs.

Parents of children who are blind or visually impaired need critical information to fulfill their natural role as their child's best and only lifetime advocate. Federal law not only encourages

their participation in the educational process, but identifies the key roles they must play if their children are going to reach their full potential and their maximum level of

independence. Quality parent education on an ongoing basis will provide the tools for parents to understand their child's individual needs and how those needs can best be met in

both the home and school environments.

Conclusion: Students with visual impairments have the right to an appropriate education that is guided by knowledgeable specialists who work collaboratively with parents, the student and other education team members. Access to training on an ongoing basis is

essential for all team members, especially parents who provide the necessary continuity and support in their child's education.

The American Foundation for the Blind's Josephine L. Taylor Leadership Institute, Education Work Group

28

Motor Skills are Essential to Learning!

What are motor skills?

A motor skill is a function, which involves the precise movement of muscles with the intent to perform a specific act.

Most purposeful movement requires the ability to "feel" or sense what one's muscles are doing as they perform the act. Motor difficulties occur when an individual lacks the ability to

move in the way he or she originally intended. This can have a significant effect on classroom performance and motivation in school.

Does your child or student exhibit any of the following?

Difficulty with handwriting or letter formation

Cannot copy correctly from the board

Loses place when reading, frequently

Skips math problems on a page

Bumps into others

Falls out of chair

Exhibits poor posture, seated or standing

Difficulty organizing a desk or binder

29

Motor difficulties can be addressed in variety of ways. Some motor skills difficulties can be overcome through development and maturity. In education, a frequent response to motor difficulties is to refer the child to special education services. This is not always necessary or appropriate. Some students just need to be taught a simple activity or strategy, which they practice to remedy the problem. Others, whose difficulty is more involved, may require the

intervention of a professional in special education.

Why are we seeing more children with motor skill difficulties today?

Numerous students in every classroom across the country, these days, experience difficulty writing, lose their place on a page, skip math problems, and have trouble paying attention. Many students lack the development and training of the muscles needed for fine and gross

motor skills important for a successful classroom experience. Frequently, children hide their difficulties by becoming "class clowns" or "trouble makers" because they are embarrassed.

Sometimes these behaviors are a mask for hiding the true problem of being unable to complete class work well. These students need brain engaging strategies, direct teaching

and guided practice to assist their progress toward improvement and successful completion of schoolwork.

Over the years, school curricula have placed less emphasis on direct teaching of fine and gross motor activities in the classroom and yet we expect students to write neatly, which

requires developed motor skills.

Integrating motor activities into the classroom and home environment can be a tremendous help in reading, writing, attention, and memory. Students who learn to develop specific

motor movements can incorporate such skills into successful participation in school activities. The CLIME® Program's multi-sensory approach to learning and writing, is

particularly helpful for students, kindergarten through third grade, including those with Attention Deficit Hyperactivity Disorder or learning disabilities. The CLIME® Program can also

be applied to students in higher grade levels.

Armed with The CLIME® Program's effective strategies, teachers and parents can help students improve using simple exercises and interventions within or outside the classroom

setting. Whether or not a student qualifies for any particular type of special services,

30

incorporating motor activities, which are easily performed on a regular basis, can help them improve their skills and obtain the best results.

A Motor Skill Solution!

The CLIME® Program offers the avenue for learning tried and true activities that address the motor skills listed above and more. Designed by EduCLIME, with contributions from special

education teachers, occupational therapists, physical therapists and adapted physical education teachers, The CLIME® Program helps improve motor skills for both general and

special education students

What's the difference between fine and gross motor skills?

Motor skills are skills involving movement and motion. A child with motor impairments has trouble moving in a controlled, coordinated, and efficient way. Occupational and physical

therapists will work to strengthen your child's motor skills, with occupational therapists dealing primarily with fine motor skills and physical therapists concentrating on gross motor

skills.

The BabyCenter Editorial Team

Motor skills are motions carried out when the brain, nervous system, and muscles work together. Fine motor skills are small movements — such as picking up small objects and

holding a spoon — that use the small muscles of the fingers, toes, wrists, lips, and tongue. Gross motor skills are the bigger movements — such as rolling over and sitting —

that use the large muscles in the arms, legs, torso, and feet.

31

. What causes mental retardation? 17 possible conditions

Medically Reviewed by George Krucik, MD, MBA

Share

Mental retardation or intellectual disability, (MR/ID), exists in children whose brains do not develop properly or function within the normal range. There are four levels of retardation:

mild, moderate, severe, and profound. Sometimes, MR/ID may be classified as other or unspecified. Mental retardation involves both a low IQ and problems adjusting to everyday

life.

MR/ID can result in learning, speech, physical, and social disabilities. Severe cases are diagnosed at birth. However, milder forms might not be noticed until a child fails to meet a

common developmental goal. Almost all cases of MR/ID are diagnosed by the time a child reaches 18 years of age.

Levels of Mental Retardation

MR/ID is divided into four levels based on IQ and degree of social adjustment.

Mild Mental Retardation

At this level, a person:

takes longer to learn to talk, but can communicate well once he or she knows how

32

fully independent in self-care

has problems with reading and writing

is socially immature

is unable to deal with responsibilities of marriage or parenting

may benefit from specialized education plans

has an IQ range of 50 to 69

may have associated conditions, including autism, epilepsy, or physical disability

Moderate Mental Retardation

At this level, a person:

is slow in understanding and using language

has only a limited ability to communicate

can learn basic reading, writing, counting skills

is a slow learner

is unable to live alone

can get around on own

can take part in simple social activities

has an IQ range of 35 to 49

Severe Mental Retardation

At this level, a person:

has noticeable motor impairment

has severe damage to and/or abnormal development of central nervous system

has an IQ range of 20 to 34

Profound Mental Retardation

33

At this level, a person:

is unable to understand or comply with requests or instructions

is immobile

must wear adult diapers

uses very basic nonverbal communication

cannot care for own needs

requires constant help and supervision

has an IQ of less than 20

Other Mental Retardation

Children in this category are often blind, deaf, mute, and physically disabled. These factors prevent physicians from conducting screening tests.

Unspecified Mental Retardation

Signs of MR/ID exist, but there is not enough information to assign the child to a level.

What Causes Mental Retardation?

According to Psychology Today, only 25 percent of MR/ID cases have a known cause (Psychology Today, 2010).

When they are known, the cayses of mental retardation include:

trauma before or during birth, such as oxygen loss, alcohol exposure, or infection

genetic abnormalities, such as inherited abnormal genes, Down syndrome, fragile X syndrome, and PKU (phenylketonuria)

lead or mercury poisoning

34

severe malnutrition or other dietary issues

early childhood sickness, such as whooping cough, measles, or meningitis

Symptoms of Mental Retardation

Symptoms of MR/ID will vary based on the level of the disability. They can include:

failure to meet intellectual standards

sitting, crawling, or walking later than other children

problems learning to talk or trouble speaking clearly

memory problems

inability to understand the consequences of actions

inability to think logically

childish behavior beyond a normal age

lack of curiosity

learning difficulties

IQ below 70

inability to lead a normal life because of the inability to communicate, take care of oneself, or interact with others

Individuals who are intellectually disabled will often have some of the following behavioral issues:

aggression

dependency

withdrawal from social activities

attention-seeking behavior

depression during adolescent and teen years

lack of impulse control

passivity

tendency toward self-injury

35

stubbornness

low self-esteem

low tolerance for frustration

psychotic disorders

attention difficulties

Physical signs of MR/ID include short stature and malformed facial features. However, physical signs are not always present.

How Is Mental Retardation Diagnosed?

A diagnosis of MR/ID requires that both intellectual and adaptive skills be well below average. There are three parts to the evaluation:

interviews with parents

observations of the child

standard tests

Your child will be given standard intelligence tests, such as the Stanford-Binet Intelligence Test, to determine IQ. Other tests, such as the Vineland Adaptive Behavior Scales, will be

given to assess your child’s daily living skills and social abilities compared with other children in the same age group. It is important to remember that children from different cultures and

socio-economic statuses may perform differently on these tests. Results of these tests will be combined with information obtained from interviews with parents and observations of

the child to assist in the diagnosis.

The screening process might include visits to many different professionals including the following:

psychologist

speech pathologist

social worker

pediatric neurologist

developmental pediatrician

36

physical therapist

Laboratory and imaging tests may be performed as well to detect metabolic and genetic disorders and structural problems with the brain. It is important to rule out such things as

hearing loss, learning disorders, neurological disorders, and emotional problems as the cause for delayed development before making a diagnosis of MR/ID.

Once MR/ID has been diagnosed, the family, school, and primary care physician will use the results of these tests and evaluations to develop a treatment and education plan.

Treatment Options for Mental Retardation

Ongoing counseling will often be needed to help the child cope with disabilities.

Parents with intellectually disabled infants and toddlers will get a family service plan that describes their child’s needs. The plan will also detail the services the child will need to help

him or her with normal development. Family needs are also addressed in the plan.

When the child is ready to attend school, a new plan, called the Individualized Education Program (IEP), will be put in place to assist the child with his or her educational needs.

The main goal of treatment is to assist the child in reaching his or her full potential in terms of education and social and life skills. Treatment may include behavior therapy, occupational

therapy, counseling, and in some cases, medication. All children with MR/ID benefit from special education, and the federal Individuals with Disabilities Act (IDEA) requires that public

schools provide free and appropriate education to children with mental retardation and other developmental disabilitiesProblems Learning and Functioning

If a kid has an intellectual disability, it means that he or she learns and develops more slowly than other kids. At one time, intellectual disabilities were called "mental retardation," but

that term is not used as much anymore because it hurts people's feelings.

Someone who has an intellectual disability will have trouble learning and functioning in everyday life. This person could be 10 years old, but might not talk or write as well as a typical 10-year-old. He or she also is usually slower to learn other skills, like how to get

dressed or how to act around other people.

37

But having an intellectual disability doesn't mean a person can't learn. Ask anyone who knows and loves a person with an intellectual disability! Some kids with autism, Down

syndrome, or cerebral palsy may be described as having an intellectual disability, yet they often have a great capacity to learn and become quite capable kids.

Just like other health problems, an intellectual disability can be mild (smaller) or major (bigger). The bigger the disability, the more trouble someone will have learning and

becoming an independent person.

What Causes Intellectual Disabilities?

Intellectual disabilities happen because the brain gets injured or a problem prevents the brain from developing normally. These problems can happen while the baby is growing

inside his or her mom, during the baby's birth, or after the baby is born. Many times, though, doctors don't know the cause.

Here are some problems that can cause intellectual disabilities:

There's a problem with the baby's genes, which are in every cell and determine how the body will develop. (Genes are inherited from both parents, so a baby might receive genes

that are abnormal or the genes might change while the baby is developing.)

There's a problem during the pregnancy. Sometimes, the mom might get an illness or infection that can harm the baby. Taking certain medicines while pregnant can cause

problems for the baby. Drinking alcohol or taking illegal drugs also can damage a baby's developing brain.

During childbirth, the baby doesn't get enough oxygen.

The baby is born way too early.

After being born, the baby gets a serious brain infection.

A serious head injury can hurt the brain and cause intellectual disabilities at any point during life. Some of these disabilities are temporary and others can be permanent. (That's why it's

important to wear your bike helmet and always wear a seatbelt in the car!)

Doctors figure out that someone has an intellectual disability by testing how well the person thinks and solves problems. If a problem is spotted, doctors and other professionals can

work with the family to decide what type of help is needed.

What's Happens at School?

38

During school, a kid with an intellectual disability will probably need help. Some kids have helpers that stay with them during the school day. They may be in special classes or get

other services to help them learn and develop.

Someone with an intellectual disability often gets help in learning "life skills." Life skills are the skills people need to take care of themselves as they get older, such as how to cook a

meal or ride a public bus to get to work. Adults with intellectual disabilities often have jobs and learn to live independently or in a group home.

Kids with intellectual disabilities want to develop their skills to the best of their abilities. They want to go to school, play, and feel support from loving families and good friends.

What can you do? If you know someone who has an intellectual disability, be a friend. How? Sometimes, it might mean telling a teacher if you see this person being teased or bullied.

Other times, it can be as simple as saying something kind, like "Hey, I like your hat"!

If you can't think of anything, just say, "hi." It's a little word that could make that person's day.

Reviewed by: Mary L. Gavin, MD

Date reviewed: August 2014

(ID ,)once called mental retardation, is characterized by below-average intelligence or mental ability and a lack of skills necessary for day-to-day living. People with intellectual

disabilities can and do learn new skills, but they learn them more slowly. There are varying degrees of intellectual disability, from mild to profound.

What is intellectual disability?

Someone with intellectual disability has limitations in two areas. These areas are:

Intellectual functioning. Also known as IQ, this refers to a person’s ability to learn, reason, make decisions, and solve problems.

39

Adaptive behaviors. These are skills necessary for day-to-day life, such as being able to communicate effectively, interact with others, and take care of oneself.

IQ (intelligence quotient) is measured by an IQ test. The average IQ is 100. A person is considered intellectually disabled if he or she has an IQ of less than 70 to 75.

To measure a child’s adaptive behaviors, a specialist will observe the child’s skills and compare them to other children of the same age. Things that may be observed include how

well the child can feed or dress himself or herself; how well the child is able to communicate with and understand others; and how the child interacts with family, friends, and other

children of the same age.

Intellectual disability is thought to affect about 1% of the population. Of those affected, 85% have mild intellectual disability. This means they are just a little slower than average to learn

new information or skills. With the right support, most will be able to live independently as adults.

What are the signs of intellectual disability in children?

There are many different signs of intellectual disability in children. Signs may appear during infancy, or they may not be noticeable until a child reaches school age. It often depends on

the severity of the disability. Some of the most common signs of intellectual disability are:

Rolling over, sitting up, crawling, or walking late

Talking late or having trouble with talking

Slow to master things like potty training, dressing, and feeding himself or herself

Difficulty remembering things

Inability to connect actions with consequences

Behavior problems such as explosive tantrums

Difficulty with problem-solving or logical thinking

In children with severe or profound intellectual disability, there may be other health problems as well. These problems may include seizures, mood disorders (anxiety, autism,

etc.), motor skills impairment, vision problems, or hearing problems

What causes intellectual disability?

40

Anytime something interferes with normal brain development, intellectual disability can result. However, a specific cause for intellectual disability can only be pinpointed about a

third of the time.

The most common causes of intellectual disability are:

Genetic conditions. These include things like Down syndrome and fragile X syndrome.

Problems during pregnancy. Things that can interfere with fetal brain development include alcohol or drug use, malnutrition, certain infections, or preeclampsia.

Problems during childbirth. Intellectual disability may result if a baby is deprived of oxygen during childbirth or born extremely premature.

Illness or injury. Infections like meningitis, whooping cough, or the measles can lead to intellectual disability. Severe head injury, near-drowning, extreme malnutrition, exposure to

toxic substances such as lead, and severe neglect or abuse can also cause it.

None of the above. In two-thirds of all children who have intellectual disability, the cause is unknown.

Can intellectual disability be prevented?

Certain causes of intellectual disability are preventable. The most common of these is fetal alcohol syndrome. Pregnant women shouldn’t drink alcohol. Getting proper prenatal care,

taking a prenatal vitamin, and getting vaccinated against certain infectious diseases can also lower the risk that your child will be born with intellectual disabilities.

In families with a history of genetic disorders, genetic testing may be recommended before conception.

Certain tests, such as ultrasound and amniocentesis, can also be performed during pregnancy to look for problems associated with intellectual disability. Although these tests

may identify problems before birth, they cannot correct them.

How is intellectual disability diagnosed?

Intellectual disability may be suspected for many different reasons. If a baby has physical abnormalities that suggest a genetic or metabolic disorder, a variety of tests may be done to

41

confirm the diagnosis. These include blood tests, urine tests, imaging tests to look for structural problems in the brain, or electroencephalogram (EEG) to look for evidence of

seizures.

In children with developmental delays, the doctor will perform tests to rule out other problems, including hearing problems and certain neurological disorders. If no other cause

can be found for the delays, the child will be referred for formal testing.

How is intellectual disability diagnosed? continued...

Three things factor into the diagnosis of intellectual disability: interviews with the parents, observation of the child, and testing of intelligence and adaptive behaviors. A child is

considered intellectually disabled if he or she has deficits in both IQ and adaptive behaviors. If only one or the other is present, the child is not considered intellectually disabled.

After a diagnosis of intellectual disability is made, a team of professionals will assess the child’s particular strengths and weaknesses. This helps them determine how much and what

kind of support the child will need to succeed at home, in school, and in the community.

What services are available for people with intellectual disability?

For babies and toddlers, early intervention programs are available. A team of professionals works with parents to write an Individualized Family Service Plan, or IFSP. This document

outlines the child’s specific needs and what services will help the child thrive. Early intervention may include speech therapy, occupational therapy, physical therapy, family

counseling, training with special assistive devices, or nutrition services.

School-age children with intellectual disabilities (including preschoolers) are eligible for special education for free through the public school system. This is mandated by the

Individuals With Disabilities Education Act (IDEA). Parents and educators work together to create an Individualized Education Program, or IEP, which outlines the child’s needs and the

services the child will receive at school. The point of special education is to make adaptations, accommodations, and modifications that allow a child with an intellectual

disability to succeed in the classroom.

What can I do to help my intellectually disabled child?

42

Steps to help your intellectually disabled child include:

Learn everything you can about intellectual disabilities. The more you know, the better advocate you can be for your child.

Encourage your child’s independence. Let your child try new things and encourage your child to do things by himself or herself. Provide guidance when it’s needed and give positive

feedback when your child does something well or masters something new.

Get your child involved in group activities. Taking an art class or participating in Scouts will help your child build social skills.

Stay involved. By keeping in touch with your child’s teachers, you’ll be able to follow his or her progress and reinforce what your child is learning at school through practice at home.

Get to know other parents of intellectually disabled children. They can be a great source of advice and emotional support.

What are behavioral disorders?

Behavioral disorders typically develop in childhood or adolescence. While some behavioral issues may be normal in children, those who have behavioral disorders develop chronic

patterns of aggression, defiance, disruption and hostility. Their behaviors cause problems at home, school or work, and can interfere with relationships. Children with behavioral

disorders may develop personality disorders, depression, or bipolar disorder as adults.

Children with behavioral disorders may throw frequent and extended tantrums, hurt themselves or others, get involved in criminal activities, lie, smoke, use alcohol or drugs, be

openly defiant, or engage in early sexual activity. They may skip or fail school. They also have a higher than average risk of suicide.

Although the cause of behavioral disorders is not known, risk factors have been identified, such as family history of mental illness or substance abuse, exposure to tobacco or illicit drugs during fetal development, abuse, stress, lack of supervision, and inconsistent but

harsh discipline. Children with behavioral disorders may have other mental, emotional or behavioral disorders, such as attention-deficit hyperactivity disorder (ADHD). There may also be overlap with developmental delay. Because of this, the American Academy of Pediatrics

recommends routine screening for developmental delay as part of routine well-child examinations.

Behavioral Disorder Symptoms, Causes and Effects

43

Behavioral disorders, also known as disruptive behavioral disorders, are the most common reasons that parents are told to take their kids for mental health assessments and

treatment. Behavioral disorders are also common in adults. If left untreated in childhood, these disorders can negatively affect a person’s ability to hold a job and maintain

relationships.

What Are the Types of Behavioral Disorders?

According to BehaviorDisorder.org, behavioral disorders may be broken down into a few types, which include:

Anxiety disorders

Disruptive behavioral disorders

Dissociative disorders

Emotional disorders

Pervasive developmental disorders

Attention Deficit Hyperactivity Disorder (ADHD)

According to Centers for Disease Control and Prevention, ADHD is a condition that impairs an individual’s ability to properly focus and to control impulsive behaviors, or it may make

the person overactive.

ADHD is more common in boys than it is in girls. According to the Wexner Medical Center at Ohio State University, males are two to three times more likely than females to get ADHD.

Emotional Behavioral Disorder

An emotional behavioral disorder affects a person’s ability to be happy, control their emotions and pay attention in school. According to Gallaudet University, symptoms of an

emotional behavioral disorder include:

Inappropriate actions or emotions under normal circumstances

44

Learning difficulties that are not caused by another health factor

Difficulty with interpersonal relationships, including relationships with teachers and peers

A general feeling of unhappiness or depression

Feelings of fear and anxiety related to personal or school matters

Oppositional Defiant Disorder (ODD)

ODD is a behavioral disorder characterized by hostile, irritable and uncooperative attitudes in children, according to Children’s Mental Health Ontario. Children with ODD may be

spiteful or annoying on purpose, and they generally direct their negative actions at authority figures.

Anxiety

Anxiety is a normal emotion, and all people feel anxiety at some point in their lives. However, for some people, anxiety may get to a point where it interferes with their daily

lives, causing insomnia and negatively affecting performance at work or school, according to the Mayo Clinic. Anxiety disorders involve more than regular anxiety. They are serious

mental health conditions that require treatment. Examples of these types of mental conditions include:

Post-traumatic stress disorder

Obsessive-compulsive disorder

Generalized anxiety disorder

Panic disorder

Obsessive-Compulsive Disorder (OCD)

OCD is characterized by fears and irrational thoughts that lead to obsessions, which, in turn, cause compulsions, according to the Mayo Clinic. If you have OCD, you engage in

compulsive, repetitive behavior despite realizing the negative consequences of — or even the unreasonable nature of — your actions. Performing these repetitive acts does nothing

more than relieve stress temporarily.

If you or a loved one is experiencing any of these behavioral disorders, it is important to get help as soon as possible, because these conditions can affect quality of life to such a degree

that they may lead to self-harm. Please call 1-888-997-3147 for assistance.

45

What Causes a Behavioral Disorder?

A behavioral disorder can have a variety of causes. According to the University of North Carolina at Chapel Hill, the abnormal behavior that is usually associated with these disorders

can be traced back to biological, family and school-related factors.

Some biological causes may include:

Physical illness or disability

Malnutrition

Brain damage

Hereditary factors

Other factors related to an individual’s home life may contribute to behaviors associated with a behavioral disorder:

Divorce or other emotional upset at home

Coercion from parents

Unhealthy or inconsistent discipline style

Poor attitude toward education or schooling

What Are the Signs of a Behavioral Disorder?

Someone who has a behavioral disorder may act out or display emotional upset in different ways, which will also vary from person to person.

Emotional Symptoms of Behavioral Disorders

According to Boston Children’s Hospital, some of the emotional symptoms of behavioral disorders include:

Easily getting annoyed or nervous

Often appearing angry

Putting blame on others

46

Refusing to follow rules or questioning authority

Arguing and throwing temper tantrums

Having difficulty in handling frustration

Physical Symptoms of Behavioral Disorders

Unlike other types of health issues, a behavioral disorder will have mostly emotional symptoms, with physical symptoms such as a fever, rash, or headache being absent.

However, sometimes people suffering from a behavioral disorder will develop a substance abuse problem, which could show physical symptoms such as burnt fingertips, shaking or

bloodshot eyes.

Short-Term and Long-Term Effects of a Behavioral Disorder

If left untreated, a behavioral disorder may have negative short-term and long-term effects on an individual’s personal and professional life. People may get into trouble for acting out, such as face suspension or expulsion for fighting, bullying or arguing with authority figures.

Adults may eventually lose their jobs. Marriages can fall apart due to prolonged strained relationships, while children may have to switch schools and then eventually run out of

options.

According to HealthyChildren.org, the most serious actions a person with a behavioral disorder may engage in include starting fights, abusing animals and threatening to use a

weapon on others.

The earlier a behavioral disorder is diagnosed and properly treated, the more likely it is that a child or adult suffering from it will be able to control their behavior. Contact us at 1-888-

997-3147 for assistance in finding treatment options.

Is There a Test or Self-Assessment I Can Do?

Mental health professionals and treatment centers can evaluate people to determine if they a behavioral disorder. Tests called functional behavioral assessments offer problem-solving

help to address behavioral problems in students. According to Center for Effective Collaboration and Practice, these assessments are based on many techniques and strategies

for identifying problem behaviors. Individualized educational program teams use these assessments to choose interventions that address specific behavioral problems. These teams

are involved in the education of students, and they may include parents and teachers.

47

Medication: Behavior-Modifying Drug Options

A person may receive prescription medications to help manage a behavioral disorder. Though medication will not cure the disorder, it is effective in assisting with treatment to

control and modify behaviors.

Behavioral Drugs: Possible Options

Many drugs are available for behavioral problems, and the type of drug that will be prescribed depends on the specific condition being treated. The Positive Environments

Network of Trainers of the California Department of Education lists Ritalin and Dexedrine as short-acting medications for the treatment of ADHD. They may help a child focus better,

reduce impulsive behavior and reduce motor restlessness.

Ritalin is also included in a group of medications known as long-acting stimulants. Other types of medications in this group include Concerta, Methylin ER, Methylin CD, Focalin, and

Metadate ER. These medications may also be effective against ADHD. Concerta may prevent drug abuse, as can Vyanase and Daytrana. Some professionals recommend Wellbutrin as a

primary ADHD treatment.

People with an anxiety disorder, OCD or ADHD may benefit from antidepressants, including Paxil, Tofranil, Anafranil, Prozac, Luvox, Celexa, Zoloft and Norpramin. Other medications

that may help include Daytrana, Biphetamine, Dexedrine, Adderall XR and Strattera. These medications are aimed at decreasing impulsivity, reducing hyperactivity, decreasing

obsessive-compulsive actions and reducing feelings of depression.

Medication Side Effects

Medications for behavioral disorders may have side effects. They can increase emotional issues, increase suicidal thoughts and aggravate seizure conditions. Some of the possible

side effects include:

Insomnia

Appetite reduction

Tremors

Depression

Abnormal heart rhythms

48

Behavior Drug Addiction, Dependence and Withdrawal

An individual may become addicted to the medication taken to treat a behavioral disorder. As a result, the person may need professional help with weaning off that medication. You

may experience withdrawal symptoms if you abuse certain medications.

If you suspect that you, your child or someone else you know has become dependent on prescription medication, contact us at 1-888-997-3147 for immediate assistance.

Medication Overdose

Children are more likely than adults to accidentally overdose on medication, including behavioral medications. A person who is depressed because of a behavioral disorder may

attempt an overdose on purpose. People who are depressed or have suicidal thoughts have a high risk for overdose, according to the National Coalition Against Prescription Drug Abuse.

Depression and Behavioral Disorders

According to the Cleveland Clinic, a behavioral disorder may trigger depression. The opposite is also possible, with depression being a trigger for a behavioral disorder, which can also lead

to substance abuse.

Dual Diagnosis: Addiction and Behavioral Disorders

It is not uncommon for people with a behavioral disorder to also have an addiction to drugs or alcohol. According to Psychology Today, an individual who has a panic disorder may also

be addicted to alcohol.

Children with ADHD may be at a higher risk for developing a substance abuse or alcohol dependence issue if the condition carries over into adulthood, according to WebMD.

Getting Help for a Behavioral Disorder

Because of the severity of these mental health issues, getting help for a behavioral disorder is crucial. Cognitive behavioral therapy along with medication is an effective way to treat

disorders such as ODD. The sooner you get help, the easier it will be to restore your life to normal. Call us at 1-888-997-3147 to find a treatment center that’s tailored to your

individual needs and will be able to help get you on the road to recovery.

49

Psychiatric and Behavioral Problems

Morgan Adams in Behavioral

Intellectual disability is fairly common, and it occurs in approximately 1 to 2 percent of people. Psychiatric and behavior problems occur three to six times more in these individuals than in the general population, so the assessment of these patients is important in treating

these issues. How Is Intellectual Disability Diagnosed? Intellectual disability is normally diagnosed before the age of 18 and is defined as when an IQ of a person is 75 or lower

Behavioral Disorder Symptoms, Causes and Effects

Behavioral disorders, also known as disruptive behavioral disorders, are the most common reasons that parents are told to take their kids for mental health assessments and

treatment. Behavioral disorders are also common in adults. If left untreated in childhood, these disorders can negatively affect a person’s ability to hold a job and maintain

relationships.

What Are the Types of Behavioral Disorders?

According to BehaviorDisorder.org, behavioral disorders may be broken down into a few types, which include:

Anxiety disorders

Disruptive behavioral disorders

Dissociative disorders

Emotional disorders

Pervasive developmental disorders

Attention Deficit Hyperactivity Disorder (ADHD)

According to Centers for Disease Control and Prevention, ADHD is a condition that impairs an individual’s ability to properly focus and to control impulsive behaviors, or it may make

the person overactive.

50

ADHD is more common in boys than it is in girls. According to the Wexner Medical Center at Ohio State University, males are two to three times more likely than females to get ADHD.

Emotional Behavioral Disorder

An emotional behavioral disorder affects a person’s ability to be happy, control their emotions and pay attention in school. According to Gallaudet University, symptoms of an

emotional behavioral disorder include:

Inappropriate actions or emotions under normal circumstances

Learning difficulties that are not caused by another health factor

Difficulty with interpersonal relationships, including relationships with teachers and peers

A general feeling of unhappiness or depression

Feelings of fear and anxiety related to personal or school matters

Oppositional Defiant Disorder (ODD)

ODD is a behavioral disorder characterized by hostile, irritable and uncooperative attitudes in children, according to Children’s Mental Health Ontario. Children with ODD may be

spiteful or annoying on purpose, and they generally direct their negative actions at authority figures.

Anxiety

Anxiety is a normal emotion, and all people feel anxiety at some point in their lives. However, for some people, anxiety may get to a point where it interferes with their daily

lives, causing insomnia and negatively affecting performance at work or school, according to the Mayo Clinic. Anxiety disorders involve more than regular anxiety. They are serious

mental health conditions that require treatment. Examples of these types of mental conditions include:

Post-traumatic stress disorder

Obsessive-compulsive disorder

Generalized anxiety disorder

51

Panic disorder

Obsessive-Compulsive Disorder (OCD)

OCD is characterized by fears and irrational thoughts that lead to obsessions, which, in turn, cause compulsions, according to the Mayo Clinic. If you have OCD, you engage in

compulsive, repetitive behavior despite realizing the negative consequences of — or even the unreasonable nature of — your actions. Performing these repetitive acts does nothing

more than relieve stress temporarily.

If you or a loved one is experiencing any of these behavioral disorders, it is important to get help as soon as possible, because these conditions can affect quality of life to such a degree

that they may lead to self-harm. Please call 1-888-997-3147 for assistance.

What Causes a Behavioral Disorder?

A behavioral disorder can have a variety of causes. According to the University of North Carolina at Chapel Hill, the abnormal behavior that is usually associated with these disorders

can be traced back to biological, family and school-related factors.

Some biological causes may include:

Physical illness or disability

Malnutrition

Brain damage

Hereditary factors

Other factors related to an individual’s home life may contribute to behaviors associated with a behavioral disorder:

Divorce or other emotional upset at home

Coercion from parents

Unhealthy or inconsistent discipline style

Poor attitude toward education or schooling

What Are the Signs of a Behavioral Disorder?

52

Someone who has a behavioral disorder may act out or display emotional upset in different ways, which will also vary from person to person.

Emotional Symptoms of Behavioral Disorders

According to Boston Children’s Hospital, some of the emotional symptoms of behavioral disorders include:

Easily getting annoyed or nervous

Often appearing angry

Putting blame on others

Refusing to follow rules or questioning authority

Arguing and throwing temper tantrums

Having difficulty in handling frustration

Physical Symptoms of Behavioral Disorders

Unlike other types of health issues, a behavioral disorder will have mostly emotional symptoms, with physical symptoms such as a fever, rash, or headache being absent.

However, sometimes people suffering from a behavioral disorder will develop a substance abuse problem, which could show physical symptoms such as burnt fingertips, shaking or

bloodshot eyes.

Short-Term and Long-Term Effects of a Behavioral Disorder

If left untreated, a behavioral disorder may have negative short-term and long-term effects on an individual’s personal and professional life. People may get into trouble for acting out, such as face suspension or expulsion for fighting, bullying or arguing with authority figures.

Adults may eventually lose their jobs. Marriages can fall apart due to prolonged strained relationships, while children may have to switch schools and then eventually run out of

options.

According to HealthyChildren.org, the most serious actions a person with a behavioral disorder may engage in include starting fights, abusing animals and threatening to use a

weapon on others.

53

The earlier a behavioral disorder is diagnosed and properly treated, the more likely it is that a child or adult suffering from it will be able to control their behavior. Contact us at 1-888-

997-3147 for assistance in finding treatment options.

Is There a Test or Self-Assessment I Can Do?

Mental health professionals and treatment centers can evaluate people to determine if they a behavioral disorder. Tests called functional behavioral assessments offer problem-solving

help to address behavioral problems in students. According to Center for Effective Collaboration and Practice, these assessments are based on many techniques and strategies

for identifying problem behaviors. Individualized educational program teams use these assessments to choose interventions that address specific behavioral problems. These teams

are involved in the education of students, and they may include parents and teachers.

Medication: Behavior-Modifying Drug Options

A person may receive prescription medications to help manage a behavioral disorder. Though medication will not cure the disorder, it is effective in assisting with treatment to

control and modify behaviors.

Depression and Behavioral Disorders

According to the Cleveland Clinic, a behavioral disorder may trigger depression. The opposite is also possible, with depression being a trigger for a behavioral disorder, which can also lead

to substance abuse.

Dual Diagnosis: Addiction and Behavioral Disorders

It is not uncommon for people with a behavioral disorder to also have an addiction to drugs or alcohol. According to Psychology Today, an individual who has a panic disorder may also

be addicted to alcohol.

Children with ADHD may be at a higher risk for developing a substance abuse or alcohol dependence issue if the condition carries over into adulthood, according to WebMD.

Getting Help for a Behavioral Disorder

Because of the severity of these mental health issues, getting help for a behavioral disorder is crucial. Cognitive behavioral therapy along with medication is an effective way to treat

disorders such as ODD. The sooner you get help, the easier it will be to restore your life to

54

normal. Call us at 1-888-997-3147 to find a treatment center that’s tailored to your individual needs and will be able to help get you on the road to recovery.

Psychiatric and Behavioral Problems

Morgan Adams in Behavioral

Intellectual disability is fairly common, and it occurs in approximately 1 to 2 percent of people. Psychiatric and behavior problems occur three to six times more in these individuals than in the general population, so the assessment of these patients is important in treating

these issues. How Is Intellectual Disability Diagnosed? Intellectual disability is normally diagnosed before the age of 18 and is defined as when an IQ of a person is 75 or lower….

Many drugs are available for behavioral problems, and the type of drug that will be prescribed depends on the specific condition being treated. The Positive Environments

Network of Trainers of the California Department of Education lists Ritalin and Dexedrine as short-acting medications for the treatment of ADHD. They may help a child focus better,

reduce impulsive behavior and reduce motor restlessness.

Ritalin is also included in a group of medications known as long-acting stimulants. Other types of medications in this group include Concerta, Methylin ER, Methylin CD, Focalin, and

Metadate ER. These medications may also be effective against ADHD. Concerta may prevent drug abuse, as can Vyanase and Daytrana. Some professionals recommend Wellbutrin as a

primary ADHD treatment.

People with an anxiety disorder, OCD or ADHD may benefit from antidepressants, including Paxil, Tofranil, Anafranil, Prozac, Luvox, Celexa, Zoloft and Norpramin. Other medications

that may help include Daytrana, Biphetamine, Dexedrine, Adderall XR and Strattera. These medications are aimed at decreasing impulsivity, reducing hyperactivity, decreasing

obsessive-compulsive actions and reducing feelings of depression.

Medication Side Effects

Medications for behavioral disorders may have side effects. They can increase emotional issues, increase suicidal thoughts and aggravate seizure conditions. Some of the possible

side effects include:

Insomnia

55

Appetite reduction

Tremors

Depression

Abnormal heart rhythms

Behavior Drug Addiction, Dependence and Withdrawal

An individual may become addicted to the medication taken to treat a behavioral disorder. As a result, the person may need professional help with weaning off that medication. You

may experience withdrawal symptoms if you abuse certain medications.

If you suspect that you, your child or someone else you know has become dependent on prescription medication, contact us at 1-888-997-3147 for immediate assistance.

Medication Overdose

Children are more likely than adults to accidentally overdose on medication, including behavioral medications. A person who is depressed because of a behavioral disorder may

attempt an overdose on purpose. People who are depressed or have suicidal thoughts have a high risk for overdose, according to the National Coalition Against Prescription Drug Abuse.

Depression and Behavioral Disorders

According to the Cleveland Clinic, a behavioral disorder may trigger depression. The opposite is also possible, with depression being a trigger for a behavioral disorder, which can also lead

to substance abuse.

Dual Diagnosis: Addiction and Behavioral Disorders

It is not uncommon for people with a behavioral disorder to also have an addiction to drugs or alcohol. According to Psychology Today, an individual who has a panic disorder may also

be addicted to alcohol.

Children with ADHD may be at a higher risk for developing a substance abuse or alcohol dependence issue if the condition carries over into adulthood, according to WebMD.

Getting Help for a Behavioral Disorder

56

Because of the severity of these mental health issues, getting help for a behavioral disorder is crucial. Cognitive behavioral therapy along with medication is an effective way to treat

disorders such as ODD. The sooner you get help, the easier it will be to restore your life to normal. Call us at 1-888-997-3147 to find a treatment center that’s tailored to your

individual needs and will be able to help get you on the road to recovery.

Psychiatric and Behavioral Problems

Morgan Adams in Behavioral

Intellectual disability is fairly common, and it occurs in approximately 1 to 2 percent of people. Psychiatric and behavior problems occur three to six times more in these individuals than in the general population, so the assessment of these patients is important in treating

these issues. How Is Intellectual Disability Diagnosed? Intellectual disability is normally diagnosed before the age of 18 and is defined as when an IQ of a person is 75 or lower….….

Intelligence can be defined as a general mental ability for reasoning, problem solving, and learning. Because of its general nature, intelligence integrates cognitive functions such as perception, attention, memory, language, or planning. On the basis of this definition, intelligence can be reliably measured by standardized tests with obtained scores predicting several broad social outcomes such as educational achievement, job performance, health, and longevity. A detailed understanding of the brain mechanisms underlying this general mental ability could provide significant individual and societal benefits. Structural and functional neuroimaging studies have generally supported a front parietal network relevant for intelligence. This same network has also been found to underlie cognitive functions related to perception, short-term memory storage, and language. The distributed nature of this network and its involvement in a wide range of cognitive functions fits well with the integrative nature of intelligence. A new key phase of research is beginning to investigate how functional networks relate to structural networks, with emphasis on how distributed brain areas communicate with each other

Reasoning, problem solving, and learning are crucial facets of human intelligence. People can reason about virtually any issue, and many problems may be solved. Simple and highly complex behavioral repertoires can be learned throughout the lifespan. Importantly, there

are widespread individual differences in the ability to reason, solve problems, and learn which lead to human differences in the general ability to cope with challenging situations.

These differences: (i) become more salient as the cognitive complexity of the situation

57

becomes greater1-3; (ii) are stable over time4; and (iii) are partially mediated by genetic factors.5

Various definitions of intelligence tend to converge around similar notions designed to capture the essence of this psychological factor. Jensen6 notes Carl Bereiter's definition of

intelligence: “what you use when you don't know what to do” (p 111). After their extensive survey, Snyderman and Rothman7 underscored reasoning, problem solving, and learning as

crucial for intelligence. The “mainstream science on intelligence” report coordinated by Gottfredson8 highlights reasoning, planning, solving problems, thinking abstractly,

comprehending complex ideas, learning quickly, and learning from experience. The American Psychological Association (APA) report on intelligence acknowledges that

“individuals differ from one another in their ability to understand complex ideas, to adapt effectively to the environment, to learn from experience, to engage in various forms of

reasoning, to overcome obstacles by taking thought” (p 77). 9

Humans perceive the environment, attend to relevant stimuli, memorize episodic and semantic information, communicate, and so forth. However, these activities must be

integrated in some way for: (i) adapting our behavior to the environment; (ii) selecting the most appropriate contexts; or (iii) changing the world when adaptation and selection are not an option.10 In our view, the integration of cognitive functions and abilities is dependent on

the very general mental ability we call “general intelligence” or g for short. This integration is consistent with g as ability11 or as an emergent property of the brain.12

Any cognitive ability refers to variations in performance on some defined class of mental or cognitive tasks (Figure 1). Abilities reflect observable differences in individuals' performance on certain tests or tasks. However, this performance involves the synthesis of a variety of abilities: “spatial ability,” for instance, can be regarded as an inexact concept that has no formal scientific meaning unless it refers to the structure of abilities that compose it. The problem of defining (and measuring) intelligence is the problem of defining the constructs that underlie it and of specifying their structure.13-15

For more than a century, psychologists have developed hundreds of tests for the standardized measurement of intelligence with varying degrees of reliability and validity16 The resulting measures allowed for the organization of taxonomies identifying minor and major cognitive abilities. J. B. Carroll,17,18 for example, proposed a threestratum theory of intelligence after the extensive reanalysis of more than 400 datasets with thousands of subjects from almost 20 different countries around the world. Figure 2. shows a simplified depiction of the taxonomy of cognitive abilities

This survey of factor analytic studies supports the view that intelligence has a hierarchical structure (ie, like a pyramid). There is strong evidence for a factor representing general

intelligence (g) located at the apex of the hierarchy (stratum III). This g factor provides an

58

index of the level of difficulty that an individual can handle in performing induction, reasoning, visualization, or language comprehension tests. At a lower order in the hierarchy

(stratum II), several broad ability factors are distinguished: fluid intelligence, crystallized intelligence, general memory, visual perception, auditory perception, retrieval, or cognitive

speed. Lastly, stratum I is based on specific abilities, such as induction, lexical knowledge, associative memory, spatial relations, general sound discrimination, or ideational fluency.

Factor analytic surveys reveal two main findings: (i) the g factor constitutes more than half of the total common factor variance in a cognitive test or task in samples representative of the population; and (ii) various specific cognitive abilities can be identified, including the cognitive domains of language, memory, and learning, visual perception, information processing, knowledge and so forth, indicating certain generalizations of abilities; actually, there are more than 60 specific or narrow abilities. Available test batteries (a good example would be the Wechsler Adult Intelligence Scale - WAIS) measure g in addition to several cognitive abilities and specific skills. We know how to separate these influences over cognitive performance by means of statistical analyses. There are some measures which are highly g-loaded (eg, the Vocabulary subtest of the WAIS), while others are less g-loaded (eg, the Digit Symbol Subtest of the WAIS). (Figure 3). shows how gray matter correlates become more prominent with increased g loadings of the intelligence measures. Moreover, the same measure can load differently on general and specific cognitive factors/abilities depending on the sample analyzed.19,20

Exploring the relationships between human intelligence and the brain requires a careful consideration of the structure of human intelligence. As evident from above, when

researchers state that they are measuring intelligence by means of the Standard Progressive Matrices Test (SPM - as another example) they are telling an imprecise story because the

SPM measures g plus spatial and reasoning abilities plus SPM specificity. The exact combination of these “ingredients” for the analyzed sample must be computed before

saying something clear about the measured performance. This requires that studies use a battery of tests rather than just one test. Although this was not usually done for the early

functional imaging studies of intelligence,21-25 it is now more common.26-29 Results from the older and the newer studies, however, point to the importance of both whole brain and

specific brain networks.

Brain size and human intelligence

Wickett et al30 state:

“There is no longer any doubt that a larger brain predicts greater intelligence. Several research teams, using differing scan protocols, populations, and cognitive measures, have all

59

shown that IQ and brain volume correlate at about the 0.40 level ( ...) obviously replication of this effect is no longer required. What is required now is a more fine-grained analysis of

why it is that a larger brain predicts greater intelligence, and what it is about intelligence that is most directly related to brain volume” (p 1096, emphasis added).

The meta-analysis by McDaniel31 studied the relationship between in vivo brain volume and intelligence. Thirty-seven samples comprising a total of 1530 participants were considered

simultaneously. These were the main findings: (i) the average correlation is 0.33; (ii) subsets of the 37 studies that allow partitioning by gender revealed that the correlation is higher for

females (0.40) than for males (0.34); and (iii) the correlation does not change across age (0.33). The report concludes that these results resolve a 169-year-old debate: it is clear that

intelligence and brain volumes are positively related.

Going one step further, several studies measured the volume of regions of interest (ROIs) showing the most significant correlations (controlling for total brain volumes) in frontal,

parietal, and temporal brain regions, along with the hippocampus and the cerebellum.32,33 Nevertheless, regional correlations are moderate (ranging from 0.25 to 0.50) which implies

that measures of total or local brain size are far from telling the whole story.

From this perspective, gray and white matter must be distinguished. In keeping with this, voxel-by-voxel (a voxel is a volume element analogous to a pixel) analyses also showed

specific areas where the amount of gray and white matter was correlated with intelligence scores.24,25 The amount of gray matter is considered to reflect number and density of

neuronal bodies and dendritic arborization, whereas the amount of white matter is considered to capture number and thickness of axons and their degree of myelination. Gray

matter could support information processing capacity, while white matter might support the efficient flow of information in the brain. Available reports are consistent with the statement

that both gray and white matter volumes are positively related to intelligence, but that the latter relationship is somewhat greater (unweighted mean correlation values =.27 and .31

respectively).34 It is noteworthy that new studies using diffusion tensor imaging (DTI), which is the best method to date for assessing white matter, have reported DTI correlations with

intelligence scores (see white matter section below).

A distributed brain network for human intelligence

Jung and Haier35 reviewed 37 structural and functional neuroimaging studies published between 1988 and 2007. Based on the commonalities found in their analysis, they proposed

the Parieto-Frontal Integration Theory (PFIT), identifying several brain areas distributed

60

across the brain. These P-FIT regions support distinguishable information processing stages (Figure 4).

Figure 4.

Processing stages proposed by the P-FIT model.35

This is a summary of the proposed stages.

Occipital and temporal areas process sensory information in the first processing stage: the extrastriate cortex (Brodmann areas - BAs - 18 and 19) and the fusiform gyrus (BA 37),

involved with recognition, imagery and elaboration of visual inputs, as well as Wernicke's area (BA 22) for analysis and elaboration of syntax of auditory information.

Integration and abstraction of the sensory information by parietal BAs 39 (angular gyrus), 40 (supramarginal gyrus), and 7 (superior parietal lobule) correspond to the second processing

stage.

The parietal areas interact with the frontal lobes in the third processing stage and this interaction underlies problem solving, evaluation, and hypothesis testing. Frontal BAs 6, 9,

10, 45, 46, and 47 are underscored by the model.

The anterior cingulate (BA 32) is implicated for response selection and inhibition of alternative responses, once the best solution is determined in the previous stage.

White matter, especially the arcuate fasciculus, is thought to play a critical role in reliable communication of information across the brain processing units. Nevertheless, note that the

“Geschwind area” (underlying the angular gyrus) within the arcuate fasciculus may be even more important than the entire track.36

Frontal, parietal, temporal, and occipital areas are depicted in Figure 4. However, Jung and Haier35 suggest that not all these areas are equally necessary in all individuals for

intelligence. Discrete brain regions of the dorsolateral prefrontal cortex (BAs 9, 45, 46, and 47) and the parietal cortex (BAs 7 and 40) could be considered most important for human

intelligence.

A frontoparietal network may be relevant for intelligence, but also for working memory.37 A study by Gray et al38 tested whether fluid or reasoning ability (Gf) was mediated by neural

mechanisms supporting working memory. Sixty participants performed verbal and nonverbal working memory tasks. They had to indicate if a current item matched the item they saw 3

61

items previously (3-back). Brain activity was measured by event-related functional magnetic resonance imaging (fMRI). The demand for working memory varied across trials. Results showed that: (i) participants scoring higher on the Progressive Matrices Test (a measure

related to fluid g - Gf) were more accurate in the 3-back task; and (ii) only lateral prefrontal and parietal regions mediated the correlation between Gf and 3-back performance.

These fMRI results are consistent with the voxel-based morphometry (VBM) study reported by Colom et al (N = 48).39 In agreement with the well established fact that the g factor and

working memory capacity are very highly correlated,40-45 these researchers predicted that g and working memory would share significant common neural networks. Therefore, using a

VBM approach they quantified the overlap in brain areas where regional gray matter was correlated with measures of general intelligence and working memory, finding a common

neuroanatomic framework supported by frontal gray matter regions belonging to BA 10 and by the right inferior parietal lobule (BA 40). Of note, this study also showed: (i) more gray

matter recruitment for the more cognitively complex tasks (= more highly g loaded); and (ii) the complex span task (backward digit span) showed more gray matter overlap with the

general factor of intelligence than the simple span task (forward digit span, (Figure 5). These results were interpreted after the theory proposed by Cowan,46 namely that parietal regions support “capacity limitations,” whereas frontal areas underlie the “control of

attention”.

Figure 5.

Overlap of correlations between gray matter and g (conjunction of block design and vocabulary) and gray matter and forward (FDS) and backward (BDS) digit span scores

(P<01).39

A similar commonality between intelligence and working memory was found in animal studies. Matzel and Kolata47 reviewed several reports in which performance of laboratory

mice was measured in a variety of attention and learning tasks. These are their most prominent conclusions:

The “positive manifold” (eg, scores on cognitive tasks of various kinds are positively correlated) found in humans also applied to mice

Storage and processing components of working memory accounted for the strong relationship between this cognitive function and g

Networks involved in working memory overlap with those relevant for intelligence. These findings support an evolutionary conservation process of the structure and determinants of

intelligence beyond humans.48

62

Giftedness has been also investigated with related findings. Lee et al49 used an fMRI approach to investigate the neural bases of superior intelligence. Eighteen gifted and 18

nongifted adolescents were analyzed. They solved reasoning problems, having high (complex) and low (simple) loadings on g. Increased bilateral frontoparietal activations

(lateral prefrontal, anterior cingulate, and posterior parietal cortices) were found for both groups, but the gifted subjects showed greater activations in the posterior parietal cortex.

Furthermore, activations in BAs 7 and 40 (superior and intraparietal cortices) correlated with intelligence differences. Therefore, high intelligence was associated with increased

involvement of the frontoparietal network through preferential activation of the posterior parietal regions.

Gläscher et al28 investigated the neural substrates of g in 241 patients with focal brain damage, using voxel-based lesion-symptom mapping. Statistically significant associations between g and damage within a distributed network in frontal and parietal brain regions were found. Further, damage of white matter association tracts in frontopolar areas was

also shown to be associated with differences in g. They concluded that g draws on connections between regions integrating verbal, visuospatial, working memory, and

executive processes.

Going one step further, Gläscher et al28 asked whether or not there was a neural region whose damage uniquely impacts g beyond subtests contributing to the general score. They examined this question by analyzing the nonoverlap between a disjunction of subtests and the reported lesion pattern for g. A single region was found in the left frontal pole (BA 10)

showing a significant effect unique to g. This result complements the distributed nature of g and suggests a hierarchical control mechanism. This unique area for g may be involved in the

allocation of the working memory resources necessary for successful performance on specific cognitive tasks. However, this finding should be placed within context since there

are studies showing no decline in intelligence associated with prefrontal lobotomy, presumably including the frontopolar cortex.35 Therefore, future studies are necessary to determine the specific necessity of the frontal poles to g. The comparison between lesion

cohorts and normal cohorts must be done carefully.

The structural studies reported by Colom et al27 and Karama et al50 are also consistent with the P-FIT model. In the first study (N =100) the general factor of intelligence was estimated

after nine tests measuring reasoning, verbal, and nonverbal intelligence. Their VBM approach revealed several clusters of voxels correlating with individual differences in g

scores. The main regions included the dorsolateral prefrontal cortex, Broca's and Wernicke's areas, the somatosensory association cortex, and the visual association cortex. The design

matrix in this study controlled for sex, but when total gray matter was controlled for instead of sex, significant correlations were concentrated in frontal and parietal areas only (Figure

63

6):superior, middle, and frontal gyrus, along with the postcentral gyrus and the superior parietal lobule.

Figure 6.

Regional correlations between gray matter density and individual differences in g (N =1 04). The design matrix controls for total gray matter

Karama et al50 used an automated cortical thickness protocol (CIVET51) to analyze a large sample of children and adolescents representative of the population (N=216). The most

consistent areas of association between g scores and cortical thickness were found in lateral prefrontal, occipital extrastriate, and parahippocampal areas. Similar to the study reported

by Colom et al,27 Karama et al50 identified more brain regions related to g than those in the P-FIT model, likely resulting from the synthesizing nature of the P-FIT approach (ie, if all

regions implicated in intelligence across all 37 studies were included, they would have numbered in the hundreds) as opposed to the experimental/exploratory approach

employed by these studies.

There are three other studies applying a cortical thickness approach (the third will be discussed later). Shaw et al52 analyzed the trajectory of change in the thickness of the

cerebral cortex on a sample of 307 children and adolescents. Intelligence was measured by four subtests from the Wechsler scales (vocabulary, similarities, block design, and matrix

reasoning). They found that changes in thickness are more related to intelligence than thickness itself: negative correlations were found in early childhood, whereas the correlation was positive in late adolescence (these positive correlations were identified in frontal BAs 4, 6, 8, 10, 11, and 44-46, in parietal BAs 1-3, 5, 39, 40, in temporal BAs 21, 37, and in occipital BAs 17, 18, and 19). Further, intelligence differences were associated with the trajectory of

cortical development in frontal brain regions. Finally, children with higher scores on intelligence showed more change in estimated cortical thickness along the developmental

process.

Narr et al53 studied a sample of 65 participants. They found positive associations between cortical thickness and intelligence bilaterally in prefrontal BAs 10/11 and 47, as well as in

posterior temporal BAs 36/37. These researchers also analyzed males and females separately, finding that males showed correlations in temporaloccipital association cortices,

whereas females exhibited correlations in prefrontal and temporal association cortices. These results are not entirely consistent with the parietofrontal framework and emphasize

the importance of separate analyses for males and females.25,54,55

64

Functional networks and neurotransmitters

Using an fMRI approach, Bishop et al56 reported a study based on previous evidence showing that a polymorphism (val158met) in the catechol-O-methyltransferase (COMT)

gene regulates catecholaminergic signaling in prefrontal cortex. The val158 allele is associated with higher COMT activity than the met158 allele-therefore, a lesser conten of dopamine. Twenty-two participants, genotyped for the COMT val158met polymorphism,

performed verbal and spatial fluid intelligence (Gf) items, classified according to their cognitive complexity, as estimated from the loadings on g (see ref 57). These researchers were particularly interested in the analysis of the frontoparietal network related to fluid

intelligence (the lateral prefrontal cortex, the presupplementary motor area/anterior cingulate cortex, and the intraparietal sulcus).

Findings revealed a positive effect of COMT val allele load upon the BOLD signal in regions belonging to this brain network when items showing distinguishable cognitive complexity were compared. This result suggests that the COMT val158met polymorphism impacts on

the neural network supporting fluid intelligence. The finding is a demonstration that the effect of single genes can impact blood oxygen level dependent signal as assessed by fMRI. Further evidence linking catecholamine modulation within the identified network may help explain individual differences in the neural response to high levels of cognitive complexity,

irrespective of the content domain (verbal or nonverbal).

White matter

The relationship between human intelligence and the integrity of white matter has been much less investigated, although this trend is changing rapidly. Diffusion tensor imaging (DTI) is based on the diffusion of water molecules in the brain and provides information

about the size, orientation, and geometry of myelinated axons. DTI can produce measures that include fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RA), and axial diffusivity (AD), which allow for the assessment of myelin and axonal integrity (see Figure 7).

Figure 7.

DTI is useful for fine-grained deterministic and probabilistic tractography to capture underlying cortical connectivity patterns. This can be used for the quantitative analysis of

local and global network properties using graph-theoretical approaches (eg, analysis of small-world properties).58,59

65

Using DTI, Schmithorst et al60 analyzed the relationship between intelligence and white matter structure. The sample comprised 47 children and adolescents (age range 5 to 18). White matter structure was studied using fractional anisotropy (FA) and mean diffusivity

(MD) indices. These indices were correlated with intelligence scores obtained from the Wechsler scales. These researchers found positive correlations bilaterally for FA in white

matter association areas (frontal and parietooccipital areas). These correlations were thought to reflect a positive relationship between fiber organization-density and

intelligence.

Also using a DTI approach, Yu et al61 computed correlations between the integrity of several tracts (corpus callosum, cingulum, uncinate fasciculus, optic radiation, and corticospinal

tract) and intelligence. On the basis of their scores on the Wechsler scales, 79 participants were divided in two groups: average and high intelligence. White matter integrity was

assessed by fractional anisotropy (FA). The results showed that high intelligence participants display more white matter integrity than average intelligence participants only in the right uncinate fasciculus. Therefore, the right uncinate fasciculus might be an important neural basis for intelligence differences. A sample of 15 participants with mental retardation was

also analyzed. These participants were compared with the 79 healthy controls and they showed extensive damage in the integrity of several white matter tracts: corpus callosum,

uncinate fasciculus, optic radiation, and corticospinal tract.

Tang et al62 used both DTI and fMRI during an n-back memory task in 40 young adults who had also completed a battery of intelligence tests. Correlations between the BOLD signal

obtained from the n-back task and intelligence were mainly concentrated in the right prefrontal and bilateral parietal cortices. These correlations were negative (the higher the intelligence, the lower the activation during the n-back task) which supports the efficiency model of brain function. Further, white matter tracts connecting these areas also showed

correlations to g. Specifically, integrity of interhemispheric connections was positively correlated to some intelligence factors in females but negatively correlated in males.

Chiang et al63 have reported the first study combining a genetic informative design and a DTI approach for analyzing the relationships between white matter integrity and human intelligence. Intelligence was assessed by the Multidimensional Aptitude Battery, which

provides measures of general intelligence, verbal (information, vocabulary, and arithmetic), and nonverbal intelligence (spatial and object assembly). The sample comprised 23 pairs of

identical twins and 23 pairs of fraternal twins. White matter integrity, quantified using FA, was used to fit structural equation models (SEM) at each point in the brain. Afterwards

three-dimensional maps of heritability were generated. White matter integrity was found to be under significant genetic control in bilateral frontal, bilateral parietal, and left occipital

66

lobes (values ranging from .55 to .85). FA measures were correlated with the estimate of general intelligence and with nonverbal intelligence in the cingulum, optic radiations,

superior fronto-occipital fasciculus, internal capsule, the isthmus of the corpus callosum, and the corona radiata. Further, common genetic factors mediated the correlation between

intelligence and white matter integrity which suggests a common physiological mechanism and common genetic determination.

Networks for human intelligence

As noted above, gray matter supports information processing capacity and white matter promotes efficient flow of information across the brain. Connections are relevant for

intelligence and these connections might be organized in networks. From this perspective, Li et al64 reported a study testing the hypothesis that high levels of intelligence involve more

efficient information transfer in the brain.21,65,66 Studying a sample of 79 participants, brain anatomical networks were constructed by means of diffusion tensor tractography. These networks included intrahemispheric and interhemispheric connections. Six white-

matter tracts were further constructed: the genu of the corpus callosum, the body of the corpus callosum, the splenium of the corpus callosum, the cingulum, the corticospinal tract,

and the inferior fronto-occipital fasciculus. Thereafter, they calculated the topological properties of the networks for every participant. The sample was divided between average and high intelligence according to scores on the Wechsler scales. Higher global efficiencies

were revealed for the latter group: higher intelligence was found to display shorter characteristic path length and a higher global efficiency of the networks. This was

interpreted as a characteristic of a more efficient parallel information transfer in the brain anatomy. Therefore, the efficiency of brain structural organization could be an important

biological basis for human intelligence, as originally proposed by Haier et al.21,66

Song et al67 analyzed 59 adults for studying the relationships between spontaneous brain activity at rest and individual differences in intelligence. Intelligence was assessed by the Wechsler scales. Using fMRI, the bilateral dorsolateral prefrontal cortices were the seed regions for investigating the correlations across subjects between individual intelligence scores and the strength of the functional connectivity between the seed regions and the

remaining brain regions. These researchers found that brain regions in which the strength of the functional connectivity significantly correlated with intelligence scores were distributed

in the frontal, parietal, occipital and limbic lobes. Furthermore, functional connectivity within the frontal lobe and between the frontal and posterior brain regions predicted

differences in intelligence. These results are consistent with the relevance of a network view for human intelligence.

67

van den Heuvel et al68 used resting state fMRI and graph analysis for exploring the presumed organization of the brain network. Functional connections of this brain network

were analyzed computing correlations among the spontaneous signals of different brain regions during rest. The sample comprised 19 subjects and intelligence was measured by the

Wechsler scales. They found associations between global communication efficiency - more long-distance connections - and scores of intelligence. This was interpreted as suggesting

that a difference in the efficiency with which the brain integrates information between brain regions is related to differences in human intelligence. The strongest effects were found in frontal and parietal regions. Furthermore, intelligence differences were not related to the

level of local information processing (local neighborhood clustering) and to the total number of functional connections of the brain network.

Beyond these specific studies, the so-called “connectome project” deserves close attention.69 There is strong agreement regarding the fact that the human brain comprises a

wide variety of functional systems. Obtaining brain images during rest shows large-amplitude spontaneous low frequency fluctuations in the fMRI signal. These fluctuations are

related across areas sharing functions and the correlations show up as an individual's functional connectome. Biswall et al69 report findings obtained from 1414 participants from

35 laboratories. Their main results were: (i) there is a universal functional architecture; (ii) there are substantial sex differences and age-related gradients; and (iii) it is possible to

establish normative maps for the functional boundaries among identified networks.

Go to:

Integration of intelligence and cognitive findings

The frontoparietal network is relevant for intelligence, but also for other cognitive functions.70 Thus, for instance, Wager and Smith71 reported a meta-analysis of 60 positron-

emission tomography (PET) and fMRI studies of working memory. The effect of three content domains (verbal, spatial, and object), three executive functions (updating, temporal

order, and manipulation) along with their interactions were analyzed. Brain areas most involved in all these cognitive facets were located in the frontal and parietal lobes: (i) spatial

and nonspatial contents were separated in posterior, but not anterior areas; (ii) executive manipulation evoked more frontal activations, but with some exceptions; and (iii) the

parietal cortex was always implicated in executive processing. The meta-analysis by Wager, Jonides, and Reading72 after 31 PET and fMRI studies of shifting attention also highlights this

fronto-parietal network (medial prefrontal, superior and inferior parietal, medial parietal, and premotor cortices).

Similarly, Marois and Ivanoff 3 analyzed the capacity limits of information processing in the brain. Three basic limitations for perception, working memory, and action were explicitly considered. Their revision was based mainly on fMRI evidence and these were the basic

68

conclusions: (i) perception and action limitations are related to fronto-parietal brain networks; and (ii) working memory capacity limitations are associated to parieto-ccipital

brain networks. The lateral prefrontal cortex may support general target consolidation and response selection, using a flexible coding system for processing relevant information in any

given task. In contrast, the lateral parietal cortex might provide support to more specific processing goals. This brain region is more sensitive to perception than to action.

Thus, core cognitive functions (especially working memory) and intelligence share a frontoparietal brain network. If this network is involved for most individuals, it could be possible to predict individual differences in intelligence based on brain data.74 This was

attempted by Choi et al75 using structural (cortical thickness) and functional magnetic resonance imaging. Their regression model explained 50% of the variance in IQ scores. Even

when this figure may be questioned on several grounds, the main approach underscores that brain images might be employed for estimating intelligence levels in some instances

using a neurometric approach.

Finally, experimental confirmatory approaches should be welcomed to increase refinement of ongoing research efforts. In this regard, transcranial magnetic stimulation (TMS) may help

test hypotheses aimed at determining whether or not specific brain regions are really important for understanding individual differences in human intelligence. TMS induces transient changes in brain activity noninvasively. It does this by producing changes in a

magnetic field that, in turn, evoke electric currents in the brain which promote depolarization of cellular membranes. Cognitive neuroscience often relies on a correlation

approach, whereas TMS allows studying (almost) causal brain-behavior relationships in higher cognitive functions.76,77 The study reported by Aleman and van't Wout78

exemplifies this approach using a working memory task (forward and backward digit span). Working memory (and intelligence) performance is partially supported by the dorsolateral

prefrontal cortex. Using repetitive TMS (rTMS) - adapted in the Hz band for suppressing cognitive processing - over the right dorsolateral prefrontal cortex, a significant decrease of

performance in the forward and backward digit span test was found. Thus, regional suppression (or enhancement) might be produced to experimentally test specific

predictions.

Go to:

Conclusion

Regardless of the use of exploratory (correlation) or confirmatory (experimental) approaches, we do agree with Kennedy79: “as with more _eras', it is the underlying

technology that makes the era possible [...] new advances in acquisition, analysis, databasing, modeling, and sharing will continue to be necessary.” This is especially true for

analyzing human intelligence because this psychological factor is undoubtedly rooted in

69

widely distributed regions in the brain. Frontal and parietal lobes likely comprise crucial processing areas for intelligence, but integrity of hard connections across the entire brain or

spontaneous harmonic coactivation among distant regions appear also to be relevant. Creating a comprehensive picture for what can be called “neuro-intelligence”80 should

prove as challenging as it is exciting.

Go to:

Acknowledgments

RC was partly supported by grant PSI2010-20364 from the Ministerio de Ciencia e Innovación (Spain).

Go to:

REFERENCES

1 .Gottfredson L. Intelligence: is it the epidemiologists' elusive “fundamental cause” of social class inequalities in health? J Person Soc Psychol. 2004;86:174–199. [PubMed]

2 .Lubinski D. Introduction to the special section on cognitive abilities: 100 years after Spearman's (1904) “General Intelligence, Objectively Determined and Measured”. J Person

Soc Psychol. 2004;86:96–111. [PubMed]

3 .Schmidt F, Hunter J. General mental ability in the world of work: occupational attainment and job performance. J Person Soc Psychol. 2004;86:162–173. [PubMed]

4 .Deary IJ, Whalley LJ, Lemmon H, Crawford JR, Starr JM. The stability of individual differences in mental ability from childhood to old age: followup of the 1932 Scottish Mental

Survey. Intelligence. 2000;28:49–55.

5 .Bouchard T. Genetic influence on human intelligence (Spearman's g): how much? Ann Hum Biol. 2009;36:527–544. [PubMed]

6 .Jensen AR. The g Factor. The Science of Mental Ability. Westport, CONN: Praeger. 1998

7 .Snyderman M, Rothman S. Survey of expert opinion on intelligence and aptitude testing. Am Psychol. 1987;42:137–144.

8 .Gottfredson L. Mainstream science on intelligence: an editorial with 52 signatories, history, and bibliography. Intelligence. 1997;24:13–23.

9 .Neisser U, Boodoo G, Bouchard TJ, et al. Intelligence: knowns and unknowns. Am Psychol. 1996;51:77–101.

10 .Sternberg R. The Triarchic Mind. London, UK: Penguin Books. 1988

70

11 .Spearman C. General intelligence objectively determined and measured. Am J Psychol. 1904;15:201–293.

12 .van der Maas H, Dolan CV, Grasman RPPP, Wicherts JM, Huizengan HM, Raijmakers MEJ. A dynamical model of general intelligence: The positive manifold of intelligence by

mutualism. Psychol Rev. 2007;113:842–861. [PubMed]

13 .Hunt EB. Human Intelligence. Cambridge,UK: Cambridge University Press. In press.

14 .Johnson W, Bouchard T. The structure of human intelligence: It is verbal, perceptual, and image rotation (VPR), not fluid and crystallized. Intelligence. 2005;33:393–416.

15 .McGrew K. CHC theory and the human cognitive abilities project: standing on the shoulders of the giants of psychometric intelligence research. Intelligence. 2009;37:1–10.

16 .Jensen AR. Bias in Mental Testing. New York, NY: Free Press; 1980

17 .Carroll JB. Human Cognitive Abilities A Survey of Factor Analytic Studies. Cambridge, UK: Cambridge University Press; 1993

18 .Carroll JB. The higher-stratum structure of cognitive abilities: Current evidence supports g and about 10 broad factors. In Nyborg H, ed. The Scientific Study of General Intelligence:

Tribute to Arthur R. Jensen. Amsterdam, the Netherlands: Pergamon. 2003:5–21.

19 .Colom R, Abad FJ, García LF, Juan-Espinosa M. Education, Wechsler's Full Scale IQ, and g. Intelligence. 2002;30:449–462.

20 .Colom R, Thompson, PM. Understanding human intelligence imaging the brain. In Chamorro-Premuzic T, Furnham A, von Stumm S, eds. Handbook of Individual Differences.

London, UK: Wiley-Blackwell. In press.

21 .Haier RJ, Siegel, BV Jr, Nuechterlein KH, et al. Cortical glucose metabolic rate correlates of abstract reasoning and attention studied with positron emission tomography. Intelligence.

1988;12:199–21.

22 .Haier RJ. Cerebral glucose metabolism and intelligence. In Vernon PA, ed. Biological Approaches to the Study of Human Intelligence. Norwood, NJ: Ablex Publishing. 1993:317–

331.

23 .Haier RJ, White NS, Alkire MT. Individual differences in general intelligence correlate with brain function during nonreasoning tasks. Intelligence. 2003;31:429–441.

24 .Haier RJ, Jung RE, Yeo RA., et al. Structural brain variation and general intelligence. NeuroImage. 2004;23:425–433. [PubMed]

25 .Haier RJ, Jung RE, Yeo RA, et al. The neuroanatomy of general intelligence: sex matters. NeuroImage. 2005;25:320–327. [PubMed]

26 .Colom R. Intelligence? What intelligence? Behav Brain Sci. 2007;30:155–56.

71

27 .Colom R, Haier RJ, Head K, et al. Gray matter correlates of fluid, crystallized, and spatial intelligence: Testing the P-FIT model. Intelligence. 2009;37:124–135.

28 .Gläscher J, Rudrauf D, Colom R, et al. The distributed neural system for general intelligence revealed by lesion mapping. PNAS. 2010;10:4705–4709. [PMC free article]

[PubMed]

29 .Haier RJ, Colom R, Schroeder DH, et al. Gray matter and intelligence factors: Is there a neuro-g? Intelligence. 2009;37:136–144.

30 .Wickett JC, Vernon PA, Lee DH. Relationships between factors of intelligence and brain volume. Person Indiv Diff. 2000;29:1095–1122.

31 .McDaniel MA. Big-brained people are smarter: a meta-analysis of the relationship between in vivo brain volume and intelligence. Intelligence. 2005;33:337–346.

32 .Luders E, Narr KL, Thompson PM, Toga AW. Neuroanatomical correlates of intelligence. Intelligence. 2009;37:156–163. [PMC free article] [PubMed]

33 .Toga AW, Thompson PM. Genetics of brain structure and intelligence. Ann Rev Neurosci. 2005;28:1–23. [PubMed]

34 .Gignac G, Vernon PA, Wicket JC. Factors influencing the relationship between brain size and intelligence. In: Nyborg H, ed. The Scientific Study of General Intelligence. Oxford, UK:

Pergamon Press. 2003:93–106.

35 .Jung RE, Haier RJ. The parieto-frontal integration theory (P-FIT) of intelligence: Converging neuroimaging evidence. Behav Brain Sci. 2007;30:135–187. [PubMed]

36 .Catani M, Jones DK, Ffytche DH. Perisylvian language networks of the human brain, Ann Neurol. 2005;57:8–16. [PubMed]

37 .Gray J, Thompson PM. Neurobiology of intelligence: Science and ethics. Nat Rev. 2004;5:471–482. [PubMed]

38 .Gray J, Chabris, C, Braver, T. Neural mechanisms of general fluid intelligence. Nat Neurosci. 2003;6:316–322. [PubMed]

39 .Colom R, Jung RE, Haier RJ. General intelligence and memory span: Evidence for a common neuro-anatomic framework. Cogn Neuropsychol. 2007;24:867–878. [PubMed]

40 .Colom R, Rebollo I, Palacios A, Juan-Espinosa M, Kyllonen PC. Working memory is (almost) perfectly predicted by g. . Intelligence. 2004;32:277–296.

41 .Colom R, Abad FJ, Rebollo I, Shih PC. Memory span and general intelligence: A latent-variable approach. Intelligence. 2005;33:623–642.

42 .Colom R, Abad FJ, Quiroga MA, Shih PC, Flores-Mendoza C. Working memory and intelligence are highly related constructs, but why? Intelligence. 2008;36:584–606.

72

43 .Engle RW. Working memory capacity as executive attention. Curr Dir Psychol Sci. 2002;11:19–23.

44 .Kane MJ, Hambrick DZ, Conway ARA. Working memory capacity and fluid intelligence are strongly related constructs: comment on Ackerman, Beier, and Boyle (2005). Psychol

Bull. 2005;131:66–71. [PubMed]

45 .Oberauer K, Schulze R, Wilhelm O, Süb H. Working memory and intelligence--Their correlation and their relation: comment on Ackerman, Beier, and Boyle (2005). Psychol Bull.

2005;131:61–65. [PubMed]

46 .Cowan N. Working Memory Capacity. New York, NY: Psychology Press; 2005

47 .Matzel LD, Kolata S. Selective attention, working memory, and animal intelligence. Neurosci Biobehav Rev. 2010;34:23–30. [PMC free article] [PubMed]

48 .Kolata S, Wu J, Light K, Schachner M, Matzel LD. Impaired working memory duration but normal learning abilities found in mice that are conditionally deficient in the close homolog

of L1. J. Neurosci. 2008;28:13505–13510. [PMC free article] [PubMed]

49 .Lee KH, Choi YY, Gray JR, et al. Neural correlates of superior intelligence: stronger recruitment of posterior parietal cortex. NeuroImage. 2006;29:578–586. [PubMed]

50 .Karama S, Ad-Dab'bagh Y, Haier RJ, et al. the Brain Development Cooperative Group Positive association between cognitive ability and cortical thickness in a representative US

sample of healthy 6 to 18 year-olds. Intelligence. 2009;37:145–155. [PMC free article] [PubMed]

51 .Ad-Dab'bagh Y, Lyttelton O, Muehlboeck JS, et al. The CIVET imageprocessing environment: A fully automated comprehensive pipeline for anatomical neuroimaging

research. In Corbetta M, ed. Proceedings of the 12th Annual Meeting of the Organization for Human Brain Mapping. Florence, Italy: Elsevier. 2006

52 .Shaw P, Greenstein D, Lerch J, et al. Intellectual ability and cortical development in children and adolescents. Nature. 2006;440:676–679. [PubMed]

53 .Nar KL, Woods RP, Thompson PM. Relationships between IQ and regional cortical gray matter thickness in healthy adults. Cereb Cortex. 2007;17:2163 – 2171. [PubMed]

54 .Haier RJ, Benbow CP. Sex differences and lateralization in temporal lobe glucose metabolism during mathematical reasoning. Dev Neuropsychol. 1995;11:405–414.

55 .Jung RE, Haier RJ, Yeo RA, et al. Sex differences in N-acetylaspartate correlates of general intelligence: an 1H-MRS study of normal human brain. NeuroIimage. 2005;26:965–

972. [PubMed]

56 .Bishop SJ, Fossella J, Croucher CJ, Duncan J. COMT val158met genotype affects recruitment of neural mechanisms supporting fluid intelligence. Cereb Cortex,.

2008;doi:10.1093/cercor/bhm240. [PMC free article] [PubMed]

73

57 .Duncan J, Seitz JR, Kolodny J, et al. A neural basis for general intelligence. Science. 2000;289:457–460. [PubMed]

58 .Gong G, Rosa-Neto P, Carbonell F, et al. Age- and gender-related differences in the cortical anatomical network. J Neurosci. 2009;2:15684–15693. [PMC free article] [PubMed]

59 .Mori S, Wakana S, Nagae-Poetscher LM, Van Zijl PCM. MRI Atlas of Human White Matter. Amsterdam, the Netherlands: Elsevier; 2005

60 .Schmithorst VJ, Wilke M, Dardzinski BJ, Holland SK. Cognitive functions correlate with white matter architecture in a normal pediatric population: a diffusion tensor MRI study.

Hum Brain Map. 2005;26:139–147. [PMC free article] [PubMed]

61 .Yu C, Li J, Liu Y, et al. White matter tract integrity and intelligence in patients with mental retardation and healthy adults. NeuroImage. 2008;40:1533–1541. [PubMed]

62 .Tang, CY, Eaves EL, Ng, JC, et al. Brain networks for working memory and factors of intelligence assessed in males and females with fMRI and DTI. Intelligence. 2010;38:293–

303.

63 .Chiang M, Barysheva M, Shattuck DW, et al. Genetics of brain fiber architecture and intellectual performance. J Neurosci. 2009;29:2212–2224. [PMC free article] [PubMed]

64 .Li Y, Liu Y, Li J, et al. Brain anatomical network and intelligence. Comp Biol. 2009. 2009;5:1–17.

65 .Neubauer AC, Fink A. Intelligence and neural efficiency: Measures of brain activation versus measures of functional connectivity in the brain. Intelligence. 2009;37:223–229.

66 .Haier RJ, Siegel BV, MacLachlan A, Soderling E, Lottenberg S, Buschsbaum MS. Regional glucose metabolic changes after learning a complex visuospatial/motor task: a positron

emission tomographic study. Brain Res. 1992;570:134–143. [PubMed]

67 .Song M, Zhou Y, Li J, et al. Brain spontaneous functional connectivity and intelligence. NeuroImage. 2008;41:1168–1176. [PubMed]

68 .van den Heuvel MP, Stam CJ, Kahn RS, Pol H. Efficiency of functional brain networks and intellectual performance. J Neurosci. 2009;29:7619–7624. [PubMed]

69 .Biswal BB, Mennes M, Zuo XM, et al. Toward discovery science of human brain function. Proc Natl Acad Sci U S A. 2010;107:4734–4739. [PMC free article] [PubMed]

70 .Naghavi HR, Nyberg L. Common fronto-parietal activity in attention, memory, and consciousness: shared demands on integration? Conscious Cogn. 2005;14:390–425.

[PubMed]

71 .Wager TD, Smith, EE. Neuroimaging studies of working memory: a meta-analysis. Cogn Affect Behav Neurosci. 2003;3:255–274. [PubMed]

74

72 .Wager TD, Jonides J, Reading S. Neuroimaging studies of shifting attention: a meta-analysis. NeuroImage. 2004;22:1679–1693. [PubMed]

73 .Marois, R. and Ivanoff J. Capacity limits of information processing in the brain. Trends Cogn Sci. 2005;9:296–305. [PubMed]

74 .Haier RJ. What does a smart brain look like? Inner views show how we think. Sci Am Mind. 2009 Nov

75 .Choi YY, Shamosh NA, Cho SH , et al. Multiple bases of human intelligence revealed by cortical thickness and neural activation. J Neurosci. 2008;41:10323–10329. [PubMed]

76 .Pascual-Leone A, Bartres-Faz D, Keenan JP. Transcranial magnetic stimulation: studying the brain-behaviour relationship by induction of 'virtual lesions'. Phil Trans R Soc London B.

1999;354:1229–1238. [PMC free article] [PubMed]

77 .Sack AT. Transcranial magnetic stimulation, causal structure-function mapping and networks of functional relevance. Curr Opin Neurobiol. 2006;16:593–599. [PubMed]

78 .Aleman A, van't Wout M. Repetitive transcranial magnetic stimulation over the right dorsolateral prefrontal cortex disrupts digit span task performance. Neuropsychobiol.

2008;57:44–48. [PubMed]

79 .Kennedy DN. Making connections in the connectome era. Neuroinformatics, 2010;8:61–62. [PubMed]

80 .Haier RJ. Neuro-intelligence, neuro-metrics and the next phase of brain imaging Studies. Intelligence. 2009;37:121–123.

81 .Colom R, Jung R, Haier RJ. Distributed brain sites for the g-factor of intelligence. Neuroimage. 2006;31:1359–1365. [PubMed]

Articles from Dialogues in Clinical Neuroscience are provided here courtesy of Les Laboratoires Servier

Human intelligence, 

mental quality that consists of the abilities to learn from experience, adapt to new situations, understand and handle abstract concepts, and use knowledge to manipulate

one’s environment.

Much of the excitement among investigators in the field of intelligence derives from their attempts to determine exactly what intelligence is. Different investigators have emphasized different aspects of intelligence in their definitions. For example, in a 1921 symposium the American psychologists Lewis M. Terman and Edward L. Thorndike differed over the definition of intelligence, Terman stressing the ability to think abstractly and Thorndike emphasizing learning and the ability to give good responses to questions. More recently, however, psychologists have generally agreed that adaptation to the environment is the key

75

to understanding both what intelligence is and what it does. Such adaptation may occur in a variety of settings: a student in school learns the material he needs to know in order to do well in a course; a physician treating a patient with unfamiliar symptoms learns about the underlying disease; or an artist reworks a painting to convey a more coherent impression. For the most part, adaptation involves making a change in oneself in order to cope more effectively with the environment, but it can also mean changing the environment or finding an entirely new one

MULTIPLE INTELLIGENCES,

A THEORY THAT CAN BE APPLIED TO NURSING

By Margot Phaneuf

For some time we have been hearing about a theory that has radically changed our

understanding of human intelligence and how to measure it. Traditional I.Q. tests, as

developed many years ago by Binet and Simon, deal mainly with the ability to solve

logical and mathematical problems, oral expression and the speed at which different

types of data can be processed. As such, they only measure some very limited aspects of

intelligence. Following work by Howard Gardner, an American cognitive psychologist

and “developmentalist” who teaches education at Harvard University, it is now generally

accepted that human intelligence is much more complex, and that it conceals forms of

intelligence of which we make little use in nursing.

In fact, most people have all the forms of intelligence described by Gardner, if only to

different degrees. Each person demonstrates distinctive personal traits, using each of

these forms of intelligence but in their own personal combination. This explains why

many students are unable to draw on the forms of intelligence needed for the types of

teaching that we offer. Students cannot meet requirements that are not adapted to their

intellectual capacities, because too often we use forms of teaching that rely on theory and

deduction, where abstraction is critical to success. As a result, these students develop

negative images of themselves and are never able to attain their full potential. As can be

Linguistic

Existential Logical mathematical

Naturalist Intrapersonal

76

Musical Interpersonal

Bodily kinetic Spatial

Different Forms of Intelligence

From Howard Gardner.

One Intelligence or Many? Alternative Approaches to Cognitive Abilities

Han S. Paik

Washington University

To this day, how exactly to define intelligence is still debated. There are, however, two major schools of thought on its nature and properties. This paper examines and evaluates the two

opposing theories on the nature of intelligence. The two opposing theories of intelligence are the one general intelligence school of thought and the multiple intelligences school of

thought. The general intelligence proponents believe that there is one factor from which all intelligence is derived; the multiple intelligences proponents believe that there are different

kinds of intelligence. Each theory has merit and evidence to support its claims.

In the last decade of the nineteenth century, a French physician named Alfred Binet was commissioned by the school system to develop a way to differentiate those students who

were uneducable, or severely mentally handicapped, from the other students. He developed an intelligence test to do so. The very first intelligence tests, introduced a decade earlier,

emphasized sensory tasks, physical measures, and simple processes. Unlike these tests, Binet developed an intelligence test that consisted of items that required complex processes

of the mind and examined the comprehensive individual. Consequently, the results from Binet's scales were successful in discriminating between the two types of students. The

success of Binet's test led to a much greater question to be asked: what exactly are these tests measuring? What the tests claimed to measure was intelligence. But, if they measured

intelligence, then the next question that arose was this: what exactly is intelligence? It is at this point that the great debate on the definition of intelligence began.

There is a general consensus that there are different levels of intelligence, and that different individuals have different capacities of intelligence. In other words, "individuals differ from

one another in their ability to understand complex ideas, to adapt effectively to the environment, to learn from experience, to engage in various forms of reasoning, to

overcome obstacles by taking thought" (Neisser et al., 1996, p. 77). But, how many and what

77

kinds of different types of intelligences exist, and how to define intelligence, is still at debate.

Two Theories on the Nature of Intelligence

Today, there are two major schools of thought on the nature of intelligence. The first, supported by such psychologists as Eysenck, Galton, Jensen, and Spearman, believe that all

intelligence comes from one general factor, known as g. The proponents of the other school of thought include Gardner, Sternberg, and Thurstone. These psychologists think that there

is more than one general type of intelligence, or in other words, that there are different types of intelligences. An interesting note about this school of thought is that there is

disagreement, even within that camp, on exactly how many different types of intelligences there are.

One General Intelligence

There are strong arguments to support the theory of one general type of intelligence. The most convincing evidence for a single general intelligence model is the fact that there is

proof of a single general factor that governs the level of intelligence of an individual. This is also known as the positive manifold (Spearman, 1904). Furthermore, there is a very high

correlation between IQ and very simple cognitive tasks, which supports the theory of one general intelligence (Eysenck, 1982).

Positive manifold. The first argument in support of one general intelligence is the fact that there is a high positive correlation between different tests of cognitive ability. Spearman

(1904), in doing his research, administered to many people different types of tests, covering several different areas of cognitive ability. When he examined the results of these different

tests, he found that there was a positive correlation between the tests for a given individual. In other words, if a certain person performed well on a test of verbal abilities, then that

same person also performed well on another test of another cognitive ability, for instance, a mathematics test. Spearman named this positive correlation among tests the positive

manifold. This positive manifold was also called the general intelligence factor, or g. This is the single factor that determines the intelligence of the individual. Jensen (1997) supported

the theory of one general intelligence by stating, "the positive correlation between all cognitive test items is a given, an inexorable fact of nature. The all-positive inter item

correlation matrix is not an artifact of test construction or item selection, as some test critics mistakenly believe" (p. 223). This positive manifold led Spearman (1904) to find a large first

factor that was dubbed general intelligence, or g.

78

Reaction time and g. Another strong argument in support of one general intelligence is the fact that there is a very high correlation between reaction time and IQ. According to Eysenck

(1982), "IQ correlates very highly (.8 and above, without correction for attenuation) with tests which are essentially so simple, or even directly physiological that they can hardly be considered cognitive in the accepted sense" (p. 9). For instance, an example of the type of

tests used to measure reaction time is a test in which a light is turned on. The participant is asked to press a button as soon as he or she sees the light go on. From tests such as these,

the reaction time can be measured. Given that only very simple sensory and motor movements are necessary to respond, it is difficult to argue that cultural, environmental,

gender, socio-economic, or educational discrepancies will affect the participants ability to respond to the testers' questions (Eysenck, 1982).

Common definitions of intelligence are "success in problem solving, ability to learn, capacity for producing noegenetic solutions, understanding of complex instructions or simply all-

round cognitive ability" (Eysenck, 1982, p. 8). A common thread in all of these definitions of intelligence is that they all require the nervous system, especially the brain, and sensory

organs to be functioning properly. Furthermore, in order for these types of tasks to be completed, they require that the information processing that goes on within the bodily

systems is relatively without error.

Jensen (1993), as well as others, synthesized these facts and conjectured that "the most obvious hypothesis is that speed of information processing is the essential basis if g, and one possible neurological basis of speed of processing is the speed of transmission through nerve

pathways" (p. 54). The speed of information transmission can be reasonably well measured or extrapolated from reaction time scores. Therefore, if an individual has faster neural

processing speed, then he or she have a better reaction time. In turn, given that reaction time is highly correlated with IQ, then those individuals with faster neural processing speeds have higher IQ's. Consequently, neural processing speed determines the level of intelligence

of the individual; this intelligence is the one general intelligence, g.

Summary. Sternberg and Gardner (1982) summarized the theory of one general intelligence by stating "general intelligence can be understood componentially as deriving in part from

the execution of general components in information processing behavior" (p. 251). And Spearman (1973/1923) concluded that "cognitive events do, like those of physics, admit

throughout of being reduced to a small number of definitely formulatable principles in the sense of ultimate laws" (p. 341). These psychologists, as well as many others, believe that

intelligence can be defined by a single factor. Whether that single factor be termed positive manifold, neural processing speed, or g, the complexities of the human mind and its

processes can be reduced to a single factor, defined as intelligence.

79

Multiple Intelligences

The different proponents of one general intelligence all agree that there is a single factor that determines intelligence, and the proponents of multiple intelligences agree that there is

more than one single type of intelligence. However, the different proponents of multiple intelligences do not agree on how many different intelligences there are, or could be. I

believe that the theories put forth by Gardner and Sternberg have the most merit. Both of them have their own theory on multiple intelligences; Gardner (1983) believes there are

seven forms of intelligence; Sternberg (1985) believes there are three forms of intelligences.

Gardner's theory. Gardner's theory of multiple intelligences suggests that there are seven different forms of intelligence. They are linguistic, musical, spatial, bodily, interpersonal,

intrapersonal and logico-mathematical. In developing his theory, Gardner (1983) attempted to rectify some of the errors of earlier psychologists who "all ignore[d] biology; all fail[ed] to

come to grips with the higher levels of creativity; and all [were] insensitive to the range of roles highlighted in human society" (p. 24). So, Gardner based his own theory of intelligence

on biological facts. Li (1996) summarizes Gardner's theory as follows:

Premise 1: If it can be found that certain brain parts can distinctively map with certain cognitive functioning (A), then that cognitive functioning can be isolated as one candidate of

multiple intelligences (B). (If A, then B).

Premise 2: Now it has been found that certain brain parts do distinctively map with certain cognitive functioning, as evidenced by certain brain damage leading to loss of certain

cognitive function. (Evidence of A).

Conclusion: Therefore, multiple intelligences. (Therefore B.). (p. 34)

Gardner's theory has a very solid biological basis. Premise two takes into account the brain as a major physical determinant of intelligence. By studying individuals who had speech

impairment, paralysis, or other disabilities, Gardner could localize the parts of the brain that were needed to perform the physical function. He studied the brains of people with

disabilities postmortem and found that there was damage in specific areas, in comparison to those who did not have a disability. Gardner found seven different areas of the brain, and so

his theory consists of seven different intelligences, each related to a specific portion of the human brain (Li, 1996).

Gardner looked to develop a theory with multiple intelligences also because he felt that the current psychometric tests only examined the linguistic, logical, and some aspects of spatial

intelligence, whereas the other facets of intelligent behavior such as athleticism, musical talent, and social awareness were not included (Neisser et al., 1996).

80

Sternberg's theory. The triarchic theory of intelligence developed by Sternberg is "a comprehensive theory, more encompassing. . . because it takes into account social and

contextual factors apart from human abilities" (Li, 1996, p. 37). Sternberg (1985) felt that the theories that preceded him were not incorrect, but, rather, incomplete. Consequently, his

theory, like Gardner's, takes into account creative or musical intelligence. But as for the other six intelligences from Gardner's theory, Sternberg classifies them into two different

types of intelligences: analytic (or academic) and practical. These two types of intelligences differ and are defined as follows: Analytic problems tend to have been formulated by other

people, be clearly defined, come with all information needed to solve them, have only a single right answer, which can be reached by only a single method, be disembodied from

ordinary experience, and have little or no intrinsic interest. Practical problems tend to require problem recognition and formulation, be poorly defined, require information

seeking, have various acceptable solutions, be embedded in and require prior everyday experience, and require motivation and personal involvement. (Neisser et al., 1996, p. 79)

If an individual could solve one or the other of these types of problems well, then that individual would have a high analytic or practical intelligence, respectively. Also, there exist

virtuosos, or individuals who are extremely talented in the fine arts, these people would have a high creative intelligence.

One reason why Sternberg's theory has received so much acclaim is that in real-life situations, is has proven itself. For example, Brazilian street children can do the math that

they need to know in order to run their street businesses, but they are unable to pass a math class in school (Carraher, Carraher, & Schliemann, 1985). Evidence such as this shows

that there are two different types of mathematical intelligence, an academic classroom mathematical intelligence and a street wise practical intelligence.

Other theories. In addition to Gardner's and Sternberg's theories on multiple intelligences, there are other theories as well, including Thurstone's and Guilford's. Both were proponents of multiple intelligences. Thurstone (1924) stated that "the biological function of intelligence

is to protect the organism from bodily risk and to satisfy its wants with the least possible chance of recording failure on the environment" (p. 162). With this in mind, he found several

primary mental abilities. As expected, these abilities are those abilities that the individual uses in order to survive and succeed in society. He found this using factor analysis, like

Spearman, but Thurstone took the factor analysis a step further and rotated the factors. He arrived at 13 different factors as opposed to Spearman's one and called these primary mental abilities. These factors included spatial, perceptual, numerical, logical, verbal,

memory, arithmetical reasoning, and deductive abilities (Thurstone, 1938). Guilford (1967) found that the structure of intellect was composed of 4 contents, 5 operations, and 6

processes. Each of these was mixed and matched to come up with 120 different combinations of abilities.

81

Conclusion

There are two distinct schools of thought on the nature of intelligence. The proponents of one general intelligence have a theory that explains the biological reasons for intelligence.

Given that they see neural processing speed as the root for intelligence, their theory has an effective causal explanation. On the other hand, the theory of one general intelligence does

not encompass all peoples. In the example with the Brazilian street children, they would most likely score poorly on an intelligence test, and be labeled with a low general

intelligence. However, they are intelligent enough to be able to do all of the math that they need to know how to do. A drawback to the general intelligence school of thought is that it

is heavily dependent on psychometric evaluations. Consequently, it cannot take into account the vast array of different talents that people have.

As for multiples intelligences, there are many theorists in that school of thought as well. Some of the theories presented by the proponents of multiple intelligences are excessive

and have too many constructs to measure for example, Guilford's theory. But there are reasonable explanations of intelligence put forth by those from the school of multiple

intelligences. Gardner's theory has a very clear causal explanation for intelligence, like the explanation of one general intelligence. But, unfortunately, it is very difficult to pinpoint and

confirm Gardner's hypotheses experimentally, because of the delicacy involved with the human brain. Sternberg's theory does not have a biological basis to it, and that detracts from

its validity. But that may also be its strength. The theory does not focus on the brain and biological functions, but on different social situations. Therefore, the theory applies to

different social situations and environments, as none of the other theories does. But, given that there still is a substantial debate about the nature of intelligence, and no one theory is

accepted by all, there is still room for improvement on any given theory.

Peer Commentary

Intelligence: Two Major Schools of Thought

Valerie L. Dammann

Northwestern University

I enjoyed reading and rereading Paik's review paper regarding intelligence--one versus multiple. Paik does a good job of covering the two different schools of thought regarding

intelligence and what each psychologist believes to be true. I agree with Neisser et al. (1996) that there are different levels of intelligence and each individual has a different measure of

intelligence. I also believe that individuals' intellectual performance varies depending on the situation in which they find themselves. This is why I tend to agree more with the

82

psychologists who believe in multiple intelligences, such as Gardner, Sternberg, and Thurstone, rather than those who believe in one intelligence, such as Eysenck, Galton,

Jensen, and Spearman.

After researching articles written on these theories, Paik has covered the main points well, although I would like to have seen him go into further detail regarding Gardner's seven

different forms of intelligence. Paik does a nice job of explaining Gardner's Premise 2, which takes into account the brain as a major physical determinant of intelligence. Paik also does a nice job of stating the main points of Sternberg and Thurstone, although I would like Paik to

have talked a little more about how Thurstone took Spearman's method of factor analysis one step further by rotating the factors (Thurstone, 1938).

Paik concludes his paper by reiterating the two distinct schools of thought regarding intelligence. He briefly covers the main points for one general intelligence as well as for

multiple intelligences and concludes with the debate about the nature of intelligence and how no one theory is accepted by all and there is still room for improvement on any given

theory. Overall, I enjoyed reading Paik's review paper on intelligence and gained a little more knowledge about the subject.

Peer Commentary

Calling Attention to More Diverse Approaches to Intelligence

KwangMin Jang

Northwestern University

In the article "One Intelligence or Many? Alternative Approaches to Cognitive Abilities," Paik summarizes and evaluates the two major schools of thought on the nature of intelligence. As Paik correctly notes, some researchers such as Spearman and Jensen argue that there is one general intelligence, or g, which many abilities have in common, whereas other researchers

such as Gardner and Sternberg think there are many different intelligences that are independent of each other. However, there is not only an either-or approach to intelligence

such as one versus many. There are still other approaches that try to make a compromise between the two opposing approaches. The other approaches "opt for a multifactorial

description with factors hierarchically arranged and something like g at the top" (Neisser et al., 1996, p. 96).

83

Therefore, although Paik argues well enough about the two opposing theories of intelligence in terms of the relations among many different abilities--one versus many--what is further needed for better understanding of the nature of intelligence is to give more attention to

diverse approaches to intelligence. This is needed because, "in a field where so many issues are unresolved and so many questions unanswered, the confident tone that has

characterized most of the debate on these topics is clearly out of place" (Neisser et al., 1996, p. 97). That is what Paik also concluded in his paper as "there still is a substantial debate

about the nature of intelligence, and no one theory is accepted by all".

Other approaches besides the psychometric and multiple intelligence approaches to intelligence should briefly be mentioned here. Paik has already discussed the psychometric

and multiple intelligence approaches in detail. The other approaches considered here are developmental approaches and biological approaches (Neisser et al., 1996). These

approaches give us a broader understanding about the development and physiological structure of intelligence.

In the developmental perspectives on intelligence, two researchers deserve to be mentioned. One is the Swiss psychologist Jean Piaget and the other is the Russian

psychologist Lev Vygotsky. They were interested in how intelligence develops in the first place. Piaget thought that intelligence develops in all children through "the assimilation of

new information into existing cognitive structures and the accommodation of those structures themselves to the new information" (Neisser et al., 1996, p. 80). He devised a

method to assess children's understanding of conservation, the principle that material quantity is not changed by changes of shape. In his method, a child watched water being

poured from a small container to a large one and was asked if the large container had less water in it. The answer indicated the development of that child's intelligence. Whereas

Piaget thought that intelligence naturally develops fully in all children, Vygotsky believed that intelligence is social in origin and has potential to develop throughout life. He thought that "language and thought first appear in early interactions with parents, and continue to

develop through contact with teachers and others" (Neisser et al., 1996, p. 80).

From the biological approaches to intelligence, researchers study the brain to understand intelligence. Developments of brain anatomy and physiology concerning the cortical

neurons, cerebral glucose metabolism, evoked potentials, nerve conduction verlocity, and sex hormones give new ideas about what intelligence is and how to measure it (Neisser et

al., 1996). For example, the brain is studied using PET and MRI scans to understand individual differences in intelligence. The biological approaches give us high hopes that many

anomalies about intelligence will be resolved in the near future by advances of research methods.

84

As briefly reviewed here, there is a wide range of conceptions of intelligence. Paik reviewed the psychometric approaches and multiple intelligence approaches well in his paper.

However, there are still other approaches that have contributed to our understanding of intelligence. I have reviewed only some of them here, such as developmental and biological

approaches. In a field such as intelligence with many anomalies, we should not limit our study to an either-or approach. Instead, we should study diverse approaches and hesitate to

conclude too early.

Author Response

Additional Theories of Multiple Intelligences: A Barrage of Opinions

Han S. Paik

Washington University

After reading the peer commentaries on my article, "One Intelligence or Many? Alternative Approaches to Cognitive Abilities," it seems that there is a general consensus among the

readers that there is a lack of development of the theories of multiple intelligences. There was an overall sense of a sufficient summary of the two different theories and the paper in

general, but commentators seemed to feel that the section on multiple intelligences was lacking in depth and breadth. None of the readers commented on the discussion of one

general intelligence, but all of them did comment on different parts of the section concerning multiple intelligences.

In response to the comments put forth by Dammann and Jang, I feel that the suggestions that they offer would add more detail and provide a more expansive view of other theories of multiple intelligences, but that was not my objective in writing this paper. I attempted to discuss, and not necessarily evaluate, the two opposing major schools of thought, the camp of one general intelligence and the camp of multiple intelligences. In the discussion of these two different views on intelligence, I tried to provide an objective view of the two different

camps, and not obscure the reader's perception of either theory with my own judgments. Consequently, I did my best to spend an equal amount of time explaining both of the

theories.

Unfortunately, there are inherently quite a few more different theories on multiple intelligence, compared to the number of theories on one general intelligence. In my detailed

explanation of one general intelligence, there is in that camp widespread agreement on many things. On the other hand, there are several different theories of multiple

intelligences, and all psychologists do not completely agree. As a result, I was forced to choose those theories of multiple intelligences that I felt would best represent that camp.

85

In her commentary, "Intelligence: Two Major Schools of Thought," Dammann cites Gardner's seven different forms of intelligence and Thurstone's method of factor analysis compared to Spearman's method as areas that could use more attention to detail. I attempted to provide

an overview of Gardner's theory, so I stated the biological evidence to support his theory and the different forms of intelligences that he believed exist. I did not go into further detail

regarding Thurstone's use of factor analysis, namely that in doing his research, Thurstone rotated the different factors to arrive at thirteen factors instead of Spearman's one factor.

Jang states in his peer commentary that there is a need "to give more attention to diverse approaches to intelligence." This would give a better understanding of the nature of

intelligence. I concede that a further discussion would give my article on the theories of intelligence a more comprehensive view of the theories that exist today. The two

approaches that Jang mentions that I excluded from my article are the developmental and biological approaches to intelligence. As I stated before, I did not want my article to overflow

with the many different perspectives on multiple intelligences while the theory of one general intelligence went by the wayside. The reason that I did not include a discussion of

the developmental approaches to intelligence in my article is that what Jang discusses is not necessarily a theory of intelligence. It is closer to a method to test intelligence, or a

psychometric evaluation of a person. It is similar to Binet and his tests and theories. This is not within the scope of my paper. The biological approach that Jang mentions in his

commentary is very similar to the one general intelligence school of thought. It is related to the neural processing speed and the arguments and premises that come with that theory of

intelligence.

All of the criticisms from each of the peer commentators were well accepted. I admittedly did not include many of the different theories of multiple intelligences that exist today, but I

did not do so for a reason. There is equal merit to both schools of thought, and I did not want one or the other to dominate an article that was intended to represent both equally.

References

Carraher, T. N., Carraher, D., & Schliemann, A. D. (1985). Mathematics in the streets and in schools. British Journal of Developmental Psychology, 3, 21-29.

Eysenck, H. J. (1982). Introduction. In H. J. Eysenck (Ed.), A model for intelligence (pp. 1-10). New York: Springer-Verlag.

86

Gardner, H. (1983). Frames of mind: The theory of multiple intelligences. New York: Basic Books.

Guilford, J. P. (1967). The nature of human intelligence. New York: McGraw-Hill.

Jensen, A. R. (1993). Why is reaction time correlated with psychometric g? Current Directions in Psychological Science, 2, 53-56.

Jensen, A. R. (1997). The psychometrics of intelligence. In H. Nyborg (Ed.), The scientific study of human nature: Tribute to Hans J. Eysenck at eighty (pp. 221-239). New York:

Elsevier.

Li, R. (1996). A theory of conceptual intelligence: Thinking, learning, creativity and giftedness. Westport, CT: Praeger.

Neisser, U., Boodoo, G., Bouchard, T. J., Jr., Boykin, A. W., Brody, N., Ceci, S. J., Halpern, D. F., Loehlin, J. C., Perloff, R., Sternberg, R. J., & Urbina, S. (1996). Intelligence: Knowns and

unknowns. American Psychologist, 51, 77-101.

Spearman, C. (1904). "General intelligence" objectively determined and measured. American Journal of Psychology, 15, 201-293.

Spearman, C. (1973/1923). The nature of "intelligence" and the principles of cognition. New York: Arno Press.

Sternberg, R. J., & Gardner, M. K. (1982). A componential interpretation of the general factor in human intelligence. In H. J. Eysenck (Ed.), A model for intelligence (pp. 231-254). New

York: Springer-Verlag.

Sternberg, R. J. (1985). Beyond IQ: A triarchic theory of human intelligence. New York: Cambridge University Press.

87

Thurstone, L. L. (1924). The nature of intelligence. New York: Harcourt Brace.

Thurstone, L. L. (1938). Primary mental abilities. Chicago: Univeristy of Chicago Press.

Last modified August 1998

Visited times since July 2001

88