CHAPTER SEVENTEEN PHYSICAL AND COGNITIVE DEVELOPMENT IN LATE ADULTHOOD

CHAPTER SEVENTEEN

PHYSICAL AND COGNITIVE DEVELOPMENT IN LATE ADULTHOOD

Copyright © 2009 Pearson Education Canada 17-2

I. VARIABILITY IN LATE ADULTHOOD

The scientific study of aging is known as gerontology

Late adulthood is now thought of as a period of tremendous individual variability rather than one of universal decline


A. Characteristics of the Elderly PopulationLife expectancy:

– Increases as adults get older• A 65 year old man is likely to live to be 82• An 80 year man old is likely to live to be 90• A 65 year old woman is likely to live to be 87• A woman in her mid 80’s can expect to live to over

92There are more elderly women than men, but the

gender gap has been narrowing in Canada since 1981

(continued)


Characteristics of the Elderly Population (continued)Subgroups:

– Young-old (60 to 75)– Old-old (75 to 85)– Oldest-old (85 and up) (fastest growing group)

From 1981 to 2000, the over-65 population in Canada increased by about two-thirds, and the over-85 population almost tripled

Frail elderly: older adults whose physical and/or mental impairments are so extensive that they cannot care for themselves

In the future, there may not be enough young and middle aged adults to care for the elderly

(continued)


Characteristics of the Elderly Population (continued)

Health– The majority of older Canadian adults across all three

age subgroups regard their health as good or excellent– Poor health is proportionately higher than in younger

groups • Fair or poor health is self-reported by 32 % of those

over 75 years of age– Health is the single largest factor determining the

trajectory of an adult's physical or mental status over the years beyond 65

– An optimistic view helps seniors recover better from illnesses such as stroke

– Chronic illness at age 65 is predictive of more rapid declines in later life

(continued)


Self-Ratings of Elders’ Health



Cognitive Functioning– Alzheimer’s disease, an irreversible degenerative

condition, is the most common cause of dementia

– Other sources of mental confusion include intercurrent illnesses, infections, metabolic disturbances and drug intoxications

• Little of the cognitive impairment is reversible

Even among those over 85, the majority do not have cognitive impairments

(continued)


Percentage of Adults with Cognitive Impairments (USA)



Cognitive Functioning (continued)– Variations in hormones are related to variations in

cognitive performance in men and women

– The relationship between hormones and cognition is not understood

• Giving women hormone replacement therapy does not improve their cognitive functioning

• Hormone replacement therapy may increase the chance of serious cognitive dysfunction

(continued)



Mental Exercise– Humans who challenge themselves with complex

mental activities can delay or even reverse the normal decline in brain mass that is part of primary aging

– Some enhancement or better maintenance of intellectual skills results from an "engaged" and intellectually active lifestyle

(continued)



Limitations on Activities:– Functional status: a measure of an individual’s ability

to perform certain roles and tasks, particularly self-help tasks and other chores of daily living

– Activities of Daily Living (ADLs): self-help tasks such as bathing, dressing, and using the toilet

– Instrumental Activities of Daily Living (IADLs): more complex daily living tasks such as doing housework, cooking, and managing money

– The proportion of older adults with disabilities increases with age

– The physical problems or diseases that are most likely to contribute to some functional disability in late adulthood are arthritis and hypertension


Proportions of Canadian Seniors with Chronic Health Conditions


B. Longevity

Longevity appears to result from interactions among heredity, environment, and behavioural choices

The maximum life span– Those over 100 represent the fastest growing

population group– Maximum lifespan seems to be ~ 110 or 120 years– Hayflick limit: the theoretical proposal that each

species is subject to a genetically programmed time limit after which cells no longer have any capacity to replicate themselves accurately

(continued)


Longevity (continued)

The maximum life span (continued)– Telomere: string of repetitive DNA at the tip of

each chromosome in the body that appears to serve as a kind of timekeeping mechanism

• The number of telomeres decreases each time a cell divides

• If there is a crucial number of telomeres, disease or death may come quickly once that number is passed

(continued)



Individual Heredity– There is a large range of individual differences in

how long people live

– Some general tendency toward longevity is clearly inherited

– Identical twins are more similar in length of life than are fraternal twins

– Adults whose parents and grandparents were long-lived are also more likely to live longer

(continued)



Health Habits– The same health habits are important now as in

earlier years• Smoking, low levels of physical activity, significant

under- or over-weight predict increased death risk– Smoking limits longevity: 65-year-old male smoker

can expect to live six years less than a non-smoker and a female smoker will live 8.5 years less

– Smokers are also more likely to suffer disease related disabilities—by age 65 more than half of all smokers will have a disability (compared to one-third of non-smokers)

(continued)



Health Habits (continued):– Physical exercise is clearly linked to greater

longevity and lower rates of diseases such as heart disease, cancer, osteoporosis, diabetes, gastrointestinal problems, and arthritis

• Delays admission to nursing homes• Improves strength and motor skills after only 12

weeks of exercise• helps maintain higher levels of cognitive

performance among the elderly

(continued)



Health Habits (continued):– Physical exercise is even more important in later

years than in youth– As much as half of the decline in physical (and

perhaps cognitive) function can be prevented through improved lifestyle, especially exercise

– Still, only 27% of older adults are active enough to see these benefits

– Canada’s Physical Activity Guide recommends 30 to 60 minutes of exercise daily, that can be accumulated in segments of 10 minutes or longer

– Obesity in this age group is rising (19% for men, 27% for women)


II. PHYSICAL CHANGES

Despite variability in health and functioning among the elderly, there are several changes in physical functioning that characterize the late adult years for almost everyone


A. The Brain & Nervous System

Four main changes occur in the brain: – a reduction of brain weight– a loss of grey matter– a loss of density in the dendrites– slower synaptic speed

Loss of dendrites is not only primary aging, but is linked to education: less cerebral cortex atrophy occurs in those with more education

Loss of dendrites results in slowing synaptic speed, and therefore slowing in reaction time

Synaptic plasticity can not make up for the loss of dendrites

(continued)


The Brain & Nervous System (continued)

There is an insignificant loss of neurons themselves, and there are so many redundancies in the nervous system that there is little impact

When significant interconnectivity is lost, which occurs as dendrites shrink in number, "computational power" declines and symptoms of old age appear

Although new neurons continue to be produced in adulthood, the effects of this regeneration are not known


B. The Senses & Other Body SystemsVision

– Presbyopia (farsightedness) increases– An enlarged "blind spot" on the retina reduces field of

vision – The pupil does not widen or narrow as much or as

quickly resulting in more difficulty seeing at night and responding to rapid changes in brightness

– Diseases of the eye (in a minority of people) such as cataracts or glaucoma, further diminish visual acuity and adaptability

– Younger people cope better with changes in vision– Vision loss has a greater impact on an elderly person’s

sense of well-being

(continued)


The Senses & Other Body Systems (continued)

Hearing:– Presbycusis isn’t usually functionally limiting until late

adulthood– Men lose more hearing than women do, likely due to

more occupational exposure– The ability to hear high-frequency sounds (part of human

speech) is diminished– Word discrimination becomes problematic, especially

under noisy conditions– Tinnitus, a persistent ringing in the ears, increases– Severe hearing loss is associated with social and

psychological problems– Physical changes in the ear contribute to problems

(continued)


The Senses & Other Body Systems (continued)

Taste, Smell, and Touch:– The ability to taste the four basic flavours does not

seem to decline over the years of adulthood– Other changes in the taste system do affect taste:

• less saliva• flavours seem blander, but this may be a result of a

loss of the sense of smell– The sense of smell clearly deteriorates in old age– Loss of smell/taste can result in nutrition problems

A loss of sensitivity to touch, cold and heat can have safety implications


C. Theories of Biological Aging

Genetically Programmed Senescence theory:– Physical changes and declines associated with

aging– Age-related declines are the result of species-

specific genes for agingRepair of Genetic Material and Cross-linking

theory: – The organism’s inability to repair breaks in DNA

strands results in a loss of cellular function leading to aging

– The formation of undesirable bonds between proteins or fats results in decreased cell function

(continued)


Theories of Biological Aging (continued)

Free radicals:– Are molecules or atoms that possess an unpaired

electron– Occur naturally as a result of metabolism– Participate in harmful chemical reactions that

cause irreparable cell damage that accumulates over time

– Some foods may promote the creation of free radicals (fats, food preservatives)

– Some foods may defend against them (antioxidants such as Vitamins C, E, A, lutein)

(continued)


Theories of Biological Aging (continued)

Terminal drop theory– The hypothesis that mental and physical

functioning decline drastically only in the few years immediately preceding death

– Most declines are gradual

– Only changes in IQ seem to fit the terminal drop pattern


D. Behavioural Effects of Physical ChangesGeneral Slowing:

– The biggest single behavioural aspect of aging• Dendritic changes result in synaptic slowing• Arthritic diseases affect the joints and muscles

– General slowing of brain activity interferes with older adults’ retrieval of the knowledge needed to accomplish tasks

– More car accidents per mile occur, due to• Stiffness, decreased night vision and adjustment to

glare, inability to judge speed of oncoming traffic, increased reaction time

– Decreased reaction time can lead to burns(continued)


Behavioural Effects of Physical Changes (continued)

Sleeping and Eating Patterns:– More frequent wakening occurs after age 65

– (REM) sleep is decreased

– More likely to wake early in the morning and go to bed early at night

– Daytime naps compensate for early risingImpaired satiety may result in a constant feeling

of hunger that may cause overeating– Some adults cope with this by adopting a rigid

eating schedule

(continued)


Behavioural Effects of Physical Changes (Continued)

Motor Functions– Reduction in stamina, dexterity, and balance

– Older adults fall more often, and because of osteoporosis, such falls more often result in fractures

– Problems with fine-motor movements increase, and new skills, such as computer skills are very difficult to learn

(continued)


Behavioural Effects of Physical Changes (Continued)

Sexual activity – declines from middle adulthood to late adulthood

for many reasons• Decreasing testosterone in men• State of overall health• Medication side effects• Stereotyping

More than 70% of adults continue to be sexually active in old age


III. MENTAL HEALTH

Dementia: a neurological disorder involving problems with memory and thinking that affect an individual’s emotional, social, and physical functioning

Dementia is the leading cause of institutionalization of the elderly in Canada, especially women

Depression is also a concern in the late adult years


A. Alzheimer's Disease & Other DementiasAlzheimer’s disease:

– A very severe form of dementia– Early onset is slow, with subtle memory difficulties

and repetitive conversation, and disorientation in unfamiliar settings

– Memory for recent events goes next– Memory for long ago events and well rehearsed

cognitive tasks are retained until late in the illness, as they can be accessed by many alternative neural pathways

– Eventually failure to recognize family members, inability to communicate, and inability to perform self-care occurs

(continued)


Alzheimer's Disease & Other Dementias (continued)

Alzheimer’s disease (continued): – Changes in appetite regulation may result in

significant overeating– Facial expressions and emotions of others are

difficult to process– Some can not control their own emotions, and

display sudden bursts of anger or rage, or become excessively dependent

– As many as 40% may be depressed

(continued)



Diagnosing and Treating Alzheimer’s Disease– Definitive diagnosis can only occur after death– Neurofibrillary tangles, surrounded by plaques, are

more likely than in other dementias– Since normal aging affects memory, it is difficult to

recognize early Alzheimer’s– Mild cognitive impairment may be a better predictor– Medication to increase neurotransmitters seem to

slow the disease’s progress– Strategies such as making notes can help improve

some memory tasks

(continued)



Heredity and Alzheimer’s Disease:– Genetic factors seem to be important to some, but

not to all cases of Alzheimer’s• Heavy drinking may trigger a harmful gene

Other Types of Dementia– Small strokes may cause multi-infarct dementia

• While the brain damage is irreversible, therapy can improve the patient’s functioning

– Multiple causes exist (see notes) and about 10% are reversible with treatment, so careful diagnosis is necessary

(continued)



Incidence of Alzheimer’s and Other Dementias:– 2 to 8% of all adults over age 65 show significant

symptoms of dementia– Almost 2/3 of those with dementia have

Alzheimer's disease– The rate of dementia rises rapidly among people in

their 70s and 80s– 11% of adults over 75 and 34.5% of adults over 85

have moderate to severe symptoms of dementia


The Real World/Caregiving: Institutionalization among the Canadian Elderly

The average older adult will spend at least a few years with some kind of disability or chronic disease

About the same number of older Canadian women and men between 65 and 74 (approx. 2% each) require institutional care in any given year, but far more women in the old-old group are institutionalized

Factors most closely associated with institutionalization:– the odds of living in an institution increase directly with age– seniors with a serious cognitive impairment– those with uncorrected visual impairment– seniors with low or lower-middle household income– those seniors who perceived themselves as having only fair or

poor health were 2.6 times higher than for seniors who had good to excellent self-perceived health status

In Canada there is a growing need to create alternatives to institutionalization such as community support and home care


B. Depression

Mental health is low in early adulthood and slowly improves with age, but depression is a complex issue in the elderly

Diagnosis, Definitions and Prevalence:– Signs of depression in older adults may be

dismissed as old-age “grumpiness” by family members (ageism)

– Depression is often left untreated by health professionals

– Depression can be mistaken for dementia because both share symptoms of confusion and memory loss

(continued)


Depression (continued)

Diagnosis, Definitions and Prevalence (continued):– Older adults are more likely to report physical

symptoms related to depression no matter what their emotional state, so may be misdiagnosed as depressed

– Depressed mood (Geriatric dysthymia) may be mistaken for clinical depression

– Geriatric dysthymia does not usually progress to clinical depression and is related to life stresses

– Clinical depression is less common, but when it occurs, problems are of long duration and are severe enough to interfere with the ability to carry out normal activities

(continued)



Risk factors for depression and dysthymia– Inadequate social support– Inadequate income– Emotional loss– Nagging health problems– Health status (the strongest predictor)

• the more disabling conditions older adults have, the more depressive symptoms they have

– Gender: • two times as many women are depressed

– Poverty– Education—poorly educated older adults are more

likely to be depressed(continued)



Suicide– Suicide rates for all ages have increased almost 75%

since the 1950s– Elderly Canadians’ suicide rate is now slightly below the

national average– Women in Canada have higher depression rates, but

elderly men are more than 5 times as likely to commit suicide, perhaps because

• Elderly men tend to have several risk factors at once

• Elderly men are more troubled by economic stress

• Men do not adjust as well as women to the death of a spouse

• Men are more successful in suicide attempts(continued)



Therapy and Medication:– Psychotherapy, especially interventions to develop

optimistic thought patterns

– Antidepressants are useful but• They may interfere with other life-sustaining drugs• They significantly increase the risk of falls

Prevention:– Help older adults improve their health

– Provide opportunities for social involvement, especially participation in activities with children

– Support for the spiritual needs of the elderly


IV. COGNITIVE CHANGES

Among the young old (aged 65-75), cognitive changes are still fairly small

But the old old and the oldest old show average declines on virtually all measures of intellectual skill, with the largest declines evident on any measures that involve speed or unexercised abilities


A. MemoryShort Term Memory Function

– The more any given cognitive task makes demands on working memory (short term memory), the larger the decline with age

– Younger adults outperform older adults on retrospective memory tasks (remembering something that has happened recently)

– Older adults outperform younger adults on prospective memory tasks in a natural setting, such as their home (remembering an event in the future, like a doctor’s appointment)

• Older adults under-perform on such tasks when in a controlled laboratory setting where there are no external memory cues, such as a calendar or reminder note

(continued)


Short Term Memory Changes with Age


Memory (continued)

Strategy Learning– The learning process takes longer for older adults; however,

when allowed more time, older adults' performance was more similar to that of younger participants

Everyday Memory– On virtually all "everyday" tasks older adults recall less well

than younger adults

– Task-specific prior knowledge gives the elderly some recall advantage

Preliminary Explanations– Older adults take longer to register some new piece of

information, encode it, and retrieve it


B. Wisdom & Creativity

Wisdom: a hypothesized cognitive characteristic of older adults that includes accumulated knowledge and the ability to apply that knowledge to practical problems of living

Performance on wisdom tasks does not decline with ageThe speed of accessing wisdom-related knowledge

remains constant across adulthoodCohen’s four-stage theory of mid- to late-life creativity

describes the potential for creative work through adulthood– re-evaluation phase – liberation phase – summing-up phase – encore phase

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CHAPTER SEVENTEEN PHYSICAL AND COGNITIVE DEVELOPMENT IN LATE ADULTHOOD