CHAPTER 3PHYSICAL AND COGNITIVE DEVELOPMENT IN INFANCY

THE BRAIN

• Contains tens of billions of nerve cells at birth• Shaken baby syndrome - Brain swelling and

hemorrhaging• Brain’s development

• Lateralization

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Four Lobes

DENDRITIC SPREADING

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SYNAPTIC DENSITY IN THE HUMAN BRAIN FROM INFANCY TO ADULTHOOD

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THE COMPETENT NEWBORNReflexes

[Surgery]

SENSORY CAPABILITIES OF THE NEWBORN

HABITUATION/DEHABITUATION

HABITUATION/DEHABITUATION

What does habituation imply about memory processes of infants?

CEPHALOCAUDAL AND PROXIMODISTAL PATTERNS

• Cephalocaudal• Proximodistal• Hierarchical integration

THE FIRST YEAR

• Average North American (full term) newborn ~ 20 inches long; 7 pounds

• Lose ~5 to 7% of body weight adjusting to feeding. Back to birth wt in 2 wks.

• Double birth weight by 5 months; nearly triple by 12 months

THE FIRST TWO YEARS

1 year: ~30 inches tall. 2 years: ~35 inches tall—nearly half of their eventual adult height

INTEGRATING THE BODILY SYSTEMS: THE LIFE CYCLES OF INFANCY

Behavior becomes integrated through the development of various body rhythms

SLEEP

• Considerable individual variation• newborns can sleep 16 to 18 hours a day (average

~16)• preferred patterns of sleep vary

• Infants spend a greater amount of time in REM (rapid eye movement) sleep• by 3 months of age, the percentage of time in REM

sleep decreases [next]

SIDS

• Children in U.S. = 1910 (2011)

• The leading cause of death in children under 1 year old (except for congenital abnormalities and short gestation)

• Risk of SIDS is highest at 4 to 6 weeks of age

• Occurs in children of every race and socioeconomic group

(Congenital abnormalities = 5013; Short gestation = 4106)

DECLINING RATES OF SIDS

U.S. rates have dropped dramatically as parents put babies “back to sleep.”

• Move by themselves - 6 months

• Sit unsupported - 6 months.

• Crawling - 8-10 months• Standing with support - 8

months• Infants can walk holding

onto furniture by 9 months and walk alone by ~1 year.

GROSS MOTOR SKILLS — LARGE MUSCLE ACTIVITIES

• Can begin using a “sippy cup”• Can be spoon fed• Can be introduced to SMALL-SIZED solid foods

Physical MilestonesFirst Year

Eating:

Small Motor Coordination:

• Can pick up toys in both hands (and bang them together!)• Will practice dropping objects• May throw objects (especially…everything)• Will begin to pick up “Cheerios” or other small object with thumb

and index finger

FINE MOTOR SKILLS

• By 3 months infants can coordinate movements of limbs.

• Infants can grasp an object by 11 months.

• By age 2, infants can drink from a cup without spilling.

BENEFITS OF BREAST FEEDING

• Appropriate weight gain; lowered risk of childhood obesity • Fewer allergies• Reduction of diarrhea, respiratory infections, bacterial and

urinary tract infections • Denser bones in childhood and adulthood • Reduced childhood cancer and reduced incidence of breast

cancer in mothers• Lower incidence of SIDS

Breast Feeding

Breast Feeding

Breast Feeding

INTRODUCING SOLID FOODS

• Most babies begin to eat solid foods b/t 4-6 months

• Foods are introduced gradually • Weaning

DEVELOPMENT OF THE SENSES

Infants hear from the time they are born—and even before

VISION

Infants show clear visual preferences that are present at birth:

• Prefer to look at patterns and complex stimuli, • Prefer to look at faces,• Minutes after birth they show a preference for

certain colors, shapes, configurations. Robert Fantz found

that 2- and 3-month-old infants preferred

to look at more complex stimuli.

VISION, CONT.

• Newborn infants cannot see beyond a distance of 20 feet• By ~6 months, the average infant's vision is 20/20• Gibson's "visual cliff" experiments indicates depth

perception

VISUAL PERCEPTION

HEARING, TOUCH, AND PAIN

• Prenatally at 7 months, infants can hear sounds such as mother’s voice and music

• Immediately after birth, infants cannot hear soft sounds or pitch as well as adults do

• Infants also display amazing resiliency • Within several minutes after the circumcision

surgery (which is performed without anesthesia), they can nurse and interact in a normal manner with their mothers

SMELL AND TASTE

• Newborns can differentiate odors• Sensitivity to taste might be present even before birth • At only 2 hours of age, babies made different facial

expressions when they tasted sweet, sour, and bitter solutions

COGNITIVE DEVELOPMENT IN INFANCY

© 2006 Pearson Education/Prentice-Hall Publishing

Infant cognition develops through changes in the way children approach problems (infants learn by doing).

ASSIMILATION AND ACCOMMODATION

• Processes of development• Schemes: • Behavioral scheme

• Mental scheme

• Assimilation: Using existing schemes to deal with new information or experiences

• Accommodation: Adjusting schemes to fit new information and experiences

Which one?1. Infant uses sucking schema to suck on larger bottle/nipple after presentation of smaller

one.2. One-year-old grabs every “round, rolly object” and tries to grab and throw; sees a beach

ball.

PIAGET

• Equilibration• Individuals go through four

stages of development• Cognition is qualitatively different

• Sensorimotor stage: Lasts from birth to about age 2.• Infants construct an understanding of the world by coordinating

sensory experiences (such as seeing and hearing) with physical actions

• Object permanence: Understanding that objects and events continue to exist:• When they cannot directly be seen, heard, or touched

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SENSORIMOTOR STAGE

• Six substages Primary: reflexes determine interaction

• Accidentally sucks fist, feels good, so suck some more (provides info about the world = cognitive development).

• Secondary: Begins to act on world (e.g., Rattles a rattle)

• Repeats actions; Goal-directed behavior; Develops object permanence

• Tertiary circular reactions: deliberate variation of actions Miniature “experiments” Hit drum, then table, then floor, then

head with a stick

• Beginning of thought ~18-24 months of age• Mental representation

EVALUATING AND MODIFYING PIAGET’S SENSORIMOTOR STAGE  

• Motor emphasized at the expense of sensory -–largely ignores sensory and perceptual abilities of infants

• Piaget's claim that certain processes are crucial in stage transitions is not always supported by the data

• Some researchers conclude that infants’ perceptual abilities are highly developed very early in development

Criticism of Piaget

LANGUAGE DEVELOPMENT

• All human languages have some common characteristics

• Receptive/expressive

You talkin’ to me?!

KEY MILESTONES IN LANGUAGE DEVELOPMENT

• Babies' sounds and gestures go through this sequence during the first year• Crying:• Cooing:• Babbling: [text is wrong]• First Words ~ 10 to 14 months

• Average is 15 words by 15 months; First words are typically

holophrases (Holophrastic stage ~12-18 months)

LANGUAGE SOUNDS

• ~ 2-years-old, children can form noun-

verb sentences• Overextension • Underextension

A one-year-old signing “sleep”

LEARNING THEORY/NATIVIST APPROACHES

• Learning theory• Chomsky > genetic;

innate mechanism • All languages > similar

underlying structure • LAD

• Interactionist view

INFANT-DIRECTED SPEECH (IDS)[MOTHERESE]

Use of this type of speech is related to the early appearance of words

FIGURE 3.9 - MILESTONES IN GROSS MOTOR DEVELOPMENT

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