1

Janet Belsky’s Experiencing the Lifespan, 3e

Chapter 3: Infancy: Physical and

Cognitive Development

Meredyth Fellows, West Chester University of PA

The Expanding Brain

n  Cerebral Cortex

n  Outer furrowed mantle of brain n  Site of every conscious perception,

action, thought n  Influences behavior a few months

after birth n  Brain volume quadruples during first

4 years

The Expanding Brain

n  Neurons formed during fetal period n  After birth, synaptogenesis occurs

n  Proliferation of connections at the synapses (often referred to as exuberant synaptogenesis)

n  Pruning follows n  Myelination: formation of fatty layer

encasing axons n  Visual cortex myelinated by 1 year n  Frontal lobes, age 20 or beyond

Neural Pruning and Plasticity

n  Plasticity: The brain is “plastic” (malleable) during early childhood before pruning is complete. n  Plasticity allows other brain

regions to compensate following injury.

n  Brain is less plastic following childhood.

2

Basic Newborn States: Reflexes

n  Reflexes: n  Automatic responses or

actions programmed by noncortical brain centers

n  Present at birth; promote survival

Sucking

Rooting

Grasping

Nutrition: Breast Milk

•  Recommended for first 6 months ▫  Protects from diseases ▫  Correlational studies show that breast-fed babies:

�  are more alert during first 2 weeks �  experience fewer gastrointestinal problems and

middle ear infections �  are more resistant to colds and flu �  appear to be superior in later measures of

intelligence in elementary school

Malnutrition: Developing World Concern

n  Undernutrition: chronic lack of adequate food n  Kwashiorkor: lack of protein,

amino acids n  Micronutrient Deficiencies

n  Stunting: excessively short stature caused by chronic inadequate nutrition n  Below 5th percentile in height for

norms for their age n  Takes serious toll on cognition,

health, and every activity of life

Stunted baby on left; normal baby on right

United States: Developed Country

n  Food Insecurity n  Concern for lack of sufficient funds for food

n  1 in 5 mothers report this fear

n  Severe Food Insecurity n  1 in 10 mothers report lack of food for children

n  See chart next page n  U.S. Federal Nutrition Programs for

Children

3

Crying: First Communication Signal

n  Crying: n  Lifetime peak at about 5 weeks n  Reflex dominated before the cortex is “on-line” at

4 months n  Vital to survival (responsive parenting is a must!)

n  Colic: frantic, continual crying during first 3 months n  Immature digestive system n  May contribute to parental stress, but is

temporary!

Intervention: What Quiets a Young Baby?

n  Pacifier, breast, bottle n  Swaddling

n  Mirrors womb

n  Kangaroo Care n  Hold close to body

n  Infant Massage n  Calms infants n  Contributes to growth in

premature babies

Swaddling

Sleeping: Main Newborn State

n  Newborns, sleep 18 hours a day n  90% of time in sleep or

drowsy state n  Unlike adult sleep cycle,

newborns drop immediately into REM sleep.

n  Wake every 3-4 hours n  6 months, may sleep 6

hours a night n  1 year, 12 hours a night

and naps during day

4

Sleep Cycles

Brain-wave patterns and lifespan changes in sleep and wakefulness

Intervention: Self-Soothing

n  Bidirectional influences: Sleep deprivation contributes to irritability in both parents and the infant.

n  By 6 months, upon waking, infants can self-sooth.

n  What do experts suggest? n  Erikson & Bowlby: sensitively respond to crying

infant during first year n  Behaviorists disagree: Do not respond! n  Ultimately the decision is yours!

Sudden Infant Death Syndrome: SIDS n  (1 in 1,000 in the United States); top-

ranking cause of infant death in the developed world.

n  Possible relationship with mothers who smoke during pregnancy

n  Peak risk zone 1 to 10 months n  Possible relationship with too few or too many

neurons in area of brain involved in coordinating tongue movements and maintaining breathing airway

n  Reduce risk: n  When infants sleeps, place infant on his/her

back n  Keep away from fluffy bedding!

5

Sensory and Motor Development

n  Hearing n  In the womb, fetuses can discriminate different

tones n  Smell

n  Within the 1st week, infants prefer smell of breast milk

n  Taste: n  Infants stop sucking and wrinkle face in response

to bitter, sour, or salty tastes n  Avidly suck on sweet solutions

n  Pain management technique - have infant suck on sweet substance

What Do Newborns See? n  Researchers use the preferential-looking paradigm

and habituation techniques n  Observe changes in the infant’s interest in a stimulus

from extreme interest to habituation, and finally renewed interest to another new stimulus

Focusing on Faces

n  Newborns prefer faces to other stimuli, especially mother’s face

n  Prefer attractive-looking people

n  Infants mimic facial expressions

Newborns looked most at the face-like drawing. Are we biologically programmed to selectively look at faces?

Depth Perception: the Visual Cliff Experiment

n  When 8 month-old babies begin to crawl, they perceive differences in depth and fear heights. n  Notice survival

response!

Visual Cliff

6

Expanding Body Size and Motor Milestones

n  Growth is most pronounced in infancy, slows down during childhood, increases during pre-adolescence

n  Motor Milestones n  Cephalocaudal: lift head, pivot

upper body, sit up, stand n  Proximodistal: control of shoulders

before control of arms and fingers n  Mass-to-Specific: gross motor skills

before fine motor skills n  Importance of myelination

Contemporary View: Variations in Motor Milestones

n  Traditional view: motor milestones viewed as static stages (sit, crawl, walk)

n  Contemporary researchers site variation among infant motor advances (e.g., belly-crawling, scooting, etc.). n  Important: Rate at which babies master motor

milestones has no relation to later intelligence. n  Developmental disorders are the exception.

Intervention: Baby-Proofing, the First Person−Environment Fit

n  Shape the home environment to fit the child’s developmental milestones. n  View environment from baby’s perspective,

then eliminate dangerous environmental opportunities.

n  Create an environment suitable for exploration while keeping baby safe from harm.

n  Anticipate and stay ahead of the developing child.

Cognitive Development: Piaget

n  Stage Approach n  Studied his own

children n  Schemas n  Assimilation n  Accommodation n  Adaptation

7

Circular Reactions: Sensorimotor Stage

n  Repetitive action-oriented schemas (habits) n  Through circular reactions, the infant explores

and incorporates new information into existing schemas.

n  Primary Circular Reactions n  The infant’s first habits (body-centered)

n  Secondary (about 4 months to 1 year) n  Infant explores environment

n  Tertiary (begin about 1 year) n  “Little scientist” activities (baby explores the properties

of objects)

When Infants Begin to Think: Sensorimotor Stage

n  Evidenced by n  Deferred imitation:

n  When infant repeats an action observed at an earlier time

n  Means−end behavior:

n  Occurs about 1 year, when infant performs a different or separate action to reach a goal

n  Limitation in Thinking: A-not-B error: n  Approaching year 1, even though a baby sees an object

hidden in a second hiding place, he/she returns to the originally viewed hiding place to find it!

Object-Permanence: Sensorimotor Stage

n  Understanding that objects exist even when out of sight

n  Around 5-6 months, infants begin to look for hidden objects.

n  At about 8 months infant develops object permanence (“little-scientist stage”).

8

Critiquing Piaget

n  Infants understand basic principles about the physical world earlier than Piaget believed. n  By using preferential looking and setting up physically

impossible situations, even young babies look surprised (“This cannot occur!”).

Critiquing Piaget and a New Perspective

n  Understanding of physical reality emerges gradually, not in unitary, qualitatively different stages as Piaget believed.

n  New perspective: information-processing

n  A perspective on understanding cognition that divides thinking into specific steps and component processes, much like a computer

Emerging Infant Social Cognition

n  Social Cognition: any skill related to understanding feelings and negotiating interpersonal interactions. n  We make inferences about people’s inner

feelings and goals, based on their actions. n  Research suggests this begins as early as 5

months. n  Joint Attention

n  This is the first sign of “getting human intentions” when a baby looks at an object to which an adult points or the infant follows a person’s gaze.

Language: Basic Principles

n  Noam Chomsky’s nature-oriented concept: LAD, Language Acquisition Device n  Hypothetical brain structure that enables

our species to learn and produce language n  Unique to our human species n  Chomsky’s concept is in opposition to

Skinner’s nurture-oriented perspective. n  We learn language by being reinforced for

producing specific words.

9

Language: Basic Principles

n  The specific language learned is dependent on nurture—the place where you were reared.

n  Presently, the social-interactionist view: n  Interactions between baby and caregivers—

each wants to communicate, one encourages the other

n  Emphasis on the social function of language

Language: Basic Principles

n  Telegraphic speech n  First word-combining stage

n  Infant-directed speech (IDS) (from caregivers) n  Higher-pitched, elongated vowels, and

exaggerated tones attract baby’s interest. n  Research suggests that IDS helps babies to

master language.

Final Thoughts

n  Babies “connect” with the human world. n  From face

perception, to joint attention, to early language—as babies we are driven to connect with the human world.