Chapter 3:
Infancy: Physical and Cognitive Development
Meredyth Fellows, West Chester University of PA
The Expanding Brain
0 Cerebral Cortex
0 Outer furrowed mantle of brain
0 Site of every conscious perception, action,
thought
0 Influences behavior a few months after
birth
0 Brain volume quadruples during first 4
years
The Expanding Brain
0 Neurons formed during fetal period
0 After birth, synaptogenesis occurs
0 Proliferation of connections at the
synapses (often referred to as
exuberant synaptogenesis)
0 Pruning follows
0 Myelination: formation of fatty layer
encasing axons
0 Visual cortex myelinated by 1 year
0 Frontal lobes, age 20 or beyond
Neural Pruning and Plasticity
0 Plasticity: The brain is “plastic”
(malleable) during early
childhood before pruning is
complete.
0 Plasticity allows other brain
regions to compensate
following injury.
0 Brain is less plastic following
childhood.
Basic Newborn States: Reflexes
0 Reflexes: Sucking, Rooting,
Grasping
0 Automatic responses or actions
programmed by noncortical
brain centers
0 Present at birth; promote
survival
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
Crying: First Communication
Signal
0 Crying:
0 peak at about 5 weeks
0 Reflex dominated before the cortex is “on-line” at 4
months
0 Vital to survival (responsive parenting is a must!)
Sleeping: Main Newborn State
0 Newborns, sleep 18 hours a
day
0 90% of time in sleep or
drowsy state
0 Unlike adult sleep cycle,
newborns drop immediately
into REM sleep.
0 Wake every 3-4 hours
Sleep Cycles
Brain-wave patterns and lifespan changes in sleep and wakefulness
Intervention: Self-Soothing
0 Bidirectional influences: Sleep deprivation contributes to
irritability in both parents and the infant.
0 By 6 months, upon waking, infants can self-sooth.
0 What do experts suggest?
0 Erikson & Bowlby: sensitively respond to crying infant during
first year
0 Behaviorists disagree: Do not respond!
0 Ultimately the decision is yours!
Sensory and Motor Development
0 Hearing
0 In the womb, fetuses can discriminate different tones
0 Smell
0 Within the 1st week, infants prefer smell of breast
milk
0 Taste:
0 Infants stop sucking and wrinkle face in response to
bitter, sour, or salty tastes
0 Avidly suck on sweet solutions
0 Pain management technique - have infant suck on sweet
substance
Focusing on Faces
0 Prefer faces to other stimuli,
especially mother’s face
0 Prefer attractive-looking people
0 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
0 When 8 month-old babies
begin to crawl, they
perceive differences in
depth and fear heights.
0 Notice survival response!
Visual Cliff
Expanding Body Size and Motor Milestones
0 Growth is most pronounced in
infancy, slows down during
childhood, increases during preadolescence
0 Motor Milestones
0 Cephalocaudal: lift head, pivot upper
body, sit up, stand
0 Proximodistal: control of shoulders
before control of arms and fingers
0 Mass-to-Specific: gross motor skills
before fine motor skills
0 Importance of myelination
Cognitive Development: Piaget
0 Stage Approach
0 Studied his own
children
0 Schemas
0 Assimilation
0 Accommodation
0 Adaptation
Circular Reactions: Sensorimotor Stage
0 Repetitive action-oriented schemas (habits)
0 Through circular reactions, the infant explores and
incorporates new information into existing schemas.
0 Primary Circular Reactions
0 The infant’s first habits (body-centered)
0 Secondary (about 4 months to 1 year)
0 Infant explores environment
0 Tertiary (begin about 1 year)
0 “Little scientist” activities (baby explores the properties of objects)
When Infants Begin to Think:
Sensorimotor Stage
0 Evidenced by
0 Deferred imitation:
0 When infant repeats an action observed at an earlier time
0 Means−end behavior:
0 Occurs about 1 year, when infant performs a different or separate
action to reach a goal
0 Limitation in Thinking: A-not-B error:
0 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
0 Understanding that objects
exist even when out of sight
0 Around 5-6 months, infants
begin to look for hidden
objects.
0 At about 8 months infant
develops object permanence
(“little-scientist stage”).
Critiquing Piaget and a New Perspective
0 Understanding of physical reality emerges
gradually, not in unitary, qualitatively different
stages as Piaget believed.
0 New perspective: information-processing
0 A perspective on understanding cognition that divides
thinking into specific steps and component processes,
much like a computer
Emerging Infant Social Cognition
0 Social Cognition: any skill related to understanding feelings
and negotiating interpersonal interactions.
0 We make inferences about people’s inner feelings and goals,
based on their actions.
0 Research suggests this begins as early as 5 months.
0 Joint Attention
0 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
0 Noam Chomsky’s nature-oriented concept: LAD,
Language Acquisition Device
0 Hypothetical brain structure that enables our species to
learn and produce language
0 Unique to our human species
0 Chomsky’s concept is in opposition to Skinner’s nurtureoriented perspective.
0 We learn language by being reinforced for producing
specific words.
Language: Basic Principles
0 The specific language learned is dependent on nurture—the
place where you were reared.
0 Presently, the social-interactionist view:
0 Interactions between baby and caregivers—each wants to
communicate, one encourages the other
0 Emphasis on the social function of language