Experiencing the Lifespan, 3e Cerebral CortexExperiencing the Lifespan, 3e Chapter 3: Infancy:...
Transcript of Experiencing the Lifespan, 3e Cerebral CortexExperiencing the Lifespan, 3e Chapter 3: Infancy:...
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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.
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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
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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
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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!
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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
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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
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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”).
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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.
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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.