Physical Development in Infancy

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Physical Development in Infancy

• Chapter 4
• Robert S. Feldman

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An Interesting Head Count
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Principles of Growth

• Cephalocaudal principle
• Proximodistal principle
• Principle of hierarchical integration
• Principle of independence of systems

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See how they grow
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Nervous System and Brain

• _________________comprises the brain and the
  nerves that extend throughout the body
• __________ are the basic cells of the nervous
  system

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Quick Check

• Neurons
• Dendrites
• Axons
• Neurotransmitters
• Synapses

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Major Systems of the Brain

• Brain stem
• Limbic system
• Cerebral cortex

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How great brains grow!

• Birth
• 100-200 billion neurons
• Relatively few neurons-neuron connections
• During first two years
• Billions of new connections established and
  become more complex

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Use it or lose it!

• Synaptic ___________
• Unused neurons are eliminated
• Allows established neurons to build more
  elaborate communication networks with other
  neurons
• Development of nervous system proceeds most
  effectively through loss of cells
• Myelin

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Form and Function Brain Growth

• Neurons reposition themselves with growth,
  becoming arranged by function
• Cerebral cortex
• Subcortical levels

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Dont shake the baby!

• Shaken Baby Syndrome
• Brain sensitive to forms of injury
• Shaking can lead to brain rotation within skull
• Blood vessels tear?severe medical problems,
  long-term disabilities, and sometimes death

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Environmental Influences on Brain Development

• Plasticity
• Sensitive period

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Do Baby Einstein programs really work?
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What do babies do all day?

• Life Cycles of Infancy
• Wake
• Sleep
• Eat
• Defecate

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Rhythms and States

• _________
• One of major body rhythms
• Degree of awareness infant displays to both
  internal and external stimulation
• Change in state alters amount of stimulation
  required to get infants attention

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Sleep Perchance to Dream

• Major state
• 16-17 hours daily (average) wide variations
• Different than adult sleep
• 2 hour spurts periods of wakefulness
• Cyclic pattern
• By 16 weeks sleep about 6 continuous hours by 1
  year sleep through night
• (See table 4-2)

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REM Sleep

• Period of active sleep
• Closed eyes begin to move in a back-and-forth
  pattern
• Takes up around one-half of infant sleep
• May provide means for brain to stimulate itself
  through autostimulation

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Do babies dream?
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Did you find examples in the text that suggest
that cultural practices affect infants sleep
patterns?
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SIDS

• Sudden infant death syndrome
• Leading cause of death in children under 1 year
  of age
• Back-to-sleep guidelines (AAP)
• Differential risk
• Boys
• African American infants
• Low birthweight
• Low APGAR scores
• Mothers smoking
• Some brain defects
• Child abuse

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SIDS is found in children of every race and
socioeconomic group and in children who have had
no apparent health problems

• Back-to-sleep is important!

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Reflexes Inborn Physical Skills

• Reflexes unlearned, organized involuntary
  responses that occur automatically in presence of
  certain stimuli

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Ethnic and Cultural Differences and Similarities
in Reflexes

• Reflexes
• Genetically determined
• Universal
• Cultural variations in ways displayed
• Moro reflex
• Serves
• Diagnostic tool
• Social function
• Survival function

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Dynamic Systems

• Dynamic systems theory describes how motor
  behaviors are assembled
• Motor skills do not develop in vacuum
• Each skill advances in context of other motor
  abilities
• As motor skills develop, so do non-motoric skills
  
• Theory places emphasis on childs own motivation
  (a cognitive state) in advancing important
  aspects of motor development

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Developmental Norms

• Comparing Individual to Group Norms
• Represent the average performance of a large
  sample of children of a given age.
• Permit comparisons between a particular childs
  performance on a particular behavior and the
  average performance of the children in the norm
  sample.
• Must be interpreted ________________.
• Brazelton Neonatal Behavior Assessment Scale
  (NBAS)

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Nutrition in Infancy

• Fueling Motor Development
• Without proper nutrition, infants cannot reach
  physical potential and may suffer cognitive and
  social consequences
• Infants differ in growth rates, body composition,
  metabolism, and activity levels

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So what is a healthy caloric allotment for
infants?

• About 50 calories per day for each pound of
  weight
• Most infants regulate their caloric intake quite
  effectively on their own
• If are allowed consume as much they seem to want,
  and not pressured to eat more, they will be
  healthy

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Malnutrition

• Children living in many developing countries
• Slower growth rate
• Chronically malnourished during infancy later
  lower IQ score

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Undernutrition Dietary Deficiencies

• Undernutrition also has long-term costs,
  including mild to moderate cognitive delays
• Up to 25 of 1- to 5-year-old US children have
  diets that fall below minimum caloric intake
  recommended by nutritional experts

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When Malnutrition Is Severe

• Maramus
• Kwashiorkor

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Nonorganic Failure to Thrive

• Sufficient nutrition
• Symptoms
• Reversal

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From Research to Practice

• Fast-Food Babies
• Develop taste for certain foods at an early age
  and then tend to stick with those foods as they
  get older
• Like food _____________
• Often consume convenience foods that are high in
  sugar and fat and low in nutrients

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Is Breast Best?

• Advantages of breastfeeding

• Advantages of formula feeding

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Introducing Solid Foods When and What?

• Solids can be started at 6 months but are not
  needed until 9 to 12 months (AAFP)
• Introduced gradually, one at a time
• Cereal?strained fruits

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Learning the World

• Sensation
• Perception

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Visual Perception Seeing the World

• Newborns distance vision ranges from 20/200 to
  20/600
• By __ months, average infants vision is already
  20/20
• Other visual abilities grow rapidly
• Binocular vision
• Depth perception

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When Going Off the Deep End is a Good Thing!
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Infant Visual Preference

• Preferences that are present from birth
• Genetically preprogrammed to prefer particular
  kinds of stimuli
• Prefer to look at patterned over simpler stimuli

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Auditory Perception The World of Sound

• Infants
• Hear _____________and have good auditory
  perception after they are born
• Are more sensitive to certain frequencies
• Reach adult accuracy in sound localization by age
  1
• Can discriminate groups of different sounds
• React to changes in musical key and rhythm
• Can discriminate many language related sounds

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Smell and Taste in a Small World

• Smell
• Well developed at birth
• Helps in recognition of mother early in life
• Taste
• Have innate sweet tooth
• Show facial disgust at bitter taste
• Develop preferences based on what mother ate
  during pregnancy

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Ouch!

• Contemporary Views on Infant Pain
• Developmental progression in reaction to pain
• Infants born with capacity to experience pain
  produces distress
• Exposure to pain in infancy may lead to permanent
  rewiring of nervous system resulting in greater
  sensitivity to pain during adulthood

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The Power of Touch

• Touch is one of most highly developed sensory
  systems in a newborn
• Even youngest infants respond to gentle touches
• Several of the basic reflexes present at birth
  require touch sensitivity to operate

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Does massage work?
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Multimodal Perception Combining Individual
Sensory Inputs

• New area of study in infant research
• Some researchers argue that sensations are
  initially integrated with one another in the
  infant
• Others maintain that infants sensory systems are
  initially separate and that brain development
  leads to increasing integration

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What are affordances?

• Perceptible affordances
• Exist where information on actions that are
  afforded are perceptible
• These are dependent on language, culture,
  context, and experience and vary for different
  individuals

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Becoming an Informed Consumer of Development

• Exercising Your Infants Body and Senses
• Attempts to accelerate physical and
  sensory-perceptual development yield little
  success
• Yet
• Infants need sufficient physical and sensory
  stimulation

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How can this be accomplished?
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