PHYSICAL DEVELOPMENT IN INFANCY

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CHAPTER 6

• PHYSICAL DEVELOPMENT IN INFANCY

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Height and Weight North American babies are
born typically at 20 inches long and 7.5 pounds,
with growing rate considerably slower in the
second year of life.
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The Brain contains 100 billion nerve cells.

• Brain Development Central nervous system begins
  as a long, hollow tube on the embryos back.
• First stage Neurons produced between 10 and 26
  weeks after conception, with cells generating at
  about 250,000 per minute during this period.
• Second stage Cell migration where cells move
  from the center to appropriate locations.
• Third stage Cell elaboration continues years
  after birth, even to very old adults.
• Myelin sheath Encases most axons with a layer
  of fat cells as insulation.
• Rapid growth between neurons in the brain through
  synaptic connections.

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The Brains Lobes and Hemispheres the cerebral
cortex perception, language, and thinking

• Frontal lobe voluntary movement thinking
• Occipital lobe vision
• Temporal lobe hearing
• Parietal lobe sensations, touch, information
  processing

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Lateralization and Hemisphericity the
specialization functions of left and right
sections of the brain.
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Early Experience and the Brain Enriched
environments may have a positive effect on brain
development.
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Sleep What are the effects of sleep on
development?

• Sleep-waking cycle Infants sleep in the range
  of 10 21 hours, with adult patterns of sleep
  developed at four months.
• REM sleep About one-half of infants sleep is
  REM, falling to 40 percent by three months. It
  may promote brain development.
• Shared sleeping Could promote breastfeeding and
  faster response time to babys needs, although
  there are cultural variations many feel it could
  be dangerous
• SIDS Research shows that incidence of SIDS
  decreases when infants sleep on their backs.

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NUTRITION

• Nutritional Needs and Eating Behaviors Infants
  triple their weight and increase length by 50
  percent in one year. Infants need fat and
  high-calorie foods.
• Breast versus Bottle Feeding Breastfeeding has
  many benefits fewer allergies, reduction of
  diarrhea and respiratory infections, less otitis
  media, reduced cancers in baby and mother, lower
  SIDS incidence, neurological and cognitive
  development, visual acuity.
• Malnutrition in Infancy Caused by early weaning
  from breast milk where infant receives deficient
  amounts of protein.

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Toilet Training In America it is expected by
age three, attained by 84 percent (daytime) and
66 percent (nighttime). Many modern parents are
using the readiness approach.
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Health A decline in infectious diseases caused
by immunizations given from two months to age 16.
Accidents are the major cause of infant deaths
from choking, falls, poisoning, and car accidents.
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MOTORDEVELOPMENTThe New Look In Motor
Development This is now viewed as an
interaction of many factors rather than just a
milestone reached because of age. Environment,
central nervous system development, and the
bodys physical support qualities all contribute
to motor coordination (dynamic systems theory)
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Reflexes Serve as important building blocks for
subsequent purposeful motor activity.

• Sucking reflex Newborns automatically suck an
  object placed in their mouth.
• Rooting reflex Infants stroked cheek responds
  by turning toward the touch.
• Moro reflex Neonatal response to a sudden,
  intense noise or movement.
• Stepping reflex Babies flex their legs up and
  down in response to pressure.
• Grasping reflex Infant grasps when palms are
  touched. Each of the reflexes is linked to
  survival and gradually disappears, except for
  blinking.

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Gross Motor Skills large muscle activities

• Development of posture Dynamic process linked
  with sensory modalities skin, muscles,
  vestibular organs in the inner ear, and cues from
  vision and hearing.
• Learning to walk Constant kicking leading to a
  gradual forward movement to balance of weight,
  usually achieved by first year.
• Summary of further development The sequence of
  gross motor skills is uniform as infants gain
  independence. Most two-year olds are motor
  proficient. Despite some parents training,
  all infants appear to reach motor proficiency at
  around the same age.

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Fine Motor Skills the finely tuned movements
finger dexterity. This skill is linked to
maturation of hand-eye coordination in the first
two years of life. Vision development is a key
to development fine motor skills.
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SENSORY AND PERCEPTUAL DEVELEOPMENT
What Are Sensation and Perception? Stimulus
activates response from the senses, producing
sensations, while perception is the
interpretation of what is sensed. The ecological
view is that perception brings the organism in
contact with its environment fro the purposes of
adaptation.
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Visual Perception Newborns vision is estimated
at 20/600 to 20/40 by the first birthday.

• Color Babies can distinguish between green and
  red.
• Visual preferences Infants prefer to look at
  patterns rather than at color they prefer
  concentric circles to colored ones.
• Depth perception Some indication that at two to
  four months they are aware of depth
  inconclusive research.
• Visual expectations Infants anticipate what
  they are about to see, can even infer from what
  they see.

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Other Senses

• Hearing Have higher sensory thresholds, meaning
  the stimulus needs to be stronger. Research
  demonstrates ability of fetus to hear in the
  womb.
• Touch and Pain One-year-olds can connect
  information about vision to that of touch.
  Although demonstrating stress from circumcision,
  male infants also show remarkable resiliency and
  ability to cope with it.
• Smell Newborns can differentiate odors,
  recognizing the smell of the mothers breast pad.
• Taste Newborns react to different tastes from
  sweet to sour.

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Intermodal Perception The integration of two or
more sensory modalities. Even newborns
demonstrate elemental forms of intermodal
perception, which certainly affects their ability
to survive, and which becomes ore sophisticated
through nurturing.
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Perceptual-Motor Coupling and Unification It is
unclear whether there is a distinction between
motor development and perception. Do babies
perceive in order to move or move in order to
perceive? Current intelligence leans towards a
coupling of both that eventually leads to
locomotion and control.