THE PHYSICAL SELF: DEVELOPMENT OF THE BRAIN, THE BODY,

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THE PHYSICAL SELF DEVELOPMENT OF THE BRAIN, THE
BODY, MOTOR SKILLS
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Physical Development

• In the 1st few months, children grow nearly an
  ounce each day and an inch each month
• First two years marked by rapid growth.
• Doubling their birth weight by 4 to 6 months.
• Tripling their birth weight by the end of their
  1st yr. of life (21 pounds).
• Growth is rapid but irratic.
• Children may stagnate in growth for days or even
  weeks before experiencing a growth spurt (over
  centimeter in a day).
• By age 2, toddlers already have half their
  eventual adult height and have quadrupled their
  birth weight to some 30 pounds
• From age 2 until puberty, children gain about 2
  to 3 inches in height and 6 to 7 pounds in weight
  each year

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Changes in Body Proportions

• A newborns head is 70 of its eventual adult size
  and represents ¼ of the infants length
• Cephalocaudal Development
• Trunk grows fastest during the 1st year
• At 1yr, the head accounts for 20 of total body
  length
• Proximodistal Development
• During prenatal development, chest and internal
  organs form 1st followed by arms legs and then
  hands feet
• Throughout infancy and childhood, arms legs
  continue to grow faster than hands and feet

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Skeletal Development

• Skeletal structure starts as soft cartilage
  during prenatal and gradually hardens
  (Ossification).
• Discuss Epiphysis (growth centers where new
  cartilage is formed.
• This is why infants cannot initially set up or
  balance themselves
• Neonates skull consists of several soft bones
  that can be compressed to allow for the passing
  thru cervix and birth canal
• Skull bones are separated by 6 soft spots called
  fontanelles
• By age 2, these soft spots solidify leaving
  smaller seams (sutures) which allow the skull to
  expand as the brain grows larger
• Bones in ankle/feet and wrist/hand increases as
  child matures
• Skeletal age is often determined thru x-ray of
  hands/feet to examine bone density and
  interconnections
• Girls mature faster than boys (This may explain
  why girls tend to be healthier and more resistant
  to illnesses)
• African-American children develop faster than
  Caucasian children --At birth, girls are 4 to 6
  wks ahead of boys regarding skeletal maturity by
  age 12, the maturity gap widens 2 full years
• Bones in skeletal system grow and harden at
  different rates
• Skull and hands mature first leg bones reach
  mature development in late teens
• In general, mature skeletal development occur by
  age 18

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Skeletal Development Cont.

• While children grow and develop at different
  rates, the best predictor of maturity is skeletal
  development.

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Presence of Teeth

• In general, infants get their first tooth around
  6 months to a year. However,
• There are differences as a function of gender and
  ethnicity.
• Because girls mature faster than boys and
  African-Americans mature faster than Caucasian
  infants. Both groups tend to get their first
  tooth earlier
• In some cases, children are born with their first
  tooth
• By age 2, children generally have all 20 of their
  primary teeth

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Muscular Development

• Neonates are born with all the muscle fibers they
  will ever need
• At birth, muscle tissue is 35 water (later
  replaced by nutrients and salts) accounting for
  18 to 24 of the babies weight
• Muscle development proceeds in Cephalocaudal and
  Proximodistal manner. Muscles in head and neck
  maturing faster than muscles in trunk and limbs
• With growth spurts in muscles, boys make
  significant gains in strength and size
• Variations in physical growth depends on genes
  and cultural practices
• People from Asia, South America, Africa tend to
  be smaller than North America, North Europe, and
  Australia

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Development of the Brain

• Brain grows from 25 of its adult weight at birth
  to 75 of adult weight by age 2.
• The last 3 prenatal months and the first 2 years
  after birth are termed the period of the brain
  growth spurt (more than half of brains weight
  added at this time).
• The brain function consists of a trillion
  specialized cells that transmit
  exectrical/chemical signals.
• Synapses
• Neurons100 to 200 billion cells produced in
  neural tube during 2nd trimester
• Glial2nd type of nerve cell that provide
  nourishment and encasement to neurons

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Cell Differentation and Synaptogenesis

• Neurons assume specialized functions as they
  migrate to certain areas of the brain
• Synaptogenesis
• As neurons become more specialized, the
  interconnections forms to provide for reasoning
  and problem-solving
• Through appropriate stimulation, children develop
  appropriate synapses. Neurons that fail to
  interconnect (about half) fail to surviveThis is
  the pruning process
• An infants brain exhibits high plasticity
  (capability of change and adaptation). As we get
  older, brain cells become more rigid and
  inflexible
• Much research seems to suggest that early
  experiences (both in humans and animals) play a
  vital role toward brain formation.
• Maximal development for certain talents are
  related to sensitive periods where environmental
  stimulation is necessary for brain formation

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Cerebral Lateralization

• The brain divides into left and right
  hemispheres.
• Left side/brain controls right side/body and
  contains centers for speech, hearing, verbal
  memory, decision making, language, and expression
  of positive emotions
• Right side/brain control left side of body and
  contains centers for processing visual-spatial
  information, nonlinguistic sounds such as music,
  touch sensations, and expression of negative
  emotions
• 90 of adults are left hemisphere dominant
• Brain lateralization was initially thought to
  occur by end of puberty.
• Recent research identifies prenatal
  lateralization
• Brain lateralization/plasticity remain quite high
  for the first 3 years of life. Gradually
  diminishes with age.

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Motor Development

• By the end of the first month, most babies can
• Lift their chins while lying flat on stomach
• Lift their chests
• Reach for objects
• Roll over and sit up with some support.
• Motor develop has been used as a predictor for
  long-term developmental outcomes in the past
• More recent research suggest that variations in
  motor gains do not significantly predict
  long-term developmental outcomes
• (See Table 5.1 on page 152 for sequence of motor
  development).

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Explanations for Sequencing and Early Timing of
Early Motor Development

• Maturational viewpoint Biological/genetic
  blueprint determines the sequence of nervous and
  muscular system development (Downward/Outward).
• Cross cultural studies have indicated consistent
  developmental patterns.
• Twin study in which one child allowed to practice
  motor skills while the other not allowed to
  practice. Upon testing, no long-term significant
  adjustment outcomes.
• Experiential viewpoint Experience/practice
  becomes vital towards facilitating motor
  development.
• Several studies have noted cultural differencies
  in motor development due to child rearing
  practices.
• Iranian study (children spend 1st 2 yrs lying on
  backs in cribs/feeding, little playmotor
  development significantly impacted. Delayed in
  talking, sitting up, walking. 15 of the 3 to 4
  year olds could walk.
• Dynamical Systems Theory viewpoint Motor
  development is an active reorganization of
  previously mastered capabilities that are
  adjusted due to environmental exploration and
  curiosity dev.

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Goldfield Study (1989)

• Infants emergence to crawling around 7 to 8
  months.
• Regularly turned and raised their heads to
  interesting sights and sounds
• Developed distinct schemes for reaching and
  grasping
• Developed distinct schemes (leg thrust movements)
  to allow for greater mobility
• Infants development is goal directed
• While highly dependent of maturation and
  influenced by experiences, the child is actively
  navigating and engaging the environment and
  developing more complex schemes/talents in the
  process of constructing his/her understanding of
  the world

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Fine Motor Development

• Birth 3 months
• Innate and primitive reflexes (palmer grasp)
  evolve into more voluntary motor
  movements/reaching (around 2 months).
• 3 months
• Refined fine motor skills and improved grasping
• Refined hand-eye coordination
• 4-5 months
• Refined ability to sit up and move their hands
  across their bodies.
• Develop hand to hand movements during
  transferring of objects and development of ulnar
  grasp (grasping of objects by pressing fingers to
  palm.
• 6 months
• Pincer grasp develops (ability to use thumbs to
  counter the strength of fingers).
• Refined grasping techniques facilitates changes
  in play and exploration.
• Wheeled toys (once banged) are likely to be
  scooted soft objects are likely to be squeezed.

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Fine Motor Development Cont.

• As children get older, greater development of
  fine motor skills.
• Parents and teachers facilitate development thru
  play/creativity with crayons, blocks, markers,
  etc.
• Kids have yet to master speed with fine and gross
  motor skills.Therefore, 2 to 3 yr olds may still
  have difficulty catching and throwing a ball.

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Exploring the New Environment

• As children develop greater awareness of their
  competencies, they are truly experiencing a new
  environment.
• Children Explore.Parents Childproof.
• Children on the move..Parents in Pursuit.
• Motor develop facilitates development across
  other domains
• Children with greater mobility are better able to
  explore relationships with other people.
• Greater confidence due in part to their ability
  to retreat when they feel appropriate.
• Children explore people as well as objects.

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Role of Nutrition in Infancy

• Deficiencies in nutrition during infancy can
  permanently stunt development, particularly in
  brain functioning and development
• Breast feeding remains the healthiest option for
  ensuring infants obtain proper nutrients.
  Advantages are as follows
• Correct balance of fat and protein. Human milk
  have higher fat content/lower protein. Essential
  for brain development/ mylenization/ nervous
  system.
• Nutritional Completeness. Human milk has all
  that a child needs (1st 6 months). If bottle
  feeding, you need iron supplementation
• Protection against diseases. Breast feed babies
  develop greater resistance against disease.
  Receive antibodies from mom
• Protection against malocclusions tooth decay.
• Digestibility. Different bacteria growth in
  body less constipation and diarrhea
• Smoother transition to solid foods. Breast fed
  babies make a smoother transition to solid foods.
  Due in part to a greater variety of experience
  in taste thru mothers milk.

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Nutrition/Breast feeding Cont.

• Breast feeding declined in the United States from
  1940s to 1970s.
• The natural childbirth movement in the late 70s
  brought a return to breast feeding in US.
• Today, 2/3 of mothers breastfeed.
• Generally practiced among the well-educated and
  middle social class mothers.
• Babies, from poverty-strickened areas, who are
  breastfed are more likely to be healthy and
  survive their first year.
• Babies breast fed exclusively for the first 6
  months would save the lives of 1 million babies
  annually (Grant, 1995).