Berger LS 7e Ch 5 by 5Lj7x3L3

VIEWS: 8 PAGES: 58

									                            Kathleen Stassen Berger


                       Part II             Chapter Five


The First Two Years: Infant and Toddlers

Body Changes

Brain Development

Senses and Motor Skills

Public Health Measures
                    Prepared by Madeleine Lacefield       1
                             Tattoon, M.A.
“Adults don’t change
  much in a year or two.
Their hair might grow
  longer, grayer, or
  thinner; they might be
  a little fatter; or they
  might learn something
  new.
 But if you saw friends
  you hadn’t seem for
  two years, you’d
  recognize them
  immediately.”
                             2
• “By contrast, if you cared for
  newborn 24 hours a day for a
  month, went away for two years,
  and then came back,you might
  not recognized him or her,
  because the baby would have
  quadrupled in weight, grown
  taller by more than a foot, and
  sprouted a new head of hair.
• Behavior would have changed,
  too. Not much crying, but some
  laughter and fear—including of
  you.”




                                    3
“A year or two is not much compared
  with the 75 or so years of the
  average life span. However, in two
  years newborns reach half their adult
  height, talk in sentences, and
  express almost every emotion—not
  just joy and fear but also love,
  jealousy, and shame.”

                                      4
Biosocial Development




                        5
               Body Changes
– In infancy
  • growth is fast
  • neglect can be severe
  • gain needs to be monitored
  • health check-up need to include
    – height, weight and head circumference




                                              6
                 Body Size
• rapid growth
    • infants typically double their birth weight by
      the 4th month and triple by the 1st birthday
    • physical growth slows in the 2nd year
    • by 24 months weight is about 30 lbs, height
      about 32”-36”
  – these numbers are “norms” (average)


                                                  7
                     Body Size
• “norms”
   – an average or standard for a particular population

• “particular population”
   – a representative sample of North American infants

• “percentiles”
   – a number that is midway between 0 and 100, 50th
     percentile = with ½ the children above it and ½ below it




                                                                8
                     Body Size
• Weight increase in the early months is fat,
  providing insulation for warmth and
  nourishment

• Nourishment keeps the brain growing, if
  teething or illness interfere with eating

• When nutrition is temporarily inadequate, the
  body stops growing but not the brain
   – this is known as a phenomenon called
     “head-sparing”

                                                  9
                         Sleep
• Infants sleep about 17 hours or more a day




• Regular and ample sleep correlates with normal brain
  maturation, learning, emotional regulation, and
  psychological adjustment in school and within the family

                                                        10
                      Sleep
  • Over the first month the amount of time spent in
    each type or stage of sleep changes
  • Newborns dream a lot, or at least they have a high
    proportion of “REM sleep”

– REM sleep
  • rapid eye movement sleep is a stage of sleep
    characterized by flickering eyes behind closed lids,
    dreaming, and rapid brain waves
  • 3 months patterns of alertness and sleep
  • 3 to 4 months slow wave sleep increases
                                                      11
                          Sleep
• Sleep Patterns can be…
   – affected by birth order
      • first born typically receive more attention
   – diet
      • parents might respond to predawn cries with food,
        and/or play (babies learn to wake up night after
        night)
   – child-rearing practices
      • “Where should infants sleep?”
         – co-sleeping or bed-sharing
   – brain maturation
                                                        12
“Who Sleeps Where?”




                      13
            Brain Development
– the newborn’s skull is disproportionately large
– large enough to hold the brain, which at birth is 25%
  of the adult brain
– the neonate’s body is typically 5% of the adult weight
– by age 2 the brain is almost 75% of the adult brain
  weight
– the child’s total body weight is only about 20% of its
  adult weight



                                                       14
      Connection in the Brain

– Head circumference provides a rough idea
  of how the brain is growing, and that is why
  medical checkups include measurement of
  the skull.

– Head typically increases about 35% within
  the 1st year


                                            15
         Basic Brain Structures
– The brain’s communication system begins with nerve
  cells, called neurons.
   • Neurons are one of the billions of nerve cells in the
     central nervous system, especially the brain.

– Infants have billions of neutrons
   • Located in the brain or in the brain stem
      – the region that controls automatic responses,
        I.e., heartbeat, breathing, temperature, and
        arousal
   • 70% of the neurons are in the cortex
                                                        16
       Basic Brain Structures
• The cortex is crucial for humans…
  – 80% of the human brain materials in the cortex
  – in other mammals the cortex is proportionally
    smaller, and non-mammals have no cortex
  – most thinking, feeling, and sensing take place
    in the cortex, although other parts of the brain
    join in.




                                                  17
              Basic Brain Structures
• Areas of the cortex specialize
  in particular functions:
   – Visual
   – auditory
   – an area dedicated to the
      sense of touch for each
      body part
   – regional specialization
      within the cortex occurs
      not only for motor skills
      and senses but also for
      aspects of cognition

                                       18
• 6 months recognize mother/father’s face




                                            19
       Basic Brain Structures
• Between brain areas, neurons are
  connected to other neurons by intricate
  networks of nerve fibers called axons and
  dendrites
  – a neuron has a single axon and numerous
    dendrites, which spread out like the branches of
    a tree
  – axons and neurons meet the dendrites of other
    neurons at intersections called synapses which
    are critical communication links within the brain

                                                  20
Basic Brain Structures




                         21
           Basic Brain Structures
• Transient Exuberance and Pruning
   – The fivefold increase in dendrites in the cortex
     occurs in the 24 months after birth, with about
     100 trillion synapses being present at age 2
   – The expanded growth is followed by pruning in
     which unused neurons and misconnected
     dendrites atrophy and die
   – Synapses, dendrites, and even neurons continue
     to form and die throughout life, though more
     rapidly in infancy than at any other time

                                                   22
           Basic Brain Structures
• Experience Shapes the Brain
   – brain structure and growth depends on genes and
     experiences
   – experiences produce “postnatal rise and fall”
   – some dendrites wither away because they are
     underused; no experiences have caused them to
     send a message to the axons of other neurons.
   – increasing cognitive complexity of childhood is related
     to a loss of synapses
   – Issue with Fragile X syndrome


                                                         23
         Basic Brain Structures

• Stress and the Brain
  – example of the role of experience in brain
    development begins when the brain
    produces cortisol and other hormones in
    response to stress, which happen
    throughout life



                                                 24
            Basic Brain Structures
• Necessary and Possible Experiences
   – Scientist William Greenough identified two
     experience-related aspects of brain development
      • The development of experience-expectant
        referring to brain functions that require certain
        basic common experiences, which an infant can
        be expected to have in order to develop normally
      • The development of experience-dependent
        referring to brain functions that depend on
        particular, variable experience and that therefore
        may or may not develop in a particular infant
                                                             25
          Basic Brain Structures
• Necessary and Possible Experiences
  – Basic, common experiences must happen for
    normal brain maturation to occur, and they almost
    always do happen
    • The brain is designed to expect them and use them
      for growth
  – in contrast, dependent experiences might happen.
    Because of them, one brain differs from another
  – experience varies; language babies hear or how
    their mothers reacts to frustration
  – all people are similar, but each person is unique,
    because of early experiences

                                                    26
        Basic Brain Structures
• Necessary and Possible Experiences
  – The last part of the brain to mature is the
    prefrontal cortex
    • The area for anticipation, planning, and
      impulse control
       – Virtually inactive in early infancy
         » telling an infant to stop crying is pointless
         » shaking a baby to stop crying, “shaken baby
           syndrome,” is useless
       – Gradually becomes more efficient over the
         years of childhood and adolescence


                                                           27
         Basic Brain Structures
• Implications for Caregivers
  – Early brain growth is rapid and reflects
    experience…
    • caressing a newborn,
    • talking to a preverbal infant
    • showing affection toward a small person
  – …are essential to develop that person’s full
    potential

                                                28
            Basic Brain Structures
• Implications for Caregivers
   – Each part of the brain has sequence of…
      • growing
      • connecting
      • pruning
   – Stimulations are meaningless before the brain is
     ready
      • advisable to follow the baby’s lead
      • infants respond most strongly and positively to their
        brain’s need
   – Self-righting is the inborn drive to remedy a
     developmental deficit
                                                          29
         Basic Brain Structures

• Implications for Caregivers
  – the human brain is designed to grow and
    adapt
    • some plasticity is retained throughout life
    • the brain protects itself from overstimulation
      – ex., overstimulated babies cry or sleep
    • babies adjust to understimulation
      – by developing new connections lifelong
      – Sensitive period
                                                  30
            Basic Brain Structures
• Implications for Caregivers
   – Neuroscientist once thought that brains were
     influenced by
      • Genes and prenatal influences
   – By contrast, social scientist by
      • Childhood environment was crucial…
         – Cultures
         – Societies
         – Parents
      • …credited or blamed for child’s emotions and/or
        actions
                                                          31
         Basic Brain Structures

• THINK LIKE A SCIENTIST
  – Plasticity and Orphans




                                  32
             Senses and Motor Skills
– Piaget called the first period of
  intelligence the
   • Sensorimotor stage
       – cognition develops from the
          senses and motor skills
       – infant brain development depends
          on sensory experiences and early
          movement
   • within hours of birth vital organs are
      functioning, assessing basic senses
      and motor responses (Brazelton
      Neonatal Assessment Scale;
      measures 26 items of newborn
      behavior)

                                              33
     Sensation and Perception
– All the senses function at birth
  • open eyes, sensitive ears, and responsive
    noses, tongues, and skin
– Very young babies attend to everything
  • Infants don’t focus on anything in particular
  • To about age one taste in the primary way
    humans learn about objects


                                               34
    Sensation and Perception
– Sensation is the response of a sensory
  system…
  • eyes, ears, skin, tongue, nose
– …when it detects a stimulus
  • when the inner ear reverberates with sound
  • The retina and pupil of the eye intercept
    light



                                            35
     Sensation and Perception
– Perception is the mental processing of
  sensory information…
  • the brain notices and processes a
    sensation…
– when the brain interprets a sensation…
– Infant’s brains are attuned to experiences
  that are repeated, striving to make sense
  of them

                                               36
      Senses and Motor Skills
– Hearing
  • Hearing is acute at birth
  • Certain sounds trigger reflexes
  • Sudden noises startle newborns
  • Rhythmic sounds soothe them and put them to
    sleep
  • The first days of life infants turn their heads
    towards sound
  • They soon connect sight and sound with accuracy


                                                  37
      Senses and Motor Skills

– Seeing
  • At birth vision is the least mature
  • The infant eyes are sensitive to bright light
    even though the eyes open in mid-
    pregnancy
  • Newborns are “legally blind” they can only
    see objects 4” – 30” away


                                                38
     Senses and Motor Skills
– Seeing
  • At two months infants look more intensely
    at faces and often smile
  • At three months infants look more closely
    at the eyes and mouth
– The ability to focus the two eyes in a
  coordinated manner in order to see one
  image is known as binocular vision (@14
  months)
                                            39
     Senses and Motor Skills
– Tasting, Smelling and Touching




                                   40
     Senses and Motor Skills
– Tasting, Smelling and Touching
  • At birth the senses of taste, smell and touch
    function and rapidly adapt to the social
    world
  • As infants learn their caregiver’s smell and
    touch (handling) they relax and cuddle
  • Over time infants become responsive to
    whose touch it is and what it communicates


                                               41
      Senses and Motor Skills

– Early sensation seems to have two goals:
  • Social interaction
    – To respond to familiar caregivers
  • Comfort
    – To be soothed amid the disturbances of infant
      life




                                                      42
   Senses and Motor Skills
– Motor Skill is the learned ability to move
  some part of the body, from a large leap
  to a flicker of the eyelid.
  (motor refers to movement of muscles;
  the abilities needed to move and control
  the body)



                                           43
     Senses and Motor Skills
– Reflexes are a responsive movement
  that seems automatic because it almost
  always occurs in reaction to a particular
  stimulus. Newborns have many reflexes,
  some of which disappear with
  maturation (a reflex is an involuntary
  response to a particular stimulus



                                         44
      Senses and Motor Skills
– Reflexes
  • Infants have dozen of reflexes
    – three sets are critical for survival
      » that maintain oxygen supply
      » that maintain constant body temperature
      » that manage feeding




                                                  45
       Senses and Motor Skills
– Gross Motor Skills are physical abilities involving
  large body movements (gross meaning “big”)
   • walking
   • jumping
– Walking progress
   • from reflexive,
   • to hesitant
   • to adult-supported stepping
   • to a smooth coordinated gait

                                                    46
      Senses and Motor Skills

– Gross Motor Skills
  • Three factors combine to allow toddlers to
    walk
    – muscle strength
    – brain maturation within the motor cortex
    – practices




                                                 47
      Senses and Motor Skills

– Fine Motor Skills are physical abilities
  involving small body movements,
  especially of the hands and fingers (fine in
  this text means “small”)
  • drawing
  • picking up a coin




                                             48
         Senses and Motor Skills
– Ethnic Variation
   • healthy infants develop skills in the same sequence
   • they vary in the age at which they acquire them (the
     table on the next slide show some “norms”)

– Walking, when grouped by ethnicity:
  • Generally African American are ahead of Hispanic
    Americans
  • Hispanic American are ahead of European American
  • Internationally the earliest walkers are in Uganda
  • The latest walkers are in France


                                                            49
Senses and Motor Skills




                          50
      Senses and Motor Skills

– Genes are only a small part of most ethnic
  differences

– Cultural patterns of child rearing can affect
  sensation, perception, and motor skills




                                              51
      Public Health Measures
– 8 billion children were born between 1950
  – 2005
– 2 billion died before age 5
  • Deaths could be twice this if not for:
    – Child care
    – Preventive care – immunization
    – Clean water
    – Adequate nutrition
    – Medial treatment, etc. Oral rehydration therapy

                                                        52
          Public Health Measures
– Immunization is a process that stimulates the body’s immune
  system to defend against attack by a particular contagious
  disease (immunization acquired either naturally, by having the
  disease or though vaccination)
   • immunization successes
      – Smallpox
      – Polio
      – Measles
   • problem with immunization
      – parents don’t notice if their children does not get seriously
        ill
      – minor disease can kill
      – parents are concern about side effects of vaccinations

                                                                   53
      Public Health Measures

– Sudden Infant Death Syndrome (SIDS)
  • die unexpectedly in their sleep
  • No apparent cause of death
  • 1990 in the U.S., 5000 babies died of SIDS,
    1 in 800




                                             54
ISSUES AND APPLICATONS

      Back to Sleep




                         55
                       Nutrition

• has been discuss indirectly throughout
  the chapter
    • Breast is Best
      – Good nutrition starts with mother’s milk
        » Colostrum, a thick, high-calorie fluid secreted by the
          woman’s breast at the birth of a child.
        » About 3 days later the breast begins to produce milk
        » Breast fed babies are less likely to get sick



                                                                   56
                  Nutrition
– Malnutrition
  • protein-calorie malnutrition is a condition in
    which a person does not consume sufficient
    food of any kind
  • the deprivation can result in several
    illnesses, severe weight loss, and
    sometimes death
  • to measure a child’s nutritional status,
    compare weight and height with the
    "norms"

                                                57
• Kwashiorkor
• marasmus




                58

								
To top