CHD2220 Test Two Study Guide Chapter 5 Perceptual Physical and Motor Development in Infancy Infants gradually come to know people by mutual touch speech and glances Gradually learn to fixate and track objects in space and control movements to access objects Physical Growth First two years Changes in Height and Weight Average newborn weighs 7 lbs Average measurements are 20 inches from head to tow Birth weight doubles by five months Triples by first birthday Gains 5 6 lbs in 2nd year 4 5 lbs in third year Height increases by half in 1st year Additional 5 6 inches in 2nd year Changes in Body Proportions Changes progress in two fundamental principles of physical growth Cephalocaudal Head to Tail Principle growth of the head and upper body precede growth in lower body o 8 weeks after conception head in half fetus length 25 of length at birth and 12 in adulthood Proximodistal Near to Far Principle body grows from the center outward o Torso develops prior to arms and legs arms and legs prior to hands and fingers Childproofing the Environment Light sockets stairs drop offs security gates dangerous objects and substances Nutrition in Infancy Breast milk of a mother contains nutrients in perfect proportion to the infant s needs during the first 3 4 months of life Formulas made from cow s milk are nutritionally acceptable for babies of mothers who cannot or choose not to breast feed Infants need fats proteins carbohydrates minerals and vitamins met adequately by both human milk and formula Breast feeding promotes early development of infant brain and positive effects on long term cognitive intellectual development as well as immunological benefits Infant s immune system does not become effective until middle of first year Vulnerable to infection Colostrum a thin yellowish fluid secreted by the breast for several days before milk is produced Contain antibodies that cannot be duplicated in formula Babies that were breast fed were not hospitalized as much as formula fed babies Decrease in SIDS diabetes lower rates of obesity less likely to develop ADHD Mothers who breastfeed more quickly lose their pregnancy weight American Academy of Pediatrics recommends mothers breastfeed infants for 6 months and continue 6 moths longer after solid food is introduced of women who make an attempt to breast feed their infants Do not put infants through low fat low calorie diets health is less than 50 risk Development of the Brain the body nervous system development Structure of the Brain Central Nervous System constitutes the most complicated physical structure in All aspects of development are mediated either directly or indirectly by central Brain structure emerges in the prenatal stage During prenatal stage 250 000 new nerve cells add each minute resulting in 100 billion nerve cells in a newborn Brain structure continues to evolve through first 10 years of life Neurons highly complex biological structures than conduct electrochemical impulses Neurons line up into sequences or NERVE PATHWAYS that conduct impulses throughout the body Synapse microscopic gap forming when the axon of one cell butts up against the dendrite of another cell Neurotransmitters impulses transmitted across the synapse from cell to cell by these chemicals Myelination axons develop an insulating fatty coating that improves the efficiency of nerve impulse transmission Continues throughout childhood adolescence and adulthood Synaptogenesis synapses begin to develop in very large numbers prenatally and continue to increase in Plasticity of the Brain extraordinarily large numbers through the first 3 years of life Highest level of synaptic density in the third year of life At this point in development prenatal stage the brain contains 1000 trillion synapses 50 more than the adult brain During prenatal stage of development the essential architecture of the brain is formed Late in gestation nerve cells begin to fire sending impulses through various pathways in developing brain organizing brain function After birth brain is bombarded by pattern stimulation particularly through routine interaction with caregivers The fundamental structure of the nervous system is designed to manage the storage and transfer of all of the information necessary to support the biological function of bodily systems and the psychological functions of sensations perception learning and intelligence The nervous system is an evolving system of circuits that is designed with more potential capacity than it is ever likely to need Plasticity if one part of the nervous system becomes damaged or unable to function Hemispherectomy the radical removal of half of a child s brain in the treatment of extreme cases of brain seizures Demonstration of plasticity After the second year the rate of production of new synapses levels decreases and they disappear Elimination process is based on a simple neurological principle pathways that get used repeatedly survive those that go unused disappear Use it or Lose it Principle results in leveling off of the number of synapses from the end of the second year through approximately the tenth year or around the time kids graduate elementary school The greater the variation and organization of incoming stimuli the greater number of pathways that survive Pruning synapses and cells that are not stimulated are eliminated through this massive and continuing destructive process Pruning happens in years of adolescence adult brain contains 50 of synapses that were in the brain of a three year old Early experience triggers genetic mechanisms that influence every aspect of brain development proliferations of neurons formation of synapses migration of neurons differentiation of Perceptual Development Methods of Study functional areas of the brain pruning away unused cell and synapses to consolidate adaptive capabilities of brain Children who experience more varied organized repetitious and more consistently challenging interaction will better develop Sensation refers to the ability to passively receive and register information concerning internal and external events and to transmit that information to the central nervous system Perception refers to the infants active searching for information and the processing of that sensory information by the brain Visual Preference Method researcher presents pairs of stimuli to the baby The researcher observes the infant from a hidden vantage point between the two stimuli detects which one infant is looking at by
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