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Chapter Five. First Two Years: Infants & toddlers Biosocial Development Cognitive Development Psychosocial development. Biosocial Development. What does biosocial development mean? Development is multidimensional
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Chapter Five First Two Years: Infants & toddlers Biosocial Development Cognitive Development Psychosocial development
Biosocial Development What does biosocial development mean? Development is multidimensional All changes- physical, social, emotional, and cognitive- effect each other mutually Rapid development with neglect having severe consequences.
Body growth Sleep patterns Brain development Sense and motor skills Nutrition and diseases
Body Size Most notable time for physical changes in each of the first 12 months they grow an inch birth weight usually doubles by 4 months and triples by end of first year head-sparing—biological protection of the brain when malnutrition temporarily affects body growth
Sleep Newborns sleep about 17 hours per day needed for rapid growth Sleep is divided as REM and Quiet sleep REM declines with age quiet sleep increases at about 3 months Infant’s sleep patterns influenced by brain waves and parents’ caregiving practices
Early Brain Development Most critical biosocial aspect of growth newborn’s skull disproportionately large at birth, 25% of adult brain weight by age 2, 75% of adult brain weight Both under and over- stimulation are harmful for development.
Connections in the Brain Head measurement increases 35% in first year brain development: changes in the brain’s communication system Communication in the brain takes place through neurons which exist in the cortex Each part of the cortex specializes in particular functioning
Basic Brain Structures Neurons—long thin nerve cells that make up nervous system created before birth 70% in cortex (brain’s outer layer) Axons—nerve fibers that extend from neurons that send impulses Dendrites—nerve fibers extending from neurons that receive impulses
Neurons—long thin nerve cells that make up nervous system created before birth 70% in cortex (brain’s outer layer) Axons—nerve fibers that extend from neurons that send impulses Dendrites—nerve fibers extending from neurons that receive impulses
Each neuron has a single axon (nerve fiber) that extends from it and meets the dendrites of other neurons at intersections called synapses. • axons and dendrites don’t actually • touch at synapses • Electrical impulses trigger brain chemicals called neurotransmitters, which carry information from axon of sending neuron across synaptic gap to dendrites of receiving neuron
At birth more than 100 million neurons are present However, the number of axons and dendrites are far lesser. Formation of dendrites, synapses and axons determines brain development Exuberance
Phenomenal growth is referred to as transient exuberance—fivefold increase in dendrites in first 2 years • As many as 15,000 connections may be made per neuron • Though synapses, dendrites, axons and neurons are formed throughout life, the rapidity of formation decreases.
Specifics of brain structure and growth depend partly on experience exuberance is transient underused neurons are inactivated, or pruned Reactions to Stress: experiencing stress may cause overproduction of stress hormone developing brain can lose capacity to react normally to stress normal neuron connections may have been pruned for rapid response to repeated stress Experience Enhances the Brain
The Senses and Motor Skills Sensorimotor Stage cognition develops between senses and motor skills sensation—the response of sensory system when it detects stimulus begins with outer organ—nose, eyes, etc. perception—mental procession of sensory information when brain interprets sensation begins in the brain and requires experience cognition—thinking about what was perceived
Begins prenatally and is acute at birth Newborns particularly attentive to human voice Newborns’ sensitive hearing combines with brain to distinguish sounds Listening
Vision the least mature sense at birth Visual experience combined with visual cortex maturation improves vision Binocular vision—ability to focus two eyes in a coordinated manner to see single image Looking
taste—functions at birth; calmed by sugar, sensitive to sour touch—comforted by human touch; feel pain smell—can distinguish between odors and have preferences Early sensation is organized for social interaction comfort Tasting, Smelling, and Touching
Abilities need to move a control the body Increases due to the infant’s increase brain capacity And because of obtained bodily proportions Motor Skills
Reflexes Involuntary response to stimuli Reflexes for survival are categorized maintain oxygen supply (breathing) maintain body temperature (crying, kicking) manage feeding (rooting and sucking) swallowing aids feeding crying when stomach empty
Gross Motor Skills • Involve large muscles and body movements crawling, creeping, walking • Fine Motor Skills:Small, finely tuned movements, especially of hands and fingers, including successful grabbing, grasping a moving object and • transferring objects from hand to hand • adjusting reach
Severe Malnutrition Interferes with all kinds of development-brain, body and emotions marasmus and kwashiorkor diseases are direct result of malnutrition In marasmus, early growth is decreased, body tissues are wasted, and the infant eventually dies In kwashiorkor, water retention occurs in stomach and limb due to protein deficiency Malnutrition