Chapter 5: Biosocial Development The First Two Years

1. Chapter 5: Biosocial DevelopmentThe First Two Years Dr. M. Davis-Brantley

2. Body Size • Infants double their birth weight by the 4th month and triple it by the end of the 1st year • Fat is typically acquired to provide storage for nourishment • Stored nutrition comes into play to keep the brain nourished if the child can not eat due to sickness or teething • Head-sparing • The biological protection of the brain when malnutrition temporarily affects body growth

3. Sleep • New babies typically spend 17 or more hours sleeping • Ample sleep correlates with brain maturation, learning, emotional regulation, and psychological adjustment • Growth hormones are released during sleep more so than during waking hours • REM Sleep • Rapid Eye Movement sleep: flickering of eyes, dreaming and rapid brain waves • Decreases significantly after 4 months • Children are too immature in their brain, digestion, and circadian rhythm to sleep on command

4. Early Brain Development: Basic Brain Structures • Neuron—is a nerve cell of the central nervous system (most neurons are in the brain) • Most neurons are created during pregnancy and are at their peak during mid-pregnancy • Cortex • The outer layer of the brain in humans that is the primary location for most of our thinking, feeling, and sensing • Frontal cortex is in the front and is responsible for executive functioning which includes planning, self-control, and self-regulation (very immature at birth)

5. Early Brain Development: Basic Brain Structures • Neurons need to communicate with one another in order to function • They are connected by an intricate network of nerve fibers • Axon—is a nerve fiber that extends from the neuron and transmits electrical impulses from that neurons to the dendrites of the other neurons • Dendrite—A nerve fiber that extends from a neuron and receives electrical impulses transmitted from other neurons via their axons • Synapse—The intersection between the axon of one neuron and the dendrites of other neurons • Synapses are critical in communication links in the brain

6. Early Brain Development • At birth, the brain contains more than 100 billion neurons, but not enough dendrites and synapses • During the first months and years, major spurts of growth and refinement in axons, dendrites, and synapses occur (connections are being made) • Transient Exuberance is the great increase in the number of dendrites that occurs in an infant’s brain over 1st 2 years of life • Enables neurons to become connected and communicate with other neurons within the brain • This leads to expanding of neurons and connections in the brain • Grows more during this time than any other time throughout lifespan

7. Sensation and Perception • Sensation—is the response to sensory system when it detects a stimulus • Perception—The mental processing of sensory information when the brain interprets a sensation • The brain applies meaning to the sight or sound that is sense

8. The Senses • Listening • Hearing is acute at birth and began during the last trimester of pregnancy • Hearing develops as child begins to distinguish between different sounds • Child also begins to mimic certain sounds as she/he is learning language • Looking • Vision is the least mature sense at a birth and newborns can focus on objects 4 to 30 inches • With maturation of the visual cortex vision improves

9. Motor Skills • Reflex—is a responsive movement that seems automatic, because it always occurs in reaction to a specific stimulus • 3 Classes of reflexes include: • Those that maintain oxygen supply • Those that maintain constant body temp. • Reflexes that manage feeding

10. Gross Motor Skills • Physical abilities involving large body movements such a walking and jumping • B/n 8 and 10 months most infants can lift their bodies and engage in coordinating the movements of their bodies to crawl, climb, and eventually walk (after 10 months)

11. Fine Motor Skills • Physical abilities involving small body movements, especially of the hands and fingers • During first 2 months babies wave their hands at dangling objects • By 3 months they can usually touch the object • By 4 months some infants can actually grab an item but their timing is not accurate • By 6 months child can grab and hold onto an object • After 6 months they can transfer objects from one hand to another • By 12 months they can coordinate and manipulate

12. Baby’s Health • Immunization is the process by which the body’s immune system is stimulated to defend against the attack of a contagious disease • The healthy person is given a small dose of the inactive virus which stimulates that production of antibodies • Sudden Infant Death Syndrome (SIDS) is when a seemingly health infant (at least 2 months of age) dies unexpectedly in her/his sleep • Decrease in amount of SIDS deaths has been linked to not putting babies to sleep on their stomachs and fewer parents smoking • Ethnicity can play a significant role

13. Baby’s Health • Nutrition • Breast is Best • For newborns, good nutrition starts with breast milk • Colostrum is a high-calorie fluid secreted by the breasts at birth, 3 days later milk comes • Breast milk is sterile & at body temp. • Contains more iron, vitamins A & C, and other important nutrients • WHO recommends the child is breast fed exclusively for 4-6 months • Formula may be better when the mother is HIV+

14. Baby’s Health • Malnutrition • Protein-calorie malnutrition is a condition in which a person does not consume sufficient food of any kind • Marasmus a disease of severe protein-calorie malnutrition during early infancy, in which growth stops, body tissues waste away, and the infant eventually dies • Kwashiorkor a disease of chronic malnutrition where deficiency of protein causes the child’s face, legs, and abdomen to bloat and makes the child more vulnerable to diseases such as measles, diarrhea, influenza • 3 consequences of chronic malnourishment include: • Brains may not develop normally • The are no reserves to protect the child if disease strikes • Childhood diseases become far more lethal than typically would be • The above stated disease can result