Birth &amp; Infant Physical, Perceptual and Motor Development Lecture 4 January 17, 2008 Overview Birth Stages of labor Video The amazing newborn Physical condition Reflexes Senses States sleeping and crying Feeding Infancy Body growth Motor Development Perceptual development a focus on vision Brain development Visual brain development Video Childbirth Stages of labor Stage 1 Dilation of the cervix (the opening from uterus to vagina Accomplished through contractions of the uterus Stage 2 Fetus goes from uterus to vagina Head &quot;crowns&quot; Body emerges Stage 3 Placenta, umbilical cord expelled Childbirth continued Changing notion of traditional childbirth Past: home delivery, natural family event Current: hospitals, medical event (U.S.) Holland 33% give birth at home US 1% give birth at home Concern about &quot;medicalization&quot; of childbirth Moms not involved in decision-making process Treating a natural process like disease Pain medication Some form used in 80-95% of births in U.S. Sedative drug relax mom &amp; relieve pain; cross placental barrier baby may also be sedated Regional anesthesia e.g., epidural may prolong labor; cause trouble with pushing; headaches The Cesarean Section (C-section) C-section - surgical procedure - typically w/ regional anesthesia - mother awake Why needed? Medical emergencies, breech psoitions failure to progress Prevalence - 5.5% of births in 1970; 29% of births in 2004 most common form of major surgery Concern is that it is done unnecessarily; Drs too cautious? Why is high rate a problem? Major surgery longer recovery Mom is sore less mobile Expensive possible financial strain Modern Childbirth - Alternatives Movement to return to natural childbirth Natural or prepared childbirth (e.g., Lamaze) Goal is to make hospital birth as comfortable and rewarding as possible Typical components: classes, relaxation, coach Benefits: moms report feeling more in control Use of doula (pregnancy couch) and social support Birthing centers Combine intimacy of home birth w/ medical technology of hospital Delivery typically performed by licensed midwife Encourage preparation. Focus on family and control Birth video The Newborn's Physical Condition Newborn Baby's Appearance Average dimensions 20 in., 7.5 lbs. Often not at attractive best Babiness features have appeal Assessing health status - The Apgar Scale Purpose: Used to assess the newborn's physical condition on 5 criteria: heart rate, respiratory effort, muscle tone, color, reflex response (e.g., coughing) Timing: Ratings given at 1 and 5 minutes What do numbers mean: Score 7-10 indicates good physical condition Score of 4 or below signals an emergency Newborn Baby's Capacities - Reflexes A reflex is an inborn, automatic response to a particular form of stimulation. Purpose and Examples Provide newborns with adaptive responses to their environments Allow us to assess health of baby's nervous system Stimulate early development of muscles and CNS Some have survival value e.g., rooting, sucking, grasping Some are precursors of later motor skills e.g., stepping reflex Duration most disappear during first 6 mon Newborn Sensory Capacities Taste and Smell Prefer sweet Soothing Nurse more after mom has vanilla Attracted to odor of mother's lactating breast Hearing Prefer complex sounds such as voices. Can distinguish almost all sounds in human languages Can orient to sounds at 2 months. Vision Least mature of newborn senses 20/400 vision; ~20/20 by 1 year See best at 9-12&quot; Touch Sensitivity to touch and pain present at birth Touch helps stimulate physical and emotional development Touch Newborn Massage Dieter, Field and others (2003) Subjects preterm newborns (average 30 wks gestation) Tx: 3 15 min sessions of massage per day for 5 days vs. no massage Results: massaged newborns gained 52% more weight per day than those not massaged Conclusions: Touch can improve preterm newborn health Newborn States Two major newborn states Sleep Spend greatest amt of time in sleep - 1618 hrs a day Not in a row! Wake up every 3-4 hrs. Alternate betw REM and non-REM sleep. REM = rapid eye movement. In REM sleep, brain &amp; body parts are active. in non-REM, body is quieter Newborn States Crying Function: Babies communicate physical needs Three types of cries: Basic starts softly and gradually becomes more intense (hungry? Tired? Uncomfortable?) Mad more intense Pain sudden long burst, pause, gasp Impact: stimulate strong feelings of arousal &amp; discomfort. Do Something! Infant Feeding and Nutrition: Breast Milk vs. Formula Breast milk is recommended. 6 mos. exclusively, 1 year w/ foods Advantages: Correct balance of fat and protein Nutritional completeness Protection against disease Mom passes antibodies Digestibility Smoother transition to solid foods Used to changes of milk taste with mom's diet Often cheaper, more immediate, safer Infant Feeding continued Why formula is often considered Medical reasons Medications Baby on a restricted diet Societal structures and barriers Work schedule Access to a lactation room Infant Body Growth Infants grow in spurts Infants grow unevenly Cephalocaudal growth first in head and then feet Growth is most rapid in infancy Double weight by 3 mos Triple weight by 12 months Height: grow 7 inches in first year Infant Motor Development Cephalocaudal - head to feet Raise head before standing Proximodistal - center out Coordination of trunk and arm precedes hand, fingers Mass-to-specific Gross before fine Example &quot;monster&quot; walking before smooth walking or buttoning shirt Perceptual Development in Infancy: A Focus on Vision Last sense to reach full capacity Depth Perception The ability to judge the distance of objects from one another and from ourselves Independent movement (e.g., crawling) plays a <a href="/keyword/vital-role/" >vital role</a> in its refinement Now they can test/see distance between themselves and objects Depth Perception Gibson and Walk (1960) Visual cliff study Glass top table Mom calling on other side Would the child cross? Infants 8 months or older would not crawl across &quot;deep&quot; side 8-mo-olds can percieve depth Brain Development Myelination = process in which neural fibers are coated with an insulating fatty sheath Gila provide the fatty sheath Improve speed of neuron communication Development continues through adolescence Growth of cerebral cortex 0-2 yrs brain grows from 25 to 75% of adult weight Synaptogenesis continues postnatally Synaptic overproduction more synapses are formed than will be used Synaptic pruning The elimination of unnecessary synapses; synapses strengthened/pruned through experience - plasticity; &quot;use it or lose it&quot; Visual Development and the Brain Hubel &amp; Wiesel Infant monkeys raised with one eye closed for 6 mos Results Eye could not see Eye was mechanically fine Nerons in visual area no longer dedicated to &quot;bad eye&quot; &quot;good eye&quot; took over &quot;bad eye&quot; neurons Adult monkeys' vision unchanged Conclusions Plasticity brain changes in response to the enviro stimulation Critical period a time when an organism displays a heightened sensitivity to certain environmental stimuli; infancy is a critical period for vision Visual Development and the Brain Video clip from Secret Life of the Brain (~12 min) Visual Development and the Brain Summary of video