Infancy: Physical DevelopmentAnnouncementsOutline •Physical growth and development during infancy •Motor development •Sensation and perception during infancyPatterns of Growth •Cephalocaudal •ProximodistalHeight and Weight in Infancy • Average Weight: • Typical Length: • Growth rate • By 2 years of ageThe First Year •First Weeks: •Lose 5 to 7 percent of their body weight •First Year: •4 months = 2X birth weight •1 year = 3X birth weightThe Brain •Contains tens of billions of nerve cells at birth •Cerebral cortex •Two hemispheres, •Four main lobes in each hemisphere • frontal lobes, occipital lobes, temporal lobes, parietal lobes •Lateralization -- specialization of function in one hemisphere or the otherThe Brain • Changes in neurons • Myelination • Connectivity increasesNeural Development (Nature) and Experience (Nurture) • Pruning: • Neurons that remain  organized, strengthened • “Use it or lose it” principle: KEY: Early experiences are extremely importantBrain development during infancy Increase followed by decrease in synaptic densityDevelopmental Psych in Real Life Shaken Baby Syndrome or Abusive Head Trauma • What is it? • Shaking the baby, even for only 5-10 seconds can cause serious injury • Shaking baby causes “whiplash”-like concussion • Most common around 4 months of age when crying is at peak • Incidence? • 1,300 children, nearly all infants, suffered severe or fatal abusive head trauma Keenen, et al., 2004Developmental Psych in real life Shaken Baby Syndrome or Abusive Head Trauma • Result? • If not fatal can result in mental retardation, paralysis, retinal damage, learning disorders, seizures • Babies most vulnerable due to large head, weak neck muscles, soft plates in head • Prevention? • Carry and talk to baby • Put baby down and take a break • Understand causes of crying Keenen, et al., 20043-13 Sleep • Typical newborns • Common Infant sleep problem • REM sleep3-14 Sleep • Sudden infant death syndrome (SIDS): Occurs when an infant stops breathing, usually at night • Suddenly dies without an apparent cause3-15 SIDS - Findings • Occurs mostly in infants with abnormal brain stem functioning involving serotonin • Factors associated with higher SIDS rates: • Low birth weight • Ethnic Differences • Second-hand smoke • Co-sleeping • Don’t use a pacifier when sleeping • Sleep in a room without a fanSIDS - recommendationsNutrition: Breastfeeding • Breast milk almost always the best food • Recommendation = breastfeed for 6 monthsBottle Feeding •Formula = iron-fortified • Required if mother • Has infectious illness • Is taking drugs or meds that could harm infant •Does NOT reduce emotional bonding between mother and baby. Breast feeding http://vad2.mhhe.com/CAP/1708_640x480_CAP.mpgNutritional Needs •What is most common vegetable eaten in infancy? •Infants should eat 50 calories per day for each pound they weigh •Many U.S. parents are feeding their 4- to 24-month-old babies too few fruits and vegetables, and too much junk food (c) 2012 The McGraw-Hill Companies, Inc.3-20 Motor Development • Reflexes • Gross motor skills • Fine motor skillsDynamic Systems Theory • Perception and action tied together • Motor skills develop • Changing nervous system • Infant’s movements • Infant’s goals to reach • Environmental supportReflexes •Biologically based behaviors •Survival reflexes •Primitive ReflexesSurvival reflexes •Breathing •Rooting •Sucking •Pupillary •BlinkPrimitive reflexes •Moro (Startle reflex) •Palmer •PlantarPrimitive Reflexes • Babinski • Stepping • Swimming • Tonic neckGross Motor Skills •Skills that involve large-muscle activities • Sitting with support • Sitting without support • Pull themselves up • Stand aloneGross Motor Development in the Second Year •Toddlers •13–18 months •18–24 monthsFine Motor Skills • Finger dexterity • Pincer grip • 0-2 years - infants refine how they reach and grasp • Perceptual-motor coupling  coordinated grasping • Role of ExperienceStudying the Infant’s Perception •Visual Preference Method •Orienting response •Habituation •DishabituationPerception of Pattern and Depth •Preference for face •Preference for bull’s-eye target •Preference for black-and-white stripes rather than circleDeveloping Senses •Vision •Hearing •Smell •TasteInfant responses to tastes SWEET SOUR BITTERVisual Cliff •Depth perception -- visual cliff • 3-4 months - Infants develop the ability to use binocular cues to perceive depth (Gibson & Walk,