Tâm lý học - Chapter 4: Physical development in infancy

Chapter 4: Physical Development in Infancy©2011 The McGraw-Hill Companies, Inc. All rights reserved.Life-Span Development Thirteenth Edition1Patterns of Growth:Cephalocaudal Pattern: sequence in which the earliest growth always occurs from the top downwardProximodistal Pattern: sequence in which growth starts in the center of the body and moves toward the extremities©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy2Height and WeightAverage North American newborn is 20 inches long and 7 ½ poundsAt 2 years of age, infants weigh 26 to 32 pounds and are half their adult height. ©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy3The Brain:Contains approximately 100 billion neurons at birthExtensive brain development continues after birth, through infancy, and laterHead should be protectedShaken Baby Syndrome: brain swelling and hemorrhaging from child abuse trauma©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy4The Brain:The Brain’s DevelopmentAt birth, the brain is 25% of its adult weight; at 2 years of age, it is 75% of its adult weightMapping the BrainFrontal, Occipital, Temporal, and Parietal LobesLateralizationLeft-brained vs. Right-brained©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy5©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy6The Brain:Changes in NeuronsContinued myelinationGreater connectivity and new neural pathwaysChanges in Regions of the BrainDramatic “blooming and pruning” of synapses in the visual, auditory, and prefrontal cortex ©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy7©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy8Changes in regions of the brain:“Blooming and pruning” of synapses varies by brain regionPace of myelination varies as well©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy9The Brain:Early Experience and the BrainDepressed brain activity has been found in children who grow up in a deprived environmentRepeated experience wires (and rewires) the brainBrain is both flexible and resilient©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy10©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in InfancyThe Brain11SleepTypical newborn sleeps 18 hours per dayInfants vary in their preferred times for sleepingMost common infant sleep-related problem is night wakingConsistently linked to excessive parental involvement in sleep-related interactions with their infant©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy12SleepREM Sleep – eyes flutter beneath closed lidsSleep cycle begins with REM sleep in infantsMay provide infants with added self-stimulationREM sleep may also promote brain developmentWe do not know whether infants dream or not©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy13SleepShared SleepingVaries from culture to cultureAmerican Academy of Pediatrics discourages shared sleepingPotential benefits:Promotes breast feeding and a quicker response to cryingAllows mother to detect potentially dangerous breathing pauses in baby©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy14SleepSIDS (Sudden Infant Death Syndrome): infants stop breathing and die without apparent causeHighest cause of infant death in U.S. annuallyHighest risk is 2-4 months of ageMany other risk factors associated with SIDS©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy15NutritionNutritional Needs and Eating Behavior50 calories per day for each pound they weighFruits and vegetables by end of 1st yearPoor dietary patterns lead to increasing rates of overweight and obese infantsBreast feeding reduces risk of obesity©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy16©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in InfancyNutrition17NutritionBreast Versus Bottle FeedingConsensus: Breast feeding is betterAmerican Academy of Pediatrics strongly endorses breast feeding throughout the first yearNumerous outcomes for child and mother ©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy18NutritionMalnutrition in InfancyEarly weaning can cause malnutritionTwo life-threatening conditions resulting from malnutritionMarasmus: a severe protein-calorie deficiency resulting in a wasting away of body tissuesKwashiorkor: a severe protein deficiency that causes the abdomen and feet to swell with waterSevere and lengthy malnutrition is detrimental to physical, cognitive, and social development©2011 The McGraw-Hill Companies, Inc. All rights reserved.Physical Growth and Development in Infancy19The Dynamic Systems View:Infants assemble motor skills for perceiving and actingMotor skills represent solutions to goalsDevelopment is an active process in which nature and nurture work together as part of an ever-changing system©2011 The McGraw-Hill Companies, Inc. All rights reserved.Motor Development20Reflexes: built-in reactions to stimuli; automatic and inbornRooting ReflexSucking ReflexMoro ReflexGrasping ReflexSome reflexes continue throughout life; others disappear several months after birth©2011 The McGraw-Hill Companies, Inc. All rights reserved.Motor Development21Gross Motor Skills: large-muscle activitiesThe Development of PosturePosture – a dynamic process linked with sensory information in the skin, joints, and muscles, which tell us where we are in spaceLearning to WalkOccurs about the time of their first birthdayInfants learn what kinds of places and surfaces are safe for locomotion©2011 The McGraw-Hill Companies, Inc. All rights reserved.Motor Development22Gross Motor Skills: large-muscle activitiesThe First Year: Motor Development Milestones and VariationsSome milestones vary by as much as two to four monthsExperience can modify the onset of motor accomplishmentsSome infants do not follow the standard sequence of motor development©2011 The McGraw-Hill Companies, Inc. All rights reserved.Motor Development23©2011 The McGraw-Hill Companies, Inc. All rights reserved.Motor Development24Gross Motor SkillsDevelopment in the Second YearToddlers become more skilled and mobileBy 13-18 months, toddlers can pull a toy or climb stairs; by 18-24 months, toddlers can walk quickly, balance on their feet, walk backward and stand and kick a ballEven when motor activity is restricted, many infants reach motor milestones at a normal age©2011 The McGraw-Hill Companies, Inc. All rights reserved.Motor Development25Fine Motor Skills: finely tuned movementsUsing a spoon, buttoning a shirt, reaching and graspingPalmer grasp: grasping with the whole handPincer grip: grasping with the thumb and forefingerPerceptual-motor coupling is necessary for infants to coordinate grasping©2011 The McGraw-Hill Companies, Inc. All rights reserved.Motor Development26What are Sensation and Perception?Sensation: occurs when information interacts with sensory receptors (eyes, ears, tongue, nostrils, and skin)Perception: the interpretation of what is sensed©2011 The McGraw-Hill Companies, Inc. All rights reserved.Sensory and Perceptual Development27What are Sensation and Perception?Ecological View: we directly perceive information that exists in the world around usAffordances: opportunities for interaction offered by objects that fit within our capabilities to perform activities©2011 The McGraw-Hill Companies, Inc. All rights reserved.Sensory and Perceptual Development28Visual PerceptionVisual Acuity and Human FacesNewborn’s vision is about 20/240 but 20/40 by 6 months of ageInfants show an interest in human faces soon after birthSpend more time looking at their mother’s face than a stranger’s face as early as 12 hours after being bornA 2-month-old scans much more of the face than the 1-month-oldColor Vision©2011 The McGraw-Hill Companies, Inc. All rights reserved.Sensory and Perceptual Development29©2011 The McGraw-Hill Companies, Inc. All rights reserved.Sensory and Perceptual DevelopmentVisual Perception1 month2 months3 months1 year30©2011 The McGraw-Hill Companies, Inc. All rights reserved.Sensory and Perceptual DevelopmentVisual Perception31Visual PerceptionPerceptual Constancy: sensory stimulation is changing but perception of the physical world remains constantSize Constancy: recognition that an object remains the same even though the retinal image of the object changesBabies as young as 3 months show size constancyShape Constancy: recognition that an object remains the same shape even though its orientation to us changes©2011 The McGraw-Hill Companies, Inc. All rights reserved.Sensory and Perceptual Development32Visual PerceptionDepth PerceptionEleanor Gibson and Richard Walk studied development of depth perception using a “visual cliff”Infants 6-12 months old can distinguish depthNature, Nurture, and the Development of Infants’ Visual Perception©2011 The McGraw-Hill Companies, Inc. All rights reserved.Sensory and Perceptual Development33©2011 The McGraw-Hill Companies, Inc. All rights reserved.Sensory and Perceptual DevelopmentDepth Perception34Other SensesHearingFetuses can hear and learn sounds during the last two months of pregnancy and can recognize their mother’s voice at birthTouch and PainNewborns do respond to touch and can also feel pain ©2011 The McGraw-Hill Companies, Inc. All rights reserved.Sensory and Perceptual Development35Other SensesSmellNewborns can differentiate odorsTasteSensitivity to taste may be present before birth©2011 The McGraw-Hill Companies, Inc. All rights reserved.Sensory and Perceptual Development36Intermodal Perception: the ability to integrate information from two or more sensory modalitiesPerceptual–Motor Coupling: perception and action are coupledAction educates perception©2011 The McGraw-Hill Companies, Inc. All rights reserved.Sensory and Perceptual Development37