Presentation on theme: "Chapter Three Tools for Exploring the World: Physical, Perceptual, and Motor Development."— Presentation transcript:
1 Chapter ThreeTools for Exploring the World: Physical, Perceptual, and Motor Development
2 3.1 The Newborn: Learning Objectives How do reflexes help newborns interact with the world?How do we determine whether a baby is healthy and adjusting to life outside the uterus?What behavioral states are common among newborns?What are the different features of temperament? Do they change as children grow?
3 The Newborn’s Reflexes Reflexes: the newborn is born with unlearned responses triggered by specific stimuliCertain reflexes have survival valuerooting, sucking, eye blinksOther reflexes are developmental precursors to later voluntary motor behaviorsstepping a precursor to walkingReflexes reflect the health of the child’s nervous system
4 Assessing the Newborn The five Apgar scores 1. Heart rate 2. Respiration3. Muscle tone 4. Reflexes5. Skin toneEach scored from 0 to 2; then summedGood physical condition: total of 7+Needs special attention: total of 4-6Life-threatening: total of 3 or less
5 Assessing the Newborn (cont’d) Neonatal Behavioral Assessment Scale (NBAS)Includes 28 behavioral and 18 reflex itemsAssesses four systemsAutonomic: body regulation (e.g., breathing)Motor: activity level and control of bodyState: maintaining states (e.g., alertness)Social: interacting with people
6 The Newborn’s StatesAlert inactivity: calm, eyes open and attentive; deliberately inspecting environmentWaking activity: open but unfocused eyes; uncoordinated motionsCrying: cries vigorously; motion is agitated and uncoordinatedSleeping: eyes closed; degree of activity and quality of breathing alternate
7 Crying Basic cry Starts softly and builds in volume and intensity Often seen when the child is hungryMad cryMore intense and louderPain cryStarts with a loud wail, followed by a long pause, then gasping
8 Sleeping Newborns sleep an average of 16-18 hours/day Sleep cycles Newborns: 4-hour cycle; 3 hours sleep and 1 hour awakeBy 3 to 4 months: 5-to-6-hour cycleBy 6 months: sleep 10 to 12 hours at nightREM sleep50% of newborn sleep25% by 12 months
9 Co-sleepingThe practice of sleeping in the same room or bed with the childMuch more common in cultures valuing interdependence than independenceResearch shows no evidence of increased dependenceCo-sleeping has the advantage of avoiding elaborate sleep-time rituals
10 Sudden Infant Death Syndrome (SIDS) SIDS: sudden, inexplicable death of a healthy babyRisk factorsPremature birth and low birth weightParental smokingChild overheating and sleeping on stomachAfrican-American infants (often sleep on stomach)Reducing risk? Sleeping on back or sides
12 Dimensions of Temperament Temperament: consistent styles or patterns of infant behaviorNumber of temperament dimensions still debated (ranging from 2 to 9)Rothbart’s (2007) three dimensions indicate how much a childis generally happy, active, vocal, and seeks stimulation (surgency/extroversion)is angry, fearful, frustrated, shy, and not easily soothed (negative affect)focuses attention, is not easily distracted, and can inhibit impulses (effortful control)
13 Rothbart’s Dimensions of Temperament Three dimensions are not independentHigh effortful control predicts high surgency/extroversion, but low negative affectScores during infancy predict personality in adolescents and adults
14 Hereditary and Environmental Contributions to Temperament Heredity and twin studiesIdentical twins are more similar in temperament than are fraternal twinsHeredity influences negative affect more than other temperament dimensionsHeredity contributes more to temperament in childhood than during infancy
15 Hereditary and Environmental Contributions to Temperament (cont’d) Asian babies are less emotional, whereas Russian babies show more fear and negative affect compared to Euro-American babiesParental characteristics influence temperamentParental responsiveness reduces infant emotionalityDepressed mothers have more fearful infants
16 Hereditary and Environmental Contributions to Temperament (cont’d) Heredity and environment interactTemperament influences environment’s effect on childrenFearful children cheated more if disciplined with power assertion, but less if parents were nurturing and supportiveTemperament influences how others treat the child and his or her experiences
17 Stability of Temperament Studies suggest that temperament tends to be somewhat stable from infancy through adulthoodTemperament predisposes, but does not always guarantee, later personality characteristicsParents can nurture children to behave in ways somewhat different from their temperament
18 3.2 Physical Development: Learning Objectives How do height and weight change from birth to two years of age?What nutrients do young children need? How are they best provided?What are the consequences of malnutrition? How can it be treated?What are nerve cells, and how are they organized in the brain?How does the brain develop? When does it begin to function?
19 Growth of the BodyGrowth is more rapid in infancy than during any other period after birthInfants double their weight by three monthsInfants triple their weight by one yearAverage is not the same as normalChildren of the same age can vary greatly in their heights and weightsHeight depends largely on heredity
20 FIG 3.2 Boys and girls grew taller and heavier from birth to 3 years of age but the range of normal heights and weights is quite wide.
21 Nutrition and GrowthRapid growth requires young babies to consume large amounts of calories relative to body weightBreast-feeding is the best way to ensure proper nourishmentBottle-feeding has advantages and disadvantagesAll family members can enjoy intimacy with bottleFormulas can promote proneness to allergies and reduced immunity
22 Nutrition and Feeding New foods should be introduced one at a time Growth slows at two years and children become finicky eatersFinicky eating may have survival valueToddlers do not know which foods are safe and stick with familiar foodsVirtually all finicky eaters receive adequate nutritionNew foods still introduced one at a time
23 MalnutritionWorld-wide about 1 in 4 children under age five are malnourished (UNICEF, 2006)Malnourished children develop more slowlyMalnutrition is most damaging during infancy due to rapid growth rateGiving malnourished children adequate diets is challenging because they are listless, quiet, and inactiveThese characteristics call less urgent attention to the children’s needs
24 The Emerging Nervous System The brain and the rest of the nervous system consist of cells known as neuronsNeurons consist of a soma, dendrites, the axon, and terminal buttonsTerminal buttons release chemicals called neurotransmitters
25 FIG 3.4 A nerve cell includes dendrites that receive information, a cell body has life-sustaining machinery, and, for sending information, an axon that ends in terminal buttons.
26 The Brain The brain has 50 to 100 billion neurons Cerebral cortex: the wrinkled surface of the brainHemispheres: the two halves of the brainCorpus callosum: the thick band of fibers connecting the two hemispheres
27 The Making of the Working Brain The brain weighs about three-quarters of a pound at birth – about 25% of an adult brainAt around three years of age, the child’s brain is about 80% of an adult’s brain weight
28 Emerging Brain Structures At 3 weeks after conception, the neural plate, a flat structure of cells, formsBy 28 weeks after conception, the brain has all the neurons it will ever haveIn the 4th month of prenatal development, axons begin to form the fatty sheath, myelinHelps speed neural transmissionImproves coordination and reaction timesNumber of synapses peaks at 12 monthsSynaptic pruning: certain unnecessary synapses soon begin to disappear
29 Growth of a Specialized Brain: Brain-Mapping Methods Methods to study origins and time course of brain specializationStudying children with brain damageMeasuring the brain’s electrical activity through electrodes place on scalp (EEG or electroencephalogram)Using magnetic fields to track brain blood flow (fMRI, functional magnetic resonance imaging)
30 Five General Principles of Brain Specialization Specialization is early in developmentEx.: newborns’ left hemisphere generates higher electricity in response to speechSpecialization takes two specific formsSpecialized areas become more focused and less diffuseStimuli triggering brain activity become more specific than general
31 Five General Principles of Brain Specialization (cont’d) 3. Different brain systems specialize at different ratesEx.: systems for sensory and perceptual processes specialize before those for higher-order processes4. Environmental stimulation is necessary for successful specializationexperience-expectant growthexperience-dependent growth
32 Five General Principles of Brain Specialization (cont’d) 5. Plasticity is a benefit of the immature brain’s lack of specializationAtypical experiences may disrupt normal course of development (e.g., brain damage disrupting speech)Plasticity: brain is very flexible, allowing recovery of function, especially in young children
33 Experience-expectant growth Brain Specialization Principle: Experience-Expectant vs. Dependent-GrowthExperience-expectant growthAll human brains require exposure to experiences common to all individuals (e.g., exposure to faces) to fine-tune their circuits and to have different regions specializeExperience-dependent growthBrain circuits and regions also are fine-tuned according to each person’s unique experiences (e.g., learning to play the violin vs. learning to play soccer)
35 3.3 Early Motor Skills: Learning Objectives What are the component skills involved in learning to walk? At what age do infants master them?How do infants learn to coordinate the use of their hands?
36 FIG 3.5 Locomotor skills improve rapidly in the 15 months after birth and progress can be measured by many developmental milestones.
37 Locomotion By 7 months, infants can sit alone Toddling: at around 14 months, toddlers may stand alone briefly and walk without assistanceDynamic systems theoryInstead of simple maturation, motor development involves many distinct skills that are organized and reorganized over time to meet specific task demands
38 Posture and BalanceInfants are “top-heavy” and easily lose their balanceWithin a few months, infants use inner ear and visual cues to adjust postureInfants must relearn balance each time they achieve new postures
39 SteppingMany infants move their legs alternately in a stepping-like motion as early as 6-7 monthsInfants use environmental cues to judge whether a surface is suited to walking (e.g., flat vs. bumpy)
40 Coordinating SkillsWalking skills must be learned separately and then integrated with othersDifferentiation: mastery of component skillsIntegration: combining components into the sequence needed to accomplish the taskUnsupported, independent walking occurs at about 12 to 15 months, once children have mastered and coordinated its component skills
41 Cultural Impact on Motor Development Some cultural practices encourage certain skills early and others discourage themEx.: parents in Africa carry children piggyback style, which promotes walking at earlier ages than in the U.S.Ex.: in Paraguay, mothers constantly carry toddlers, delaying motor skillsDespite cultural differences in average age of skill development, children acquire skills within a normal rangeUh, I don’t see how these two examples differ from each other…elaborate?
42 Fine Motor SkillsFine motor skills are associated with grasping, holding, and manipulating objectsAt 4 months, infants clumsily reach for objectsBy 5 months, they coordinate movement of the two handsBy 2-3 years, children can use zippers but not buttonsTying shoes is a skill that develops around age 6 years
43 Handedness About 90% of children prefer to use their right hand Most children grasp with their right hand by age 12 months, with a clear preference seen by preschool agePreference is affected by heredity, but environmental factors also influences itLeft-handedness has increased since U.S. teachers stopped urging right-handedness
44 3.4 Perception: Learning Objectives Are infants able to smell, to taste, and to experience pain?Can infants hear? How do they use sound to locate objects?How well can infants see? Can they see color and depth?How do infants coordinate information between different sensory modalities, such as between vision and hearing?
45 Coming to Know the World: Smell and Taste Perception Perception: brain processes receiving, selecting, modifying, and organizing sensory inputsNewborns have keen senses of smell and tasteOdors: they distinguish pleasant from unpleasant, or familiar from unfamiliar (e.g., mother’s breast or perfume)Taste: they differentiate among salty, sour, bitter, sweet, and changes in mother’s breast milkFacial reactions (e.g., lip licking) show they have a “sweet tooth”
46 Coming to Know the World: Touch and Pain Babies react to touch with reflexes and other movementsIn reaction to painful stimuli, babies manifest the pain cry – a sudden, high-pitched wail – and they are not easily soothed
47 Coming to Know the World: Hearing Startle reactions suggest that infants are sensitive to soundInfants hear less well than adultsThey best hear pitches in the range of human speech (neither high nor low pitches) and differentiate consonants from vowelsThey prefer pleasant more than unpleasant melodies and can remember songsBy 4 months, they recognize their own names
48 Coming to Know the World: Seeing Newborns respond to light and track moving objects with their eyesVisual acuity (clarity of vision) is the smallest pattern that can be distinguished dependablyInfants at 1 month see at 20 feet what adults see at feetBy 1 year, infants’ visual acuity is the same as adults
49 Coming to Know the World: Color Cones: sets of neurons located along the retina at the back of the eye, each specialized to one of the three light wavelengthsNewborns perceive few colors3- to 4-month-old infants can perceive colors similarly to adults
50 Coming to Know the World: Depth Perception Visual cliff research6-week-olds react with interest to differences in depth (heart rate deceleration)By 7 months, they show more fear than interest to the cliff’s deep end (heart rate acceleration and refusal to cross the deep side)Fear of depth seems to develop around the time babies can crawl
51 Coming to Know the World: Depth Perception (cont’d) Seven cues adults use to infer depthCues Closer compared to distant objects...Kinetic cues … appear larger while movingVisual expansion … fill more of the retinaMotion parallax … move fasterRetinal disparity … yield greater disparitySound … sound louderPictorial cuesLinear perspective … have wider parallel linesTexture gradient … are coarser and distinctly textured
52 Coming to Know the World: Depth Perception (cont’d) Few-week old babies use kinetic, visual expansion, and motion parallax weeks after birth to see depthInfants use sound to accurately gauge depth4- to 6-month-old babies use retinal disparity7-month-old babies use linear perspective and texture gradient to see depth
53 Coming to Know the World: Perceiving Objects Perceiving objects involves interpreting patterns of lines, textures, and colorsObject perception is limited in newborns, but develops rapidly in the first few monthsBy 4 months, infants use several cues to discern that a stimulus is an objectelements that move togethersimilar colors and texturesaligned edges
54 Perceiving FacesNewborns prefer to look at moving faces, suggesting an innate attraction to themBy 4 weeks, infants track all moving stimuli, including faces and nonfacesBefore 6 months, infants have a prototype of a face that includes both human and nonhuman facesBetween 6 to 12 months, the prototype is fine-tuned to reflect familiar faces, which they prefer viewingBy 7 to 8 months, infants process faces similarly to adults, as a unique arrangement of features
55 Integrating Sensory Information Infants visually recognize objects they only touched previouslyInfants soon begin to perceive the link between visual images and soundsIntersensory redundancy: simultaneously available multimodal sensory information (e.g., sight, sound, touch)Infants perceive best when sensory information is redundantWhy? Brain regions specialized for a specific sense are not yet developed
56 3.5 Becoming Self-Aware: Learning Objectives When do children begin to realize that they exist?What are toddlers’ and preschoolers’ self-concepts like?When do preschool children begin to acquire a theory of mind?
57 Origins of Self-Concept Self-awarenessMirror test: red rouge surreptitiously rubbed on child’s nose; child placed in front of mirror and behavior is observed9-month-old infants smile at the image in the mirror but do not seem to recognize it as themselvesBy months, infants see the image in the mirror and touch their own nose, suggesting they know the image is theirs
58 Origins of Self-Concept (cont’d) Toddlers look more at photographs of themselves than other childrenToddlers refer to themselves by name and use personal pronouns “I” or “me”They use “I” in the present and in the past, showing awareness of the self’s continuity over timeToddlers understand ownership, indicated by use of “mine” in reference to possessionsPreschoolers describe the self in terms of possessions, physical characteristics, preferences, and competencies
59 Theory of Mind (TOM)Theory of mind: naïve understanding of the relationship between mind and behaviorDevelops in three phases (Wellman, 1993, 2002)Phase 1: by 2 years, aware of desires; speak of wants and likesUnderstand that people have desires and that desires cause behavior (e.g., “Ew peas; I not eat.”)Phase 2: by 3 years, distinguish the mental from physical worldUse mental verbs (“think”, “believe”, “forget”), but still emphasize desires as main causes of behavior
60 Theory of Mind (TOM) (cont’d) Phase 3: by 4 years, know that behavior can be based on beliefs about events, even if belief is falseFalse belief tasksChild hears story about Sally, who puts ball in the basket and leavesChild told the ball is moved from the basket to the box, which Sally does not knowChild is asked, “When Sally comes back, where will Sally look for the ball ”3 &1/2-year-olds: Sally will look in the box (wrong)4-year-olds: Sally will look in the basket (correct)
61 Theory of Mind (TOM) (cont’d) How does TOM develop?Could reflect expanding mental state language and grammatical skillsMight be due to interactions with others, who provide insights into people with different mental states, perspectives, feelings, intentions, moodsTOM and autismAutism spectrum disorder (ASD)Echoic speech and later language acquisitionObsessive and compulsive interest in objectsDisinterest in other people
62 Theory of Mind (TOM) (cont’d) Autism spectrum disorder (ASD) (cont’d)Awkward social interactions with other peopleDo not follow rules governing social interactionsSymptoms emerge around 18 to 24 monthsDiagnosed in 1 out of U.S. children80% of diagnoses are in boysIs heritableAtypical brain functioning; perhaps abnormal neurotransmitter levelsCannot be cured, but medications and a supportive environment help a lot
63 Theory of Mind (TOM) (cont’d) ASD and TOMVery slowly grasp false beliefSome argue they may not have a TOMmindblindness is a defining feature of ASDSome attribute mindblindedness to other deficitscannot inhibit irrelevant actionshave problems shifting smoothly between actionsSome attribute to a “focused” processing styletoo much emphasis on perceptual details instead of the bigger coherent picture