2 Infancy: Physical Development: Truth or Fiction? The head of the newborn child doubles in length by adulthood, but the legs increase in length about five times.Infants triple their birth weight within a year.
3 Infancy: Physical Development: Truth or Fiction? Breastfeeding helps prevent obesity later in life.A child’s brain reaches half of its adult weight by the age of 1 year.
4 Infancy: Physical Development: Truth or Fiction? The cerebral cortex – the outer layer of the brain that is vital to human thought and reason – is only one-eighth of an inch thick.Native American Hopi infants spend the first year of life strapped to a board, yet they begin to walk at about the same time as children who are reared in other cultures.
5 Infancy: Physical Development: Truth or Fiction? Infants need to have experience crawling before they develop fear of heights.
6 Infancy: Physical Development Physical Growth and Development
7 What are the Sequences of Physical Development? Cephalocaudal DevelopmentUpper part of the head to the lower parts of the bodyProximodistal DevelopmentTrunk outward – from body’s central axis toward peripheryDifferentiationTendency of behavior to become more specific and distinct
8 What Patterns of Growth Occur in Infancy? Weight doubles at about 5 months; triples by first birthdayHeight increase by 50% in first yearInfants grow 4 to 6 inches in second year; and gain 4 to 7 poundsGrowth appears continuous but actually occurs in spurts
9 Figure 5.1 Growth Curves for Weight and Height (Length) from Birth to Age 3 Years. The curves indicate the percentiles for weight and length at different ages. Lines labeled 97th show the height and weight of children who are taller and heavier than 97% of children of a particular age. Lines marked 50th indicate the height and weight of the average child of a given age. (Source: Figures 1-4, Kuczmarski, R.J., et.al. [2000, December 4]. CDC Growth charts: United States. Advance data from vital and health statistics, no Hyattsville, MD: National Center for Health Statistics.)Figure 5.1 Growth Curves for Weight and Height (Length) From Birth to Age 2 Years
10 Figure 5.2 Changes in the Proportions of the Body Figure Changes in the Proportions of the Body. Development proceeds in a cephalocaudal direction. The head is proportionately larger among younger children.Figure 5.2 Changes in the Proportions of the Body
11 What is Failure to Thrive? Growth impairment during infancy and early childhoodCauses may be organic or non-organicBiologically based or non-biologically basedLinks to physical, cognitive, behavioral and emotional problemsDeficiencies in caregiver-child interaction may play a roleCanalization – catch up growth once FTT is resolved
12 What are the Nutritional Needs of Children? Infants require breast milk or iron fortified formulaSolid foods may be introduced about 4 to 6 monthsIron-enriched cereal, strained fruits, vegetables and meatsWhole cow’s milk delayed until 9 to 12 monthsTeething biscuits in later part of first year
13 Guidelines for Infant Nutrition Build up variety of foodsAvoid overfeeding or underfeedingDon’t restrict fat and cholesterolDon’t overdo high-fiber foodsAvoid items with added sugar and saltEncourage high-iron foodsU.S. Dept of Agriculture, 2000
14 Developing in a World of Diversity Alleviating Protein-Energy Malnutrition (PEM)
15 Why do Women Bottle-feed or Breastfeed their Children? Choice to breastfeed is influenced byAttitudes regarding benefits for bonding and infant healthFear of pain, unease with breastfeeding and public breastfeedingDomestic and occupational arrangementsCommunity and familial supportLevel of education
16 What are the Advantages and Disadvantages of Breast Milk? Conforms to digestion processPossesses needed nutrientsContains mother’s antibodiesHelps protect against infant diarrheaIs less likely, than formula, to cause allergiesDisadvantages of breast milkHIV, alcohol, drugs and environmental hazards may be transmitted through breast milkPhysical demands on mother
18 What are Neurons?Basic unit of nervous system, receive and transmit messagesNeurons vary according to function and location, but all containCell BodyDendritesAxonNeurotransmitters
19 Figure 5.3 Anatomy of a Neuron Figure 5.3 The Anatomy of a Neuron. “Messages” enter neurons though dendrites, are transmitted along the axon, and then are sent through axon terminals to muscles, glands, and other neurons. Neurons develop via proliferation of dendrites and axon terminals and myelination.Figure 5.3 Anatomy of a Neuron
20 How do Neurons Develop? As child matures Myelin Sheaths Axons grow in lengthDendrites and axon terminals proliferateConnection networks become more complexMyelin SheathsMakes messages more efficientMyelination occurs with maturationInhibition of myelination results in disease
21 What is the Brain? Command center of organism Brain of neonate weighs less than one poundBy first birthday, the brain triples in weight, reaching nearly 70% of adult weight
22 Figure 5.4 The Growth of Body Systems as a Percentage of Total Postnatal Growth. The brain of the neonate weighs about one-fourth its adult weight. In keeping with the principle of cephalocaudal growth, it will triple in weight by the first birthday, reaching nearly 70% of its adult weight.Figure 5.4 Growth of Body Systems as a Percentage of Total Postnatal Growth
23 Structures of the Brain MedullaControls basic body functions - heartbeat, respirationCerebellumMaintains balance, control motor behavior, coordinate eye movements with body sensationsCerebrumAllows human learning, thought, memory and language
24 Figure 5.5 Structures of the Brain Figure 5.5 Structures of the Brain. The convolutions of the cortex increase its surface area, and apparently, its intellectual capacity. (In this case, wrinkles are good). The medulla is involved in vital functions such as respiration and heartbeat; the cerebellum is involved in balance and coordinator.Figure 5.5 Structures of the Brain
25 How Does the Brain Develop? Growth Spurts in Brain DevelopmentPrenatal – fourth and fifth monthsProliferation of neuronsPrenatal – 25th week through 2 years oldProliferation of dendrites and axon terminals
26 Figure 5.6 Increase in Neural Connections in the Brain Figure 5.6 Increases in Neural Connections in the Brain. A major growth spurt in the brain occurs between the 25th week of the prenatal development and the end of the second year after birth. This growth spurt is due primarily to the proliferation of dendrite and axon terminals.Figure 5.6 Increase in Neural Connections in the Brain
27 Brain Development in Infancy MyelinationAt birth brain areas well myelinated includeHeartbeat and respirationSleeping and arousalReflex activityMyelination of sensory areasHearing – begins about 6th month of pregnancy and continues to age 4Vision – begins shortly before full term but develop rapidly
28 How do Nature and Nurture Affect the Development of the Brain? Brain development is affected by maturation (nature) and sensory stimulation and motor activity (nurture)Rats in enriched environmentMore dendrites and axon terminalsHuman infants have more neural connections than adultsIf activated by experience, connection survivesIf not activated, connection does not survive
30 What is Motor Development? Developments in the activity of muscles, and is connected with changes in posture, movement, and coordinationFollows cephalocaudal and proximodistal patternsLifting and holding head before torsoVoluntary reachingLocomotionSequence: rolling over, sitting up, crawling, creeping, walking, running
32 What are the Roles of Nature and Nurture in Motor Development? Maturation (nature)Myelination and differentiation is needed for certain voluntary motor activitiesExperience (nurture)Experimentation to achieve milestonesSlight effect in training to accelerate motor skills
34 How do Sensation and Perception Develop in the Infant? Process of integrating disjointed sensations into meaningful patterns through perceptionFocus on vision and hearingMost research is one these areas
35 Development of Visual Acuity and Peripheral Vision Neonates are nearsightedGreatest gains in visual acuity between birth and 6 monthsBy about 3 to 5 years of age, approximate adult levelsNeonates have poor peripheral visionPerceive stimuli within 30 degree angleBy 7 weeks increases to 45 degreesBy 6 months of age, equal to adult
36 What Captures the Attention of Infants What Captures the Attention of Infants? How do Visual Preferences Develop?Neonates attend longer to stripes than blobsBy 8 to 12 weeks, prefer curved lines over straightInfants prefer facesDiscriminate maternal and stranger facesPrefer attractive facesPay most attention to edges
37 Figure 5.11 Preferences in Visual Stimuli in 2-Month-Olds Figure Preferences for Visual Stimuli in 2-Month-Olds. Infants appear to prefer complex to simple visual stimuli. By the time they are 2 months old, they also tend to show preference for the human face. Researchers continue to debate whether the face draws attention because of its content (that is, being a face) or because of its stimulus characteristics (complexity, arrangement, etc.)Figure 5.11 Preferences in Visual Stimuli in 2-Month-Olds
38 Figure 5.12 Eye Movements of 1- and 2-Month Olds Figure Eye Movements of 1- and 2-Month-Olds. One-month-olds direct their attention to the edges of objects. Two-month-olds “move in from the edge.” When looking at a face, for example, they focus on the eyes and other inner features. (Source: Salapatek, 1975.) How do researchers explain this change?Figure 5.12 Eye Movements of 1- and 2-Month Olds
39 How do Researchers Determine Whether Infants will “Go Off the Deep End”? Depth PerceptionDevelops around 6 months (onset of crawling)Research using the Visual CliffGibson and Walk (1960)Relationship between crawling and fear of heights
40 Figure 5.13 The Visual Cliff Figure The Visual Cliff. This young explorer has the good sense not to crawl out onto an apparently unsupported surface, even when mother beckons from the other side. Do infants have to experience some of life’s “bumps” before they avoid going off the deep end?”Figure 5.13 The Visual Cliff
41 What are Perceptual Constancies? How do they Develop? Perceptual constancy – perception of object remains stable although sensations may differ under various conditionsSize constancy – perception of object’s size remains stable although retinal size may differAppears by 2 1/2 to 3 monthsShape constancy – perception of object‘s shape remains stable although shape on retina may changeAppears by 4 to 5 months
42 Strategies for Studying the Development of Shape Constancy A Closer LookStrategies for Studying the Development of Shape Constancy
43 What are Perceptual Constancies? How do they Develop? Perceptual constancy – perception of object remains stable although sensations may differ under various conditionsSize constancy – perception of object’s size remains stable although retinal size may differAppears by 2 1/2 to 3 monthsShape constancy – perception of object‘s shape remains stable although shape on retina may changeAppears by 4 to 5 months
44 How Does the Sense of Hearing Develop in Infancy? Neonates can orient toward direction of a sound18 months locate sounds as well as adultsBy 3 1/2 months discriminate caregivers’ voicesInfants perceive most speech sounds present in world languagesBy 10 to 12 months, lose capacity to discriminate sounds not found in native language
45 Figure Declining Ability to Discriminate the Sounds of Foreign Languages. Infants show a decline in the ability to discriminate sounds not found in their native language. Before 6 months of age, infants from English-speaking families could discriminate sounds found in Hindi (red bars) and Salish, a Native American language (green bars). By 10 to 12 months of age, they could no longer do so. (Source: Werker, 1989)Figure 5.14 Declining Ability to Discriminate the Sounds of Foreign Languages
46 Effects of Early Exposure to Garlic, Alcohol, and – Gulp - Veggies A Closer LookEffects of Early Exposure to Garlic, Alcohol, and – Gulp - Veggies
47 Do Children Play an Active or Passive Role in Perceptual Development? Neonates perception is largely passiveLater, intentional action replaces captureSystematic search replaces unsystematicAttention becomes selectiveIrrelevant information gets ignored
48 What is the Evidence for the Roles of Nature and Nurture in Perceptual Development? Sensory changes are linked to maturation of nervous system (Nature)Experience also plays a role (Nurture)Critical periodsNewborn kittens with patched eye – become blind in that eyeNature and nurture interact to shape perceptual development.
49 Lessons in Observation Sensation and Perception in Infancy What does research tell us about the sensory capacities of newborns, such as Carter and Aiden? Cite evidence from the video that supports this research in regard to vision and hearing.Slide 05:48 (Chapter 5, Slide 48)Slide was omitted in original chapter presentation
50 Lessons in Observation Sensation and Perception in Infancy Slide 05:48 (Chapter 5, Slide 48)Slide was omitted in original chapter presentation
51 Lessons in Observation Sensation and Perception in Infancy Discuss how the newborn’s capacities for vision and hearing are adaptive in the context of Carter’s initial interaction with mom.Infants have clear visual preferences. Discuss the visual preferences of infants in the context of the response of 2-month-old Giuseppina to the stimuli presented by Dr. Basow. What method is Dr. Basow using as a test of Giuseppina’s visual preferences? What other methods are commonly used to study infant sensory and perceptual capacities?
52 Lessons in Observation Sensation and Perception in Infancy Does the newborn’s preference for looking at faces more than at other objects indicate that form perception is innate? Why or why not?