Chapter 3

1. Chapter 3 Physical and Cognitive Development in Infancy

2. Physical Growth and Development in Infancy • Head • large relative to the rest of the body • flops around uncontrollably • Infant becomes capable of • Rolling over • Sitting • Crawling • standing • stooping • climbing • usually walking

3. The First Year • Average North American newborn -- 20 inches long; 7½ pounds • Most newborns lose 5 to 7 percent of their body weight adjusting to feeding • They double their birth weight by the age of 4 months; nearly triple it by their first birthday • Infants grow about 1 inch per month during the first year

4. From Age 1 to 2 Years • At 2 years of age, children weigh approximately 26 to 32 pounds • gaining a quarter to half a pound per month • attain about one-fifth of their adult weight • At 2 years, the average child is 32 to 35 inches tall • nearly half of their eventual adult height

5. The Brain • Cerebral cortexcovers the forebrain like a wrinkled cap • Two halves, or hemispheres, based on ridges and valleys in the cortex • Lateralization -- specialization of function in one hemisphere or the other • Example: Spatial ability

6. Neuron • Parts of the neuron • Axon carries signals away from the cell body • Dendrites carry signals toward it • Myelin sheath -- a layer of fat cells -- provides insulation and helps electrical signals travel faster down the axon • At the end of the axon are terminal buttons, which release chemicals called neurotransmitters into synapses • Synapses -- tiny gaps between neurons' fibers • Transient exuberance

7. Changes in Neurons • The infant’s brain is literally waiting for experiences to determine how connections are made • Experience enhances brain development • Experience-expectant brain growth • Examples: Maturation, eating, sensory • Experience-dependent brain growth • Examples: Language, siblings, parent interaction

9. Changes in Regions of the Brain • Both heredity and environment influence synaptic overproduction and subsequent retraction • Pruning -- unused connections are replaced by other pathways or disappear • Prefrontal cortex -- the area of the brain where higher-level thinking and self-regulation occur

10. Sleep • Considerable individual variation in how much infants sleep • typical newborn sleeps 16 to 17 hours a day • preferred times and patterns of sleep also vary • Infants spend a greater amount of time in REM (rapid eye movement) sleep • by 3 months of age, the percentage of time in REM sleep decreases

11. SIDS • Sudden infant death syndrome (SIDS) -- condition that occurs when infants stop breathing, usually during the night, and die suddenly without an apparent cause • SIDS is the highest cause of infant death in the United States • Risk of SIDS is highest at 2 to 4 months of age

12. Risk Factors for SIDS • SIDS decreases when infants sleep on their backs • More common in low birth weight infants • Infants who are passively exposed to cigarette smoke are at higher risk • More frequent in infants who sleep in soft bedding or use a pacifier when they go to sleep

13. Benefits of Breast Feeding • Appropriate weight gain and lowered risk of childhood obesity • Fewer allergies • Prevention or reduction of diarrhea, respiratory infections, bacterial and urinary tract infections, and otitis media • Denser bones in childhood and adulthood • Reduced childhood cancer and reduced incidence of breast cancer in mothers and their female offspring • Lower incidence of SIDS • When should a mother not breast feed ?

14. Nutritional Needs • Nutritionists recommend that infants consume approximately 50 calories per day for each pound they weigh • This is more than twice an adult’s requirement per pound • Many U.S. parents are feeding their 4- to 24-month-old babies too few fruits and vegetables, and too much junk food

15. Reflexes • Reflexes -- built-in reactions to stimuli – automatic, involuntary • Allow infants to respond adaptively to their environment • Examples: Rooting and sucking, Moro or startle reflex, coughing, sneezing, blinking, shivering, and yawning

16. Gross Motor Skills • Skills that involve large-muscle activities • Sitting with support -- 2 months • Sitting upright without support -- 6 to 7 months of age • Pull themselves up and hold on to a chair -- 8 months • Stand alone – 10 to 12 months

18. Gross Motor Development in the Second Year • Toddlers become more mobile • 13–18 months • can pull a toy attached to a string • use their hands and legs to climb up a number of steps • 18–24 months • toddlers can walk quickly or run stiffly • walk backwards without losing their balance • stand and kick a ball without falling and stand and throw a ball • jump in place

19. Fine Motor Skills • Finely tuned movements • anything that requires finger dexterity • At birth, infants have very little control over fine motor skills • During the first two years of life, infants refine how they reach and grasp • Perceptual-motor coupling is necessary for the infant to coordinate grasping • Experience plays a role in reaching and grasping

20. Sensory and Perceptual Development • Sensation occurs when information interacts with sensory receptors -- the eyes, ears, tongue, nostrils, and skin • Example: Everything… • Perception is the interpretation of what is sensed • Example: Mommy, foods, HOT!

21. Studying the Infant’s Perception • Visual Preference Method -- Infants look at different things for different lengths of time • Orienting response -- to determine if an infant can see or hear a stimulus • Habituation -- decreased responsiveness to a stimulus after repeated presentations of the stimulus • Examples: Pacifier, holding hands, football game? • Dishabituation -- is the recovery of a habituated response after a change in stimulation • Example: sleeping in the car…

23. Visual Acuity and Color    • Newborn’s vision is estimated to be 20/600 on the well-known Snellan eye examination chart • By 6 months of age -- vision is 20/40 or better • By about the first birthday, the infant’s vision approximates that of an adult • By 8 weeks, possibly even by 4 weeks, infants can discriminate among some colors • (Banks & Salapatek, 1983; Aslin & Lathrop, 2008)

24. Perception of Pattern and Depth • Infants prefer to look at a normal human face rather than one with scrambled features • Can babies detect attractiveness? • They prefer to look at a bull’s-eye target or black-and-white stripes rather than a plain circle • Depthperception -- visual cliff • Infants develop the ability to use binocular (two-eyed) cues to depth by about 3 to 4 months of age (Gibson & Walk, 1960)

25. Hearing, Touch, and Pain • Prenatally at 7 months, infants can hear sounds such as mother’s voice and music • Immediately after birth, infants cannot hear soft sounds or pitch as well as adults do • Newborns respond to touch and feel pain • Infants also display amazing resiliency • Within several minutes after the circumcision surgery (which is performed without anesthesia), they can nurse and interact in a normal manner with their mothers

26. Smell and Taste • Newborns can differentiate among odors • Example: Mom vs. Dad • Sensitivity to taste might be present even before birth • At only 2 hours of age, babies made different facial expressions when they tasted sweet, sour, and bitter solutions • At about 4 months of age, infants begin to prefer salty tastes, which as newborns they had found to be aversive (Windle, 1940; Rosenstein & Oster, 1988; Harris, Thomas, & Booth, 1990)

27. Piaget’s Theory of Cognitive Development • Piaget thought we build mental structures that help us to adapt to the world • Adaptation involves adjusting to new environmental demands

28. Processes of Development • Developing brain creates schemes, which are actions or mental representations that organize knowledge • Assimilation -- children use their existing schemes to deal with new information or experiences • Examples: Banging, chewing, dropping, hot dirt, parties • Accommodation -- children adjust their schemes to take new information and experiences into account • Examples: no cats!, get splashed • Examples: Juice, in the hoop, “Bye, Bye” (Lamb, Bornstein, & Teti, 2002)

29. Equilibrium and Disequilibrium • Cognitive conflict -- disequilibrium • the child is constantly faced with inconsistencies and counterexamples to existing schemes • An internal search for equilibrium creates motivation for change • the child assimilates and accommodates, develops new schemes, and organizes and reorganizes old and new schemes

30. Sensorimotor Stage • Sensorimotor intelligence: From birth to 2 years: infants construct an understanding of the world by coordinating sensory experiences (such as seeing and hearing) with physical actions

31. Cognitive Development • Sensorimotor stage • Primary circular reactions • Stage 1: Stage of reflexes • Examples: Sucking, arms up! • Stage 2: First acquired adaptation • Examples: Bottle vs. pacifier, crying

32. Sensorimotor Stage • Secondary circular reactions • Stage 3: Make interesting events last • Examples: Rattle on table, bouncing, Peek-a-boo, ripping paper • Stage 4: New adaptation and anticipation or “The means to the end” • Examples: The “drop game,” books, Exersaucer, feeding Mommy, size • Objectpermanence • Examples: Mommy, keys, which hand?

33. Object Permanence • One of the infant’s most important accomplishments • Watch an infant’s reaction when an interesting object disappears. If the infant searches for the object, it is inferred that the baby knows it continues to exist • A-not-Berror is the term used to describe the tendency of infants to reach where an object was located earlier rather than where the object was last hidden

34. Sensorimotor Stage • Tertiary circular reactions • Stage 5: New means through active experimentation • Example: Cabinet, water • Little scientist • Examples: Beans, vacuum • Stage 6: Mental representations • Example: Little cowboy…, bandaid • Deferred imitation • Examples: DVD, spanking • Make-believe play • Examples: Dolls, trucks, “Sip…” “Bite…”

35. Learning, Remembering, and Conceptualizing • Infants can learn through operant conditioning • Examples: Reading a book, building a castle, using signs • Attention is the focusing of mental resources on select information and improves cognitive processing on many tasks • Joint attention involves individuals focusing on the same object or event and involves: • The ability to track another’s behavior • One person directing another’s attention • Reciprocal interaction

36. Learning, Remembering, and Conceptualizing • Meltzoff (2007) concludes that infants don’t blindly imitate everything they see and often make creative errors • He argues that beginning at birth there is an interplay between learning by observing and learning by doing • Critics say the newborns simply engage in automatic responses to a stimulus

37. Learning, Remembering, and Conceptualizing • Memory involves the retention of information over time • Some infants as young as 2 to 6 months can remember some experiences through 1½ to 2 years of age • Implicit memory refers to memory without conscious recollection • Explicit memory refers to conscious memory of facts and experiences • Infantile or childhood amnesia -- few memories before age 3

38. Language Development • Language -- a form of communication—whether spoken, written, or signed—that is based on a system of symbols • All human languages have some common characteristics • Rules describe the way the language works • Infinite generativity -- the ability to produce an endless number of meaningful sentences using a finite set of words and rules (Berko Gleason, 2009)

39. Key Milestones in Language Development • Babies' sounds and gestures go through this sequence during the first year • Crying: can signal distress, but there are different types of cries that signal different things • Cooing: about 1 to 2 months, gurgling sounds that are made in the back of the throat and usually express pleasure during interaction with the caregiver • Babbling: In the middle of the first year, babies babble -- strings of consonant-vowel combinations, such as “ba, ba, ba, ba” • Gestures: Infants start using gestures, such as showing and pointing, at about 8 to 12 months of age • Example: simple signs (operant conditioning)

40. Recognizing Language Sounds • First words occur between 10 to 15 months (average is 13 months) • Overextension -- the tendency to apply a word to objects that are inappropriate for the word’s meaning • Underextension -- the tendency to apply a word too narrowly • Examples: Duck, Shoes, Train

41. Two-Word Utterances • Occurs by the time children are 18 to 24 months of age • “Big ball” • “Where cat?” • Telegraphic speech is the use of short, precise words without grammatical markers such as articles, auxiliary verbs, and other connectives • “Mommy hold you” • “No mo’ monkey jump bed…”

42. Biological Influences • The ability to use language requires vocal apparatus as well as nervous system capabilities • Brain regions predisposed for language • Broca’s area -- an area in the left frontal lobe of the brain involved in producing words • Wernicke’s area -- a region of the brain’s left hemisphere involved in language comprehension • Aphasia -- a loss or impairment of language processing as a result of damage to brain

44. Biological Influences • Language Acquisition Device (LAD) -- Humans are biologically prewired to learn language at a certain time and in a certain way and to detect the various features and rules of language

45. Environmental Influences • Behaviorists opposed Chomsky's LAD hypothesis • Stated that language was nothing more than chains of responses acquired through reinforcement • The behavioral view is no longer considered a viable explanation of how children acquire language • Example: Not all imitation: “I runded…” • Language is not learned in a social vacuum • Most children learn at a very early age

46. Environmental Influences • Vocabulary development is linked to the family’s socioeconomic status and the type of talk that parents direct to the child • Compared to professional parents, parents on welfare: • Talked much less to young children • Talked less about past events • Provided less elaboration • Child-directed speech is language spoken in a higher pitch than normal, using simple words and sentences • Other strategies include recasting, expanding, labeling