Infant Capacities and the Process of Change

1. Infant Capacities and the Process of Change The Development of Children (5th ed.) Cole, Cole & Lightfoot Chapter 4

2. What does this mean? “Babies control and bring up their families as much as they are controlled by them; in fact, we may say that the family brings up a baby by being brought up by him.” Erik Erikson in Childhood and Society

3. Why is this the case? Compared with many animals that are able to negotiate their environments at birth almost as well as their parents, human beings are born in a state of marked immaturity…. For many years, human offspring must depend on their parents and other adults for their survival.” Cole, Cole & Lightfoot, p. 114

4. Overview of the Journey • Brain development • Earliest capacities • Coordination with the social world • Mechanisms of development • First postnatal BSB shift

5. Brain Development Neurons and Neural Networks Experience and Development The CNS and the Brain

6. At birth, the brain has all the cells it will have, yet it is ¼ the size of an adult brain. Why? • Dendrite size and branching • Axon branching and myelination (speed)

7. Neural Networks in Postnatal Life

8. Experience and Development Synapticpruning Exuberant synapto-genesis

9. Rats Raised in Enriched Environments • Increased rates of learning in standard laboratory tasks, such as learning a maze • Increased overall weight of the cerebral cortex (the part of the brain that integrates sensory information) • Increased amounts of acetylcholinesterase, a brain enzyme that enhances learning • Larger neuronal cell bodies and glial cells (which provide insulation, support and nutrients to neuronal cells) • More synaptic connections Rosenzweig, 1984

10. Active Interaction with the Environment • Rats were raised with an enriched environment but were housed singly in small cages so that could do no more than observe what was going on around them • The learning capacity of these rats differed in no way from that of the animals that were housed in individual cages away from the enriched environment • What might this imply for child-rearing? For teaching?

11. Brain Elements and Functions

12. Six Mammalian Species Why the difference?

13. Cortex Development • Matures later than the lower-lying areas of the CNS, spinal cord, brain stem • Primary motor area • First area of the cortex to develop • Responsible for voluntary (nonreflexive) movement • Begins with raising head (1 month), control of arms and trunk (3 months); leg control is last to develop • Primary sensory areas • Begins with touch, then visual, then auditory • By 3 months, all primary sensory areas are relatively mature • Frontal cortex(e.g., planning, decision-making) • Begins to function in infancy but continues to develop throughout childhood

14. Earliest Capacities Sensory Processes Response Processes

15. Sensory Processes • Normal full-term newborns enter the world with all sensory systems functioning, but not all of these systems have developed to the same level due to different developmental rates (i.e., heterochrony) • Indications of sensation • Turning of the head, variation in brain waves, changes in rate of sucking on a nipple • Habituation: Becomes bored and stops attending • Dishabituation: Interest is renewed after the infant perceives a change in the stimulus

16. Hearing • Infants only minutes old will startle with a loud noise and may even cry • Will also turn their heads toward the source of a noise

17. Hearing • Infants can distinguish the sound of the human voice from other kinds of sounds, and seem to prefer it • Are particularly interested in speech with the high pitch and slow, exaggerated pronun-ciation (i.e., “baby talk”) • Evidence that by 2 days old, some babies would rather hear the language that has been spoken around them than a foreign language

18. Hearing Capacity At 2 months of age: • Present phoneme (e.g., /pa/) • Habituate (i.e., return to baseline sucking rate) • New phoneme(e.b., /ba/) • Dishabituate(i.e., sucking rate increases)

19. New Consonant • Both groups hear a consonant sound • Habituate • Experimental group hears a new consonant sound at time marked 0 • Infants are able to distinguish consonant sounds

20. Auditory Discrimination and Culture Infants can distinguish among language sounds that do not occur in their native language, but this capacity diminishes during the first year of life.

21. Infants’ Visual Capacity Based on studies of infant eye movement when a striped visual field passes in front of the eyes, it is evident that visual capacity increases dramatically over the first few months of life.

22. Fantz Looking Chamber (1960s) • Demonstrated that babies less than 2 days old can distinguish among visual forms • Tend, however, to focus on areas of high contrast, such as lines and angles

23. Development of Visual Scanning Due to brain maturation

24. Perception of Faces • Infants show a preference for patterned stimuli over plain stimuli • Babies as young as 9 minutes old will look longer at a schematic moving face than a scrambled one

25. Visual Preferences of Infants

26. Expressions of Various Tastes • Neutral stimulus (water) • Sweet stimulus • Sour stimulus • Bitter stimulus

27. Early Sensory Capacities

28. Response Processes • Reflexes • Automatic (involuntary) responses to specific types of stimulation… • Emotions • Two basic emotions, contentment (+) & distress (-), split into primary emotions (e.g., joy, anger, fear) at 3-6 months… • Temperament • Individual modes of responding to the environment that appear to be consistent across situations and stable over time…

29. Reflexes Present at Birth

30. Grasping Reflex • When a finger or some other object is pressed against the baby’s palm, the baby’s fingers close around it • Disappears in 3-4 months; replaced by voluntary grasping

31. Stepping Reflex • When the baby is held upright over a flat surface, he makes rhythmic leg movements • Disappears in first 2 months, but can be reinstated in special contexts (e.g., when partially submerged in water)

32. Infant Expression of Emotions Joy Anger Sadness Disgust Distress Interest Fear Surprise

33. Infant Expression of Emotions Joy Joy Anger Anger Sadness Sadness Disgust Disgust Distress Distress Interest Interest Fear Fear Surprise Surprise

34. Temperaments • Three broad categories • Easy babies: Playful, regular in their biological functions, adapt readily to new circumstances • Difficult babies: Irritable, irregular in their biological functions, often respond intensely and negatively to new situations or try to withdraw from them • Slow-to-warm-up babies: Low in activity level, responses are typically mild, tend to withdraw from new situations, require more time than easy babies to adapt to change • Moderate temperamental stability over first 8 years of childhood • Impact of both genetic and environmental components

35. Coordination with the Social World Sleeping Feeding Crying

36. Sleep Patterns in Infants NREM Sleep REM Sleep During first 2-3 months of life, infants begin their sleep with active (REM) sleep and then fall into quiet (NREM) sleep. Subsequently, the sequence reverses and shifts toward the adult pattern.

37. Pattern of Sleep/Wake Cycles Newborns sleep ~16½ hours /day, but the longest period of sleep is only 3-4 hours.

38. Feeding • When fed “on demand”, majority of newborns preferred a 3-hour schedule • Interval gradually increased to 4-hour schedule by 2 ½ months • By 7 or 8 months, 4x/day

39. Nursing Behavior Early feeding attempts are rather uncoordinated Infant’s nostrils are blocked while he/she is attempting to feed This elicits a head-withdrawal reflex that interferes with feeding Later attempts become much more coordinated resulting in nursing – an evidence of learning.

40. Crying • Increases from birth to about 6 weeks and then starts to decrease • At a few months of age, infants begin to cry voluntarily (“crying on purpose”) as the cerebral cortex becomes involved • Crying helped by nursing, holding baby to shoulder, rocking, patting, cuddling, swaddling (reduces over-stimulation from uncontrolled limb movements)

41. Mechanisms of Developmental Change Biological-Maturation Perspective Environmental-Learning Perspective Constructivist Perspective Cultural-Context Perspective

42. Mechanisms of Developmental Change Biological-MaturationPerspective

43. Reflex Coordination • Early, simple reflexes arise from the brain stem • More complex, coordinated reflexes result from the maturation of the cerebral cortex

44. Early Attention to Human Speech In 1-month-old baby born without a cerebral cortex • On first exposure to sound of human speech, there is a marked decrease in heart rate, indicating attention • After 5 additional presentations of the sound, the infant has habituated

45. Mechanisms of Developmental Change Environmental-LearningPerspective

46. Classical Conditioning • Sight of a light (CS) elicits no particular response • Loud sound of gong (UCS) causes baby to blink (UCR) • Sight of light (CS) is paired with sound of gong (UCS), which evokes an eyeblink (UCR) • Sight of light (CD) is sufficient to cause the baby to blink (CR), evidence that learning has occurred

47. Operant Conditioning • An organism will tend to repeat behaviors that lead to rewards and will tend to give up behaviors that fail to produce rewards or lead to punishment • Requirement: Behavior must occur before it can be reinforced

48. Operant Conditioning • After only 25 occasions on which the head turning was reinforced with the pacifier, most of the babies had tripled the rate at which they turned their heads. • Conversely, those infants who were rewarded with a pacifier for holding their heads still, learned to move their heads less during the course of the experiment.

49. Mechanisms of Developmental Change ConstructivistPerspective(Piaget)

50. Piaget’s Theory of Developmental Change via Schemas Assimilation(Incorporated into anexisting schema) Accommodation(Modification of aprior schema) Equilibration Leads to developmental stages…