Infancy

1. Infancy Chapter 4-6 Psyc311 Dr. Jen Wright

2. There are a lot of physical changes that happen during the first years of life, • The most important (and dramatic) of which is brain development.

3. One of the last organs to fully develop…

4. brain development • Largest brain/body mass of any animal. • Encephalization Quotient (EQ) = 7.4 • Dolphin = 5.3 • Chimp = 2.5 • Elephant = 1.9 • Whale = 1.8 • Most development happens outside (instead of inside) the womb • Monkey newborn 70% adult size • Human newborn 25% adult size • Most growth occurs in first 3 yrs • 3 yr old 80% adult size

6. brain development • Neurogenesis – proliferation of neurons through cell division • At peak, 250,000 cells “born” every minute • Synaptognesis – formation of connections • Each neuron forms thousands of connections • Axons elongate towards specific targets • Dendritic “tree” increases in size and complexity • 6 mos have 2 x more synaptic connections

7. Synaptic pruning – elimination of excess synapses • Streamlines neural processing • Without synaptic pruning, children wouldn't be able to walk, talk, or even see properly. • Myelination – insulating sheath • Happens at different rates into adolescence • Certain areas are myelinated first

10. importance of experience • Plasticity – brain’s ability to change w/ experience • Experience-expectant plasticity (experiences present throughout evolution) • Economizes on material encoded in genes • Development will occur within a normal range of environments • Level of vulnerability in timing • Sensitive periods

11. importance of experience • Experience-dependent plasticity (experiences of individual) • Brain sculpted by idiosyncratic experiences • Brain responsive to richness of stimuli • Important in development of expertise • More brain resources dedicated to processing • E.g. musicians’ cortical representation of hands

12. Gene/Environment Interaction Two levels of environmental influence: • Environment • Genes: Genotype • Genes: Phenotype

13. Effect of deprivation

15. Sleep and brain development • Infants sleep about 17 hours or more a day • Regular and ample sleep correlates with normal brain maturation, learning, emotional regulation, and psychological adjustment in school and within the family.

16. states of arousal • Arousal exists along a continuum from deep sleep to intense activity.

18. REM sleep – critical for neural development in brain, esp. for activity-dependent development • E.g. visual system • Facilitates learning/memory • Sleep deprivation linked with later problems • E.g. ADHD • Babies most at risk of disruption • Premature infants in IC units • Snoring

19. What is attachment? • Attachment refers to the close, emotional bond between an infant and his/her primary caregiver.

20. Early views of attachment • Psychoanalytic Theory (Freud) • Driven by oral needs during the first year • Emphasized early experiences on later outcomes • Behaviorist Perspective • Driven by the need for food • Learns to associate contact with mother with food • Mother’s closeness continually reinforced

21. Ethology • Rooted in Darwin’s Evolutionary Theory • Focused on the adaptive value of behavior • Bond necessary for survival • Lorenz (1952) - Imprinting

22. Primary criticism of these early perspectives • Love (i.e., attachment) seen as secondary to instinctive or survival needs • Harlow believed that the need for love and affection was necessary for survival

23. Harlow’s Monkeys (1958) • Early work with monkeys • Cloth & wire mother • Only one equipped with feeding apparatus • Monkeys randomly assigned • Observed for 5 months • Both groups preferred cloth mother

24. Infant monkey fed on cloth mother 24 . Infant monkey fed on wire mother . . . . . 18 . Hours per day spent with cloth mother . Contact Time with Wire and Cloth Surrogate Mothers 12 . Mean hours per day . 6 . . . . . . . . . . Hours per day spent with wire mother 0 1-5 11-15 21-25 6-10 16-20 Age (in days)

25. http://www.youtube.com/watch?v=hsA5Sec6dAI • http://www.youtube.com/watch?v=caM4-f6ZZBE&feature=related

26. John Bowlby • Observations of children in institutionalized care • Infant has built-in behaviors to keep parent close • Gives way to true affectionate bond • Serves 2 purposes • Secure base • Internal working model

27. Does attachment vary by individual? • Ainsworth (1979) • Developed Strange Situation • Work revealed 4 types of attachment behavior • Securely Attached • Insecure Avoidant • Insecure Resistant • Insecure Disorganized • http://www.youtube.com/watch?v=QTsewNrHUHU

30. mirror neurons • Found in the frontal and parietal lobes • Fire when you • engage in an activity (reaching out one’s hand) • observe someone else engaging in the same activity. • Fire more strongly when action has some purpose or content • reaching out one’s hand for a cup. • MN’s play a clear role in learning/imitation. • May also play a role in “mind-reading” • grasping intentions, goals, desires.

33. crying • Crying – infant form of communication • Response to distress • Development of emotional self-regulation • Mastery of environment – agency • Biofeedback loop • Soothing • Swaddling – tight wrapping of baby in cloth • Touch • Sweet taste • Soft, rhythmic sounds

34. When an infant’s needs are met, they are able to turn their focus to the world around them and explore. • Their brains take in and adapt to stimulation from the external world. • When they aren’t met, they become fixated on trying to get their needs met • They stop exploring and shut out other stimulation from the external world.

35. crying disorders • Colic (1 in 10 infants; birth – 12 weeks) • Extended periods of intense crying • Cause unknown • Immature nervous system • Hyper-sensitivity • Digestive problems • Prolonged crying (beyond 12 weeks) • Exhibit developmental and behavioral disorders

36. Prolonged crying expose the brain to high levels of cortisol, adrenaline, and other damaging chemicals. • Damage to hippocampus • Reduced levels of vasopressin and serotonin • Reduced levels of emotional regulation • Impaired memory • Increased levels of aggression/violence/bullying • Increased levels of anxiety disorders

37. stress and brain development • Exposure to excessive stress hormones is bad for brain development. • Early symptoms of PTSD • The brain can become incapable of producing normal stress responses. • Hyper-vigilance (Ghosts in the Nursery) • Emotional flatness • Physical/emotional abuse and neglect can be equally damaging.

38. emotional self-regulation Strategies learned for adjusting emotional state to a comfortable (adaptive) level of intensity in order to accomplish goals Infants: withdrawal, distress, need soothing 4 mos: can shift focus of attention 1 year: approach/retreat from stimulus

39. Parent response to distress important Sympathetic: child more easily soothed, more interested more self-regulated Non-responsive (wait to intervene): child enters into rapid, intense distress harder to soothe doesn’t develop self-regulation

40. emotions of others “emotional contagion”: babies match the emotional expressions of caregiver Still face experiment 7-10 mos: infants perceive facial expressions as organized patterns, can match facial expression to emotion 8-10 mos: social referencing- relying on another person’s emotional reaction to appraise situation (e.g.- visual cliff)

41. social referencing Example of how adults help child regulate emotion Permits toddlers to compare their assessments of situations with others Helps young children move beyond simply reacting to emotional messages

42. basic emotions Emotions that can be directly inferred from facial expressions happiness, interest surprise, fear, anger sadness, disgust Universal in humans and our primate ancestors • Long evolutionary history of adaptation • Important communicative function • Present in infancy

43. emotional expression Earliest emotions: global arousal states of attraction and withdrawal These basic states set the stage for further development Over time (6+ mos), these develop into well-organized, sustained signals (dynamic systems perspective)

45. emotions and cognition: bi-directional Emotional reactions Dynamic bidirectional interplay between emotion and cognition. • Lead to learning that is essential for survival • Influence how a situation is perceived, interpreted, and remembered. • Limbic system • amygdala/hippocampus link • Improve memory of event • Highlight issues of importance • Make things personally relevant

46. temperament • Constitutionally based individual differences in • Emotion • Motor function • Attentional reactivity • Self-regulation • Influences the way that children develop, display, and control emotions • Foundation for later personality

47. Temperament styles • Types • Easy • Difficult • “Slow to warm up” • Differences in punishment/reward • Differences in sociability • Bi-directional issues • Gender • Cultural differences • Goodness of fit (with parents/environment)

50. Gene/environment interactions • Passive genotype-environment correlation. • Evocative genotype-environment correlation. • Each child’s genes elicit other people’s responses, and these responses shape development. • In other words, a child’s environment is partly the result of his or her genes. • Active genotype-environment correlation. • Children, adolescents, and especially adults choose environments that are compatible with their genes (called niche-picking), • thus genetic influences in adulthood increase.