BRAIN & PERCEPTUAL DEVELOPMENT

1. Feldman Modules 3-2 & 3-3 Santrock Chapters 3 & 4 BRAIN & PERCEPTUAL DEVELOPMENT

2. At birth, the brain is at about 30% of it’s adult weight. At age 2, the brain is at about 70% of its adult weight. Brain reaches 90% of adult weight by age 6 Brain Development

3. Prenatal : neurogenesis – 2nd trimester, fetal period Post Natal (after birth) (cycle) Synaptogenesis – dendrite formation Synaptic pruning Myelination Brain Development

4. Synaptic Transmission

5. The human brain has 100 – 200 billion neurons at birth. During the first two years, fibers from these form synaptic connections at a rapid rate and some neurons die as a result. Brain Development - Synaptogenesis

6. Experience determines brain development. Neurons not stimulated lose their synaptic connections. Neurons often stimulated strengthen connections by growth of new dendrites Brain Development – Synaptic Pruning

7. Brain Development – Glial Cells and Myelination Glial cells multiply rapidly during the first two years. (About half the brain’s volume) Glial cells produce myelin to coat neuron axons. Myelination improves the efficiency of neural transmission.

8. The order in which cortical regions develop corresponds to the order in which capacities emerge in the growing child. Cerebral Cortex

9. In the first year, there is a burst of synaptic growth in the auditory and visual areas. Areas supporting language show dramatic growth during toddlerhood. One of the last regions to develop are the frontal lobes. Cerebral Cortex

10. Rapid frontal lobe growth at ages 3-6 Myelination of cerebellum-cortex links, reticular formation, corpus callosum Brain Development

11. Specialization of functions in the two hemispheres of the cortex is called lateralization. For most people, language, logic and positive emotion are processed by the left hemisphere. Spatial and wholistic tasks and negative emotions are right hemisphere. Lateralization is very plastic. Cerebral Cortex – Lateralization & Plasticity

12. Brain growth spurts, as measured by weight, size and EEG, occur: 3 to 4- months – reach for objects 8 months – crawl, search for objects 12 months – walk 1.5 -2 years – talk Ages 9, 12, 15, 18-20 Brain Development – Sensitive Periods

13. Results in deficits in: Concentration Attention Anger and other impulse control Brain Development - Understimulation

14. Does not result in geniuses. May cause infant withdrawal. May lead to disappointed parents. May cause strain between infants and parents. Brain Development - Overstimulation

15. Reward and pleasure centers (limbic system) mature before judgment centers (pre-frontal cortex) do. Baird & others (1999) found that 10-18 year olds process emotional information using the amygdala, 20-40 year olds use the frontal lobe. Brain Development in Adolescence

16. Production of new neurons throughout life Growing new dendrites through the 70’s Brains rewire themselves – functional plasticity Myelination between cortex & limbic system in 40’s & 50’s Decrease in lateralization Brain Changes in Adulthood

17. Early-life idea density at 22 linked to fewer incidences of mild cognitive impairment Positive emotions linked to longevity Teachers showed more moderate intellectual declines Sisters with high folic acid levels showed little Alzheimer-like damage Mankato Nun Study

18. Normal age related cell death in the brain does not lead to loss of ability to engage in everyday activities. Dementia: a set of disorders occurring almost entirely in old age and leading to impairment of many aspects of thought and behavior Mental Disabilities in Older Adulthood

19. Alzheimers: most common form • Close to 50% of people over age 80 are affected • Starts with memory loss, faulty judgment, anxiety, aggressive outbursts, reduced initiative, social withdrawal, depression Later purposeful movement may degenerate, may lose speech, lapse into a coma Dementias

20. Neurofibrillary tangles: twisted threads from collapsed neural structures Amyloid plaques: deposits of deteriorated protein surrounded by clumps of dead nerve cells Lowered levels of acetylcholine and serotonin (Drugs limiting acetylcholine breakdown reduce dementia symptoms.) Alzheimer

21. Familial: early onset, rapid progress • Genes on chromosomes 1, 14, and 21 • Dominant • Related to Down syndrome • Sporadic: no obvious family history • Abnormal gene on chromosome 19 • leads to excess ApoE4 blood protein that carries cholesterol and is linked to amyloid formation • Some have no known genetic markers Alzheimer Risk Factors

22. Toxic substances Viruses Defects in the blood-brain barrier Vitamin and mineral deficiencies Excess dietary fat Cardiovascular disease Head injury Elevated aluminum levels Alzheimer Risks

23. Vitamin C and E Anti-inflammatory drugs (aspirin, ibuprofen) Education Active lifestyle Protective Factors

24. 5 to 10% of cases Series of small strokes leaves areas of dead brain cells Risks include high blood pressure, cardiovascular disease, diabetes Also smoking , heavy alcohol use, high salt intake, very low dietary protein, obesity, inactivity, and stress In most cases caused by atherosclerosis Cerebrovascular Dementia

25. Subcortical dementia Involves dopamine-producing neurons in the substantia nigra of the brain Symptoms include muscle tremors, slowed movements, and partial facial paralysis Drug treatment is partially successful Parkinson Disease

26. Depression Prescription drugs Surgery Environmental changes Social isolation Reversible Dementia

27. Sensation is detection Perception is organization & interpretation Sensory & Perceptual Development

28. The Newborn – Sensory Capacity Newborns are sensitive to touch and to pain. Facial expressions show that they distinguish sweet, sour and bitter. Newborns like the smell of bananas, vanilla,strawberry& chocolate, but dislike rotten eggs & fish. 6-day olds (but not 2-day olds) prefer the smell of their mother’s breast pad Infants prefer the sounds of human speech, recognize mom’s voice. Vision is the least developed sense at birth.

29. The fetus can hear even before birth. • DeCasper & Spence, 1986 – Cat in the Hat research • Newborns need more volume, are less pitch sensitive, not as good at sound localization, and have auditory preferences Hearing – Prenatal & Infant

30. Newborns like the smell of banana, vanilla, & strawberry & dislike the smell of rotten eggs & fish. 6-day olds (but not 2-day olds) prefer the smell of their mother’s breast pad Smell - Infant

31. Research adding saccharin to amniotic fluid showed greater swallow & potential taste sensitivity in fetuses At 2 hours of age, babies make different faces to sweet, sour, salty & bitter Taste - Infant

32. Vision Birth, vision is 20/400 – 20/600 1 year – 20/20 visual acuity By 2 months can focus on objects and discriminate colors as well as adults Eye movements also under control for scanning and tracking

33. 2-3 months – sensitive to binocular cues 6-7 months sensitive to pictorial (monocular) depth cues Crawling promotes 3-dimensional understanding (affordance of falling) Depth Perception

34. The Visual Cliff

35. The Ecological View (Gibson) The purpose of perception is for us to adapt to and interact with the environment. All objects have affordances or opportunities for interaction that fit with out abilities to perform activities. Sensory & Perceptual Development

36. Visual preference – length of time the infant looks; reflection in the eyes; Franz looking chamber • Habituation & dishabituation • Decreased responsiveness (looking, sucking, heartrate, respiration) • Orienting & tracking • Turning head or tracking with eyes • Equipment • videotape, computer, recording heart rate, etc. Sensory & Perceptual Development – Research Methods

37. Pattern Perception Newborns prefer patterned to plain stimuli As infants develop contrast sensitivity they prefer more complex patterns. Infants first respond to parts of a pattern, then to the whole pattern. • By 12 months, they have the perceptual property of closure.

38. Face Perception Newborns prefer simple drawings of faces with features arranged naturally. 2-5 months they prefer a complex face to other complex patterns 2 months, look longer at mother’s face 3 months, discriminate photos of two strangers

39. Size constancy ( 3 mos. – 11 years) Shape constancy ( 3 mos.) By 12 months, perceptual property of closure Infants – Perceptual Constancy

40. Differentiation Theory Infants look for stable or invariant features of the environment Over time, the baby differentiates or detects finer and finer stable features Some theorists believe that in some sense, the infants impose meaning on the patterns that they perceive.

41. Infants form expectations about what they are going to see as early as 3 months • Spelke • at 4 months infants recognize the solidity & continuity of objects • At 6-8 months, (but not 4), they perceive gravity & support Visual Expectations

42. 4. Possible outcome: Screen drops, revealing one object. 1. Objects placed in case. 2. Screen comes up. 3. One object is removed. 4. Possible outcome: Screen drops, revealing two object. Perceptual/Cognitive Development • Baby Mathematics • Shown a numerically impossible outcome, infants stare longer (Wynn, 1992)

43. All of the sensory systems with the possible exception of touch experience gradual decline as a person ages. • Vision • Hearing • Taste • Smell Senses in Adulthood

44. Middle Adulthood • Presbyopia, loss of accommodation (ability to adjust focus at different distances) between ages 40 and 59 • 50’s & 60’s – blood supply to eye declines, need more light, smaller visual field Vision in Adulthood

45. Late Adulthood • Dark adaptation is more difficult • Glare sensitivity increases • Continuation of degeneration of function from Middle Adulthood • Possible retinal degeneration Vision in Adulthood

46. Cataracts – 30% of people by age 70 Glaucoma – pressure from fluid buildup in the eye damages the optic nerve; 1% in 70’s, 10% in 90’s; treated with eye drops Macular degeneration – deterioration of retina; 1 in 6 people 75+; leading cause of blindness in older adults Diseases of the Eye

47. Ability to taste appears to start decline in the 60’s, leading to a preference for spicy and junk food Older adults (60 +) lose some of their sense of smell and may enjoy food less Taste & Smell