Psychology 361 -- Chapter 5: What to study

p. 164: define cerebral cortex; Why might professors not want to discuss the findings illustrated in Figure 5.2 with their college-age students? This figure also shows that men's brains are larger than women's; as noted, this is mainly because of larger male body size. However, the claim that these size differences are unrelated to IQ is controversial.

p. 168-169: neuron, neural proliferation, glial cells, neural migration, synapse, dendrite, axon, synaptogenesis, neuronal death, synaptic pruning.

p. 168: You aren't responsible for exact numbers, but note the incredibly large number of neurons and how fast they are being formed. Note that most neurons are formed before 7 months of gestation; the text cites data suggesting some capacity for neural generation or regeneration later, but at best this is very limited. The result is that major disruptions to neural proliferation or migration, as occurs with some teratogens like alcohol, have permanent effects. The book isn't quite clear that there are three processes: neural proliferation, neural migration, and synaptogenesis in that order.

p. 168: note the incredible number of synapses per neuron.  p. 169: What are the functions of neuronal death and synaptic pruning? (Efficiency and specialization) Check out Figure 5-6 and discussion of neural pruning.

p. 170 bottom: Note that there are links between synaptic connections and newly acquired brain functions. The big story of child development is the development of the brain. Example: voluntary motor movements linked with development in the motor cortex.

p. 171: define the bold-faced terms. Be able to give summaries of the differences in brain function between right and left hemispheres. A basic difference is in verbal versus spatial functions.

p. 171: Note emotional lateralization: see Figure 5-7 and text discussion. When we discuss personality, I will link personality systems to this figure.

p. 171: What deficits typically occur as a result of damage to the left hemisphere? What hemisphere processes language among people who use sign language?

p. 172: Note the sensitive period for the effects of brain damage: Age when the damage occurs is of critical importance. However, even adults can achieve partial recovery.

p. 173: What is dyslexia? What were the results of the Kraus (1996) study?
What is the lateralization theory of reading difficulties (i.e., Baringa, 1996; Witelson, 1983)?

p. 174: The brain's plasticity: The first sentence is a non sequitur: Just because the brain is developing rapidly does not imply that genes alone are not responsible for neural connections.

Define Plasticity and Experience-expectant processes.

p. 174: Re experience-expectant processes, note Riesen's study of rearing Chimpanzees in darkness: Did they recover their eyesight when placed in lighted conditions? This study shows that even though some systems may be open to change by altering later environments, other systems are not open to change--a true critical period phenomenon because age when placed in the dark is critical to the results. Placing an adult in a dark environment for a similar period would not have any effect on their retinas.

p. 174: Define Experience-dependent processes. Know the basic results of the Rosenzweig research both on weight of brain regions and on brain biochemistry. Note the similar findings in a human who was blind, deaf and mute. What is an enriched environment in these studies?
 

p. 175: What were the results of Black and Greenough (1998) on the effects of enriched environments for older animals? Note that the effects are not as strong as in younger animals--a sensitive period phenomenon.

p. 175: What were the results of Kuhl et al. (1997)? Why is this is another example of a critical or sensitive period phenomenon? What is an auditory map?

p. 175-176: What are the results of child abuse on the brain (Perry, 1997)? Note the differences between stimulated and unstimulated brain in Figure 5-8 on p. 177.

p. 186: Define cephalocaudal and proximal-distal development. Note that being tall is an advantage in life.

p. 187: Note that the CAP data indicate 2/3 of the variation in height and weight result from people having different genes.

pp. 187-188: What are the developmental gender differences in height? (See Figure 5-11 and photo on p. 188.)
p. 188: Summarize the results of the Bradley et al. (1994) study.
p. 188: What is relation between height and social class in the U.S.? Realize that these results are compatible with most of the variation being the result of genetic differences (see p. 187). The huge differences in height of different peoples around the world mentioned on p. 188 is also influenced genetically.
 

p. 191: Notice that nutritional supplements, particularly those directed at iron-deficiency anemia, had positive effects on physical and cognitive development in the U.S.
p. 191: What is catch up growth? Note the quote from Tanner (1970).
What did Graham (1966) and Stroch  et al., 1982 find? The point is that the severity of the deficit is critical--another example of a critical or sensitive period phenomenon. But as the last paragraph on p. 191 shows, timing is also important--the sensitive or critical period idea.

p. 192: define secular trend. What are the secular trends in height and weight? (see Figure 5-12). There are similar secular trends in age of menarche--girls getting their first menstrual period sooner and sooner (see Figure 5-17 on p. 203). Note that most people in developed countries are achieving their maximum growth. We live in a golden age. What does the fact that the great majority of people have adequate nutrition to achieve theirr maximum height mean for the heritability of height? (This relates to the concept of heritability in Chapter 2.)

p. 192: Obviously better nutrition is partly responsible for these secular trends, but note also that better health is also a factor. Childhood diseases often retard growth. p. 192-193: Another factor is genetic: marriage of people from different regions results in 'hybrid vigor' as a result of increase in genetic heterozygosity. (Heterozygosity is defined in Chapter 3).

p. 199: What are anorexia nervosa and bulimia nervosa? p. 200: What are the psychological correlates of these disorders? (depression for both, obsessive-compulsive for anorexia, poor self-image for bulemia. (Note photo on p. 199.)

p. 201 : Define pituitary gland, hormones, spermache, menarche, secondary sex characteristic and primary sex characteristic, testosterone, estrogen.

p. 202-203: The secular trend in age of menarche is slowing down among middle class girls in the U.S. and has stopped in Denmark, but some data show that African-American girls continue to show this effect, entering menarche at age 8-9. Note the very high age of menarche in undeveloped countries like New Guinea. Nevertheless, sexual maturation is not the same as sexual attraction; as the text notes on p. 203, children begin to have sexual attraction around age 10, 4 years after a surge in the hormone DHEA, an androgen. (Note: There is no evidence that girls' brains mature any faster than previously. Therefore the huge social difference brought about by better nutrition and health care in modern times: A great many girls who are reproductively mature but not cognitively mature.)

pp. 203: Genetic variation influences age of menarche, but certainly environmental factors like nutrition and health care are also important. What are the effects of intense exercise on menarche? What does amenorrheic mean? What are the correlates of menarche with parent-child relationships (Steinberg 1987; Moffit et al, 1992). Note that a 'genetic inheritance model' might equally well explain the data. What are the correlates of early maturation in girls on divorce and child bearing?

p. 204: Is it advantageous for boys to hit puberty relatively early? What were the results of Duke (1982)? Do his findings surprise you?

pp. 205: Is it advantageous for girls to hit puberty relatively early? How is this explained?  This explanation in terms of violating cultural standards of thinness strikes me as a bit ad hoc. These results should also be integrated with the findings on p. 203, where it was noted that poor family relationships predicts early menarche and that early menarche is genetically influenced. Here we see more data on correlates of menarche and parent-child conflict. Notice that early maturers engage in adult behavior sooner (Surprise!!), including sex, child bearing, smoking, drinking, etc.)

Figure 5-18 shows the very different patterns for boys and girls.

206: Why do you think that going to junior high after the sixth grade is a problem compared to going to high school after the 8th grade? How does changing school affect adjustment for early maturing girls (Simmons and Blyth, 1987)?

pp. 206-207: Development of gay and lesbian identity: What biological causes are mentioned? Environmental factors include distance from same-sex parent. Note boys who have a lot of older brothers tend to be gay. Note many some children express doubts about their heterosexuality by the fourth grade, but it may be much later. These children have less interest in stereotypically activities of their own gender than other children.