Chapter 12

Question 1

What is the environmental theory of hand preference ?

Answer 1

• Utility of behaviors like a soldiers shield or a mother carrying her baby (holding and shielding)
• environment reinforces right hand-use
• left-handedness is the result of brain damage

Question 2

What is the anatomical theory of hand preference ?

Answer 2

• fundamental asymmetry bias to the left hemisphere

Question 3

What is the hormonal theory of hand preference ?

Answer 3

• testosterone inhibits the left hemisphere leading to left-handedness

Question 4

What is the genetic theory of hand preference ?

Answer 4

• dominant gene for right handers and recessive gene for left handers

Question 5

What do anatomical studies of hand preference show ?

Answer 5

1. Those with a speech-dominant left hemisphere have a 27° angle in their vessels from the Sylvia fissure, this angle is 0° in speech-dominant right hemisphere individuals
2. left handers have more speech lateralization
3. Left handers are less lateralized in their hand dominance
4. many mammals show left-side preference includes left-hemisphere

Question 6

What are the 2 kinds of left-handers ?

Answer 6

1. familial
   - unique patterns of asymmetry
2. non-familial
   - have the same asymmetry as right handers

Question 7

What are some observable sex differences in cerebral organization in children?

Answer 7

1. Girls and boys differ in toy preference
2. Tests on the level of testosterone show different behavior patterns in children

Question 8

What are two explanations for gender-preference toys ?

Answer 8

1. children will pick toys that they have seen other children of the same sex playing with
2. boys may prefer toys that can be moved in space while girls prefer toys with interactions like dolls

Question 9

What are some observable behavioral differences in male vs female adults?

Answer 9

1. Motor sills
   - males are better at throwing and catching
   - females are better at fine motor tasks
2. Spatial analysis
   - men are better with navigational skills
3. Math skills
   - Men can reason better
   - females compute better
4. Perception
   - females are better with perceptual skills
5. Verbal abilities
   - females are better with language skills

Question 10

What are 5 anatomical asymmetries from sex hormones ?

Answer 10

1. Wernicke’s area
   - asymmetry is more common in men
2. Sylvian fissure
   - longer in the left hemisphere in men
3. Planum parietale
   - twice as large in men
4. Interhemispheric connections
   - women have more
5. Fingerprints
   - asymmetry between hands is more common with women

Question 11

What are 6 possible explanations for sex differences?

Answer 11

1. Hormonal effects
2. Genetics
3. Maturation rate
4. Environment
5. Preferred cognitive model
6. Higher variability within the sexes than between the sexes

Question 12

What are some potential cultural influences on cerebral organization?

Answer 12

• asian languages using characters promote more right-hemisphere participation since they require more rhythmic patterns and spatial processing
• asian languages require more short-term verbal memory= larger temporal lobe in Chinese individuals