Chapter 11 - Study Guide Cerebral Asymmetry

Question 1

What does “laterality is relative, not absolute” mean

Answer 1

although one side can be more important in a function, the other hemisphere is still involved

Question 2

What does “cerebral site is as important as cerebral side” mean

Answer 2

cortical functions are partially localized and the hemisphere side is just one feature of the localization, the site is just as important

Question 4

What does “laterality is influenced by environmental and genetic factors” mean

Answer 4

for example, females and left handers appear to be less asymmetric than right handers and males

Question 5

what does “laterality is exhibited by a large range of animals” mean

Answer 5

originally thought asymmetry was related to language and human specific, now certain animals also show asymmetry

Question 6

What is double dissociation

Answer 6

two related processes are shown to be functionally independent
damage to one brain area affects one function but no the other and vice versa
LH lesions produce deficits in language that are not produced by RH lesions.
Performing spatial tasks are disrupted by RH lesions, but not LH.
Bc RH lesions disturb tasks not disrupted by LH and vise versa, two hemispheres are doubly dissociated

Question 7

How does anatomy show asymmetry and provide examples

Answer 7

1. RH larger and heavier
2. asymmetry of L and R temporal lobe in language and music
3. left dominant for language in thalamus
4. lateral fissure slope gentler in LH
5. Broca’s area organized diff
6. nts distribution asymmetrical
7. RH futher anterior and LH posterior
8. thicker cortex in LH, larger SA in RH

Question 8

How does neurological patients show asymmetry and provide examples

Question 9

How does commissurotomy show asymmetry and provide examples

Answer 9

isolation between hemispheres show specialization
patient N.G shown spoon to left visual field, cannot verbally identify because RH lacks language but can still select object by touch
RH specialized for faces, will choose photo shown to left visual field

Question 10

How does brain stimulation show asymmetry and provide examples

Answer 10

use of electrical stimulation to block or activate areas of the brain
stimulation of LH can block ability to speak where in RH does not do so
R temporal lobe stimulation, produce deja vu and emotional responses, doesnt occur in LH
symmetry in motor and sensory, from both hemispheres

Question 11

How does sodium amytal show asymmetry and provide examples

Answer 11

inject into right side, will put right side asleep
if injected into left, majority experience aphasia
speech typically unaffected in RH if injected

Question 12

How does blood flow and metabolic activity show asymmetry and provide examples

Answer 12

increased blood flow and metabolic activity in one hemisphere during a task represents specialization
language tasks, increased blood flow and activity to LH in broca’s and wernicke’s
RH more involved in emotional processing

Question 13

How does ERPs show asymmetry and provide examples

Answer 13

event-related potentials = electrical activity in response to stimuli/event
show differences in timing, location, amplitude
during face recognition, RH shows larger amplitudes

Question 14

What is lateralization

Answer 14

idea that certain cognitive functions are predominantly controlled or processed by one hemisphere of the brain more than the other

Question 15

What are the two categories of theories about lateralization in the brain

Answer 15

1. specialization theories
2. interaction theories

Question 16

What is the specialization theory in terms of lateralization of the brain

Answer 16

each hemisphere has unique functions and process different types of information to optimize brain efficiency

Question 17

What is the interaction theory in terms of lateralization of the brain

Answer 17

both hemispheres are capable of performing functions, and don’t function in isolation
cooperate and inhibit each other’s activity
LH supresses RH ability to process language, RH can take over if LH damaged

Question 18

Theoretically, what is lateralized

Answer 18

Language, verbal memory, language-related sounds, motor control tasks = LH
Spatial abilities, nonverbal memory, music, emotional = RH

Question 19

Why is the brain lateralized

Answer 19

increase efficiency and specialization
process information quicker, less interference, optimizing cognitive function

Question 20

There is a long history of left/right brain. What is the current status of this idea

Answer 20

interplay between both hemispheres, moving away from binary model toward holistic view of brain function and organization