Hemispheric Lateralisation

Question 1

What is hemispheric lateralization?

Answer 1

when certain brain functions are found only in one hemisphere

Question 2

What does the left hemisphere focus on?

Answer 2

focuses on detail and will be more active on tasks where an individual is asked to identify small details

(e.g. reasoning, maths/science, written language)

Question 3

What does the right hemisphere focus on?

Answer 3

processes overall patterns and shows more activity when individuals are asked to make sense of

(e.g. spatial relationships, recognizing things, emotional intelligence)

Question 4

What percentage of right/left handers have left hemispheric dominance for language?

Answer 4

90% of right handers and 70% left handers

Question 5

What research did Heller and Levy do in 1981?

Answer 5

found that P’s who were shown a split photo (half smiling/half neutral) would recognize the emotion shown on the left side of the picture

Question 6

Where is the Broca’s area located?

Answer 6

in the posterior portion of the frontal lobe of the left hemisphere.

Question 7

What does the Broca’s area do?

Answer 7

produces speech

Question 8

What did the psychologist Broca find about P’s with lesions in their left frontal hemisphere?

Answer 8

That they could understand language but could not speak or write where as P’s with damage in these areas in the right hemisphere did not have the same language problem

Question 9

What is it called when you have problems producing language?

Answer 9

non-fluent aphasia

Question 10

Give an example of a Broca’s area case study

Answer 10

Sarah Scott

Question 11

What is Globial aphasia

Answer 11

cant produce language or understand language

damage to both Broca’s and Wernike’s area may lead to this

Question 12

Where is the Wernicke’s Area?

Answer 12

in the posterior portion of the left temporal lobe

Question 13

What happened to P’s who had lesions in the Wernike’s area?

Answer 13

P’s could speak but were unable to understand language. This is called Wernike’s (fluent) aphasia

Question 14

What did Wernike propose?

Answer 14

That language involves separate motor sensory regions located in different cortical regions.

Question 15

How is the motor region involved with production of speech?

Answer 15

(located in Broca’s area) is close to the area that controls the mouth, tongue and vocal cords and hence is involves in speech production

Question 16

How is the sensory region involved with speech perception?

Answer 16

(located in the Wernike’s area) is close to regions of the brain responsible for auditory and visual input.

Input from these regions is thought to be transferred to Wernike’s area where is is recognized as language and associated with meaning

Question 17

What is the arcuata fasciculus?

Answer 17

a neural loop allowing the Broca’s and Wernike@s area to work together to process and produce language.

Question 18

What are the strengths of hemispheric laterlisation/localisation (supporting research)?

Answer 18

• there is research support from human clinical cases studies of the loss of specific abilities after restricted brain damage
• e.g. receptive aphasisa following damage to the Wernike’s area and amnesia following damage to specific areas of the hippocampus
• This suggests that some functioning of the brain are localized in part

Question 19

What are the strengths of hemispheric laterlisation/localisation (application)?

Answer 19

• Research into brain lateralisation and localisation has led to useful practical applications
• Knowledge about the role played by particular brain areas has helped tailor rehabilitation programs to stimulate adjacent areas to help restore function caused by damage
• e.g. sarah scott (then and now)

Question 20

What are the weaknesses of hemispheric laterlisation/localisation (case study)?

Answer 20

• much of the research into Wernike’s and Broca’s area comes from case study evidence
• these studies involves individuals and investigate the effect of damage to the brain on their cognitive functioning
• however, these effects may be specific to the one P and may bot be generalized to others. This is particularly true as the laterlisation of language areas to the left hemisphere isn’t universal

Question 21

What are the weaknesses of hemispheric laterlisation/localisation (holistic theory)

Answer 21

• the holistic theory of brain functioning argues that localisation is largely incorrect
• Lashley’s research on rats supports the concept of equipotentiality of the cortex and suggests that very few functions of the brain are completely localised
• it may be the case that simpler functions are likely to be more localised in the brain