Lateralisation and Split-Brain research

Question 1

What is the aim of split brain research

Answer 1

To investigate the effects of brain lateralistion

Question 2

What is brain lateralisation

Answer 2

Brain lateralization refers to the fact that the two halves of the human brain are not exactly alike, with each hemisphere having functional specializations, for example, research has found that the left hemisphere is dominant for language and speech, whereas the right excels at visual-motor tasks

Question 3

Give an example of a brain area not mirrored

Answer 3

Broca’s area is not mirrored in the right hemisphere

Question 4

What connects the two brain hemispheres

Answer 4

The corpus callosum, a bundle of nerve fibres

Question 5

What gave researchers the opportunity to investigate the different abilities of the two hemispheres

Answer 5

As a treatment for severe epilspsy, surgeons cut the corpus callosum, stopping communication between the two hemispheres and creating split brain patients

Question 6

Who are the leading researchers in the field of split brain research

Answer 6

Sperry and Gazzaniga

Question 7

What was a typical study for Sperry and Gazzaniga

Answer 7

The split brain patient would fixate on a dot in the centre of the scree while information was presented to either the left or right visual field. They were then asled to make responses with either their right hand (left hemisphere), left hand (right hemisphere) or verbally (left hemisphere)

Question 8

What would happen if a split brain patient was flashed an image of a dog in their right visual field

Answer 8

They would verbally respond that they had seen a dog

Question 9

What would happen if a split brain patient was flashed an image of a dog in their left visual field

Answer 9

They would respond that they see nothing, as information in the left visual field is processed by the right hemisphere which has no language centre

Question 10

What differences in the brain hemispheres has split brain research revealed

Answer 10

The left hemisphere is responsible for speech and language, while the right hemisphere specialises in visual-spatial processing and facial recognition

Question 11

What is an important point about conclusions drawn from split brain research

Answer 11

It hasn’t shown that the brain is localised, instead it has shown that connectivity between the different regions is as imporant as the operation of the different parts

Question 12

What appears to be the strength of hemispheric lateralisation (eval)

Answer 12

It increases neural processing capacity, as by using only one hemisphere to engage in a task, this would leave the other hemisphere free to engage in another function

Question 13

What research supports the view that hemispheric lateralisation increases neural processing capacity

Answer 13

Rogers et al chemically severed the corpus callosum of chickens and found that in the domestic chicken, brain lateralisation is associated with enhanced ability to perform two tasks simultaneously, looking for food and being vigilant for predators. Suggests lateralisation improves brain efficiency

Question 14

Who chemically severed chicken’s brains

Answer 14

Rogers

Question 15

How are individual differences present in research into brain lateralisation (eval)

Answer 15

Lateralisation doesn’t appear to stay the same throughout an individual’s lifetime, with lateralised patterns found in youger people swithing to bilateral patterns in older adults. Szaflarski et al found that lagnuge became more lateralised to the left hemisphere with increasing age in children and adolescents, but after the age of 25 lateralisation decreases with each decade of life. One reason could be that using the extra processing power of the other hemisphere may in some way compensate declines in function

Question 16

What did Szaflarski do

Answer 16

Szaflarski et al found that lagnuge became more lateralised to the left hemisphere with increasing age in children and adolescents, but after the age of 25 lateralisation decreases with each decade of life

Question 17

Who found increasing lateralisation until the age of 25

Answer 17

Szaflarski et al

Question 18

Why is particiapant number an issue for research into lateralisation (eval)

Answer 18

The split brain procedure is rarely carried out today, and Andrewes points out that many studies are presented with as few as three participants or even a single participant.

Question 19

What does Anderson claim about split-brain research

Answer 19

He claims that in some cases conclusions have been drawn from individuals who either have a confounding physical disorder which made the procedure necessary, or have had less complete sectioning of the two hemispheres then was originally believed. Confounding factors and insufficient research numbers are therefore a huge issue

Question 20

Who found split brain research studies have been done on as few as 1 participant

Answer 20

Andrewes

Question 21

Why might early split brain research discoveries have been disconfirmed

Answer 21

Gazzaniga suggesed more recent discoveries have disconfirmed early discoveries. Turk et al conducted a case study of one patient, known as J.W., which demonstrated that he had developed the capacity to speak out of the right Hemisphere, with the result that he could speak about information presented to the left or the right brain. This challenges the claim that the right hemisphere is unable to handle even the most rudimentary language

Question 22

Who claimed that new discoveries were disconfirming earlier lateralisation research

Answer 22

Gazzaniga

Question 23

Who found a case study who could speak out of their right hemisphere

Answer 23

Turk et al

Question 24

Who was the case study discovered by Turk

Answer 24

J.W