Lesson 8- split brain research

Question 1

Split brain research

Answer 1

-used to study brain lateralisation as it shows what functions are dominant for which hemisphere
-patients who suffer from epilepsy have an operation that involves cutting the corpus callous to stop seizures
-communication cut, could cause problems, using patients to help us to study brain lateralisation and whether one hemisphere is more dominant in controlling certain characteristics and behaviours than the other

Question 2

Split brain research research

Answer 2

-Sperry and Gazzinga (1967) were first to study split brain patients, rsearchers wou;d send visual information to just one hemisphere at a time to study hemispheric lateralisation
Aim- to examine the extent to which the two hemispheres are specialised certain functions
Method- an image/word projected to the patients left or right visual field:
-desrcibe what you see task- picture presented in either visual field and participant had to describe what they saw
-tactile task- object placed in patients left or right hand and had to either describe what they felt or select or similar object from a series of alternate objects
-drawing task- presented with a picture in either visual field and had to simply draw what they saw

Question 3

split brain research findings and conclusion

Answer 3

describe what you see- picture presented to right visual field, processed by left hemisphere, patient could only describe verbally=superiority of left hemisphere with language production, picture presented in left visual field patient could not describe what was shown, often reported nothing present
tactile test- objects placed in right hand,processed by left hemisphere, patients would verbally describe what they felt, or could identify the test object presented in the right hand (left hemisphere) by selecting similar appropriate object from a series of alternate, objects placed in left hand patients could not decribe what they felt and could only make wild guesses, however left hand could identify a test object presented in left hand by selecting similar object
drawing task- when picture presented in rvf while right hand attempted to draw picture was never as clear as left hand, demonstrating superiority of right hemisphere for visual motor tasks, however when picture was presented to lvf left hand would consistenly draw clearer pictures than right hand, even though all participants were right handed
conclusion- left hemisphere is dominant in terms of speech and language, and right hemisphere is dominant in terms of visual-motor tasks

Question 4

split brain research strengths

Answer 4

-proves hemispheric lateralisation and both hemispheres have different functions; left responsbile for speech and language and to break information down, right responsible for visual spatial processing and facial recognition and holistic processor
-research support from Sperry and Gazzinga, helped to tell us about normal brain functioning, shows connectivity between different areas is as important as operation of other parts

Question 5

split brain research weakness

Answer 5

-has not shown that the brain is organised into different areas with specific sections responsbile for specific tasks
-only a small sample size, very few patients and only 10-15 subjected to extensive study, extremely varied group (gender, handedness, age they developed epilepsy, age which they had split brain research, age they were tested), in some cases not all pathways connecting both hemispheres were always cut allowing some communication
-threat to generalisability to this and other areas of brain research
-modern technology means scans can be used instead of surgeries, might not be relevant in todays society