split brain research and hemispheric lateralisation ao3

Question 1

Strength - research support

Answer 1

P: Sperry et al Pioneering work into the split brain phenomenon has produced impressive and sizeable body of research findings
E:The main conclusion of these appears to be that the left hemisphere is more geared towards analytical and verbal tasks, containing our language centres whereas the right is more adept at performing spatial tasks, emotional/facial recognition, music and other creative things.
E: The right hemisphere can only produce rudimentary words and phrases will contribute emotional and holistic content to language. Furthermore research suggests that the left hemisphere is the analyser while the right hemisphere is this synthesiser.
L: Such findings have provided key contributions to our understanding of brain processes

Question 2

strength - highly scientific

Answer 2

P: one strength of split brain research and hemispheric lateralisation is how scientific it is
E: this is because sperry and gazaniga had a remarkable level of control over the procedures. this can be seen by how specialised and standardised those procedures were. for example sperry presented the infomation at 1/10th of a second so that the patient wouldnt have time to move their eye across the image and so spread the information across both sides of the visual field
E: this ensured the information went to only one of the hemispheres
L; this high level of control and standardisation allowed them to replicate the research many times as well as carrying out different variations to learn more about hemispheric lateralisation.

Question 3

limitation - lack of control over extraneous variables and issues w generalisability

Answer 3

P; sperrys research has been criticised due to the lack of control over extraneous variables and issues of generalisability.
E: for example, the amount of disconnection between the hemispheres varied between 11 ppts. whereby the extent to which the corpus callosum had been cut was greater in some patients than in others. secondly, there was a lack of a valid control group because all the split brain patients had suffered from epileptic seizures whereas the control group had no epileptic seizures. hence they were not a direct comparison. thirdly, some of the split brain patients had experienced drug therapy to help with their epilepsy much longer than others - posing an extraneous variable affecting the brains ability. also, the sample of split brain patients are an unusual sample which are rarely encountered in sufficient enough numbers to be useful for research and also dont reflect the wider population.
L; all of these extraneous variables undermine how much we can learn about hemispheric lateralisation from this split brain research limiting its generalisability, population validity and internal validity.

Question 4

limitation - contradictory findings

Answer 4

P: one limitation of split brain research is contradictory findings.
E: Gazzaniga revisited split brain with a patient JW. split brain research suggests that the right hemisphere was unable to handle even the most basic language. however his patient was able to speak out oh his RH w the result that he could speak about information presented to the left or right visual field.
E: this is all due to the brains ability to adapt - brain plasticity. this was not taken into consideration in s and gs research
L: thus this contradictory evidences challebges their claims that the RH is only responsible for creativity, focused on emotional and facial recognition and the LH is more analytical containing language centres.