split brain research into hemispheric lateralisation

Question 1

hemispheric lateralisation

Answer 1

• idea that hemispheres of brain are functionally different i.e certain mental processes are mainly controlled by one hemisphere e.g language which is localised by brocas and wernickes area + lateralised to left hemp

Question 2

sperrys procedure ( before actual study)

Answer 2

• studied individuals who had undergone commissurotomy.
• involved the corpus callosum, which connects both hemispheres being cut down the middle and separating them
• separation was done to control frequent and severe epileptic seizures.
• Resulted in a lack of communication between the hemispheres.-
• Allowed Sperry to investigate independent functioning of each hemisphere.

Question 3

sperrys procedure ( during actual study)

Answer 3

• developed a procedure to project images or words to patients’ visual fields.
  An image could be shown to the right visual field (left hemisphere) and a different one to the left visual field (right hemisphere).
  In a healthy brain, both hemispheres would communicate about the stimuli.
  After commissurotomy, Sperry’s patients could not achieve this communication.

Question 4

sperrys findings -

Answer 4

image shown to right visual field - p could see what was seen

image shown to left visual field - couldn’t describe what was seen, typically said nothing was there

couldn’t describe what they saw in left visual field bc it was processed by right hemisphere, where there was no language centre to use for speech production
- as a result of comminurotony, messages couldn’t be sent from right hempishere to language centres

• right hemisphere - dominant in recognising faces

-when asked to match face from a series of other faces, picture processed by right hemp, consistency selected
- while faces shown to left hemp =. ignored

Question 5

ao3 strength

Answer 5

ChatGPT
Point: Research supports hemispheric lateralisation.

Evidence: Rogers et al. (2004) found that in domestic chickens, brain lateralisation improves the ability to perform tasks simultaneously, such as foraging and being vigilant for predators.

Elaboration: Using one hemisphere for a task allows the other hemisphere to focus on different functions.

Tail: This evidence highlights the benefits of brain lateralisation in enhancing cognitive efficiency.

Stretch: However, since this research is based on animals, conclusions for humans are uncertain. Additionally, the limited human studies take an idiographic approach, making findings specific to individual cases.

Question 6

ao3 strength 2

Answer 6

SUPPORT – METHODOLOGY USED

Point – Moreover, a key strength of Sperry’s research is the unique methodology he used.

Evidence – Sperry’s experiment used highly specialised and standardised procedures. Sperry’s
method of presenting visual information to one hemisphere at a time was quite ingenious.

Elaboration – It typically asked participants to stare at a given point whilst one eye was
blindfolded. The image projected would be flashed up for one tenth of a second to one visual field,
meaning the split brain patient would not have time to move their eye across the image.

Link – This suggests Sperry’s research is both reliable and valid due to the procedures used.

Question 7

ao3 weakness 1

Answer 7

Point: There are concerns about the generalisability of Sperry’s results.

Evidence: Researchers caution against generalising findings from split brain patients, as they represent an unusual sample and the procedure is rarely performed today.

Elaboration: Furthermore, Sperry’s experimental group consisted of epileptic patients, while the control group had no epilepsy history, complicating accurate comparisons.

Link: These factors suggest that Sperry’s results should be interpreted cautiously, as the groups may not be representative of the wider population.

Question 8

ao3 weakness 2

Answer 8

Point: Sperry’s research oversimplifies the functional differences between hemispheres as merely verbal versus non-verbal tasks.

Evidence: Modern neuroscientists argue that the distinction is less clear-cut, with hemispheres constantly communicating to complete tasks, as shown in Lashley’s maze study.

Elaboration: Additionally, one hemisphere can sometimes compensate for the other, as seen in the case of JW, who learned to speak using the right hemisphere after left hemisphere damage—a phenomenon known as brain plasticity.

Link: Thus, while Sperry’s research is important, it may be more limited than initially thought due to this oversimplification.