Biopsychology : Hemispheric lateralisation and Split brain research Flashcards
Define the theory of hemispheric lateralisation
the theory that the two hemispheres are functionally different and certain mental processes and behaviours are mainly controlled by one hemisphere rather than both
Name the 2 people who conducted experiments into hemispheric lateralisation
Roger Sperry
Michael Gazzaniga
Who was involved in research known as ‘split brain research’?
a group of unique individuals who had undergone a commissurotomy
What is a commissurotomy?
What is the function of the corpus callosum?
a procedure that involves patients having their corpus callosum cut
it connects the two hemispheres
What did split brain research allow to be investigated?
2 things
the extent to which each hemisphere was specialised
which brain functions were lateralised
Describe the procedure used in split brain research
2 points
1)an image / word projected to the patients right visual field and the same or different image / word was then projected to the left visual field
2)they did this by blind folding one eye then flashing the image / word on screen for 1/10th of a second
Why did researchers only flash the images for 1/10th of a second?
because it meant patients wouldn’t have time to move their eye across the image to spread the info across both visual fields
State the two conclusions drawn from split brain research
-language is lateralised to the left hemisphere
-drawing and face recognition is lateralised to the right hemisphere
Give one strength of split brain research
+influential research
Sperry’s research and ingenious methodology led to a large amount of research being published about lateralisation of function in the brain
this means his research was highly influential in developing neuroscientists understanding of how the brain works
Give a however point for the idea that Sperry’s research was highly influential
his research has also led to a large amount of pop-psychological research being published which simplifies the functional distinction of hemispheric lateralisation
Give a second strength of split brain research
+the methodology
the procedures used were standardised and well controlled
this means he could be confident about the conclusions he was making about hemispheric lateralisation , they were reliable results
Give a weakness of split brain research
-issues with generalising
split brain patients are an unusual group of people as they all had a history of epilepsy , additionally there was only 11 of them in the sample
this means we must be careful when generalising these findings as the sample is unlikely to be representative of the population
