lateralisation and split-brain research Flashcards
what is hemispheric lateralisation
refers to the fact that some mental processes in the Brian are mainly specialised to either the left or right hemisphere
what is split brain research
Research that studies individuals who have been subjected to the surgical separation of the two hemispheres of the brain as a result of severing the corps callosum.
what has research found about the left hemisphere
that it is dominant in for language and speech
what have research found about the right hemisphere
that is excels in visual and motor tasks.
what does the corpus callosum do
it connects the two hemispheres allowing them to communicate, so we can talk about things we have experienced in the right side of the brain.
who were the first psychologists to study the capabilities of spilt-brain patients.
Sperry and Gazzaniga
- There aim was to investigate the extent to which the two hemispheres are specialised to different functions
why were people have surgical separation of the two hemispheres
to help people with the disorder of epilepsy
what was the typical study for split brain research
the spilt brain patient would fixate on a dot in the central of a screen while information was presented to either their left or right visual field.
They would then be asked to respond with either their left hand (controlled by the right hemisphere) or their right hand (controlled by the left hemisphere), or verbally (the left) , without being able to see what their hands were doing.
what have we learned from spilt brain research
has discovered a number of differences between the two hemispheres, e.g. that the left hemisphere is responsible for speech and language, and the right specialised in visual-spatial tasks and facial recognition.
But it has not shown that the brain is organised into discrete regions with specific sections responsible for different tasks, and so is not a specific explanation for any one task but a more holistic overview of the types of tasks.
what is the main advantage seen for lateralisation
- it is generally assumed that the main advantage of brain lateralisation is that it increases processing capacity. By using only one hemisphere to engage in a particular task, this would allow the other hemisphere free to engage ins another function. However, despite this assumption, very little empirical evidence has been provided to show that lateralisation confers any advantage to the functioning of the brain.
what is supporting evidence for hemispheric lateralisation
- it is a scientific method, and thus holds high reliability.. However it lacked ecological validity, as the patients in the experiment only wee tested on one eye at a time where as spilt brain patients in the real world d use both eyes together.
what is some limitations of lateralisation
- it is argued to be ideographic as they used 11 patients which some psychologist say is just a hand full of case studies. Furthermore, they used people who had suffered from epilepsy, which was challenged as whether the results should be generalised to the ‘norm’ public.
what is support for spilt brain research
-spilt brain research is rarely carried out nowadays and thus patients who have had this procedure are rarely encounter in sufficient numbers to be useful for research.
