Bio - Lateralisation & split-brain research. Flashcards
What is hemispheric lateralisation?
Refers to the fact that some mental processes in the brain 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 corpus callosum.
What is the left hemisphere dominant for?
Language and speech.
What does the right hemisphere excel at?
Visual-motor tasks.
If language is located in the left hemisphere, how can we talk about things that are experienced in the right hemisphere e.g. face recognition?
The two hemispheres are connected allowing information received by one hemisphere to be sent to the other hemisphere through connecting bundles of nerve fibres such as the corpus callosum.
How are the two hemispheres of the brain connected?
By the corpus callosum.
What is the corpus callosum?
A bundle of nerve fibres connecting the two brain hemispheres which allows information received by one hemisphere to be sent to the other hemisphere.
What does the corpus callosum do?
Connect the two brain hemispheres and allows information received by one hemisphere to be sent to the other hemisphere.
When did the chance to investigate the different abilities of the two hemispheres come about?
When, in a treatment for epilepsy, surgeons cut the bundle of nerve fibres that formed the corpus callosum.
What was the aim of the procedure done by surgeons to cut the corpus callosum as a means of treating epilepsy?
To prevent the violent electrical activity that accompanies epileptic seizures crossing from one hemisphere to the other.
What are patients that underwent the surgical cutting of the corpus callosum often referred to as?
‘Split-brain’ patients.
Who (that we need to know about) carried out split-brain research?
Sperry (and Gazzaniga) (1967).
What was Sperry able to do to test the capabilities of the separated hemispheres in split-brain research?
They were able to send visual information to just one hemisphere at a time in order to study what is known as hemispheric lateralisation.
What did Sperry aim to study?
Hemispheric lateralisation.
Describe the procedure of the study done by Sperry which was carried out on split-brain patients
The split-brain patient would fixate on a dot in the centre of a screen while information was presented to either the left or right visual field. They would then be asked to make responses with either their left hand (controlled by the right hemisphere) or their right hand (controlled by the left hemisphere), or verbally (which is controlled by the left hemisphere), without being able to see what their hands were doing.