Split Brain Research Flashcards
What have surgeons done in the past?
They have cut the corpus Callosum in order to prevent violent electrical activity caused by epileptic seizures crossing from one hemisphere of the brain to the other. Those who have undergone this surgery are called split brain patients.
What can we study because of split brain patients?
With these patients, we can then study brain lateralisation and whether one hemisphere is more dominant than another when controlling certain characteristics and behaviours
What did sperry and gazzaniga do?
They were the first to study split brain patients and they would send visual information to one hemisphere at a time to study hemispheric lateralisation as the left hemisphere controls the right half of the body, whereas the right hemisphere controls the left half. Because the corpus callosum was split, we could see what information is processed specifically by each hemisphere and what the specialties of each hemisphere are
What was the procedures for sperry and gazzaniga
Sperry and Gazzaniga conducted many different experiments, including describe what you see tasks, tactile tests, and drawing tasks.
In the describe what you see task, a picture was presented to either the left or right visual field and the participant had to simply describe what they saw.
In the tactile test, an object was placed in the patient’s left or right hand and they had to either describe what they felt, or select a similar object from a series of alternate objects.
Finally, in the drawing task, participants were presented with a picture in either their left or right visual field, and they had to simply draw what they saw.
What were the findings of sperry and gazzaniga
In thr describe what you see, when info was presented to the right visual field they could, showing left hemisphere superiority in language but could not describe anything presented to the left visual field
The patient could describe verbally what they felt when object presented to the right hand and even identify it by selecting another object that is similar. When presented to the left hand, they couldn’t describe what they felt, but could successfully pick a similar object from a series of alternates
Finally those who saw pictures with left visual field could draw clearer and better pictures than the right hand despite participants being right handed. When presented to right visual field picture was rubbish - this shows right hemisphere superiority in visual and motor tasks
Strengths split brain research
+ split brain research has proved that hemispheric lateralisation and both hemispheres have different functions - for example left hemisphere is responsible for speech and language and the right hemisphere is responsible for visual spatial processing and facial recognition.
+ split brain research is also highly controlled and scientific
Weaknesses split brain
- many studies of split brain patients are as few as few as three participants, making it hard for results to be generalised to the target population
- split brain patients often have drug therapy for their epilepsy for much longer than others, which may affect the way in which their brain works. This means findings can’t be generalised
- data is also very artificial. In the real world, a severed corpus callous, can be compensated for by the unrestricted use of both visual fields. This means the research lacks ecological validity.
