Split brain reserach Flashcards
Define contralateral
Each hemisphere of the brain controls the opposite side of the body
What is the corpus callosum
A thick bundle of 200-300 million myelinated nerve fibres allowing for quick communication between each hemisphere
What led to the research of split brain patients
Paitients that had thier corpus callosum cut -isolating each hemisphere from the other- reduced epileptic sympotoms and it had few side effects however unusal behaviour and a sense of a loss of agency(feeling of control) led to the research
Sperry 1968
Conducted a quasi experiment comparing 11 patients who had undergone corepus callostomy using equipment that would project iunformation to each visual fiewld sperrry controlled the information that each emispher had access to. in a series of tests partciipants whould be required to either say what they had seen, draw the objevt or selcetr objects that were hidden from vuew with their hands. sperryu found that informartiom presented to the left hemspjhere could draw or selct the object by using the left hand suggesting the hemisphere are both capable iof acting indpeendetly also supporting that theory that lkanugae cnetres are in the left side of tej brian
Gazzaniga(1983) found that when each hemisoere of splut btrin paiteinets were presented with faces the right hemishphere wa smuch more able to recognise them suggesting that the roight hemisphere os specialised for facial rwcgonition
Evaluations cons:
The sample used was small and you cnnot generalise the findings on the rest of the population as their brains mayve been abnormal also the comparison group in sperrys reserahc were not people who had history with epeleptic fits so the comparison is invalid
The paitets used did no have the same level of disconnetion betwen hemisphere which coyuldve reuslted in more comunciation between hemiphere then suggested
His paitents had undergone durg therapies which couldve ingluced results
The tasks used lacked mundane realims reulsitng in low external validity as the ffects only show up in highly artificial situations
Evaluations pros
Reserach on split brain paiteints has had a fiuncadmental impact on tgh epsychloigsl and philospical undertandifn of both the unitty of consciousness and identity suggesting that the brain is a combination of separate intelligent processes woring togther
What is Hemispheric Lateralisation
The fact that the two halves of the brain are functionally different and that each hemisphere has functional specialisations, e.g. the left is dominant for language, and the right excels at visual motor tasks.
How do the two hemispheres communicate
Via the corpus callosum-a bridge of nerve fibres that send signals between the hemispheres
What are the issues caused when the corpus callosum is cut
It interrupts how we process information the hemispheres specialise in. The brain operates contralaterally; the left side controls the right side of the body, and the right side controls the left side of the body.
Give an example of hemispheric lateralisation (language)
Broca’s area, residing in the left hemisphere (specifically the left frontal lobe), is an example of hemispheric lateralisation. When damage occurs in Broca’s area, speech production is affected. However, speech production remains unaffected when the same place in the right hemisphere is damaged.
Wernicke’s area, like Broca’s, is associated with language. Wernicke’s area is responsible for making speech meaningful, as damage to this area results in fluent but meaningless speech. Patients with damage to this area can often speak with the right tones and inflections that you would find in a typical, healthy speech pattern, but the content of their words doesn’t make sense.
