Split Brain Research/hemisphereic Laterilisation Flashcards
Define hemispheric lat
Idea that 2 halves of brain r functionally different, each has functional specialisations
Neural mechanisms for some functions (lang) r localised primarily in left side + responsible for logic, analysis and problem solving
Right hand side = responsible for functions such as spatial comprehension, emotions + face recognition
What are the left and right hand side known as?
Left = analyser/lang etc (verbal)
Right = synthesiser (bringing things together) more holistic in processing stim
Split Brian research
Research that studies individual who have and a commissurotomy by severing corpus callosum which is responsible for 2 hemispheres communicating in order to reduce epilepsy as stops seizures spreading across brain
What is the side effect for split brain patients?
Info cannot move between hemispheres
What is a commissurotomy?
Surgical separation of 2 hemispheres by severing corpus callousum
Motor area
Brain cross wired (contraletral) right hemisphere controls left movement + left controls right movement
Vision wiring
Contralateral + ipsilateral, each eye receives light from left visual field and right visual field.
Info from LVF goes to visual cortex in right hemisphere + info from RVF goes to visual cortex in left hemisphere.
Info passes through corpus callousum to whichever side of brain needs to deal with it e.g speak or emotionally react
Development of split brain research
Sperry + gazzaniga
First to study capabilities of split brain patients
Used divided field method to investigate the lateralisation of brain function in languages ability
11 patients (small sample)
They flashed verbal stim + images at high speed to diff visual fields so no time for eye movement
Method in detail
Hemisphere of SB patients means info cannot be conveyed to other hemisphere due to lack of corpus callosum
When words were presented - report what saw or choose object from behind screen that was associated with word
Also asked to use left or right hand
Difference in norm and SB
Info from LVF goes to right and likewise but corpus callousum ring split means info cannot only be processed only In hem that received it.
SB patient flashed pic of dog to RVF what would they answer?
Dog, as lang is in left so always passes over anyway
If SB patient was flashes pic of cat to LVF what would they answer?
Nothing cause can’t communicate what they’ve seen to right so cannot respond. But may pick up object behind screen
