Split brain research into hemispheric lateralization
1
, Hemispheric lateralisation
Language is restricted to the left hemisphere. Language is subject to hemispheric lateralization- the
specialist areas associated with language are found in one of the brain’s hemispheres rather than both.
Whether other neural processes may be organized in this way was investigated in a series of ingenious
experiments conducted by Roger Sperry and his colleagues (split-brain research).
Split brain studies
Sperry’s (1968) studies involved a group of patients who had undergone commissurotomy- in which the
corpus collosum and other tissues which connect the 2 hemispheres were cut down the middle in order
to separate the 2 hemispheres and control severe epileptic seizures. Allowed Sperry and his colleagues
to see the extent to which the 2 hemispheres were specialized for certain functions, and whether the
hemispheres performed tasks independently of one another.
Procedure
Sperry devised a general procedure in which an image or word could be projected to an individual’s right
visual field (proceeded by the left hemisphere) and the same, or different, image could be projected to
the left visual field (processed by the right hemisphere). In the “normal” brain, the corpus collosum
would immediately share the information between both hemispheres giving a complete picture of the
visual world. However, presenting the image to one hemisphere of a split-brain individual meant that
information could not be conveyed from 1 hemisphere to another.
2
1
, Hemispheric lateralisation
Language is restricted to the left hemisphere. Language is subject to hemispheric lateralization- the
specialist areas associated with language are found in one of the brain’s hemispheres rather than both.
Whether other neural processes may be organized in this way was investigated in a series of ingenious
experiments conducted by Roger Sperry and his colleagues (split-brain research).
Split brain studies
Sperry’s (1968) studies involved a group of patients who had undergone commissurotomy- in which the
corpus collosum and other tissues which connect the 2 hemispheres were cut down the middle in order
to separate the 2 hemispheres and control severe epileptic seizures. Allowed Sperry and his colleagues
to see the extent to which the 2 hemispheres were specialized for certain functions, and whether the
hemispheres performed tasks independently of one another.
Procedure
Sperry devised a general procedure in which an image or word could be projected to an individual’s right
visual field (proceeded by the left hemisphere) and the same, or different, image could be projected to
the left visual field (processed by the right hemisphere). In the “normal” brain, the corpus collosum
would immediately share the information between both hemispheres giving a complete picture of the
visual world. However, presenting the image to one hemisphere of a split-brain individual meant that
information could not be conveyed from 1 hemisphere to another.
2
