Hemispheric Lateralisation and Split Brain Function Flashcards
hemispheric lateralisation refers to the idea that
the two half’s of the brain are functionally different
if the two half’s of the brain are functionally different,
some mental processes in the brain are specialized to either the left or right hemisphere
how are the two sides of the brain connected?
a bundle of nerve fibers called the corpus callosum
what does the corpus callosum do?
share information between the hemispheres
which side of the body does the left hemisphere control?
the right side
which side of the body does the right hemisphere control?
the left side
what does the right side of the brain control?
visual-motor tasks
what does the left ride of the brain control?
language and speech
split brain patients have undergone
a surgical procedure to control severe epileptic fits by severing the corpus callosum
Sperry date
1968
what did Sperry do?
tested whether the two hemispheres are specified for function whether tasks were performed independently from one another
in split brain patients
information cannot travel between the two hemispheres so information can can only be processed by the hemasphere that recieves it
in a normal brain…
the corpus callosum would immediatly share the information between the two hemispheres giving a complete picture of the visual world
Sperry procedure
an image or word was projected to the patients right visual field and the same or different was projected to the left visual field
Sperry Findings - describing what you see
when the picture was shown to the right visual field, the participant could describe what was shown.
when the picture was shown to the left visual field, the participants said that there was nothing there.
Sperry Findings - recognition by touch
although they could not attach a label to objects projected to the left visual field, they were able to match that object or choose an associated object from the right hemistphere
Sperry Findings - matching faces
right hemisphere seems to be dominant in facial recognition. when asked to match a picture, success was based on presentation to the left visual field.
Sperry’s & Michael Gazzaniga’s work in split brain phenomenon has produced
a sizable body of research findings
Sperry’s & Michael Gazzaniga’s main findings are
the left hemisphere is more geared towards analytic and verbal tasks while the right is more spatial tasks and music
the split brain experiments made use of
highly specilised and standardised procedures
Sperry contolled the exposure of a stimuli to
one tenth of a second
by keeping the exposure of the stimuli to only one tenth of a second, Sperry insured that
the participants couldnt move their eyes and spread the image to both visual fields
Sperry’s work promoted a
theoretical and philosophical debate between the two hemispheres and the nature of consciousness
differences in functions maybe overrated
pop psychological literature oversimplifies the distinction between L + R hemispheres and some of its potential implications
Gazzaniga suggests that discoveries from early split brain research may have been supplanted with the use of
technology
a patient called J.W developed the capacity to
speak out of the right hemisphere and can now talk from either the left or right brain
can you generalise from split brain patients?
no - they’re an unusual group of people with only a small sample due to the surgery only being performed rarely
how many patients did Sperry have?
11
