Lateralisation and split brain Flashcards
What is hemispheric lateralisation?
Two sides of the brain are NOT completely alike because the brain function is LATERALISED, so the brain functions are being specialised to DIFFERENT sides.
The motor area of the brain is CROSS-WIRED, this means what?
that the right hemisphere controls the left side of the body and the left hemisphere controls the right.
What are the two hemispheres connected by?
A corpus callosum, a bundle of NERVE FIBRES.
What was split brain research used to treat?
PAtients with severe EPILEPSY.
What did split brain surgery incorporate?
CUTTING the corpus callosum either partly, or entirely.
This meant that the patients had 2 SEPERATE brain hemispheres that could NO longer communicate through the corpus callosum. They now had ‘split-brain.’
What did Sperry study?
The EFFECTS of this split brain study in order to investigate whether the two hemispheres were SPECIALISED to the point they operated independently of each other.
What was sperrys split-brain research procedure?
patients would have an image projected to their RIGHT visual field which is processed by the LEFT hemisphere.
Presenting the image to ONE hemisphere of a split-brain patient meant that the information would ONLY be perceived by ONE hemisphere. Due to corpus callosum surgery.
what did sperry find in his split-brain research?
PPTS could only describe what they saw when it was shown to their LEFT hemisphere, which contains BOTH language centres, and not to their right hemisphere. (you show items to the left hemisphere through the RIGHT visual field.)
This was also true for held items. Participants touching an item in their left hand could not describe it as this information goes to the somatosensory cortex in the RIGHT hemisphere which does NOT have language centres.
Doing a task involving matching faces to pictures, the RIGHT hemisphere was dominant for this. This shows that FACIAL recognition is LATERALISED to the right hemisphere.
left visual field goes to the right hemisphere.
right visual field goes to the left hemisphere
left hemisphere is dominant for verbal processing. contains BOTH language centres.
right hemisphere cant share info. No language centres.
