Split-brain patients

Question 1

What is the main surgical procedure performed on split brain patients and why?

Answer 1

Cut corpus callosum to prevent epileptic seizures

Question 2

Experimental procedure for unilateral visual information?

Answer 2

Person told to look at middle point, images are then shown on right/left

Each hemisphere only sees the contralateral visual field

Question 3

If image is shown on left?

Answer 3

Cannot describe with language (broca’s area on left side). Person would say they see nothing

but can draw using the right hemispehere and left hand, allowing them to then identify the image

Question 4

If image is shown on right

Answer 4

They are able to explain it in speech, right hand can draw

Left hand cannot draw

Question 5

Adult-split brain patients vs callosal agenesis patients

Answer 5

Adults have more disconnection compared to callosal agenesis

Due to plasticity in children, allowing them to have typically minimal disconnection. Language skills, IQ are fairly normal

Some impairment may be seen in complex integration of information

Question 6

Both hemispheres understanding the experiment:

Answer 6

Some split brain people may not have ANY language comprehension in the right hemisphere, making experiments difficult

Question 7

Subcortical functions?

Answer 7

Some stimuli response is preserved even without the corpus callosum; some subcortical functions remain.

Complex cortical functions such as comparing images on two sides of a midline cannot be done

Question 8

Other left hemisphere abilities?

Answer 8

Recognizing sense of self

Interpreting behaviour to create a cohesive sense of self