Sperry 1968 (biological)

Question 1

What were the three questions?

Answer 1

What happens when two halves of the brain are disconnected ?

Do the hemispheres perform different functions?

Does each hemisphere have its own memories, perceptions and concepts ?

Question 2

What is the corpus callosom ?

Answer 2

It is a bundle of nerve fibres that connect the two hemispheres

Question 3

What was the aim ?

Answer 3

To investigate the effects of hemisphere disconnection and to show that each hemisphere has different functions and that information from one side of the brain is not accessible to the other

Question 4

What were the participants like ?

Answer 4

All had history of severe epilepsy

all had surgery this was an opportunity sample

11 participants, a recent surgery

Question 5

Procedure - pt 1 ? (Continued in another card)

Answer 5

P’s were sat in front of a projector screen and focused on the fixation point in the middle

Visual stimuli on 35 millimetre transparencies and were then back projected at one tenth of a second or less onto the screen infront of them

Question 6

Procedure - pt 2 ?

Answer 6

This was because the images could then go to either one of the visual fields any longer both visual fields could receive it therefore both hemispheres

Below the screen was a grab bag so p’s could reach objects which had been placed on a desk in-front of them. They couldn’t see this as the screen wasn’t see through

Question 7

What results were found ?

Answer 7

Left hemisphere controls language

If an object was presented to the left visual field they could draw it with their left hand and could find it with their left hand out of a tray of objects however they couldn’t name it

If it was shown to the right visual field they were able to name it, draw it with their right hand and find it among objects with right hand

When image was show to one visual field the p’s woupd only recognise it if it was shown to the same visual field, this is evidence of separate memories

Question 8

Tactile tests ?

Answer 8

Finding or sorting objects

Place in the right hand and asked to name it

If the object was placed in the left hand they would make a wild guess however they can draw it

Question 9

Tests on the right side of the brain ?

Answer 9

Naked women shown to test right visual field

They started to giggle but didn’t know why and couldnt explain why