2) Biopsychology - Split-Brain Research

Question 1

Who conducted study involving the corpus collosum being cut?

Answer 1

Sperry (1968)

Question 2

What was unique about Sperry’s participants?

Answer 2

• Their corpus collosum was cut to separate both hemispheres.

Question 3

Why did Sperry’s participants have their corpus collosum cut?

Answer 3

• To control their frequent and sever epileptic seizures.

Question 4

What does the corpus collosum do?

Answer 4

Act as a communication line between the two hemispheres.

Question 5

Why did Sperry chose to use his participants?

Answer 5

To view the independent functions of each hemisphere and whether they can function independently of each other.

Question 6

What was the procedure for Sperry’s research?

Answer 6

• The participants were sat in a chair and an image/word was presented to the person’s right visual field and the same/different could be projected on the left.

Question 7

What were the findings for Sperry’s research in terms of describing what you see?

Answer 7

Describing what you see:

• When an image was shown to the right visual field they could easily describe what they could see. If the same object was shown to the left visual field they could not describe what was there or said nothing was there.
• This shows that language is processes in the left hemisphere as only the right visual field could be described.

Question 8

What were the findings for Sperry’s research when testing for Recognition by touch?

Answer 8

Recognition by Touch:

• Individuals were able to select the matching object when using their left visual field.
• Also able to select the correct item when it was hidden.
• This shows that they were not able to verbally identify what the objects were but were able o understand what the object was by using their right hemisphere and then select the right object.

Question 9

What were the findings for Sperry’s research when testing for Composite words?

Answer 9

Composite Words:

• If two words are presented simultaneously, the person would pick the object using their left hand when using their left visual field.
• They would then say the word that they saw in their right visual field.

Question 10

What were the findings for Sperry’s research when matching faces was tested?

Answer 10

Matching Faces:

• When asked to match a face from a series of faces, the picture processed by the right side was consistently selected whereas the picture presented to the left hemisphere was consistently ignored.
• When a composite picture made up of two different halves of a face was presented, the left hemisphere dominated in verbal description whereas the right hemisphere dominated in matching pictures.

Question 11

Give a strength for Split-Brain Research in terms of research support

Answer 11

P - There is very strong evidence for split-brain research.
E - Research such as Sperry’s show that the left side is associated more with verbal tasks whereas the right is more for spatial tasks.

Question 12

Give a strength for the methodology of split-brain research

Answer 12

P - Studies involving split-brain research use highly standardised and specialised procedures
E - Participants would have been asked to stare at the “fixation point” and the image would be flashed up for a tenth of second so the individuals would not have time to move their eye across the image which would spread the information to both sides of the brain.
E - This allowed for Sperry to isolate each hemisphere of the brain.
L - Therefore developing a well-controlled procedure.