Sperry (1968)

Question 1

What is the background to sperry ?

Answer 1

-Left and right hemispheres communicate through a small group of connections.
-Main connections is called the corpus callosum.
-Hemispheric deconnection

Question 2

What is the localisation of function ?

Answer 2

Brain regions.

Question 3

What is the lateralisation of function ?

Answer 3

Hemispheres.

Question 4

Aim of Sperry

Answer 4

To record psychological effects on hemispheric deconnection in patients with severe epilepsy.
Wanted to use result stop understand how right and left hemispheres work in ‘normal’ people.

Question 5

Method of Sperry

Answer 5

-Controlled observation (quasi).
-Snap shot study.
-IV = presence/absence of split brain.
-DV = performance on various visual and tactile tasks.

Question 6

Sample of Sperry

Answer 6

11 split brain patients who experienced sever epileptic seizures.
Opportunity sampling = referred to white memorial centre in LA.

Question 7

Materials of Sperry

Answer 7

Tachistoscope - device that shows image (back projector). Couldn’t see objects beneath the screen.
Sreen to project images/words on.

Question 8

Procedure of Sperry

Answer 8

Screen with fixed point of focus (cross). One eye was covered.
Imaged flashed for 0.1 seconds.
Completed tasks to test right and left hemispheres and how they respond to input from LVF and RVF and left and right hand.

Question 9

Task 1 Sperry (verbal)

Answer 9

Recognition of visual stimuli presented to left and right hemispheres separately.
Asked to say what they saw.

Question 10

Task 2 Sperry (verbal)

Answer 10

Responding with speech to visual stimuli presented to left and right hemispheres separately.
Asked to describe visual stimulus.

Question 11

Task 3 Sperry (written)

Answer 11

Responding in writing to visual stimuli presented separately.
Identical to task 2 but wrote what they saw rather than say it.

Question 12

Task 4 Sperry (pointy)

Answer 12

Responding by pointing to visual stimuli presented separately.
Identical to task 2 but pointed to stimulus they saw.

Question 13

Task 5 Sperry (drawing)

Answer 13

Recognition of visual stimuli presented simultaneously.
Two figures flashed simultaneously and asked to draw without looking using left hand.

Question 14

Task 6 Sperry (composite words)

Answer 14

Recognition of pairs of related words presented simultaneously.
Words composed of 2 smaller words so half was LVF and half in RVF.
They could search for object, say name or write.

Question 15

Task 7 Sperry (tactile)

Answer 15

Verbal identification of objects placed in their hands.
Prevented from seeing objects in either left or right hands. Asked to say/write name of object either using right or left hand.

Question 16

What is left hemisphere responsible for ?

Answer 16

Language.

Question 17

Results in RVF

Answer 17

Can describe, point and find with right hand.

Question 18

Results in LVF

Answer 18

Unable to name, point and find with left hand.

Question 19

Conclusions of Sperry

Answer 19

-Hemispheres are independent.
-Can still continue in day to day life.
-Hemispheres are responsible for certain things.
-Dual processors can occur.
-Supports the bio approach.

Question 20

How does Sperry link to Bio area ?

Answer 20

Bio because it shows, through slip-brain patients, the way in which different abilities are localised within the 2 hemispheres of the brain and distinct areas that control for specific behaviours.