Core studies - Biological Psychology - Sperry study

Question 1

What is the Corpus Callosum

Answer 1

The region of the brain that connects the two hemispheres in order for them to communicate with one another

Question 2

What are Hemispheres

Answer 2

The two symmetrical halves oft he brain, left and right, which both have different functions

Question 3

What is Hemispheric Disconnection

Answer 3

• The split brain operation in which the corpus callosum is severed in order to stop the communication between hemispheres and as a result they act independently
• Given to severe epileptics to stop the ‘storms’ of communication in their brain that cause the seizures

Question 4

What is Lateralisation of Function

Answer 4

• The belief that the two hemispheres of the brain have different functions
• The left is in charge of language and the right is in charge of spatial awareness

Question 5

What is Contralateral Control

Answer 5

The belief that the left hemisphere controls the right side of the body and the right hemisphere controls the left side of the body

Question 6

What is a Tachistoscope

Answer 6

The apparatus used in Sperry’s study to allow the visual stimuli to be presented to the participants

Question 7

Aim

Answer 7

To record the psychological effects of hemispheric disconnection and to find evidence for lateralisation of function in ‘normal brains’

Question 8

Sample

Answer 8

• 11 people
• Had the split-brain surgery
• Previously had severe epilepsy

Question 9

Sampling Method

Answer 9

Opportunity sampling

Question 10

Research Method

Answer 10

Quasi experiment

Question 11

What was the IV

Answer 11

Whether the participants had a split brain or not

Question 12

What was the DV

Answer 12

Their (participants) performance on visual and tactile tasks

Question 13

What were the 4 tasks

Answer 13

1. ONE VISUAL FEILD TASK
2. BOTH VISUAL FEILDS TASK
3. TACTILE ONE HAND TASK
   4.TACTILE BOTH HANDS / DUAL PROCESSING task

Question 14

Main procedure

Answer 14

1. Each p was studied alone
2. The p had one eye covered, and was asked to look at a fixed point in the centre of the screen on the Tachistoscope
3. Visual stimuli were then projected onto the screen, either to the right visual field of the left visual field
4. The images were shown for 0.1 seconds each so the p had no time to change their visual field

Question 15

What was the procedure for the ONE VISUAL FEILD task

Answer 15

1. Each p was shown a visual stimulus on the screen whilst focusing on the central fixation point
2. They were shown one image in one visual field
3. They were shown the images for 0.1 seconds
4. After, they were asked to name what they had seen

Question 16

What were the result for the ONE VISUAL FEILD task

Answer 16

• When p’s were shown an image in their RVF this image would be processed in the left hemisphere which is in charge of language therefore the p’s would be able to say and draw what they had seen
• When p’s were shown an image in their LVF this image would be processed in the right hemisphere which is in charge of spatial awareness therefore they wouldn’t be able to say the word, but they could draw it

Question 17

What was the procedure for the BOTH VISUAL FEILDS TASK

Answer 17

1. Each p was shown a visual stimulus on the screen whilst focusing on the central fixation point
2. They were shown two different images, one in each visual field at the same time
3. They were shown the images for 0.1 seconds
4. After, they were asked to name what they had seen

Question 18

What were the results for the BOTH VISUAL FEILDS TASK

Answer 18

When p’s were asked to draw what they had seen they would draw the image from the LVF. But if asked to say what they had seen they would say the image seen in the RVF

Question 19

What was the procedure for the TACTILE ONE HAND task

Answer 19

• Each p was given an object in one hand
• The p’s were either asked to say or write down what was in their hand

Question 20

What were the results for the TACTILE ONE HAND task

Answer 20

If the item had been placed in the p’s right hand, it could be identified in the left hemisphere and be written with the right hand

Question 21

What was the procedure for the TACTILE BOTH HANDS / DUAL PROCESSING task

Answer 21

• The p works with their hands out of sight
• They would be given two different objects, one in each hand and then the objects are taken away
• The p is then asked to find the objects by touch from a pile of items or are asked to say what they have just held

Question 22

What were the results for the TACTILE BOTH HANDS / DUAL PROCESSING task

Answer 22

P’s were able to find the objects by touch but only by the hand where the object was first placed. If the hand that touched the object was not the hand where it was originally placed then it would reject the object, almost as if the p had never held the object before

Question 23

What were the conclusions for the TACTILE BOTH HANDS / DUAL PROCESSING task

Answer 23

This suggests that the two hemispheres are working separately so when they searched for the object they would only recognise it if it was in the same hand

Question 24

Further results from the study

Answer 24

• Hemispheric disconnection did not appear to affect the p’s intelligence or their personality
• Patients however experienced short term memory deficits, fatigue more quickly in reading, limited concentration spans and orientation problems after the split brain surgery

Question 25

Conclusions

Answer 25

1. Split brain patients appear to have two independent streams of consciousness, each with its own memories, perceptions and impulses. This supports the argument of lateralisation of function
2. People with split brains have two separate visual inner worlds each with its own train of visual images
3. Split brain patients have a lack of cross integration where a second hemisphere does not know hat the first hemisphere has been doing

Question 26

Conclusion 1

Answer 26

Split brain patients appear to have two independent streams of consciousness, each with its own memories, perceptions and impulses. This supports the argument of lateralisation of function

Question 27

Conclusion 2

Answer 27

People with split brains have two separate visual inner worlds each with its own train of visual images

Question 28

Conclusion 3

Answer 28

Split brain patients have a lack of cross integration where a second hemisphere does not know hat the first hemisphere has been doing

Question 29

Link to Key Theme

Question 30

Link to Area