SPERRY

Question 1

AIM?

Answer 1

Investigate the effects of hemisphere disconnection and show that each hemisphere has different functions.

Question 2

Research method?
Research design?

Answer 2

1. quasi.
2. independent measures.

Question 3

IV?
DV?

Answer 3

1. whether the individual has a split brain or not.
2. the individuals performance on visual & tactile tasks.

Question 4

Sample?
Sampling method?

Answer 4

1. 11 participants (with epilepsy)
2. opportunity

Question 5

Data?
Materials?

Answer 5

1. both
2. tachistoscope

Question 6

Explain the visual fields?
Explain the hemispheres & functions?
Which hands do they control?

Answer 6

1. Left visual field - right hemisphere - creativity - left hand
2. Right visual field - left hemisphere - language - right hand

Question 7

Describe the visual field tasks?

Answer 7

1. The participants using the tachistoscope would have one eye covered and were instructed to stare at the focal point.
   - they were flashed images for a 10th of a second, to either side of the focal point, to be seen in one visual field.

Question 8

Explain the visual stimuli tasks (recognition and description)?

Answer 8

Recognition - P’s could only recognise pictures that had been re-shown to the same visual field.

Description:
Left visual field - they could draw what they saw.
Right visual field - they could say what they saw.

Question 9

Describe the tactile tasks?

Answer 9

Participants were asked to say or write the name of the object in their hands.

Results:
Right hand - they were able to name the object in speech or writing
Left hand - random guesses

Question 10

Conclusion?

Answer 10

In split-brain patients, their perception in each hemisphere is independent as well as their memory.

Question 11

EVALUATION:
Research method - quasi
Data - both

Answer 11

Quasi
+ = high mundane realism - natural environment.
- = low ecological validity (would use both visual fields in real life).

Data
+ = easy to compare/rich in detail

Question 12

EVALUATION:
Validity
Reliability

Answer 12

Validity
+ = high face validity (measures disconnection of hemispheres)
- = low population validity (11 people)

Reliability
+ = high internal reliability (took part in all tests)
- = low external reliability

Question 13

EVALUATION:
Sample
Sampling method - opportunity

Answer 13

sample:
+ = ethical sample (naturally occurring brain disconnection).
- = low population validity (11 people)

Sampling method:
+ = convenient + quick
- = sample bias (all have epilepsy + split brain - cannot compare to people without)

Question 14

EVALUATION:
ethnocentrism?
Ethics?

Answer 14

Ethnocentric?
- can’t apply to all cultures as some don’t allow split-brain surgery.

Ethics?
+ informed consent
+ privacy/confidentiality
+ no physical harm
- right to withdraw compromised (they’re unique to the study)
- psychological harm (see them as different to others).