Sperry Flashcards
What area does Sperry belong to ?
The biological area
What is the background?
Earlier research using split brain animals showed many behavioural effect (Myers 1961)
Describe the research method
It is a quasi/natural park experiment
IV- having a split brain or not
DV- participant ability to perform in a variety of visual and tactile tests
Describe the sample
11 patients who had undergone hemisphere deconnection to reduce severe epilepsy
Only 2 looked at in detail- Man who had his 5 1/2 years before the experiment and a woman who had hers 4 years before
What was the visual test like ?
The participant, with one eye covered, centred their gaze on a fixed point in the centre of a translucent screen.
Visual stimuli was presented for 1/10 of a second.
What was the tactile test like?
Below the translucent screen there was a gap so that participants could reach objects but not see their hands. Objects were either placed in their right/left or both hands
What were the key findings
Information shown and responded ok one visual field could only be recognised again if shown to the same visual field
Info presented to RVF could be describe in speech and writing
Info presented to LVF, the participant said they either didn’t see anything and they could not describe it in speech or writing. However they could draw the object with their left hand (RH)
What were the conclusions?
People with split brains have two separate visual inner worlds
Split brain patients seem to have two independent streams of consciousness.
Research methods
+ IV is naturally occurring, helps us gain info without doing unethical experiments.
- only naturally occurs for a small amount of people
- no cause and effect relationship
Validity
+ high internal validity. No demands characteristics. Motivation won’t change the participants ability to perform.
- low in population validity. Epileptic patients brains may differ more than just the absence of the corpus collosum. They may have been affected by the severe epileptic seizures
- low ecological validity. Artificial task and highly controlled environment.
Reliability
+ standardised procedure. Every participant was shown the same images and given the same objects
- difficult to replicate and check for consistency. Sample is specialised and small. It is hard to get hold of more split brain patients
Sampling bias
- sample is unrepresentative. Very small sample, only 2 looked at in detail. May have been differences in the degree of the completion of the split brain procedure
Ethnocentrism
+ brain physiology should be universal, brains in the US should work the same way as others countries do. Cultural issues should not impact
- split Brain procedure are a westernised process
