Paper2: Biological-Sperry

Question 1

Describe the aim in Sperry?

Answer 1

• investigate effects of hemisphere disconnection
• further understand functions of left and right hemisphere

Question 2

Describe the sample

Answer 2

11 participants, right handed
opportunity sampling
all had severe epilepsy and had not responded to drug therapy
2 had undergone surgery sometime before the study
9 had recently undergone surgery

Question 3

What type of experiment was sperry?

Answer 3

quasi experiment

Question 4

What was the iv?

Answer 4

absence of presence of corpus callosum - already naturally occurring since Sperry did not conduct these operations

Question 5

What was the dv?

Answer 5

whether participants could name, recognise and draw objects

Question 6

Describe the method

Answer 6

participants vision is divided into right and left visual fields
hands were screened away from their vision
participants remained in silence for the study unless they were asked a question by the experimenter; prevented information to be sent to other hemisphere
had to stare at a fixation point so that the information is only presented to one visual field
images flashed for 1/10th of a second

Question 7

Describe the visual test

Answer 7

shown one stimuli at a time or both stimuli to both visual fields
when information was presented to one visual field, the other eye was covered

Question 8

Describe the visual test results

Answer 8

right
- could name image they have seen
- can point and find object w/ right hand

left
- can draw image w/ left hand
- can find object using left hand
- can’t name object

Question 9

Describe the tactile test

Answer 9

• involves touch
• participants can’t see their hands or the objects they have been given to hold

Question 10

Describe the tactile test results

Answer 10

Right hand
- can name and describe object
- can find object again if placed into a bag of other objects
- can’t find same object using left hand

Left hand
- can’t name or describe object
- can find object again using left hand if placed into a bag of other objects
- can’t find same object w/ right hand

Question 11

Describe the conclusions

Answer 11

• the corpus callosectomy patients, information presented to one hemisphere could only be dealt with by that hemisphere.
• An object presented to the left visual field or in the left hand could not be named (or ‘seen’) by the participant, but in the right they could.
• Two objects in right and left fields/hands resulted in only the one presented to the right being ‘seen’ and named.
• Sperry concluded that there are two independent hemispheres of the brain.

Question 12

Describe the strengths to the study

Answer 12

standardised procedure and stimuli presentation would have made this replicable.
very consistent - reliable

Question 13

Describe the weaknesses of the study

Answer 13

sample group may have had other issues with brain dysfunction.
a small sample so the generalisability to how the normal brain would function reduces the population validity.

Question 14

describe ethnocentrism

Answer 14

The findings were only applicable to western ideas of medicine and biological psychology and we don’t know how split brain operations occur in other cultures

Question 15

Describe the nature/nurture debate

Answer 15

biological factors such as severed corpus callosum can impact behaviour