Sperry

Question 1

What is the aim?

Answer 1

Record the psychological effects hemispheric deconnection in patients with severe epilepsy. Use the results to understand how right and left hemispheres work in ‘normal’ individuals.

Question 2

What is hemispheric deconnection?

Answer 2

• commissurotomy - name of operation (cutting through corpus collosum)
• have 2 brains function independently
• problem for functions that are cross-wired
• not a problem for lateralised functions

Question 3

What are the research methods?

Answer 3

Controlled observation, snapshot study, quasi experiment.

Question 4

What are the IV’s?

Answer 4

Presence of split brain, absence of split brain.

Question 5

What is the DV?

Answer 5

Performance on the visual & tactile tasks.

Question 6

What is the sample?

Answer 6

11 split brain patients, opportunity sampling, from White Memorial Centre, LA, USA.

Question 7

What materials were used?

Answer 7

Tachistoscope - back projector, shows an image for a specific amount of time, gap below projector screen - could reach objects, not see them.

Question 8

What were some conclusions?

Answer 8

• hemispheres work separately
• found lateralisation of function
• evidence of dual processing

Question 9

What is localisation of function?

Answer 9

• Area of the brain (e.g., memory - hippocampus)

Question 10

What is lateralisation of function?

Answer 10

• Hemispheres of the brain (e.g., left hemisphere - language)

Question 11

What was the procedure?

Answer 11

• Asked to focus on cross in middle of screen, one eye covered. Images flashed on screen for 0.1 seconds (only had time to process image in visual field it is placed in).
• Test how R + L hemispheres respond to input from RVF + LVF and R + L hand.

Question 12

What happened in Task 1?

Answer 12

Recognition of visual stimuli presented to L + R hemispheres separately.
- Visual stimulus of picture of object presented to LVF or RVF. Participant shown same image again to same or other VF, asked if they recognised object.

Question 13

What happened in Task 2?

Answer 13

Responding with speech to visual stimuli presented to L + R HS separately.
- Visual stimulus presented to either LVF or RVF. Participant asked to describe visual stimulus.

Question 14

What happened in Task 3?

Answer 14

Responding in writing to visual stimuli presented to L + R HS separately.
- Identical to task 2, required to write instead of say it.

Question 15

What happened in Task 4?

Answer 15

Responding by pointing to visual stimuli presented to L + R HS separately.
- Identical to task 2, pointing rather than saying.

Question 16

What happened in Task 5?

Answer 16

Recognition of visual stimuli presented to L + R HS simultaneously.
- 2 figures flashed simultaneously to LVF + RVF. Participant asked to draw using LH and what had been seen. Say what they had drawn without looking.

Question 17

What happened in Task 6?

Answer 17

Recognition of pairs of related words presented visually + simultaneously to L + R HS.
- Words composed of 2 smaller words presented to participant (half word in LVF, half in RVF). could say it, write it, find objects hidden from view.

Question 18

What happened in Task 7?

Answer 18

Verbal identification of objects placed in the hands.
- Couldn’t see objects in L or R hand. Asked to say/write object or retrieve object that had held using L or R hand.