Split - brain research

Question 1

What is split - brain research?

Answer 1

• a series of studies which began in the 1960s involving people with epilepsy who had experienced a surgical separation of the hemispheres of the brain to reduce the severity of their epilepsy. This enabled researchers to test lateral functions of the brain in isolation

Question 2

What does the split - brain operation involve?

Answer 2

• it involves severing the connections between the RH and LH, mainly the corpus callosum. This is a surgical procedure to reduce epilepsy.
• During an epileptic seizure, the brain experiences excessive electrical activity which travels across both hemispheres
• Split - brain studies how the hemispheres function when they can not communicate with each other

Question 3

What was Sperrys procedure?

Answer 3

• Eleven people who had split - brain operations were studied using a special set up where an image could be projected to the participants RVF ( processed by the LH) and the same or different image could be projected to the participants LVF (processed by the RH)
• in the normal brain, the corpus callosum would share the information across hemispheres

Question 4

What were Sperrys findings?

Answer 4

• when a picture of an image was showed to the RVF, the participants could describe what they saw but when the image was shown to the LVF, they could not
• this is because the image from the RVF would be processed by the LH where language centres are
• Although participants could not give verbal labels to images projected to the LVF, they could select a matching object to the picture using their left hand ( connected to the RH)
• The left hand could also select an image associated with the image shown
• when an image was shown to the LVF there was an emotional reaction

Question 5

What conclusions did sperry make?

Answer 5

The LH = verbal and the RH = silent but emotional

Question 6

What is a strength of split - brain research

Answer 6

• there is research support from recent split - brain research. Gazzinga showed that split - brain participants actually perform better than connected controls on certain tasks. For example, they are faster at identifying the odd one out in an array of similar objects. In a normal brain, it is said that the LH’s better cognitive strategies are watered down by the inferior RH

Question 7

What is a limitation of split - brain research

Answer 7

• there is generalisation issues
• A limitation is that causual relationships are hard to establish.
• The behaviour of sperrys split - brain participants was compared to a neurotypical control group. An issue is that no one in the control group had epilepsy. This is a major confounding variable. Any difference between the two groups may be due to epilepsy rather than the split brain research
• This means that some of the unique features of the split - brain participants’ cognitive abilities might have been due to their epilepsy