BIOPSYCHOLOGY - hemispheric lateralisation and split brain research

Question 1

what is hemispheric lateralisation?

Answer 1

• the idea that the two hemispheres have different functions
• certain behaviours are mainly controlled by one hemisphere rather than the other

Question 2

what does the left hemisphere consist of?

Answer 2

• Broca’s area = left frontal lobe
• Wernicke’s area = left temporal lobe
• analyser
• controls the right side of the body
• right visual field
• speech
• logical thinking

Question 3

what does the right hemisphere consist of?

Answer 3

• controls left side of the body
• Left visual field
• recognising faces

Question 4

LVF

Answer 4

• information received in the LVF is processed in the RH

Question 5

RVF

Answer 5

information received in the RVF is processed in the LH

Question 6

what is the corpus callosum?

Answer 6

connects both the hemispheres together so that they can share information

Question 7

what is split-brain research?

Answer 7

• research involving people with epilepsy
• ## the patients hemispheres were separated by surgery to reduce the severity of their epilepsy

Question 8

outline the process of Sperry’s research (1968).

Answer 8

• 11ps who had split brain surgery
• image projects to RVF and LVF
• in normal brain = corpus callosum would immediately share information between both hemispheres
• split brain ps = info cannot be conveyed from one hemisphere to another

Question 9

outline the findings of Sperry’s research.

Answer 9

pic shown to RVF (processed by LH) = ps can describe what was seen

pic shown to LVF (processed by RH) = ps could select a matching object . left hand could select the object too.

Question 10

explain the findings of Sperry’s research?

Answer 10

these observations show that certain functions are lateralised in the brain and support the view that the LH is verbal and the RH is ‘silent’ but emotional.

Question 11

give the strengths of research into hemispheric lateralisation.

Answer 11

+ fink et al (1996) - PET scans showed that the RH was more active when participants were asked to attend global elements of an image. When required to focus on finer detail - LH tended to dominate
= suggests that hemispheric lateralisation is a feature of the connected brain as well as the split brain

Question 12

give limitations of research into hemispheric lateralisation.

Answer 12

• the idea that LH as analyser and RH as synthesiser may be wrong = Nielsen analysed 1000 ppls brain scans = found that people used certain hemispheres for certain tasks - no evidence for a dominant side

Question 13

give strengths of split brain research.

Answer 13

RESEARCH SUPPORT:
- Luck et al (1989) found that split brain participants have better performance = faster at identifying the odd one out .
in normal brain = LH’s cognitive strategies are ‘watered down’ by RH
= supports sperry’s findings that RH and LH are distinct

Question 14

give limitations of split brain research.

Answer 14

• causal relationships are hard to establish
  behaviours of sperry’s split brain Ps was compared to a control group where they did not have epilepsy = this is a major confounding variable.
  any differences observed btw 2 groups may be result of epilepsy rather than split brain