Hemispheric lateralisation

Question 1

What is hemispheric lateralisation?

Answer 1

Functions that are localised to each hemisphere of the brain

Question 2

Both hemispheres

Answer 2

-Vision
-motor
-somatosensory

Question 3

Right hemisphere

Answer 3

responsible for visual and spatial processes

Question 4

Left Hemisphere

Answer 4

responsible for language processing and articulation

Question 5

Who conducted split brain research?

Answer 5

Sperry (1968)

Question 6

What was the procedure of sperrys research?

Answer 6

11 people who had split brain operation were studies using a special set up in which an image could be projected to a participants RVF (processed by the LH) and the same, or different image projected to the LVF (processed by the RH)
-In the ‘normal brain’ the corpus callous would immediately share the information between both hemispheres giving a complete picture
-however, presenting the image to one hemisphere of a split- brain ppt mean that information cannot be conveyed between hemispheres

Question 7

Findings of Sperrys research

Answer 7

ppts could not describe objects that were presented to the LVF (RH)- and said there was ‘nothing there’

Question 8

Conclusion of Sperrys research

Answer 8

These observations show how certain functions are lateralised in the brain and support the view that the LH is verbal and the RH is silent but emotional

Question 9

Evaluation of Lateralisation
fink PET

Answer 9

One strength is research showing connected brains…process information differently
-Fink et al - used PET scans to identify which brain areas were active during a visual processing task. When ppts with connected brains were asked to look at global elements of an image, the RH were more active
However, when asked to look at finer details, the LG was more dominant
-suggests that hemispheric lateralisation is a feature of the connected brain as well as split brain

Question 10

Evaluation of split brain research - Gazzaniga

Answer 10

Support from Gazzaniga - showed that split brain ppts performed better than connected controls on certain tasks - (eg faster at identifying the odd one out of similar objects than control group)- This supports sperrys findings that the ‘left brain’ and ‘right brain’ are distinct
as in the normal brain, the LH’s better cognitive strategies were ‘watered down’ by inferior RH (Kingstone)

Question 11

Evaluation of Split-brain research -Generalisation issues

Answer 11

Causal relationships hard to establish - compared to neurotypical group who had no previous experience with epilepsy, unlike split brain group
-confounding variable
-the differences could be due to the epilepsy instead of split brain