Hemispheric Lateralisation

Question 1

what is hemispheric lateralisation

Answer 1

idea that 2 halves/hemispheres = functionally diff, each one has functional specialisation

Question 2

what is split brain research

Answer 2

study how hemispheres function when unable to communicate with each other

Question 2

roles of the 2 hemispheres

Answer 2

left =dominant for language
- analyser (more cognitive)
right = dominant for visual, motor, spatial tasks
- synthesiser (more creative)
each process/control info from OPP. side of body

Question 3

outline Sperry’s split brain research

Answer 3

• aim to examine extent to which 2 hemispheres specialise for certain functions

Conducted diff tasks:
- describe what you see = picture presented to left/right visual field, pp asked to describe what saw

• tactile test = object placed in pp left/right hand, asked to describe what felt/select object from series of alternate ones
• drawing task = picture presented to left/right visual field, pp asked to draw what saw

Question 4

Pros of research into hemispheric lateralisation

Answer 4

RESEARCH SUPPORT
- Luck et al. (1989) = support Sperry, left and right brain = distinct
= found split-brain pps perform better than connected controls, on certain tasks
e.g., faster at identifying odd one out

Question 5

Cons of research into hemispheric lateralisation

Answer 5

LOW GENERALISABILITY
= small sample size (11) + use of epileptic pps = confounding variable, e.g., condition itelf, or drugs taken to treat epilepsy
= could have influenced the findings produced
- hard to extrapolate to neurotypicals
= impede validity of research

Question 6

what connects both hemispheres

Answer 6

corpus callosum

Question 7

what is split brain, why is it done

Answer 7

• operation which severs corpus callosum
• reduce epilepsy
  = cutting connections reduces excessive electrical activity between hemispheres occuring during epileptic seizures

Question 8

what does Sperry’s research show about hemispheric lateralisation

Answer 8

LH = dominant for speech and language
RH = dominant for visual motor tasks
Research = highlights diff between 2 hemispheres and functions
- split brain patients’ = lesser ability to complete tasks well when made to do so with the opp. hemisphere (did not control said function)
- e.g. worse drawing on right hand (despite mosyt pps being right-handed) because controlled by LH (RH oversees visual motor skills)