Hemispheric Lateralisation And Split Brain Research

Question 1

AO1: hemispheric lateralisation

Answer 1

lateralisation- one hemisphere of the brain being responsible for particular psychological and physical functions.

split brain is when the corpus colosseum is removed which creates hemispheric de-connection.

Question 2

AO1: Sperry and Gazzangia study:

Answer 2

conducted 3 different experiments on split brain patients; describe what you see, tactile test and drawing task.

On the describe what you see the RVF could describe and the LVF couldn’t. Shows the language centres are in the left hemisphere

on the tactile experiment the participant could describe what was in their hand for RVF but not LVF. Again shows that the language centre is in the right hemisphere

on the drawing task the LVF pictures were clear and the RVF pictures weren’t clear. Shows the participant is using his right hemisphere for this task

Question 3

Evaluation: strength- increases the ability to perform multiple tasks simultaneously.

however- animals so cant generalise

Answer 3

P: brain lateralisation increases the ability to perform multiple tasks simultaneously.
E: found in domestic chickens, brain lateralisation is associated with an ability to perform 2 tasks simultaneously (finding food and being vigilant for predators).
L: shows brain efficiency can be enhanced when it comes to research into hemispheric lateralisation
HOWEVER, as the study was done on animals it cant be generalised to target population when it comes to research into hemispheric lateralisation.

Question 4

Limitation- split brain procedure is rarely carried out

however- patients are studied in a lot of detail

Answer 4

P: split brain procedure is rarely carried out
E: studies often only include a few patients and a lot of the time they have confounding physical disorders that made the procedure necessary.
E: patients without confounding disorders are rarely encountered in enough numbers to be useful for research
HOWEVER,
despite the sample size being small, all patients are studied in a lot of detail.

Question 5

limitation- research suggests lateralisation changes with age

Answer 5

P: research suggests lateralisation changes with age
E/E: found that language became more lateralised to the left hemisphere with increasing age in children but then decreases at 25.
L: raises questions when it comes to research into lateralisation

Question 6

limitation: language might not be restricted to the left hemisphere

Answer 6

P: argued that language may not be restricted to the left hemisphere
E/E: discovered a patient who suffered damage to the left hemisphere, but developed the capacity to speak in the left hemisphere.
L: suggests that perhaps lateralisation is not fixed and that the brain can adapt following damage to certain areas.