lateralisation/ split brain eval

Question 1

W: issues with generalisation

Answer 1

ID: a weakness of research into split-brain patients is that there are issues of generalisability
Q: sperry and gazzaniga used a small sample size of 11 unusual split-brain participants, who had a history of epileptic seizures.
EX: this means that findings may have been influenced by the unique changes in the brain instead and some patients experienced more disconnection of the two hemispheres as part of their surgical procedures than others.
AN: therefore, any conclusions drawn cannot be generalised to the wider population as the findings are only representative of those who had a confounding physical disorder that made the procedure necessary.

Question 2

S: controlled procedure

Answer 2

ID: however, the research can be credited for using a controlled procedure
Q: the experiment conducted by sperry and gazzaniga used a specialised standardised methodology.
EX: for example, patients were given eye patches, and images were flashed up for a very brief time (fractions of a second), meaning there was no possibility of looking over and using the other visual field.
AN: therefore, this level of control enables the replication of his methods and the reliability of the findings to be assessed, increasing the internal validity of the study.

Question 3

W: contradicting research (turk)

Answer 3

ID: despite controlled procedures, there is contradicting evidence against split-brain research
Q: this comes from turk et al who conducted a case study on a patient known as J.W.
EX: for example, he developed the capacity to speak using his right hemisphere regardless of whether info was presented on the left or right visual field. this supports the idea of brain plasticity and that different areas of the brain are equipotential.
AN: therefore, a limitation of sperry and gazzaniga’s research is that there is evidence that goes against the ideas of hemispheric lateralisation.