Biopsychology: Lateralisation Flashcards
What is hemispheric lateralisation?
The idea that the two halves of the brain are functionally different and that certain mental processes and behaviours are mainly controlled by one hemisphere.
What did Sperry study?
Split brain research
Who took part in Sperry’s study?
The participants all had disconnected hemispheres due to severe epilepsy, allowing him to see the extent which the two hemispheres were specialised.
What was the procedure for Sperry’s Study?
Image or word shown just to the right eye (LH) and same or different image to the left eye (RH)
What were the different variations?
Describe what you see
Composing a word
Recognition by touch
Matching faces
What were the findings for describe what you see?
Right eye = can identify
Left eye = can’t verbally identify, typically reported nothing there
What were the findings for composing a word?
Right eye = would say the word
Left eye = would write the word
What were the findings for recognition by touch?
In each case the patient was not able to verbally identify what they had seen but could nevertheless ‘understand’ what the object was using the right hemisphere and select the corresponding object accordingly.
What were the findings for matching faces?
When a picture made up of two halves of a face was presented the left hemisphere dominated in terms of verbal description whereas the right dominated in terms of selecting a matching picture.
What is the evaluation fro split brain research?
Demonstrated lateralised brain functions
Strengths of methodology
Generalisation
Evaluation point: Demonstrated lateralised brain functions
Sperry’s pioneering work has produced a sizeable body of research. It suggests that the LH is the analyser whilst the RH is the synthesiser. A key contribution to our understanding of brain processes.
Evaluation point: Strengths of methodology
The experiments made use of highly specialised and standardised procedures. His method allowed him to vary aspects of the basic procedure and ensured that only one hemisphere was receiving information at a time.
Evaluation point: Generalisation
There were only 11 people who took part in the variations all of whom had a history of severe epileptic seizures. This may have caused unique changes in the brain that may have influenced findings.
