Split-brain research into hemispheric lateralisation

Question 1

Define the term hemispheric lateralisation

Answer 1

• the idea that the two halves of the brain are functionally different

Question 2

Outline Sperry’s study

Answer 2

• involved unique individuals where they had undergone an operation called commissurotomy in which tissues connecting he two hemispheres was cut
• Sperry showed an image to either the right or left eye but not both so that the visual information would not be conveyed to both of the hemispheres

Question 3

What were the key findings of Sperr's research
       ((((((4 categories))))))
- describing what you see
- recognition by touch
- composite words
- matching faces

Answer 3

• describing what you see: when object was shown to right eye patient could easily describe what they saw, however opposite was true when shown to the left eye
• recognition by touch: when projected to the left visual field they could not attach verbal labels to object but could select matching object from grab-bag using their left hand, in other words patient was able to understand what the object was but was unable to verbally label it
• composite words: if two words were presented at the same time, for eg a key on the left side and a hat on the right side the individual would write the word key with their left hand and say the word hat
• matching faces: right hemisphere appeared dominant in terms of recognising faces

Question 4

What is a strength of Sperry’s research

Answer 4

• demonstrated lateralised brain functions, and it has shown to be a key contributor to our understanding of brain processes

Question 5

What is a weakness of this research

Answer 5

• issues with generalisation

- split brain patients are a very unusual minority and so it is difficult to generalise Sperry’s findings