Split Brain Research Into Hemispheric Lateralisation AO3

Question 1

✅ What is a major strength of Sperry and Gazzaniga’s split-brain research methodology?

Answer 1

The use of highly standardised procedures — e.g., fixation point, one-eye blindfolding, image flashed for 1/10th of a second — ensured only one hemisphere received information at a time, giving high control and internal validity.

Question 2

✅ What does research using PET scans (Fink et al., 1996) show about lateralisation in typical brains?

Answer 2

Even in connected brains, the right hemisphere processed global features (e.g., forest), while the left focused on fine detail (e.g., trees), supporting lateralisation beyond split-brain patients.

Question 2

❌ Why is generalising split-brain findings problematic?

Answer 2

Only 11 patients were studied in all procedures, and all had epilepsy, which may have caused brain changes. This makes generalisation to neurotypical brains questionable and limits external validity.

Question 3

❌ What do modern neuroscientists say about verbal/non-verbal hemisphere distinctions?

Answer 3

They argue that the distinction is often oversimplified. The hemispheres constantly communicate, and tasks are not as lateralised as once thought — lateralisation is messier and more fluid.