ABSTRACT
Although Roger Wolcott Sperry made pioneering discoveries into the chemical basis of neural development, he is most famous for his research on split-brain patients – work showing that the two cerebral hemispheres have very different psychological abilities and personalities. When Sperry traced the regenerating optic nerve, he found that the original pathway from eye to brain was maintained again – indicating that the growing retinal pathways were being guided to their original places of termination regardless of the eye's position. Using cats as subjects, Sperry devised a means by which he could present visual information to each hemisphere. His results showed that the learning curves for each hemisphere to learn visual discrimination tasks was identical – proving that two separate brains could exist side-by-side inside the cranium. He emphasised that the combined effect of bi-hemispheric activity amounted to more than the simple additive effects of the two separate hemispheres.
