It wasn’t until Sperry’s split-brain research that it was possible to test the idea of hemispheric lateralisation. His studies used a unique group of participants, all of whom had undergone the same treatment for their severe epilepsy which involved cutting the corpus callosum in order to control severe epileptic seizures. While the surgery was successful in helping to control the patients’ seizures, it also left them with unique brains, giving Sperry an opportunity to test the abilities of each hemisphere as independently functioning structures. (With thanks to our sponsor 'Curriculum Press' for providing content for this podcast)