Research by [[Michael Gazzaniga]] and [[Roger Wolcott Sperry]] performed in the [[1960s]] on [[split-brain]] patients led to an even greater understanding of functional laterality. Split-brain patients are patients who have undergone corpus callosotomy (usually as a treatment for severe epilepsy), a severing of the [[corpus callosum]]. The corpus callosum is a heavy white matter tract that connects the two hemispheres of the brain and allows them to communicate. By severing these connections, the two halves of the brain act independently of one another. This process lead to a wide array ofmany interesting [[behavior]]al phenomena that allowed Gazzaniga and Sperry to research the contributions of each hemisphere in various cognitive and perceptual processes. One of their primarymain findings was that the right hemisphere of these patients was capable of rudimentary lanugage processing, but often has no lexical or grammatical abilities{{an|Kandel}}.
