Editing Split-brain (section)

=== Combination of both tests ===

In the last test the experimenters combined both the tactile and visual test. They presented subjects with a picture of an object to only their right hemisphere, and subjects were unable to name it or describe it. There were no verbal responses to the picture at all. If the subject was able to reach under the screen with their left hand to touch various objects, however, they were able to pick the one that had been shown in the picture. The subjects were also reported to be able to pick out objects that were related to the picture presented, if that object was not under the screen.<ref>{{cite journal|last=Gazzaniga|first=Michael|title=The Split Brain in Man|journal=Scientific American|year=1967|volume=217|issue=2|pages=24–29|doi=10.1038/scientificamerican0867-24|bibcode=1967SciAm.217b..24G}}</ref>

Sperry and Gazzaniga went on to conduct other tests to shed light on the [[language processing in the brain|language processing]] abilities of the right hemisphere as well as auditory and emotional reactions as well. The significance of the findings of these tests by Sperry and Gazzaniga was extremely telling and important to the psychology world. Their findings showed that the two halves of the brain have numerous functions and specialized skills. They concluded that each hemisphere really has its own functions. One's left hemisphere of the brain is thought to be better at writing, speaking, mathematical calculation, reading, and is the primary area for language. The right hemisphere is seen to possess capabilities for problem solving, recognizing faces, symbolic reasoning, art, and spatial relationships.{{citation needed|date=December 2020}}

Roger Sperry continued this line of research up until his death in 1994. Michael Gazzaniga continues to research the split brain. Their findings have been rarely critiqued and disputed; however, a popular belief that some people are more "right-brained" or "left-brained" has developed. In the mid-1980s [[Jerre Levy|Jarre Levy]], a psychobiologist at the University of Chicago, was at the forefront of scientists who wanted to dispel the notion we have two functioning brains. She believes that because each hemisphere has separate functions that they must integrate their abilities instead of separating them. Levy also claims that no human activity uses only one side of the brain. In 1998 a French study by Hommet and Billiard was published that questioned Sperry and Gazzaniga's study that severing the corpus callosum actually divides the hemispheres of the brain. They found that children born without a corpus callosum demonstrated that information was being transmitted between hemispheres, and concluded that subcortical connections must be present in these children with this rare brain malformation. They are unclear about whether these connections are present in split-brain patients though. Another study by Parsons, Gabrieli, Phelps, and Gazzaniga in 1998 demonstrated that split-brain patients may commonly perceive the world differently from the rest of us. Their study suggested that communication between brain hemispheres is necessary for imaging or simulating in one's mind the movements of others. Morin's research on inner speech in 2001 suggested an alternative for interpretation of [[commissurotomy]] according to which split-brain patients exhibit two uneven streams of self-awareness: a "complete" one in the left hemisphere and a "primitive" one in the right hemisphere.<ref>{{cite book|last=Hock|first=Roger R.|title=Forty Studies that Changed Psychology: Explorations into the History of Research|publisher=Upper Saddle River|isbn=978-0-13-114729-4|year=2005|url-access=registration|url=https://archive.org/details/fortystudiesthat00hock_1}}</ref>