ABSTRACT
In 1976, Jerre Levy and Colin Trevarthen distinguished between hemispheric ability and hemispheric dominance and introduced a concept they referred to as metacontrol. Hemispheric ability refers to how well each cerebral hemisphere can handle a particular information-processing task and has been the subject of a great deal of research over the last two decades. Levy and Trevarthen used the term hemispheric dominance to refer to the degree to which each cerebral hemisphere in commissurotomy patients tends to assume control of information processing and behavior. In experiments with four commissurotomy patients, they discovered that the ability differences between the two cerebral hemispheres are not the sole determinant of hemispheric dominance. That is, in commissurotomy patients the hemisphere that assumed control was not always the hemisphere with the greater ability to perform the task. Levy and Trevarthen refer to the neural mechanisms that determine which hemisphere will attempt to control cognitive operations as metacontrol.
