The present paper proposes to describe possible relationships existing between laterality or sidedness in behavior and neural activity mediated by the corpus callosum, the main commissural fiber system between the two cerebral hemispheres. The experiments, based on observation of human subjects, are concerned with measurement of laterality before and after division of the fibers of the corpus callosum in patients with convulsions (Van Wagenen and Herren1).
The terms sidedness and laterality in behavior refer to a fundamental neurologic and psychologic aspect of bilateral motor coordination, for it is evident that the regulation of movement in all motor activity demands a leading role or preferential use of one side of the body over the other. The fact that one of a pair of bilaterally symmetric muscle groups plays such a leading or preferential role more or less permanently in a majority of activities carried out by the organism has laid