[Functional assymmetry of the cerebral cortex in cats during formation of a conditioned reflex]

During elaboration of a symmetric active defensive reflex, the animal is given the opportunity to make instrumental movements with the right or left paw. On the first day of elaboration, the cats can be subdivided into three approximately equal groups: with the right preferred paw, with the left preferred paw and ambidexters. After stabilization of the reflex, motor asymmetry increases in both preferred groups, while the number of ambidexters diminishes. Unilateral electric shock producing seizures, which is applied to the "dominant" or "subdominant" hemisphere, exerts correspondingly differing influences on the subsequent reproduction of the reflex. Suppression of reproduction is more pronounced when the shock is applied to the "dominant" hemisphere. The result of repetitive application of electroshock to one and the same hemisphere is that the functions of the "dominant" hemisphere are effected by the hemisphere which was not subjected to direct electrical stimulation.