[Bilateral mechanisms of interference resistance in the parastriate cortex]

The influence of photic interference is manifested in animals (in cats) with an intact callosal body mainly in EP depression. The extent of EP depression depends directly on the strength of the interference and is inversely related to that of the determined stimulus. In some cases yet another effect, facilitation of EP may be manifested during the action of a weak interference. These facts are considered to result from postrevely. Section of the callosal body is followed by a weakening of the depressing influence of photic interference on EPs elicited by a certain stimulus, as well as by an enhancement of the facilitating influence on EPs of weak photic interferences. A stronger influence of a binocular photic interference, as compared with a monocular one, has been established in intact and callosotomized animals. A conclusion has been drawn that the interference resistance of a split brain is stronger than that of an intact one. A comparison of the interference resistance in the primary and secondary cortical visual projection zones has shown that after callosotomy interference resistance in the striate cortex increases to a greater extent than in the parastriate area.