Interocular transfer of visual aftereffects.

Abstract

A number of the well-known visual after-effects of adaptation exhibit interocular transfer, so that presentation of an adaptation figure to one eye produces a temporary change in the performance of the nonadapted eye. This outcome is usually attributed to the involvement of binocular visual neurons that respond to stimulation of either eye. The fact that interocular transfer is incomplete (i.e., the transferred aftereffect is smaller in magnitude than that induced and measured in the same eye) is routinely cited as evidence for the involvement of monocular neurons. This article critically examines these two interpretations, which are developed in terms of a neural model of interocular transfer. No evidence, logical or empirical, was obtained for rejecting the model. Our analysis further shows that the model must assume some type of pooling process that operates over all tested neurons, both adapted and unadapted. Finally, general implications of the interocular transfer model are discussed, the aim being to delimit the conclusions that may be drawn from interocular transfer experiments.