Previous research suggests binocular rivalry disrupts extrastriate, but not striate processes, although the locus along the visual pathway at which such disruption first occurs is uncertain. It has been argued that subjective contours arise via a two-stage process in which end-stopped cells feed into orientation-sensitive neurones in V2, and that orientation aftereffects induced with subjective contours are the product of mechanisms similar to those giving rise to real contour aftereffects. If binocular rivalry disrupts the acquisition of subjective contour aftereffects, then it follows from this model that rivalry disrupts processing in V2. Experiments reported here confirm this and provide evidence which suggests binocular rivalry arises through interactions between binocular neurones, rather than via some type of specialized binocular rivalry mechanism.

Previous research suggests that plaid-induced motion aftereffects (MAEs) involve extrastriate mechanisms (Wenderoth et al., 1988). There is evidence also that binocular rivalry occurs beyond VI and that it disrupts the processing of MAEs which are believed to be based upon extrastriate mechanisms (e.g. the spiral MAE) but not MAEs, such as linear MAE induced by a drifting grating, which are thought to arise in striate cortex (Wiesenfelder & Blake, 1990). The logical inference is that binocular rivalry during drifting plaid-induced adaptation should reduce the MAEs which result. We report experiments which confirm this prediction.