A transition between eye and object rivalry determined by stimulus coherence

Two orthogonal patterns presented to the two eyes, respectively, are percei ved as alternating in time, a phenomenon often assumed to reflect competiti on between neuronal activities corresponding to the two eyes, presumably in the primary visual cortex. Recent evidence supports a competition between neuronal activities corresponding to the two patterns (objects) at some hig her cortical processing stage after inputs from the two eyes have converged . Here, using textures made of Gabor signals, we present psychophysical dat a showing that the level of visual processing at which competition takes pl ace and is resolved, is determined by the degree of stimulus coherence. Mor eover, depending on stimulus parameters, competition may occur at several l evels of processing at the same time. (C) 2001 Elsevier Science Ltd. All ri ghts reserved.