Abstract
Cortical form vision comprises multiple, hierarchically arranged areas with feedforward and feedback interconnections. This complex architecture poses difficulties when scientists attempt to link perceptual phenomena to a particular level of the system. This difficulty has been especially salient in recent research into binocular rivalry alternations, where there is seemingly conflicting evidence for a locus in primary visual cortex or alternatively in higher cortical areas devoted to object perception. In particular, it has been shown that if orthogonal monocular gratings are flickered at 18.0 Hz and switched between eyes at 1.5 Hz, dominance of one grating survives 6–7 eye switches, thus implicating a higher binocular level for rivalry in this case. A nonlinear neural model for rivalry demonstrates that the data require two hierarchic rivalry stages for their explanation. This model demonstrates that competitive inhibition in the monocular rivalry stage is defeated by the 18.0 Hz flicker, 1.5 Hz eye switching stimulus dynamics, thereby revealing properties of a subsequent binocular rivalry stage. This result produces a synthesis of alternative rivalry theories and suggests that neural competition may be a characteristic of multiple cortical areas in the form vision pathway.