Neural Mechanisms of Visual Flow Integration and Segregation —Insights from the Pinna-Brelsta. Illusion and Variations of It

Abstract

The mechanisms involved in the cortical processing of large- field motion patterns still remain widely unclear. In particular, the integrative action of, e.g., cells and their receptive fields, their specificity, the topographic mapping of activity patterns, and the reciprocal interareal interaction needs to be investigated. We utilize a recently discovered relative motion illusion as a tool to gain insights into the neural mechanisms that underlie the integration and segregation of such motion fields occurring during navigation, steering and fixation control. We present a model of recurrent interaction of areas V1, MT, and MSTd along the dorsal cortical pathway utilizing a space-variant mapping of flow patterns. In accordance with psychophysical findings, our results provide evidence that recurrent gain control mechanisms together with the non-linear warping of the visual representation are essential to group or disambiguate motion responses. This provides further evidence for the importance of feedback interactions between cortical areas.