Abstract
Visual motion processing is often attributed to the dorsal visual pathway despite visual motion's involvement in almost all visual functions. Furthermore, some visual motion tasks critically depend on the structural integrity of regions outside the dorsal pathway. Here, based on our findings and numerous additional studies in human and non-human primates, I propose that visual motion signals are swiftly transmitted via multiple non-hierarchical routes to motion-dedicated processing regions (MT/V5 and MST) and then propagated to a multiplicity of brain areas according to task demands, reaching these regions earlier than the hierarchical flow. This not only places MT/V5 at the same or even earlier visual processing stage as that of V1, but can also elucidate many findings with implications to visual awareness. While the integrity of the non-hierarchical motion pathway is necessary for all visual motion perception, it is insufficient on its own, and the transfer of visual motion signals to additional brain areas is crucial to allow the different motion perception tasks (e.g. optic flow, visuo-vestibular balance, movement observation, action execution, dynamic form detection and perception, and even reading). Multiple provided predictions allow testing this proposal.
Meeting abstract presented at VSS 2016