Motion Integration and Disambiguation by Spiking V1-MT-MSTl Feedforward-Feedback Interaction

Motion detection registers items within restricted regions in the visual field. Early stages of cortical processing of motion advance this estimate by integrating spatio-temporal input responses in area V1 to build feature representations of direction and speed in area MT of primate cortex. The neural mechanisms underlying such processes are not yet fully understood. We propose a neural model of hierarchically organized areas V1, MT, and MSTl, with feedforward and feedback connections. Each area serves a distinct purpose and is formally represented by layers of model cortical columns composed of excitatory and inhibitory spiking neurons with conductance-based activation dynamics. Recurrent connections enhance activations by modulatory interaction and divisive normalization. MT population activities allow to estimate motion direction and speed which we show for various stimuli. The importance of the feedback connections for disambiguation is demonstrated in simulated lesion studies.