A neural model of motion processing and visual navigation by cortical areaMST

Cells in the dorsal medial superior temporal cortex (MSTd) process optic fl ow generated by self-motion during visually guided navigation. A neural mod el shows how interactions between well-known neural mechanisms (log polar c ortical magnification, Gaussian motion-sensitive receptive fields, spatial pooling of motion-sensitive signals and subtractive extraretinal eye moveme nt signals) lead to emergent properties that quantitatively simulate neurop hysiological data about MSTd cell properties and psychophysical data about human navigation. Model cells match MSTd neuron responses to optic flow sti muli placed in different parts of the visual field, including position inva riance, tuning curves, preferred spiral directions, direction reversals, av erage response curves and preferred locations for stimulus motion centers. The model shows how the preferred motion direction of the most active MSTd cells can explain human judgments of self-motion direction (heading), witho ut using complex heading templates. The model explains when extraretinal ey e movement signals are needed for accurate heading perception, and when ret inal input is sufficient, and how heading judgments depend on scene layouts and rotation rates.