Responses of cat visual cortical cells to continuously and stroboscopically illuminated moving light slits compared.

We have compared responses of cat visual cortical cells of area 17 to continuously illuminated moving slits and to moving slits illuminated stroboscopically at different rates (70-2 Hz) using quantitative multihistogram techniques. At strobe rates over 30 Hz response characteristics of cortical cells are almost identical under both conditions, except for a lower response level under stroboscopic illumination. As strobe rates decrease below 30 Hz, direction selectivity and velocity tuning are severely impaired and some cells start responding to the individual strobe flashes rather than to the motion of the slit.