Is stimulus movement of particular importance in the functioning of cat visual cortex?

On average, cells in areas 17, 18 or 19 of normal and stroboscopically reared cats respond with equal maximum firing rates to a narrow bar of light whther moving at the optimal velocity in the preferred direction of movement or flashed at the optimal position within the receptive field. Firing rates in the non-preferred direction of movement are much lower, however, suggesting that direction selectivity is mostly based on inhibition.