Fig. 6. Mean gain of the OCR obtained in response to velocity step stimuli for the `walking condition' (animal on the treadmill). For the `standing condition', the treadmill remained still. Each point is the mean value ± s.e.m. (N=12) of responses obtained in the clockwise and anticlockwise directions. The gain curves obtained for different treadmill velocities were not different, but the gain was systematically higher than for the `standing condition'.