Recovering motion information from luminance.
We review evidence that visual transient channels responding to temporal change of luminance provide inputs to motion mechanisms, and also play a part in judgments of static brightness. These channels can be adapted to give after effects of apparent dimming or brightening. Nonlinearity in these channels causes a sawtooth grating to look dark (or light) while it is moving to the left (or right). The perceptual outcome in a competitive motion situation is governed by the larger temporal change in luminance: when a white bar and a black bar suddenly change places, on a dark (light) surround it is the white (black) bar that appears to move. The motion system responds to linear, not log luminance. If a black and white picture dissolves (fades) to its own photographic negative which if shifted a few min arc to the right "reversed apparent motion" is seen toward the left. These results constrain possible models of motion perception.
D000221:Adaptation, Ocular; D005366:Figural Aftereffect / Q000502:physiology; D006801:Humans; D008027:Light; D009039:Motion Perception / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D010783:Photometry