Powerful motion illusion caused by temporal asymmetries in ON and OFF visual pathways.
Successive presentations of Glass patterns (randomly positioned pairs of dots oriented in a coherent pattern) create a strong sense of global motion along the orientation of the pattern, but ambiguous in direction. Here we report that dynamic "anti-Glass" patterns, created by successive pairs of globally structured pairs of opposite polarity, create an even more powerful motion illusion that is unambiguous in direction: the dark dots always move toward the light. The motion can be cancelled and reversed by introducing a real delay in the presentation of the light dots, suggesting that the effective stimulation of the light is about 3 ms faster than the dark dots. The most plausible explanation for this is that human on channels are faster than off channels, as has been shown in the macaque.
Del Viva
Maria Michela
MM
Department of Psychology, University of Florence, Via San Niccolò 89, Florence 50125, Italy.
Gori
Monica
M
Burr
David C
DC
D006801:Humans; D007088:Illusions / Q000502:physiology*; D009038:Motion; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods*; D013997:Time Factors; D014795:Visual Pathways / Q000502:physiology*