Seminar Series

When do you become aware of a stimulus

I compare and contrast three puzzles in the apparent timing of visual events. In one, simultaneous changes in the colour (or luminance) and motion of a stimulus (or of different stimuli) are perceived as synchronous only when they are isolated single events; with repetitive changes the colour or luminance change is perceived before the motion change. Second, regular repetitive visual flashes do not appear equal in duration; the first appears longer than the rest. Third, a moving stimulus is perceived before a stationary flash. Explanations at the neural, cognitive and phenomenological levels will be presented and discussed.