Visual illusions

The parade of lights flashing on a theatre marquee provides an important lesson in how the brain creates the illusion of motion. Whilst we know the bulb remains stationary, the lighting and dimming of each in succession makes it appear that light is moving across the marquee. Even when successive bulbs are separated by a large space, our brains fill in the missing data to create the illusion that the motion has occurred smoothly from one point to the next. But where in the brain does the illusion occur?

We have performed a series of experiments using an apparent motion illusion to show that Primary visual cortex activity along the apparent-motion trace reflects illusory perception, as a result of predictive feedback from motion area V5.

See also TMS Over V5 Disrupts Motion Prediction, Transfer of predictive signals across saccades, Detection of visual events along the apparent motion trace in patients with paranoid schizophrenia, The timing of feedback to early visual cortex in the perception of long-range apparent motion, Deciding what to see: the role of intention and attention in the perception of apparent motion, A spatio-temporal interaction on the apparent motion trace, The cortical representation of objects rotating in depth, and Apparent motion: event-related functional magnetic resonance imaging of perceptual switches and States.