The time course of visuo-motor affordances.

To measure dynamic visuo-motor coupling within the two hemispheres, we showed observers an animation of a rotating cup. They indicated with left or right buttons when a fixation dot in the center of the animation changed color. For either hand, response times changed continuously with the irrelevant position of the cup's handle, even when the perceptual asymmetry of the handle was controlled. This spontaneous lateralized motor preparation showed both top-down and bottom-up components and was more pronounced for the right than the left hand. The dynamic affordance method will help understand perception-action coupling in the brain.