Abstract
Sensorimotor adaptation is a change that compensates for a contingency between body movements and stimuli. It has been demonstrated using eye movements and color (Bompas & O'Regan, 2006; Kohler, 1951; Richters & Eskew, 2007). Can sensorimotor adaptation occur with hand movements and color, without eye movements? In the adaptation phase, we correlated leftward hand movements (using a joystick) and presentation of a high-contrast red spot, and rightward hand movements and a similar green spot. In each trial, observers heard five color names (e.g., “red”, “red”, “green”, “red”, “green”). They produced the same sequence of colors on the screen by moving the joystick to the appropriate sides. In the later test phase, observers controlled the presentation of a sequence of two flashes using leftward and rightward hand motions. Observers compared near-threshold colors of the spots, which varied around white, by judging if the second spot was “redder” or “greener” than the first spot. Although the effect is weak, observers consistently tended to respond “greener” after a leftward hand movement and “redder” after a rightward hand movement, as if to compensate for the correlation between hand movement and chromaticity they experienced in the adaptation phase. Various alternative explanations will be discussed.