Abstract
The correspondence between motion appearances and accommodative responses to two kinds of multiple-motion stimuli was examined to clarify whether the accommodation mechanism cooperates with the non-Fourier motion detection mechanism or not. The stimuli were amplitude-modulated drifting sine waves and an abruptly shifted compound sine wave that consisted of a Fourier motion component and a non-Fourier motion component moving in opposite directions. Accommodative responses were measured using an infrared optometer while observers were paying attention to each component wave's motion. The following results were obtained : (1) both the motion appearance and the accommodative state were changed depending on which component wave's motion was the object of attention; (2) each accommodative state was suitable for perceiving the attention-getting component wave's motion and separating both motion components; (3) the accommodative state shifted to one direction (far or near) as the attention-getting non-Fourier wave's spatial frequency decreased; (4) the above results were independent of the viewing distance. These results suggest that the accommodation mechanism is a cooperative system that interacts with the non-Fourier motion detection mechanism as well as the Fourier motion detection mechanism.
