SPEED DISCRIMINATION OF STEREOSCOPIC (CYCLOPEAN) MOTION

This study investigated the degree to which speed of stereoscopic tran slational motion (i.e. moving binocular disparity information) can be discriminated in a display that minimizes position information. Observ ers viewed dynamic random-element stereograms depicting arrays of rand omly positioned stereoscopic dots that moved bidirectionally. Two task s were performed: a speed discrimination task and a displacement discr imination task Across a range of conditions, speed could be discrimina ted under conditions in which displacement could not. Thus, speed of s tereoscopic motion can be discriminated when position information is m inimal. This result indicates that stereoscopic motion is sensed in a way that cannot be explained by feature tracking or by inferring the m otion from memory of position and time. (C) 1997 Elsevier Science Ltd. All rights reserved.