MOTION PROCESSING FOR SACCADIC EYE-MOVEMENTS DURING THE VISUALLY INDUCED SENSATION OF EGO-MOTION IN HUMANS

During ego-motion an observer is often faced with the task of controll ing his heading direction while simultaneously registering the movemen t of objects in order to avoid possible obstacles. Psychophysical expe riments have shown that the detection of moving objects is impaired by concurrent ego-motion, We investigated the interaction between ego-mo tion and object-motion by examining the latencies of saccades executed to moving targets under a visually induced sensation of ego-motion, S accadic latencies increased during this sensation, with a global or no n-retinotopic effect of optic flow on motion detection. Furthermore, s eparating stereoscopically the moving target and the optic flow into f oreground and background, respectively, still resulted in increased la tencies, We propose that an inhibitory influence of the perception of self-motion exists on the perception of object-motion, These results s upport a model of space constancy which strives to create a stable wor ld during locomotion. (C) 1997 Elsevier Science Ltd.