The stereoscopic (cyclopean) motion aftereffect is selective for spatial frequency and orientation of disparity modulation

Across two experiments, this study investigated the spatial frequency tunin g and orientation tuning (both in the disparity domain) of the stereoscopic (cyclopean) motion aftereffect. In Experiment I, observers adapted to a mo ving stereoscopic grating of a given cyclopean spatial frequency and tested for the motion aftereffect with a static grating of the same or different spatial frequency. Robust motion aftereffects were induced only when the sp atial frequency of the adapt and test stimuli was the same. In Experiment 2 , observers adapted to a moving stereoscopic grating of a given cyclopean o rientation and tested for the motion aftereffect with a static grating of t he same or different orientation. Robust motion aftereffects were induced o nly when the orientation of the adapt and test stimuli was the same. Togeth er, these results suggest that the stereoscopic motion aftereffect is tuned for cyclopean spatial frequency and orientation which, in turn, suggest th at the stereoscopic motion aftereffect is mediated by low-level oriented sp atial-frequency mechanisms. (C) 1999 Elsevier Science Ltd. All rights reser ved.