Abstract
INTRODUCTION Stereo-curvature aftereffects involve shifts in perceived curvature after prolonged inspection of stereoscopic 3D surfaces. Domini et al. (2001) have reported that stereo-curvature aftereffects occur at the level where disparities are coded into perceived shape curvature rather than at the level where disparities are registered to disparity curvature. However, there are other possible adaptation sources in addition to shape curvature, considering stationary adaptation stimuli used in their study. Besides, little attention has been focused on position or scale dependence of the aftereffects. METHODS In our study, adaptation stimuli were dynamically presented with changing location or scale. To examine the effect of the dynamic presentation of location, different average disparity information (ADI) was generated within the visual fields subtended to test stimuli. Aftereffect magnitude was compared among three adaptation conditions (Average_Flat, Average_Convace and Average_Convex/Fixed_Size) in terms of different ADI from which the synthesized surfaces were flat, concave or convex. To examine the effect of the dynamic scale, adaptation stimuli were presented by periodical expansion-contraction in another condition (Dynamic_Size) where there was no adaptation to the shape curvature of each instantaneous presentation. Observers were required to judge whether test stimuli appeared concave or convex. The method of constant stimuli was used to determine a PSE of flat surface. The aftereffect magnitude was defined as the difference of PSE between each adaptation condition and no-adaptor condition. RESULTS ANOVA on aftereffect magnitude showed significant differences between every pair of conditions of different ADI with Average_Convex/Fixed_Size condition the largest and Average_Convace condition the smallest. But no significant difference was found between Average_Convex/Fixed_Size and Dynamic_Size conditions. CONCLUSION Stereo-curvature aftereffects are retinal position dependent and not scale dependent. The significant aftereffect in the Dynamic_Size condition suggests that the aftereffect is not only due to shape curvature but also due to other adaptation sources such as ADI.
Meeting abstract presented at VSS 2014