Abstract
Previous studies (Brooks & Gillam, 2006) have shown that temporal interocular unmatched (TIOU) information can result in a perception of a subjective surface with quantitative depth perceived at the object boundary. The present study investigated the conditions in which quantitative depth of the subjective surface can be determined from TIOU information. In Experiment 1 three vertically aligned dots translated horizontally at a constant speed until occluded by an opaque non-textured surface. The subject's task was to adjust two probe dots to match the apparent depth of the surface boundary. Under these conditions TIOU information did not provide quantitative depth of the occluding surface. In Experiment 2 multiple columns of dots were displayed with only one column of dots occluded by the subjective surface at any given time. Under these conditions, the perceived depth of the occluding surface increased with an increase in the temporal interocular gap, demonstrating that surrounding disparity information provides information useful for recovering quantitative depth from TIOU features. In Experiment 3 a single vertical line was presented which translated horizontally until being partially occluded by the subjective surface, providing ordinal depth information. The translation speed of the line and the horizontal width of the surface were varied. The results indicated that the perceived depth of the occluding surface decreased as its width increased, even though the temporal interocular gap and translation speed indicated constant depth information. These results, considered together, (1) support the conclusion of previous research that TIOU information can provide quantitative depth information, (2) demonstrate that adjacent disparity information may provide a metric by which quantitative depth from TIOU information is perceived, and (3) demonstrate that occlusion allows for the propagation of local depth provided by TIOU information.
This work was supported by NIH AG13419-06 and NEI EY18334-01.