Stimuli with higher luminance contrast tend to be perceived closer in depth. In order to quantify this effect, we measured subjective depth on the test stimulus as a function of luminance contrast, using depth matching technique. The depth of a reference stimulus was matched to that of the test stimulus by changing the binocular disparity. To investigate a spatio-temporal characteristic of this effect, we varied the spatial frequency and temporal frequency of the test stimulus. The results show in all spatio-temporal conditions the test stimulus was perceived much closer when the luminance contrast was higher. To consider the mechanism of this effect consists of single or multi channels, we examined two models. The single channel model predicts better performance than the multi-channel model. Our results suggest that the subjective depth modulation from luminance contrast is processed by single channel mechanism.
