Seungbae LEE, Satoshi SHIOIRI¹ and Hirohisa YAGUCHI¹

Graduate School of Science and Technology, Chiba University, 1-33 Yayoicho, Inage-ku, Chiba, 263-8522 Japan
¹Department of Information and Image Sciences, Chiba University, 1-33 Yayoicho, Inage-ku, Chiba, 263-8522 Japan

(Received October 16, 2003; Accepted February 27, 2004; Revised February 9, 2004)

To investigate the effect of exposure duration on stereopsis and its spatial frequency dependency, we measured disparity threshold for the depth discrimination varying stimulus exposure duration between 0.05 and 2 s for three spatial frequencies (0.23, 0.94 and 3.75 c/deg). The results showed that disparity threshold decreased with increase in exposure duration up to a certain duration, beyond which it was approximately constant (the duration is called critical duration). The critical duration was about 150 ms for gratings with low and middle spatial frequencies (0.23 and 0.94 c/deg) while the duration was about 750 ms for gratings with high spatial frequency (3.75 c/deg). This suggests that temporal integration property varies dependently on stimulus spatial frequency. We also attempted to relate the spatial frequency dependency of the temporal integration property to the differences in temporal frequency tuning to different spatial frequency stimuli.

Key words: exposure duration, disparity threshold, stereo acuity, spatial frequency, tuning channel and stereopsis