Kazumichi MATSUMIYA^*

Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan

(Received August 3, 2005; Accepted October 25, 2005)

An impression of a surface seen through holes is created when one fuses dichoptic pairs of discs with one member of each pair black and the other white. This is referred to as the ‘sieve effect’. This stimulus contains no positional disparities. The impression of depth in the sieve effect is most evident when the size, contrast, and rim thickness of rivalrous patterns are such as to produce exclusive rivalry. I investigated how long it took for the sieve effect to recover from exclusive rivalry suppression. The magnitude of perceived depth in the effect was measured after exclusive rivalry suppression of one half-image of the sieve-effect stimulus. The results showed that the sieve effect takes approximately 630 ms to recover from exclusive rivalry suppression, compared with 200 ms for disparity-based stereopsis. Considered together with the previous report [Matsumiya and Howard: Invest. Ophthalmol. Visual Sci. 42 (2001) S403] that the sieve effect is positively correlated with the rate of exclusive rivalry, these findings suggest that the effect and exclusive rivalry are processed in the identical channel.

Key words: binocular vision, stereopsis, binocular rivalry, depth perception, the sieve effect

^*E-mail address: kmat@riec.tohoku.ac.jp