[OPTICAL REVIEW Vol. 21, No. 3 (2014) 298-303]
© 2014 The Japan Society of Applied Physics

Ecologically Valid Defocus Blur Contributes to Avoidance of Interocular Suppression in Half-Occluded Zones

Masahiro SUZUKI*

Human Media Research Center, Kanagawa Institute of Technology, Atsugi, Kanagawa 243-0292, Japan

(Received September 5, 2013; Accepted March 3, 2014)

In this study, the effect of defocus blur on the avoidance of interocular suppression in half-occluded zones, which are the monocular zones formed by occlusion, was examined. Six human adults observed a pair of colored random-dot stereograms, and the cumulative time of disappearance of the half-occluded zones was measured. There were three defocus blur conditions (blurry-background, blurry-occluder, and nonblur) and two fixation conditions (fixation-front and fixation-back). The author found that the cumulative time of disappearance was shorter under the blurry-background condition of the fixation-front condition and under the blurry-occluder condition of the fixation-back condition than under the other conditions. These results indicate that ecologically valid defocus blur contributes to the avoidance of interocular suppression in the half-occluded zones.

Key words: half-occlusion, half-occluded zones, interocular suppression, binocular rivalry, defocus blur, ecological validity, binocular vision, stereopsis

*E-mail address: msuzuki@ctr.kanagawa-it.ac.jp