在亮度对比和颜色对比下立体视知觉的定量研究

研究了在亮度对比与等亮度颜色对比的条件下，受试者分辨随机点阵立体图对的立体视敏度（最小视差）．结果表明：（１）在亮度对比条件下，立体视敏度随对比度的增加而增加，１０％的对比度即可引起立体视知觉，对比度大于３０％时达到饱和；（２）在亮度对比与等亮度颜色对比两种不同的条件下，受试者的立体视敏度不存在有统计学意义的差异；（３）当双眼分别接受不同颜色的等亮度立体图刺激时，与亮度对比条件相比，受试者的立体视敏度无明显差异；（４）当受试者双眼分别接受由亮度对比和颜色对比形成的立体图刺激时，只有当颜色对比图中图形与背景间的对比度超过等亮度值３８％以上时，才能形成立体视知觉．以上结果提示，大、小细胞系统（包括斑点系统与斑点间系统）均参与立体视知觉信息的传递．

QUANTITATIVE STUDYS OF RANDOM-DOT INDUCED STEREO VISION UNDER LUMINANCE CONTRAST AND COLOR CONTRAST

The depth perception in random-dot stereograms (RDS) was investigated under two different display conditions: equiluminance with chromaticity contrast and heteroluminance without chromaticity contrast. The main results were: (1) RDSs were found to induce depth equally well under both display modes; (2)The disparity threshold for perceiving depth in isochromatic RDSs reached its minimum and leveled off at a luminance contrast of 30%, with larger disparities, depth was perceived down to about 10% contrast;(3) When the two eyes were stimulated with chromaticity RDSs, but with different color contrast, the disparity threshold was not significantly different from that with heteroluminance RDSs; (4) Under the condition that one eye was stimulated with chromaticity RDS and the other with heteroluminance RDS, the observers could perceive depth only when contrast of the chromaticity RDS was substantially above equiluminance. The findings suggested that stereoscopic depth is mediated by both the magnocellular and parvocellular (blob and interblob) systems.