Pelekanos Vassilis, Ban Hiroshi, Welchman Andrew E
School of Psychology, University of Birmingham, UK; Department of Psychology, University of Cambridge, UK.
School of Psychology, University of Birmingham, UK; Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka, Japan; Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan.
Vision Res. 2015 May;110(Pt A):87-92. doi: 10.1016/j.visres.2015.02.010. Epub 2015 Mar 24.
The luminance contrast at the borders of a surface strongly influences surface's apparent brightness, as demonstrated by a number of classic visual illusions. Such phenomena are compatible with a propagation mechanism believed to spread contrast information from borders to the interior. This process is disrupted by masking, where the perceived brightness of a target is reduced by the brief presentation of a mask (Paradiso & Nakayama, 1991), but the exact visual stage that this happens remains unclear. In the present study, we examined whether brightness masking occurs at a monocular-, or a binocular-level of the visual hierarchy. We used backward masking, whereby a briefly presented target stimulus is disrupted by a mask coming soon afterwards, to show that brightness masking is affected by binocular stages of the visual processing. We manipulated the 3-D configurations (slant direction) of the target and mask and measured the differential disruption that masking causes on brightness estimation. We found that the masking effect was weaker when stimuli had a different slant. We suggest that brightness masking is partly mediated by mid-level neuronal mechanisms, at a stage where binocular disparity edge structure has been extracted.
正如一些经典视觉错觉所表明的那样，表面边界处的亮度对比度会强烈影响该表面的表观亮度。此类现象与一种传播机制相符，该机制被认为能将对比度信息从边界传播到内部。这个过程会被掩蔽所干扰，在掩蔽过程中，目标的感知亮度会因掩蔽物的短暂呈现而降低（Paradiso & Nakayama，1991），但这种情况发生的确切视觉阶段仍不清楚。在本研究中，我们研究了亮度掩蔽是发生在视觉层级的单眼水平还是双眼水平。我们使用了后向掩蔽，即一个短暂呈现的目标刺激会被随后出现的掩蔽物干扰，以此表明亮度掩蔽受视觉处理的双眼阶段影响。我们操纵了目标和掩蔽物的三维配置（倾斜方向），并测量了掩蔽对亮度估计造成的差异干扰。我们发现，当刺激具有不同倾斜度时，掩蔽效果较弱。我们认为，亮度掩蔽部分是由中级神经元机制介导的，处于已提取双眼视差边缘结构的阶段。
