Department of Integrated Psychological Science, Kwansei Gakuin University Nishinomiya, Japan.
Front Hum Neurosci. 2011 Oct 28;5:125. doi: 10.3389/fnhum.2011.00125. eCollection 2011.
The Craik-O'Brien-Cornsweet (COC) effect demonstrates that perceived lightness depends not only on the retinal input at corresponding visual areas but also on distal retinal inputs. In the COC effect, the central edge of an opposing pair of luminance gradients (COC edge) makes adjoining regions with identical luminance appear to be different. To investigate the underlying mechanisms of the effect, we examined whether the subjective awareness of the COC edge is necessary for the generation of the effect. We manipulated the visibility of the COC edge using visual backward masking and continuous flash suppression while monitoring subjective reports regarding online percepts and aftereffects of adaptation. Psychophysical results showed that the online percept of the COC effect nearly vanishes in conditions where the COC edge is rendered invisible. On the other hand, the results of adaptation experiments showed that the COC edge is still processed at the early stage even under the perceptual suppression. These results suggest that processing of the COC edge at the early stage is not sufficient for generating the COC effect, and that subjective awareness of the COC edge is necessary.
克雷克-奥布赖恩-科恩斯威特（COC）效应表明，感知的亮度不仅取决于相应视觉区域的视网膜输入，还取决于远距离视网膜输入。在 COC 效应中，一对亮度梯度的中央边缘（COC 边缘）使具有相同亮度的相邻区域看起来不同。为了研究该效应的潜在机制，我们考察了 COC 边缘的主观意识是否对该效应的产生有必要。我们使用视觉后向掩蔽和连续闪光抑制来操纵 COC 边缘的可见度，同时监测在线感知和适应后效的主观报告。心理物理学结果表明，在 COC 边缘变得不可见的情况下，COC 效应的在线感知几乎消失。另一方面，适应实验的结果表明，即使在感知抑制下，COC 边缘在早期阶段仍在被处理。这些结果表明，COC 边缘在早期阶段的处理不足以产生 COC 效应，并且 COC 边缘的主观意识是必要的。
