Institute of Cognitive Neuroscience & Dept. of Psychology, University College London, 17 Queen Square, WC1N 3AR London, United Kingdom.
Conscious Cogn. 2010 Dec;19(4):1045-57. doi: 10.1016/j.concog.2010.06.003. Epub 2010 Jul 3.
Conscious visual perception can fail in many circumstances. However, little is known about the causes and processes leading to failures of visual awareness. In this study, we introduce a new signal detection measure termed subjective discriminability of invisibility (SDI) that allows one to distinguish between subjective blindness due to reduction of sensory signals or to lack of attentional access to sensory signals. The SDI is computed based upon subjective confidence in reporting the absence of a target (i.e., miss and correct rejection trials). Using this new measure, we found that target misses were subjectively indistinguishable from physical absence when contrast reduction, backward masking and flash suppression were used, whereas confidence was appropriately modulated when dual task, attentional blink and spatial uncertainty methods were employed. These results show that failure of visual perception can be identified as either a result of perceptual or attentional blindness depending on the circumstances under which visual awareness was impaired.
在许多情况下，意识性视觉感知可能会失败。然而，对于导致视觉意识失败的原因和过程，我们知之甚少。在这项研究中，我们引入了一种新的信号检测度量方法，称为不可见性的主观可分辨性（SDI），它可以区分由于感觉信号减少或无法注意到感觉信号而导致的主观失明。SDI 是基于对报告目标不存在的主观信心（即，错过和正确拒绝试验）来计算的。使用这种新方法，我们发现当使用对比度降低、后向掩蔽和闪光抑制时，目标缺失在主观上与物理缺失无法区分，而当使用双任务、注意力眨眼和空间不确定性方法时，信心则得到适当调节。这些结果表明，视觉感知的失败可以被识别为是感知性失明还是注意力性失明，这取决于视觉意识受损的情况。
