Cognitive Neuroscience Research Unit, Hammel Neurorehabilitation and Research Center, Denmark.
Conscious Cogn. 2010 Dec;19(4):1069-78. doi: 10.1016/j.concog.2009.12.013. Epub 2010 Feb 4.
What is the best way of assessing the extent to which people are aware of a stimulus? Here, using a masked visual identification task, we compared three measures of subjective awareness: The Perceptual Awareness Scale (PAS), through which participants are asked to rate the clarity of their visual experience; confidence ratings (CR), through which participants express their confidence in their identification decisions, and Post-decision wagering (PDW), in which participants place a monetary wager on their decisions. We conducted detailed explorations of the relationships between awareness and identification performance, looking to determine (1) which scale best correlates with performance, and (2) whether we can detect performance in the absence of awareness and how the scales differ from each other in terms of revealing such unconscious processing. Based on these findings we discuss whether perceptual awareness should be considered graded or dichotomous. Results showed that PAS showed a much stronger performance-awareness correlation than either CR or PDW, particularly for low stimulus intensities. In general, all scales indicated above-chance performance when participants claimed not to have seen anything. However, such above-chance performance only showed when we also observed a correlation between awareness and performance. Thus (1) PAS seems to be the most exhaustive measure of awareness, and (2) we find support for above-chance performance in the absence of subjective awareness, but such unconscious knowledge only contributes to performance when we observe conscious knowledge as well. Similarities and differences between scales are discussed in the light of consciousness theories and response strategies.
人们意识到刺激的程度的最佳评估方法是什么？在这里，我们使用掩蔽视觉识别任务，比较了三种主观意识的测量方法：感知意识量表（PAS），参与者通过该量表评估他们的视觉体验的清晰度；信心评级（CR），参与者通过该量表表达他们对识别决策的信心，以及决策后押注（PDW），参与者根据他们的决策下注货币。我们对意识和识别性能之间的关系进行了详细的探讨，旨在确定（1）哪种量表与性能的相关性最好，以及（2）我们是否可以在没有意识的情况下检测到性能，以及这些量表在揭示无意识处理方面有何不同。基于这些发现，我们讨论了感知意识是否应被视为分级的还是二分的。结果表明，PAS 与性能的相关性比 CR 或 PDW 都要强得多，尤其是在低刺激强度下。总的来说，当参与者声称没有看到任何东西时，所有量表都表明存在高于机会的表现。然而，只有当我们观察到意识和性能之间存在相关性时，才会出现这种高于机会的表现。因此，（1）PAS 似乎是最全面的意识测量方法，以及（2）我们发现存在无意识表现高于机会的情况，但只有当我们观察到有意识的知识时，这种无意识知识才会对表现产生影响。我们根据意识理论和反应策略讨论了这些量表之间的异同。
