Comparison of behavioural measures of consciousness has attracted much attention recently. In a recent article, Szczepanowski et al. conclude that confidence ratings (CR) predict accuracy better than both the perceptual awareness scale (PAS) and post-decision wagering (PDW) when using stimuli with emotional content (fearful vs. neutral faces). Although we find the study interesting, we disagree with the conclusion that CR is superior to PAS because of two methodological issues. First, the conclusion is not based on a formal test. We performed this test and found no evidence that CR predicted accuracy better than PAS (p = .4). Second, Szczepanowski et al. used the present version of PAS in a manner somewhat different from how it was originally intended, and the participants may not have been adequately instructed. We end our commentary with a set of recommendations for future studies using PAS.
Consciousness and Cognition, 2013, Vol 22, Issue 3, p. 806-9