Operating characteristics and awareness

Although a large proportion of the human brain is dedicated to processing incoming sensory information, much of this processing is not accessible to consciousness. In an effort to understand what differentiates conscious from unconscious processing, we are concerned here with methodological issues in exploring the limits of unconscious processing. We first consider a conscious perceptual experience and establish an operating characteristic to disambiguate perceptual sensitivity from decision criterion. We then apply the same method to dissociate explicit measures of perception from implicit measures of sensory processing. Finally, we evaluate post-decision wagering as a proposed method for measuring awareness.