Awareness and confidence in perceptual decision-making

Abstract Perceptual decision-making employs a range of higher order metacognitive processes. Two of the most important of these are perceptual awareness; or the clarity with which one reports seeing a perceptual stimulus, and response confidence; or the certainty one has about the correctness of one's own perceptual categorizations. We used a novel false feedback paradigm to investigate the relationships between these two processes. We asked people to perform a standard psychophysical detection task. We used feedback to selectively intervene either on our participants’ trust in their own perceptual awareness of the stimulus, or on their confidence in their own responses. We measured the effects of these interventions on response accuracy; on reports of perceptual awareness; and on response confidence. We found that by undermining people's trust in their awareness of the sensory stimulus, we could reliably reduce their accuracy on the task. We suggest that the reason this occurred is that people came to rely less on evidence from their senses when making perceptual decisions. We conclude by suggesting that there is a not a one-to-one mapping between content in conscious experience and how that content is used in perceptual decision making, and that one's perception of the reliability of content also plays a role Significance statement This paper explores how different kinds of metacognitive state are related to one another and to perceptual decision making. Our focus is on the states of metacognitive confidence and perceptual awareness. We examine how an intervention on the reliability of these states influences performance in a perceptual detection task. We also examine how the intervention influences reports of the states themselves. The intervention we use is false feedback. For one group of participants, we tell them their perceptual judgement is wrong whenever they report they are uncertain in their choice (confidence intervention). For another group, we tell them their judgement is wrong whenever they report that their experience of the stimulus is unclear (awareness intervention). We find that both interventions reduce the accuracy of people's judgements, but that the awareness intervention is more effective. Also, we find that only the awareness intervention reduces reports of both metacognitive confidence in the response, and awareness of the stimuli. The confidence intervention does not influence either metacognitive state. These results suggest that we should understand confidence and awareness as separate higher level cognitive states, and that we should understand awareness as having a stronger causal role than confidence in perception and performance. It has become increasingly common to include measures of metacognition in studies of perceptual decision-making. The two most common measures are metacognitive confidence ratings, which are designed to measure subjective certainty in the correctness of one's perceptual choices [11] , and the perceptual awareness scale (PAS), which is designed to measure the clarity with which one experiences the sensory stimulus [16 , 19] . These measures are often treated as interchangeable. However, it has been shown that the two kinds of measures yield different results, even when they are included in the same task for the same participants [13 , 15 , 17 , 18 , 23] . Metacognition is typically considered a "higher order state", in contrast to "first order" cognitive states. Mental states of the first order denote our perceptions, thoughts, and emotions that by most accounts can be conscious or unconscious [7] . Mental states of a second order are most often referred to as metacognitive, i.e. mental states that are about first order mental states [5 , 10] . Here we present a simple experiment designed to further investigate the relationship between the two measures. In this experiment, we asked participants to perform a visual discrimination task. On each trial, we also asked participants to report their sensory awareness of the stimulus they had just seen, and their metacognitive confidence in their response. As an experimental manipulation, we selectively intervened on participants’ perceived reliability of the two types of metacognition. In one group (i.e. the false confidence rating group), whenever participants reported that they were “slightly confident” of their response, we told them it had been wrong, even if it was correct. In another group (i.e. the false perceptual awareness scale group), whenever participants reported that they only saw a “vague glimpse” of the stimulus, we told them their response had been wrong, even if it was correct. We then compared how these two interventions influenced participants’ confidence ratings, perceptual awareness ratings, and choice accuracy in the task. The results of the experiment suggest that such an intervention on the reliability of perceptual awareness can reduce peoples’ awareness ratings, their confidence ratings, and even their choice accuracy. Surprisingly, we find that the same kind of intervention on metacognitive confidence does not have the same effects. When people are consistently told that any response about which they are only slightly confident is also wrong, then we find that only their choice accuracy is reduced. Moreover, the evidence for this effect is weaker than for the comparable effect of false feedback about perceptual awareness.