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Published online: 4 March 2015
© The Psychonomic Society, Inc. 2015
Abstract Our visual perception is typically accompanied by a sense of subjective confidence. Since perceptual confidence is related to prefrontal activity, higher perceptual confidence may enhance cognitive control functions. To examine this interaction, we developed a novel method to selectively manipulate perceptual confidence while keeping stimulus discrimination accuracy constant. In a behavioral experiment, grating stimuli with different orientations were presented as go/no-go signals. Surprisingly, the results showed that confidence in visual discrimination of the signals on its own did not facilitate response inhibition, since when participants were presented with stimuli that yielded higher confidence, they were no better at performing a go/no-go task. These results were replicated with different (dot motion) stimuli, ruling out alternative explanations based on stimulus idiosyncrasy. In a different experiment, when the grating stimuli were presented as cues for task set preparation, we found that higher perceptual confidence also did not enhance task set preparation efficiency. This result was again replicated with dot motion stimuli. Since confidence may relate to perceptual awareness (Peirce & Jastrow, 1885), our findings may put current dominant theories in question, since these theories often suppose the critical involvement of consciousness in cognitive control. As a proof of concept, our method may also provide a new and powerful way to examine other functions of consciousness in future studies.
Keywords Perceptual confidence · Visual perception · Confidence · Cognitive control · Signal detection theory
In performing simple perceptual decisions (e.g., target discrimination), one may feel more confident in some trials than in others. Although such confidence often reflects perceptual accuracy, recent findings have suggested that the two may dissociate (Del Cul, Dehaene, Reyes, Bravo, & Slachevsky, 2009; Lau & Passingham, 2006, 2007; Rounis, Maniscalco, Rothwell, Passingham, & Lau, 2010). What functional role does perceptual confidence serve? Despite increasing interest in this topic (Fleming & Dolan, 2012; Lau, 2009), this question remains unanswered, perhaps partly because it is a challenge to test the effects of perceptual confidence per se, independently of the effects of perceptual capacity; when one manipulates confidence, perceptual capacity typically also changes.
Here we developed a novel method to dissociate the effects of confidence from those of perceptual capacity, on the basis of...