Crossmodal metaperception: Visual and tactile confidence share a common scale

Perceptual decisions are typically accompanied by a subjective sense of (un)certainty. There is robust evidence that observers have access to a reliable estimate of their own uncertainty and can judge the validity of their perceptual decisions. However, there is still a debate to what extent these meta-perceptual judgements underly a common mechanism that can monitor perceptual decisions across different sensory modalities. It has been suggested that perceptual confidence can be evaluated on an abstract scale that is not only task-independent but also modality-independent. We aimed to scrutinize these findings by measuring visual contrast and tactile vibration discrimination thresholds in a confidence forced-choice task. A total of 56 participants took part in our study. We determined thresholds for trials in which perceptual decisions were chosen as confident and for those that were declined as confident. Confidence comparisons were made between perceptual decisions either within the visual and tactile modality, respectively, or across both modalities. Furthermore, we assessed executive functions to explore a possible link between cognitive control and meta-perceptual capacities. We found that perceptual performance was a good predictor of confidence judgments and that the threshold modulation was similarly pronounced in both modalities. Most importantly, participants compared their perceptual confidence across visual and tactile decisions with the same precision as within the same modality. Cognitive control capacities were not related to meta-perceptual performance. In conclusion, our findings corroborate that perceptual uncertainty can be accessed on an abstract scale, allowing for confidence comparisons across sensory modalities.

Predicting confidence across observers and cognitive domains

Our perceptual system appears hardwired to exploit regularities of input features across space and time in seemingly stable environments. This can lead to serial dependence effects whereby recent perceptual representations bias current perception. Serial dependence has also been demonstrated for more abstract representations such as perceptual confidence. Here we ask whether temporal patterns in the generation of confidence judgments across trials generalize across observers and different cognitive domains. Data from the Confidence Database across perceptual, memory, and cognitive paradigms was re-analyzed. Machine learning classifiers were used to predict the confidence on the current trial based on the history of confidence judgments on the previous trials. Cross-observer and cross-domain decoding results showed that a model trained to predict confidence in the perceptual domain generalized across observers to predict confidence across the different cognitive domains. Intriguingly, these serial dependence effects also generalized across correct and incorrect trials, indicating that serial dependence in confidence generation is uncoupled to metacognition (i.e. how we evaluate the precision of our own behavior). We discuss the ramifications of these findings for the ongoing debate on domain-generality vs. specificity of metacognition.

Tuned inhibition in perceptual decision-making circuits can explain seemingly suboptimal confidence behavior

Current dominant views hold that perceptual confidence reflects the probability that a decision is correct. Although these views have enjoyed some empirical support, recent behavioral results indicate that confidence and the probability of being correct can be dissociated. An alternative hypothesis suggests that confidence instead reflects the magnitude of evidence in favor of a decision while being relatively insensitive to the evidence opposing the decision. We considered how this alternative hypothesis might be biologically instantiated by developing a simple neural network model incorporating a known property of sensory neurons: tuned inhibition. The key idea of the model is that the level of inhibition that each accumulator unit receives from units with the opposite tuning preference, i.e. its inhibition ‘tuning’, dictates its contribution to perceptual decisions versus confidence judgments, such that units with higher tuned inhibition (computing relative evidence for different perceptual interpretations) determine perceptual discrimination decisions, and units with lower tuned inhibition (computing absolute evidence) determine confidence. We demonstrate that this biologically plausible model can account for several counterintuitive findings reported in the literature where confidence and decision accuracy dissociate. By comparing model fits, we further demonstrate that a full complement of behavioral data across several previously published experimental results—including accuracy, reaction time, mean confidence, and metacognitive sensitivity—is best accounted for when confidence is computed from units without, rather than units with, tuned inhibition. Finally, we discuss predictions of our results and model for future neurobiological studies. These findings suggest that the brain has developed and implements this alternative, heuristic theory of perceptual confidence computation by relying on the diversity of neural resources available.

Perceptual Experience and Degrees of Belief

According to the recent Perceptual Confidence view, perceptual experiences possess not only a representational content, but also a degree of confidence in that content. The motivations for this view are partly phenomenological and partly epistemic. We discuss both the phenomenological and epistemic motivations for the view, and the resulting account of the interface between perceptual experiences and degrees of belief. We conclude that, in their present state of development, orthodox accounts of perceptual experience are still to be favoured over the perceptual confidence view.

Confidence Forced-Choice and Other Metaperceptual Tasks*

Metaperception is the self-monitoring and self-control of one’s own perception. Perceptual confidence is the prototypical example of metaperception. Perceptual confidence refers to the ability to judge whether a perceptual decision is correct. We argue that metaperception is not limited to confidence but includes other judgments such as the estimation of familiarity and the aesthetic experience of sensory events. Perceptual confidence has recently received a surge of interests due in particular to the design of careful psychophysical experiments and powerful computational models. In psychophysics, the use of confidence ratings is the dominant methodology, but other paradigms are available, including the confidence forced choice. In this latter paradigm, participants are presented with two stimuli, make perceptual decisions about these stimuli, and then choose which decision is more likely to be correct. One benefit of confidence forced choice is that it disregards confidence biases to focus on confidence sensitivity. Confidence forced choice might also be a paradigm that will allow us to establish whether confidence is estimated serially or in parallel to the perceptual decision.