Learning to discriminate the eye-of-origin during continuous flash suppression.

Helmholtz asked whether one could discriminate which eye is the origin of one's perception merely based on the retinal signals. Studies to date showed that participants' ability to tell the eye-of-origin most likely depends on contextual cues. Nevertheless, it has been shown that exogenous attention can enhance performance for monocularly presented stimuli. We questioned whether adults can be trained to discriminate the eye-of-origin of their perceptions and if this ability depends on the strength of the monocular channels. We used attentional feed-forward training to improve the subject's eye-of-origin discrimination performance with voluntary attention. During training, participants received a binocular cue to inform them of the eye-of-origin of an upcoming target. Using continuous flash suppression, we also measured the signal strength of the monocular targets to see any possible modulations related to the cues. We collected confidence ratings from the participants about their eye-of-origin judgements to study in further detail whether metacognition has access to this information. Our results show that, even though voluntary attention did not alter the strength of the monocular channels, eye-of-origin discrimination performance improved following the training. A similar pattern was observed for confidence. The results from the feedforward attentional training and the increase in subjective confidence point towards a high-level decisional mechanism being responsible for the eye-of-origin judgements. We propose that this high-level process is informed by subtle sensory cues such as the differences in luminance or contrast in the two monocular channels.

Common computations for metacognition and meta-metacognition.

Recent evidence shows that people have the meta-metacognitive ability to evaluate their metacognitive judgments of confidence. However, it is unclear whether meta-metacognitive judgments are made by a different system and rely on a separate set of computations compared to metacognitive judgments. To address this question, we asked participants (N = 36) to perform a perceptual decision-making task and provide (i) an object-level, Type-1 response about the identity of the stimulus; (ii) a metacognitive, Type-2 response (low/high) regarding their confidence in their Type-1 decision; and (iii) a meta-metacognitive, Type-3 response (low/high) regarding the quality of their Type-2 rating. We found strong evidence for the existence of Type-3, meta-metacognitive ability. In a separate condition, participants performed an identical task with only a Type-1 response followed by a Type-2 response given on a 4-point scale. We found that the two conditions produced equivalent results such that the combination of binary Type-2 and binary Type-3 responses acts similar to a 4-point Type-2 response. Critically, while Type-2 evaluations were subject to metacognitive noise, Type-3 judgments were made at no additional cost. These results suggest that it is unlikely that there is a distinction between Type-2 and Type-3 systems (metacognition and meta-metacognition) in perceptual decision-making and, instead, a single system can be flexibly adapted to produce both Type-2 and Type-3 evaluations recursively.

Metacognition tracks sensitivity following involuntary shifts of visual attention.

Salient, exogenous cues have been shown to induce a temporary boost of perceptual sensitivity in their immediate vicinity. In two experiments involving uninformative exogenous cues presented at various times before a target stimulus, we investigated whether human observers (N = 100) were able to monitor the involuntary increase in performance induced by such transients. We found that an increase of perceptual sensitivity (in a choice task) and encoding precision (in a free-estimation task) occurred approximately 100 ms after cue onset, and was accompanied by an increase in confidence about the perceptual response. These simultaneous changes in sensitivity and confidence resulted in stable metacognition across conditions. These results suggest that metacognition efficiently tracks the effects of a reflexive attentional mechanism known to evade voluntary control, and illustrate a striking ability of high-level cognition to capture fleeting, low-level sensory modulations.

Confidence at the limits of human nested cognition.

Metacognition is the ability to weigh the quality of our own cognition, such as the confidence that our perceptual decisions are correct. Here we ask whether metacognitive performance can itself be evaluated or else metacognition is the ultimate reflective human faculty. Building upon a classic visual perception task, we show that human observers are able to produce nested, above-chance judgements on the quality of their decisions at least up to the fourth order (i.e. meta-meta-meta-cognition). A computational model can account for this nested cognitive ability if evidence has a high-resolution representation, and if there are two kinds of noise, including recursive evidence degradation. The existence of fourth-order sensitivity suggests that the neural mechanisms responsible for second-order metacognition can be flexibly generalized to evaluate any cognitive process, including metacognitive evaluations themselves. We define the theoretical and practical limits of nested cognition and discuss how this approach paves the way for a better understanding of human self-regulation.

Metacognitive blindness in temporal selection during the deployment of spatial attention.

How does orienting attention in space affect the quality of our confidence judgments? Orienting attention to a particular location is known to boost visual performance, but the deployment of attention is far from being instantaneous. Whether observers are able to monitor the time needed for attention to deploy remains largely unknown. To address this question, we adapted a "Wundt clocks" paradigm, asking observers (N=140) to reproduce the phase of a rotating clock at the time of an attentional cue, and to evaluate their confidence in their responses. Attention affected the latency between objective and perceived events: the average reported phase was delayed in accordance with the known latencies of voluntary and involuntary attention. Yet, we found that confidence remains oblivious to these attention-induced perceptual delays, like a 'metacognitive blind spot'. In addition, we observed weaker metacognition specifically during the deployment of voluntary attention, suggesting a tight relationship between the attentional and metacognitive systems. While previous work has considered how visual confidence adjusts to fully attended versus unattended locations, our study demonstrates that the very process of orienting attention in space can alter metacognition.

Temporal attention causes systematic biases in visual confidence.

Temporal attention enhances the perceptual representation of a stimulus at a particular point in time. The number of possible attentional episodes in a given period is limited, but whether observers' confidence reflects such limitations is still unclear. To investigate this issue, we adapted an "Attentional Blink" paradigm, presenting observers with a rapid visual stream of letters containing two targets cued for subsequent perceptual reports and confidence judgments. We found three main results. First, when two targets fell within the same attentional episode, the second target underwent a strong under-confidence bias. In other words, confidence neglected that a single attentional episode can benefit to both targets. Second, despite this initial bias, confidence was strongly correlated with response probability. Third, as confidence was yoked to the evidence used in perceptual reports, it remains blind to delays in response selection for the second target. Notably, the second target was often mistaken with a later item associated with higher confidence. These results suggest that confidence does not perfectly evaluate the limits of temporal attention in challenging situations.