Distinct brain mechanisms for conscious versus subliminal error detection

“Therefore, analysis of variance was performed in R software using a linear mixed-effects model ((Baayen et al., 2008) R package lme4) which allowed us to include all data available (unbalanced design) and still encompass repeated-measures.”

“To detect significance differences between error and correct conditions for each type of sensor, we used a cluster-based non-parametric t-test with Monte Carlo randomization provided in the Fieldtrip software (Maris and Oostenveld, 2007).”

“, 2001), reinforcement learning (Holroyd and Coles, 2002) and conflict processing (Botvinick et al., 2001; Veen and Carter, 2002).”

“…difference between a prediction and an observed outcome: either an ongoing response that departs from the one intended given the perceived stimulus (Alexander and Brown, 2011), or an anticipated reward that departs from the usual one expected when the response is correct (Holroyd and Coles, 2002).”

“The ERN is an event-related potential that peaks on fronto-central electrodes 50 to 100 ms after making an erroneous response; it is easily observed in EEG recordings (Dehaene et al., 1994; Falkenstein et al., 2000; Gehring et al., 1993), and a similar, though harder to detect MEG component has been reported (Keil et…”

“As an extreme case, in blindsight, a patient may deny any conscious experience, while remaining able to perform way above chance in simple tasks on stimuli presented in their blind hemi-field (Kentridge and Heywood, 1999; Weiskrantz, 1996).”

“E urope PM C Funders A uthor M anuscripts E urope PM C Funders A uthor M anuscripts This model is compatible both with the view of the ERN as a conflict monitoring system (Veen and Carter, 2002; Yeung et al., 2004) or a comparison process (Bernstein et al., 1995; Falkenstein et al., 2000).”

“…peaks on fronto-central electrodes 50 to 100 ms after making an erroneous response; it is easily observed in EEG recordings (Dehaene et al., 1994; Falkenstein et al., 2000; Gehring et al., 1993), and a similar, though harder to detect MEG component has been reported (Keil et al., 2010; Miltner…”

“, 2007), but subliminal primes can modulate visual (Dehaene et al., 2001), semantic (Van den Bussche et al.”

“Among currently available methods, we think meta-d′ is the best measure of metacognitive sensitivity, and it is quickly gaining popularity (e.g., Baird et al., 2013; Charles et al., 2013; Lee et al., 2013; McCurdy et al., 2013).”

“button but only if the stimulus that led to the error was consciously perceived, thus allowing a conscious top-down intention signal to be compared with the ongoing action (Charles et al., 2013).”

“Further research is needed to elucidate the significance of the recently reported additional activity in PCC (1, 83).”

“…of variability affect the strength of error-and confidence signals in the brain; for instance, neural signatures of error detection are also modulated by the degree of sensory uncertainty of the subject (Charles et al., 2013; Navarro-Cebrian, Knight, & Kayser, 2013; Scheffers & Coles, 2000).”

“In order to elicit an ERN, target and task-irrelevant stimuli must be processed to a level of subjective awareness (Charles et al., 2013;Woodman, 2010), suggesting that the ERN represents higher-level cognitive processing that occurs after stimulus information has been brought to perceptual…”

“For instance, the hypothesis that conscious perception coincides with the ability to deploy higher-order thoughts or metacognition (the brain’s ability to represent its own knowledge states) [45] does not bode well with evidence that self-monitoring, error detection and confidence assignment partially operate non-cons…”

“However, Charles et al. (2013) recently observed dissociations between graded confidence and binary error judgments.”

“As perceptual visibility is likely to be dissociable from metacognitive confidence (Charles et al., 2013; Zehetleitner and Rausch, 2013), future studies are needed to determine the respective contributions of PFC to metacognitive accuracy and subjective visibility.”

“2014) further processing of stimulus information (Rabbitt and Vyas 1981; Charles et al. 2013) or knowledge of other influences on task performance when making their metacognitive judgments (Fleming and Daw 2017).”

“In the psychological tradition, confidence is thought to arise from the monitoring of mental content; it is sometimes framed as a form of metacognition associated with other subjective human qualities, such as introspection, awareness, and even self-reflective consciousness (Charles et al., 2013; Flavell, 1979; Kunimo…”

“The Pe (described in the last section as being a candidate for post-decisional evidence accumulation) has been linked to error awareness and shown to covary with subjective confidence, whereas the ERN and its pMFC source are thought to also operate unconsciously (Charles et al., 2013).”

“The term “epistemic feeling” has been coined to describe this subjective, on-line, experience of an error (Arango-Muñoz, 2010; Charles et al., 2013).”

“Many researchers believe normal, healthy subjects can also directly discriminate near-threshold, low-intensity targets without subjective awareness (e.g., Boyer et al., 2005; Charles et al., 2013; Merikle et al., 2001; but see Snodgrass et al., 2004 for an opposing view).”

“Parallel extraction by distinct circuits could account for the fact that confidence and performance are often correlated, but still dissociable [44,45], for instance in situations of speeded judgment [29], overconfidence [46], or when the accuracy of confidence is impaired while performance is preserved.”

“For instance, it is possible that a Dual Channel model may perform better for other kinds of phenomena (Del Cul et al., 2009; Charles et al., 2013; Charles et al., 2014).”

“Similarly, in recent years it has been shown that frontal executive networks of our brain can unconsciously register the occurrence of response errors [7–9], conflicting response alternatives [10–12] and competing task sets [13,14].”

“The phenomenon of automatic error detection [16,73] provides evidence that this is not the case.”

“The EEG analysis was performed with response-locked eventrelated potentials over fronto-central electrodes, following the standard procedure for computing an ERN [14, 15, 22].”

“Some recent studies show that errors that are due to perceptual failures trigger smaller error-related neural activity than motor errors, and reduced error awareness typically decreases ERN amplitude (Charles et al., 2013; Cohen et al., 2009; Pavone et al., 2009).”

“Different accounts postulate that the ERN reflects a mismatch between the intended and the actual response (Charles et al., 2013; Nieuwenhuis et al., 2001), the detection of conflict (Yeung et al.”

“Event-related potential and eventrelated fields of these data have been partially reported previously (Charles et al., 2013).”

“However, signal-theoretic models suggest that error awareness may contribute more directly to an interoceptive sense of uncertainty or doubt, or a graded subliminal awareness of errors (Fleming et al., 2012; Charles et al., 2013).”

“correspondence between confidence and accuracy) and conscious awareness (Charles et al., 2013; Fleming and Lau, 2014; Jachs et al., 2015).”

“In addition, it is difficult to see how this objection fits with the finding that sensory evidence continues to accumulate after the Type-1 decision, thus increasing metacognitive efficiency (Charles et al. 2013; Pleskac & Busemeyer, 2010; Moran et al. 2015; Murphy et al. 2015).”

“independently of the Ne/ERN, which implies that different error detection mechanisms exist and may proceed independently of each other (Charles et al., 2013; Falkenstein et al., 2000; Maier et al., 2015).”

“This conclusion fits with two recent experiments in which subjects performed above-chance in their confidence judgments, even on trials reported as unseen (KANAI ET AL., 2010; CHARLES ET AL., 2013).”

“Whether you are conscious of seeing a face, of making an error (Charles et al., 2013) or of being sad, that information must be in the global workspace.”

“One possibility is that the early correlate for committed decisions relates to an “all-or-none” automatic error detection system (Charles et al., 2013, although see Vocat et al., 2011, Pereira et al., 2017), while the late correlate underlies a fine-grained estimation of second-order signals (Boldt…”

“…relationship between perceptual consciousness and metacognitive awareness is not well understood, however, and some recent studies suggest that metacognitive judgement is possible in the absence of perceptual sensitivity or awareness (Charles et al., 2013; Scott et al., 2014; Jachs et al., 2015).”

“, related to perceptual decision making or memory) can be successfully deployed even when type 1 sensitivity is null [20, 21], i.”

“…the way that typical measures of cognitive control (e.g., posterror slowing, response conflict/inhibition; Rabbitt, 1966; Ridderinkhof et al., 2004; Charles et al., 2013; Wokke et al., 2016) and metacognition are related (Boldt and Yeung, 2015) remains an interesting open empirical question.”

“Although binary visibility scales such as the one used here have been widely adopted [26], for example in studies using masking [70,71], attentional blink [72], dichoptic fusion [73], and interocular suppression [74,75]; recently, the four-point perceptual awareness scale (PAS) [17] has gained in popularity.”

“…the present pattern of confidence without visibility seems to be reasonably robust as it was replicated in patients (Sahraie et al., 1998; Carota and Calabrese, 2013) and healthy human observers in a range of tasks (Schlagbauer et al., 2012; Charles et al., 2013; Zehetleitner and Rausch, 2013).”

“A similar distinction between conscious and unconscious monitoring of errors was found when visual masking was used so that participants sometimes made decisions about targets that they classified as ‘unseen’ (Charles et al., 2013).”

“…area is considered crucial in the detection of error following a false mental prediction and in the detection of internal conflict, such as dissonance between two competing goals, but it is unclear whether this is associated with conscious perception of the stimulation or not (Charles et al. 2013).”

“For example, Charles et al. (2013) showed that participants could differentiate between correct and incorrect judgments in a simple decision task, even though they did not perceive the stimulus they had to decide on.”

“4%) were analyzed by fitting a linear mixed regression model predicting RTs using equation (1), with the fixed and random effects structure specified in equations (6) and (7), respectively.”

“This is seen for example in situations, where one detects an error without knowing the correct response (Charles et al., 2013; Di Gregorio et al., 2018), or in patients with compromised ERN (Maier et al., 2015).”

“So, in some cases there could be more sensory evidence at the time of the type-2 decision than for the type-1 decision alone, which inflates type-2 sensitivity—how efficiently the observer's confidence ratings discriminate correct from incorrect decisions (Balsdon et al., 2020; Charles et al., 2013; Charles & Yeung, 2…”

“To obtain grand-average evoked response data, we first averaged individual data for each SOA separately (Charles et al., 2013), then averaged across SOAs and then across participants, separately for patients and controls groups.”

“Our results accord very well with 2 recent source localization studies using MEEG (Agam Y et al. 2011; Charles L et al. 2013); both studies located the source of the ERN to the dorsal PCC bilaterally, peaking in the left hemisphere (Tal X/Y/Z = −6/−19/38, and − 6/−22/33, respectively).”

“(2001), the findings can, in fact, easily be reconciliated (Charles et al., 2014; Charles et al., 2013).”

“This may not be overly surprising, because previous studies have shown that error detection mechanisms may unfold (at least partially) in the absence of error awareness (Nieuwenhuis et al. 2001; Overbeek et al. 2005; Cohen et al. 2009; Shalgi 2012; Charles et al. 2013).”

“In line with this proposal, several previous studies have reported activation of cognitive control processes related to non-conscious stimuli (Lau and Passingham 2007; van Gaal et al. 2010; Charles et al. 2013; Reuss et al. 2015).”

“, perceptual categorization and response selection) [12, 26].”

“The term ‘epistemic feeling’ has been coined to describe this subjective, online, experience of an error [12, 58].”

“Indeed, consciousness is portrayed in many cases as an all-or-nothing mechanism, compared with subliminal workings that are statistical and inconclusive (Charles et al., 2013).”

“If, for instance, undetected errors had been caused by incomplete visual processing of the stimuli, the Ne/ERN would not be present for this response type (Charles et al., 2013; Gibbons et al., 2011; Woodman, 2010).”

“Our claim is rather that OCD sufferers more frequently 18 For evidence of distinct conscious and non-conscious responses to conflict signalling see Charles et al., 2013.”

“Some of these studies used stimulus masking (Charles et al., 2013; Maier et al., 2008; Woodman, 2010) or stimulus degradation (Scheffers & Coles, 2000) making it difficult to identify the target.”

“Indeed, both Ne and Pe are closely related to conscious perception of the error (Nieuwenhuis et al., 2001; Charles et al., 2013).”

“2017a)—present a growing challenge to the dominant view that stimulus manipulation and/or noninvasive brain stimulation may result in task performance capacity in the absence of introspective access (Merikle 1982; Reingold and Merikle 1988; Kolb and Braun 1995; Merikle et al. 2001; Boyer et al. 2005; Charles et al. 20…”

“, the ability to reflect on and regulate one’s cognitive activity [32,33].”

“Alternatively, it has also been found that meta-d’ can be greater than d’ (Charles et al., 2013) if time-pressure on the response is increased and participants are able to detect and correct a large proportion of their fast erroneous guesses.”

“Thus far however, the possibility of such direct unconscious perception has been received with skepticism, with some authors even claiming that unconscious perception does not exist ([1–3]; but see [18,19], amongst many others, for recent counter-evidence).”

“The functional differences between each ERP could reflect distinct aspects of error detection, and this is supported by evidence that ERN largely reflects unconscious error processing but Pe reflects conscious error awareness (Charles et al., 2013, 2017; Hughes & Yeung, 2011; Wessel et al., 2011).”

“For example Charles et al. (2013) have revealed a relationship between aware errors and the activity of the posterior cingulate cortex, as well as a correlation between unaware errors and the dorsal anterior cingulate cortex, whereas O’Connell et al. (2007) have pointed out the role of the anterior…”

“This and other studies show that participants can not only differentiate between correct and erroneous responses, but also report confidence that their response was incorrect (Boldt & Yeung, 2015; Charles, Opstal, Marti, & Dehaene, 2013; Scheffers & Coles, 2000).”