Noradrenaline blockade specifically enhances metacognitive performance

Pharmacological Elevation of Catecholamine Levels Improves Perceptual Decisions, But Not Metacognitive Insight

Perceptual decisions are often accompanied by a feeling of decision confidence. Where the parietal cortex is known for its crucial role in shaping such perceptual decisions, metacognitive evaluations are thought to additionally rely on the (pre)frontal cortex. Because of this supposed neural differentiation between these processes, perceptual and metacognitive decisions may be divergently affected by changes in internal (e.g., attention, arousal) and external (e.g., task and environmental demands) factors. Although intriguing, causal evidence for this hypothesis remains scarce. Here, we investigated the causal effect of two neuromodulatory systems on behavioral and neural measures of perceptual and metacognitive decision-making. Specifically, we pharmacologically elevated levels of catecholamines (with atomoxetine) and acetylcholine (with donepezil) in healthy adult human participants performing a visual discrimination task in which we gauged decision confidence, while electroencephalography was measured. Where cholinergic effects were not robust, catecholaminergic enhancement improved perceptual sensitivity, while at the same time leaving metacognitive sensitivity unaffected. Neurally, catecholaminergic elevation did not affect sensory representations of task-relevant visual stimuli but instead enhanced well-known decision signals measured over the centroparietal cortex, reflecting the accumulation of sensory evidence over time. Crucially, catecholaminergic enhancement concurrently impoverished neural markers measured over the frontal cortex linked to the formation of metacognitive evaluations. Enhanced catecholaminergic neuromodulation thus improves perceptual but not metacognitive decision-making.

Hot metacognition: poorer metacognitive efficiency following acute but not traumatic stress

Aberrations to metacognition-the ability to reflect on and evaluate self-performance-are a feature of poor mental health. Theoretical models of post-traumatic stress disorder propose that following severe stress or trauma, maladaptive metacognitive evaluations and appraisals of the event drive the development of symptoms. Empirical research is required in order to reveal whether disruptions to metacognition cause or contribute to symptom development in line with theoretical accounts, or are simply a consequence of ongoing psychopathology. In two experiments, using hierarchical Bayesian modelling of metacognition measured in a memory recognition task, we assessed whether distortions to metacognition occur at a state-level after an acute stress induction, and/or at a trait-level in a sample of individuals experiencing intrusive memories following traumatic stress. Results from experiment 1, an in-person laboratory-based experiment, demonstrated that heightened psychological responses to the stress induction were associated with poorer metacognitive efficiency, despite there being no overall change in metacognitive efficiency from pre- to post-stress (N = 27). Conversely, in experiment 2, an online experiment using the same metamemory task, we did not find evidence of metacognitive alterations in a transdiagnostic sample of patients with intrusive memory symptomatology following traumatic stress (N = 36, compared to 44 matched controls). Our results indicate a relationship between state-level psychological responses to stress and metacognitive alterations. The lack of evidence for pre- to post-stress differences in metamemory illustrates the importance for future studies to reveal the direction of this relationship, and consequently the duration of stress-associated metacognitive impairments and their impact on mental health.

Metacognitive Feelings: A Predictive-Processing Perspective

Metacognitive feelings are affective experiences that concern the subject's mental processes and capacities. Paradigmatic examples include the feeling of familiarity, the feeling of confidence, or the tip-of-the-tongue experience. In this article, we advance an account of metacognitive feelings based on the predictive-processing framework. The core tenet of predictive processing is that the brain is a hierarchical hypothesis-testing mechanism, predicting sensory input on the basis of prior experience and updating predictions on the basis of the incoming prediction error. According to the proposed account, metacognitive feelings arise out of a process in which visceral changes serve as cues to predict the error dynamics relating to a particular mental process. The expected rate of prediction-error reduction corresponds to the valence at the core of the emerging metacognitive feeling. Metacognitive feelings use prediction dynamics to model the agent's situation in a way that is both descriptive and directive. Thus, metacognitive feelings are not only an appraisal of ongoing cognitive performance but also a set of action policies. These action policies span predictive trajectories across bodily action, mental action, and interoceptive changes, which together transform the epistemic landscape within which metacognitive feelings unfold.

Metacognition and Confidence: A Review and Synthesis

Determining the psychological, computational, and neural bases of confidence and uncertainty holds promise for understanding foundational aspects of human metacognition. While a neuroscience of confidence has focused on the mechanisms underpinning subpersonal phenomena such as representations of uncertainty in the visual or motor system, metacognition research has been concerned with personal-level beliefs and knowledge about self-performance. I provide a road map for bridging this divide by focusing on a particular class of confidence computation: propositional confidence in one's own (hypothetical) decisions or actions. Propositional confidence is informed by the observer's models of the world and their cognitive system, which may be more or less accurate-thus explaining why metacognitive judgments are inferential and sometimes diverge from task performance. Disparate findings on the neural basis of uncertainty and performance monitoring are integrated into a common framework, and a new understanding of the locus of action of metacognitive interventions is developed.

Acetylcholine and metacognition during sleep

Acetylcholine is a neurotransmitter and neuromodulator involved in a variety of cognitive functions. Additionally, acetylcholine is involved in the regulation of REM sleep: cholinergic neurons in the brainstem and basal forebrain project to and innervate wide areas of the cerebral cortex, and reciprocally interact with other neuromodulatory systems, to produce the sleep-wake cycle and different sleep stages. Consciousness and cognition vary considerably across and within sleep stages, with metacognitive capacity being strikingly reduced even during aesthetically and emotionally rich dream experiences. A notable exception is the phenomenon of lucid dreaming-a rare state whereby waking levels of metacognitive awareness are restored during sleep-resulting in individuals becoming aware of the fact that they are dreaming. The role of neurotransmitters in these fluctuations of consciousness and cognition during sleep is still poorly understood. While recent studies using acetylcholinesterase inhibitors suggest a potential role of acetylcholine in the occurrence of lucid dreaming, the underlying mechanisms by which this effect is produced remains un-modelled and unknown; with the causal link between cholinergic mechanisms and upstream psychological states being complex and elusive. Several theories and approaches targeting the association between acetylcholine and metacognition during wakefulness and sleep are highlighted in this review, moving through microscopic, mesoscopic and macroscopic levels of analysis to detail this phenomenon at several organisational scales. Several exploratory hypotheses will be developed to guide future research towards fully articulating how metacognition is affected by activity at the acetylcholine receptor.

The impact of feedback on metacognition: Enhancing in easy tasks, impeding in difficult ones

Metacognition refers to the ability to monitor and introspect upon cognitive performance. Abundant research suggests that individual metacognition is easily affected by feedback in daily life, but how feedback affects metacognition in perceptual decision-making remains unclear. Here we investigated how trial-by-trial feedback shapes perceptual metacognition in two experiments with either high (n = 82) or low difficulty (n = 90). Participants were randomly divided into a feedback group in which participants received trial-by-trial performance feedback or a no-feedback group. Results showed that, in the high-difficulty task, participants in the feedback group revealed inferior metacognitive performance than the no-feedback group, manifested as decreased metacognitive efficiency while controlling for performance sensitivity. In the low-difficulty task, however, participants in the feedback group had higher metacognitive efficiency than the no-feedback group. The distinct patterns of findings in the two experiments indicate that whether feedback promotes or impedes metacognition is adjusted by task difficulty.

Noradrenergic deficits contribute to apathy in Parkinson's disease through the precision of expected outcomes

Apathy is a debilitating feature of many neuropsychiatric diseases, that is typically described as a reduction of goal-directed behaviour. Despite its prevalence and prognostic importance, the mechanisms underlying apathy remain controversial. Degeneration of the locus coeruleus-noradrenaline system is known to contribute to motivational deficits, including apathy. In healthy people, noradrenaline has been implicated in signalling the uncertainty of expectations about the environment. We proposed that noradrenergic deficits contribute to apathy by modulating the relative weighting of prior beliefs about action outcomes. We tested this hypothesis in the clinical context of Parkinson's disease, given its associations with apathy and noradrenergic dysfunction. Participants with mild-to-moderate Parkinson's disease (N = 17) completed a randomised double-blind, placebo-controlled, crossover study with 40 mg of the noradrenaline reuptake inhibitor atomoxetine. Prior weighting was inferred from psychophysical analysis of performance in an effort-based visuomotor task, and was confirmed as negatively correlated with apathy. Locus coeruleus integrity was assessed in vivo using magnetisation transfer imaging at ultra-high field 7T. The effect of atomoxetine depended on locus coeruleus integrity: participants with a more degenerate locus coeruleus showed a greater increase in prior weighting on atomoxetine versus placebo. The results indicate a contribution of the noradrenergic system to apathy and potential benefit from noradrenergic treatment of people with Parkinson's disease, subject to stratification according to locus coeruleus integrity. More broadly, these results reconcile emerging predictive processing accounts of the role of noradrenaline in goal-directed behaviour with the clinical symptom of apathy and its potential pharmacological treatment.

Partially Overlapping Neural Correlates of Metacognitive Monitoring and Metacognitive Control

Metacognition describes the process of monitoring one's own mental states, often for the purpose of cognitive control. Previous research has investigated how metacognitive signals are generated (metacognitive monitoring), for example, when people (both female/male) judge their confidence in their decisions and memories. Research has also investigated how metacognitive signals are used to influence behavior (metacognitive control), for example, setting a reminder (i.e., cognitive offloading) for something you are not confident you will remember. However, the mapping between metacognitive monitoring and metacognitive control needs further study on a neural level. We used fMRI to investigate a delayed-intentions task with a reminder element, allowing human participants to use their metacognitive insight to engage metacognitive control. Using multivariate pattern analysis, we found that we could separately decode both monitoring and control, and, to a lesser extent, cross-classify between them. Therefore, brain patterns associated with monitoring and control are partially, but not fully, overlapping.SIGNIFICANCE STATEMENT Models of metacognition commonly distinguish between monitoring (how metacognition is formed) and control (how metacognition is used for behavioral regulation). Research into these facets of metacognition has often happened in isolation. Here, we provide a study which directly investigates the mapping between metacognitive monitoring and metacognitive control at a neural level. We applied multivariate pattern analysis to fMRI data from a novel task in which participants separately rated their confidence (metacognitive monitoring) and how much they would like to use a reminder (metacognitive control). We find support for the notion that the two aspects of metacognition overlap partially but not fully. We argue that future research should focus on how different metacognitive signals are selected for control.

Assessing prospective and retrospective metacognitive accuracy following traumatic brain injury remotely across cognitive domains

The ability to monitor one's behaviour is frequently impaired following TBI, impacting on patients' rehabilitation. Inaccuracies in judgement or self-reflection of one's performance provides a useful marker of metacognition. However, metacognition is rarely measured during routine neuropsychology assessments and how it varies across cognitive domains is unclear. A cohort of participants consisting of 111 TBI patients [mean age = 45.32(14.15), female = 29] and 84 controls [mean age = 31.51(12.27), female = 43] was studied. Participants completed cognitive assessments via a bespoke digital platform on their smartphones. Included in the assessment were a prospective evaluation of memory and attention, and retrospective confidence judgements of task performance. Metacognitive accuracy was calculated from the difference between confidence judgement of task performance and actual performance. Prospective judgment of attention and memory was correlated with task performance in these domains for controls but not patients. TBI patients had lower task performance in processing speed, executive functioning and working memory compared to controls, maintaining high confidence, resulting in overestimation of cognitive performance compared to controls. Additional judgments of task performance complement neuropsychological assessments with little additional time-cost. These results have important theoretical and practical implications for evaluation of metacognitive impairment in TBI patients and neurorehabilitation.

Do propranolol and amisulpride modulate confidence in risk-taking?

Background: Making rational choices and being able to consciously reflect on the goodness of these choices is important for successfully navigating the world. Value-based decisions have been extensively studied, but we know little about the factors that influence our confidence in value-based choice. Particularly, we know very little about the neurotransmitters that may mediate these processes.  Methods: In this double-blind, placebo-controlled study design involving 61 healthy human subjects (30 female), we assessed the contributions of dopamine (400 mg amisulpride) and noradrenaline (40 mg propranolol) to value-based decision making and the subjective confidence therein in a monetary risky gambling task.  Results: We did not find any significant effect of either of the two pharmacological manipulations, neither on value-based decision making, nor on subjective confidence.   Conclusion: We discuss these (null) findings, and release all relevant data and code. This will allow researchers to further interrogate the data, to counteract publication biases in favour of significant findings, and to use our study as a source for balanced meta-analyses.

Interoception abnormalities in schizophrenia: A review of preliminary evidence and an integration with Bayesian accounts of psychosis

Schizophrenia research has traditionally focused almost exclusively on how the brain interprets the outside world. However, our internal bodily milieu is also central to how we interpret the world and construct our reality: signals from within the body are critical for not only basic survival, but also a wide range of brain functions from basic perception, emotion, and motivation, to sense of self. In this article, we propose that interoception-the processing of bodily signals-may have implications for a wide range of clinical symptoms in schizophrenia and may thus provide key insights into illness mechanisms. We start with an overview of interoception pathways. Then we provide a review of direct and indirect findings in various interoceptive systems in schizophrenia and interpret these findings in the context of computational frameworks that model interoception as hierarchical Bayesian inference. Finally, we propose a conceptual model of how altered interoceptive inference may contribute to specific schizophrenia symptoms-negative symptoms in particular-and suggest directions for future research, including potential new avenues of treatment.

Metacognitive Awareness of Difficulty in Action Selection: The Role of the Cingulo-opercular Network

The question whether and how we are able to monitor our own cognitive states (metacognition) has been a matter of debate for decades. Do we have direct access to our cognitive processes, or can we only infer them indirectly based on their consequences? In the current study, we wanted to investigate the brain circuits that underlie the metacognitive experience of fluency in action selection. To manipulate action-selection fluency, we used a subliminal response priming paradigm. On each trial, both male and female human participants additionally engaged in the metacognitive process of rating how hard they felt it was to respond to the target stimulus. Despite having no conscious awareness of the prime, results showed that participants rated incompatible trials (during which subliminal primes interfered with the required response) to be more difficult than compatible trials (where primes facilitated the required response), reflecting metacognitive awareness of difficulty. This increased sense of subjective difficulty was mirrored by increased activity in the rostral cingulate zone and the anterior insula, two regions that are functionally closely connected. Importantly, this reflected activations that were unique to subjective difficulty ratings and were not explained by RTs or prime-response compatibility. We interpret these findings in light of a possible grounding of the metacognitive judgment of fluency in action selection in interoceptive signals resulting from increased effort.

Exploring Clinical Correlates of Metacognition in Bipolar Disorders Using Moderation Analyses: The Role of Antipsychotics

The determinants of metacognition are still poorly understood in bipolar disorders (BD). We aimed to examine the clinical determinants of metacognition, defined as the agreement between objective and subjective cognition in individuals with BD. The participants consisted of 281 patients with BD who underwent an extensive neuropsychological battery and clinical evaluation. To assess subjective cognition, participants provided a general rating of their estimated cognitive difficulties. Clinical characteristics of BD were also recorded, along with medication. We studied the potential moderation of the association between cognitive complaints and global objective cognitive performance by several clinical variables with ordinal logistic regressions. Depression and impulsivity were associated with greater cognitive complaints. The only variable that moderated the relationship between objective and subjective cognition in the global model was the prescription of antipsychotics. Patients taking antipsychotics had a poorer association between cognitive complaints and objective neuropsychological performance. This result suggests a role for dopamine in the modulation of metacognitive performance, and calls for the systematic control of antipsychotic medication in future studies documenting metacognitive deficits in severe and persistent mental disorders. Depression and impulsivity should be investigated as potential therapeutic targets for individuals with BD and cognitive complaints, before proposing an extensive neuropsychological evaluation.

Computational models link cellular mechanisms of neuromodulation to large-scale neural dynamics

Decades of neurobiological research have disclosed the diverse manners in which the response properties of neurons are dynamically modulated to support adaptive cognitive functions. This neuromodulation is achieved through alterations in the biophysical properties of the neuron. However, changes in cognitive function do not arise directly from the modulation of individual neurons, but are mediated by population dynamics in mesoscopic neural ensembles. Understanding this multiscale mapping is an important but nontrivial issue. Here, we bridge these different levels of description by showing how computational models parametrically map classic neuromodulatory processes onto systems-level models of neural activity. The ensuing critical balance of systems-level activity supports perception and action, although our knowledge of this mapping remains incomplete. In this way, quantitative models that link microscale neuronal neuromodulation to systems-level brain function highlight gaps in knowledge and suggest new directions for integrating theoretical and experimental work.

Math anxiety relates positively to metacognitive insight into mathematical decision making

The current study reports a pre-registered investigation into the interrelations between mathematics anxiety, metacognition and mathematical decision-making. Although this question has already received some attention in previous work, reliance on self-report measures of metacognition has hindered its interpretation. Here, a novel experimental mathematical decision-making task was used in which participants solved mathematical assignments of varying difficulty, and expressed their level of confidence in the accuracy of their decision both prospectively and retrospectively. Mathematics anxiety was measured using a standardized questionnaire. Both prospective and retrospective confidence judgments predicted unique variation in accuracy; however, the explanatory effect of prospective confidence disappeared after taking task difficulty into account. This suggests that prospective, but not retrospective, confidence is largely based on easily available cues indicative of performance. Results of a multiple regression analysis indicated that individual differences in mathematics anxiety were negatively related to the overall level of confidence (both prospectively and retrospectively), and positively related to metacognitive efficiency (only prospectively). Having insight in these interrelationships is important in the context of remediating mathematics anxiety, which might in turn be useful with regard to the worldwide need for more workers with degrees in science, technology, engineering, or mathematics (STEM).

Diffusion property and functional connectivity of superior longitudinal fasciculus underpin human metacognition

Metacognition as the capacity of monitoring one's own cognition operates across domains. Here, we addressed whether metacognition in different cognitive domains rely on common or distinct neural substrates with combined diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) techniques. After acquiring DTI and resting-state fMRI data, we asked participants to perform a temporal-order memory task and a perceptual discrimination task, followed by trial-specific confidence judgments. DTI analysis revealed that the structural integrity (indexed by fractional anisotropy) in the anterior portion of right superior longitudinal fasciculus (SLF) was associated with both perceptual and mnemonic metacognitive abilities. Using perturbed mnemonic metacognitive scores produced by inhibiting the precuneus using TMS, the mnemonic metacognition scores did not correlate with individuals' SLF structural integrity anymore, revealing the relevance of this tract in memory metacognition. To further verify the involvement of several cortical regions connected by SLF, we took the TMS-targeted precuneus region as a seed in a functional connectivity analysis and found the functional connectivity between precuneus and two SLF-connected regions (inferior parietal cortex and precentral gyrus) mediated mnemonic metacognition performance. These results illustrate the importance of SLF and a putative white-matter grey-matter circuitry that supports human metacognition.

Distinct signatures of subjective confidence and objective accuracy in speech prosody

Whether speech prosody truly and naturally reflects a speaker's subjective confidence, rather than other dimensions such as objective accuracy, is unclear. Here, using a new approach combing psychophysics with acoustic analysis and automatic classification of verbal reports, we tease apart the contributions of sensory evidence, accuracy, and subjective confidence to speech prosody. We find that subjective confidence and objective accuracy are distinctly reflected in the loudness, duration and intonation of verbal reports. Strikingly, we show that a speaker's accuracy is encoded in speech prosody beyond their own metacognitive awareness, and that it can be automatically decoded from this information alone with performances up to 60%. These findings demonstrate that confidence and accuracy have separable prosodic signatures that are manifested with different timings, and on different acoustic dimensions. Thus, both subjective mental states of confidence, and objective states related to competence, can be directly inferred from this natural behavior.

Effects of ketamine on brain function during metacognition of episodic memory

Only little research has been conducted on the pharmacological underpinnings of metacognition. Here, we tested the modulatory effects of a single intravenous dose (100 ng/ml) of the N-methyl-D-aspartate-glutamate-receptor antagonist ketamine, a compound known to induce altered states of consciousness, on metacognition and its neural correlates. Fifty-three young, healthy adults completed two study phases of an episodic memory task involving both encoding and retrieval in a double-blind, placebo-controlled fMRI study. Trial-by-trial confidence ratings were collected during retrieval. Effects on the subjective state of consciousness were assessed using the 5D-ASC questionnaire. Confirming that the drug elicited a psychedelic state, there were effects of ketamine on all 5D-ASC scales. Acute ketamine administration during retrieval had deleterious effects on metacognitive sensitivity (meta-d') and led to larger metacognitive bias, with retrieval performance (d') and reaction times remaining unaffected. However, there was no ketamine effect on metacognitive efficiency (meta-d'/d'). Measures of the BOLD signal revealed that ketamine compared to placebo elicited higher activation of posterior cortical brain areas, including superior and inferior parietal lobe, calcarine gyrus, and lingual gyrus, albeit not specific to metacognitive confidence ratings. Ketamine administered during encoding did not significantly affect performance or brain activation. Overall, our findings suggest that ketamine impacts metacognition, leading to significantly larger metacognitive bias and deterioration of metacognitive sensitivity as well as unspecific activation increases in posterior hot zone areas of the neural correlates of consciousness.

Human complex exploration strategies are enriched by noradrenaline-modulated heuristics

An exploration-exploitation trade-off, the arbitration between sampling a lesser-known against a known rich option, is thought to be solved using computationally demanding exploration algorithms. Given known limitations in human cognitive resources, we hypothesised the presence of additional cheaper strategies. We examined for such heuristics in choice behaviour where we show this involves a value-free random exploration, that ignores all prior knowledge, and a novelty exploration that targets novel options alone. In a double-blind, placebo-controlled drug study, assessing contributions of dopamine (400 mg amisulpride) and noradrenaline (40 mg propranolol), we show that value-free random exploration is attenuated under the influence of propranolol, but not under amisulpride. Our findings demonstrate that humans deploy distinct computationally cheap exploration strategies and that value-free random exploration is under noradrenergic control.

Advances in the computational understanding of mental illness

Computational psychiatry is a rapidly growing field attempting to translate advances in computational neuroscience and machine learning into improved outcomes for patients suffering from mental illness. It encompasses both data-driven and theory-driven efforts. Here, recent advances in theory-driven work are reviewed. We argue that the brain is a computational organ. As such, an understanding of the illnesses arising from it will require a computational framework. The review divides work up into three theoretical approaches that have deep mathematical connections: dynamical systems, Bayesian inference and reinforcement learning. We discuss both general and specific challenges for the field, and suggest ways forward.

Emotional metacognition: stimulus valence modulates cardiac arousal and metamemory

Emotion alters how we feel, see, and experience the world. In the domain of memory, the emotional valence and arousal of memorised stimuli can modulate both the acuity and content of episodic recall. However, no experiment has investigated whether arousal and valence also influence metacognition for memory (i.e. the process of self-monitoring memories). In a pre-registered study, we applied a novel psychophysiological design together with computational models of metacognition to assess the influence of stimulus valence and arousal on the sensitivity, bias, and efficiency of metamemory. To estimate the role of physiological arousal in mediating these effects, we recorded cardiac measures through pulse oximetry. We found that negative valence substantially decreased both memory performance and subjective confidence, in particular for low arousal words. Simultaneously, we found that emotional valence modulated both heart rate and heart-rate variability (HRV) during recognition memory. Exploratory trial-level analyses further revealed that subjective confidence was encoded in instantaneous heart-rate fluctuations and that this relationship was also modulated by emotional valence. Our results demonstrate that recognition memory and metacognition are influenced by the emotional valence of encoded items and that this correlation is in part related to cardiac activity.

Sources of Metacognitive Inefficiency

Confidence judgments are typically less informative about one's accuracy than they could be; a phenomenon we call metacognitive inefficiency. We review the existence of different sources of metacognitive inefficiency and classify them into four categories based on whether the corruption is due to: (i) systematic or nonsystematic influences, and (ii) the input to or the computation of the metacognitive system. Critically, the existence of different sources of metacognitive inefficiency provides an alternative explanation for behavioral findings typically interpreted as evidence for domain-specific (and against domain-general) metacognitive systems. We argue that, contrary to the dominant assumption in the field, metacognitive failures are not monolithic and suggest that understanding the sources of metacognitive inefficiency should be a primary goal of the science of metacognition.

Segregated Co-activation Patterns in the Emergence of Decision Confidence During Visual Perception

Visual metacognition-the introspection and evaluation of one's own visual perceptual processes-is measured through both decision confidence and "metacognitive efficiency." Metacognitive efficiency refers to an individual's ability to accurately judge incorrect and correct decisions through confidence ratings given their task performance. Previous imaging studies in humans and nonhuman primates reported widely distributed brain regions being involved in decision confidence and metacognition. However, the neural correlates of metacognition are remarkably inconsistent across studies concerning spatial outline. Therefore, this study investigates the neural correlates of visual metacognition by examining co-activation across regions that scale with visual decision confidence. We hypothesized that interacting processes of perceptual and metacognitive performance contribute to the arising decision confidence in distributed, but segregable co-activating brain regions. To test this hypothesis, we performed task-fMRI in healthy humans during a visual backward masking task with four-scale, post-decision confidence ratings. We measured blood oxygenation covariation patterns, which served as a physiological proxy for co-activation across brain regions. Decision confidence ratings and an individual's metacognitive efficiency served as behavioral measures for metacognition. We found three distinct co-activation clusters involved in decision confidence: the first included right-centered fronto-temporal-parietal regions, the second included left temporal and parietal regions, and the left basal forebrain (BF), and the third included cerebellar regions. The right fronto-temporal-parietal cluster including the supplementary eye field and the right basal forebrain showed stronger co-activation in subjects with higher metacognitive efficiency. Our results provide novel evidence for co-activation of widely distributed fronto-parieto-temporal regions involved in visual confidence. The supplementary eye field was the only region that activated for both decision confidence and metacognitive efficiency, suggesting the supplementary eye field plays a key role in visual metacognition. Our results link findings in electrophysiology studies and human fMRI studies and provide evidence that confidence estimates arise from the integration of multiple information processing pathways.

Altered awareness of motor symptoms in Parkinson's disease and Dementia with Lewy Bodies: A systematic review

OBJECTIVES

Altered awareness of motor symptoms is reported in people with Parkinson's disease and Dementia with Lewy Bodies, and may adversely affect quality of life and medication concordance. How symptom awareness is influenced by motor and cognitive disease severity, age and medication use is not fully understood. We carried out a systematic review of the literature on motor symptom awareness in Parkinson's disease and Dementia with Lewy Bodies.

METHODS

Pubmed and Wed of Science were searched for relevant articles published in or prior to March 2019. Data regarding participant demographics, diagnosis, cognitive status, method of assessing awareness and study findings were extracted from relevant publications.

RESULTS

Sixteen relevant publications were identified. Motor symptom awareness appears to decline over the course of Parkinson's disease. Imaging studies implicate the prefrontal cortex, with different mechanisms involved in hypokinesia and dyskinesia awareness. The hypothesis that people with right hemisphere based disease would have more severely reduced awareness is only weakly supported. Most studies focused on cognitively intact individuals, and on awareness of dyskinesia rather than hypokinesia.

CONCLUSIONS

Whilst reduced awareness of dyskinesia and to a lesser extent hypokinesia is common, there is a lack of longitudinal data on how awareness changes over time, and how it interacts with global cognitive changes. Motor symptom awareness in Dementia with Lewy Bodies is understudied. Future studies of symptom awareness should include robust assessment of overall cognitive functioning, and use a longitudinal design to elucidate how awareness changes over time. J Am Geriatr Soc 68:-, 2020.

Hydrocortisone decreases metacognitive efficiency independent of perceived stress

It is well established that acute stress produces negative effects on high level cognitive functions. However, these effects could be due to the physiological components of the stress response (among which cortisol secretion is prominent), to its psychological concomitants (the thoughts generated by the stressor) or to any combination of those. Our study shows for the first time that the typical cortisol response to stress is sufficient to impair metacognition, that is the ability to monitor one's own performance in a task. In a pharmacological protocol, we administered either 20 mg hydrocortisone or placebo to 46 male participants, and measured their subjective perception of stress, their performance in a perceptual task, and their metacognitive ability. We found that hydrocortisone selectively impaired metacognitive ability, without affecting task performance or creating a subjective state of stress. In other words, the single physiological response of stress produces a net effect on metacognition. These results inform our basic understanding of the physiological bases of metacognition. They are also relevant for applied or clinical research about situations involving stress, anxiety, depression, or simply cortisol use.

Brain dynamics for confidence-weighted learning

Learning in a changing, uncertain environment is a difficult problem. A popular solution is to predict future observations and then use surprising outcomes to update those predictions. However, humans also have a sense of confidence that characterizes the precision of their predictions. Bayesian models use a confidence-weighting principle to regulate learning: for a given surprise, the update is smaller when the confidence about the prediction was higher. Prior behavioral evidence indicates that human learning adheres to this confidence-weighting principle. Here, we explored the human brain dynamics sub-tending the confidence-weighting of learning using magneto-encephalography (MEG). During our volatile probability learning task, subjects’ confidence reports conformed with Bayesian inference. MEG revealed several stimulus-evoked brain responses whose amplitude reflected surprise, and some of them were further shaped by confidence: surprise amplified the stimulus-evoked response whereas confidence dampened it. Confidence about predictions also modulated several aspects of the brain state: pupil-linked arousal and beta-range (15–30 Hz) oscillations. The brain state in turn modulated specific stimulus-evoked surprise responses following the confidence-weighting principle. Our results thus indicate that there exist, in the human brain, signals reflecting surprise that are dampened by confidence in a way that is appropriate for learning according to Bayesian inference. They also suggest a mechanism for confidence-weighted learning: confidence about predictions would modulate intrinsic properties of the brain state to amplify or dampen surprise responses evoked by discrepant observations.

Learning in a changing and uncertain world is difficult. In this context, facing a discrepancy between my current belief and new observations may reflect random fluctuations (e.g. my commute train is unexpectedly late, but it happens sometimes), if so, I should ignore this discrepancy and not change erratically my belief. However, this discrepancy could also denote a profound change (e.g. the train company changed and is less reliable), in this case, I should promptly revise my current belief. Human learning is adaptive: we change how much we learn from new observations, in particular, we promote flexibility when facing profound changes. A mathematical analysis of the problem shows that we should increase flexibility when the confidence about our current belief is low, which occurs when a change is suspected. Here, I show that human learners entertain rational confidence levels during the learning of changing probabilities. This confidence modulates intrinsic properties of the brain state (oscillatory activity and neuromodulation) which in turn amplifies or reduces, depending on whether confidence is low or high, the neural responses to discrepant observations. This confidence-weighting mechanism could underpin adaptive learning.

Reduction in the occurrence of distressing involuntary memories following propranolol or hydrocortisone in healthy women

BACKGROUND

Pharmacological treatments targeting the neuroendocrine stress response may hold special promise in secondary prevention of posttraumatic stress disorder (PTSD). However, findings from clinical trials have been inconsistent and the efficacy of specific drugs, their temporal window of efficacy, effective doses and the characteristics of likely treatment responders remain unclear.

METHOD

Using an experimental human model of distressing involuntary memory formation, we compare the effects of two drugs that have theoretical or empirical support as secondary preventive agents in PTSD. Eighty-eight healthy women (average age: 23.5 years) received oral propranolol (80 mg), hydrocortisone (30 mg), or matched placebo immediately after viewing a 'trauma film'. They then completed daily, time-stamped intrusion diaries for 1 week, at the end of which, voluntary memory was tested.

RESULTS

While neither drug affected voluntary memory for the trauma narrative, propranolol treatment was associated with 42% fewer, and hydrocortisone with 55% fewer intrusions across the week, relative to placebo. Additionally, propranolol reduced general trauma-like symptoms, and post-drug cortisol levels were negatively correlated with intrusion frequency in the hydrocortisone group.

CONCLUSIONS

Overall, this study shows substantial reductions in intrusive memories and preserved voluntary narrative-declarative memory following either propranolol or hydrocortisone in an experimental model of psychological trauma. As such, despite some inconsistencies in clinical trials, our findings support continued investigation of propranolol and hydrocortisone as secondary preventive agents for re-experiencing symptoms of PTSD. The findings also suggest that it is critical for future research to identify the conditions governing the preventive efficacy of these drugs in PTSD.

Knowing Ourselves Together: The Cultural Origins of Metacognition

Metacognition - the ability to represent, monitor and control ongoing cognitive processes - helps us perform many tasks, both when acting alone and when working with others. While metacognition is adaptive, and found in other animals, we should not assume that all human forms of metacognition are gene-based adaptations. Instead, some forms may have a social origin, including the discrimination, interpretation, and broadcasting of metacognitive representations. There is evidence that each of these abilities depends on cultural learning and therefore that cultural selection might shape human metacognition. The cultural origins hypothesis is a plausible and testable alternative that directs us towards a substantial new programme of research.

Biological Stress Reactivity and Introspective Sensitivity: An Exploratory Study

Reaction to stressful events has an impact on several cognitive processes. High levels of stress can be detrimental to working memory, attention and decision-making. Here, we investigated whether individuals’ reactivity to stress is related to their introspective sensitivity (i.e., how well individuals monitor their own cognitive processes). To this aim, 27 participants (16 women, mean 20 years old) were exposed to a psychosocial stress protocol (trier social stress test, TSST), where individuals were asked to simulate a job interview and perform arithmetic calculations in front of a panel of experts. The salivary cortisol concentration, which is considered a hormonal index of stress reactivity, was collected during the TSST through the enzyme immunoassay DRG cortisol ELISA kit. Based on literature recommendations, we classified participants as responders and non-responders to the TSST. In a second session, through a visual search paradigm, we evaluated the introspective sensitivity of the participants. We evaluated how these individuals (i) monitor their own performance (through a confidence estimation), (ii) monitor their own attentional shifts (through a subjective number of scanned items estimation, SNSI), and (iii) monitor their own response times (through an introspective response time estimation, iRT). We found that individuals with lower biological reactivity to stress are more accurate in estimating their SNSI (p = 0.033) and iRT (p = 0.002), and in evaluating their own performance (p = 0.038) through their confidence. We argue that the effect of stress on introspection is not limited to a particular type of introspective evaluation, but rather consists of a general alteration of the introspective mechanism.

Catecholaminergic modulation of the cost of cognitive control in healthy older adults

Catecholamines have long been associated with cognitive control and value-based decision-making. More recently, we have shown that catecholamines also modulate value-based decision-making about whether or not to engage in cognitive control. Yet it is unclear whether catecholamines influence these decisions by altering the subjective value of control. Thus, we tested whether tyrosine, a catecholamine precursor altered the subjective value of performing a demanding working memory task among healthy older adults (60-75 years). Contrary to our prediction, tyrosine administration did not significantly increase the subjective value of conducting an N-back task for reward, as a main effect. Instead, in line with our previous study, exploratory analyses indicated that drug effects varied as a function of participants' trait impulsivity scores. Specifically, tyrosine increased the subjective value of conducting an N-back task in low impulsive participants, while reducing its value in more impulsive participants. One implication of these findings is that the over-the-counter tyrosine supplements may be accompanied by an undermining effect on the motivation to perform demanding cognitive tasks, at least in certain older adults. Taken together, these findings indicate that catecholamines can alter cognitive control by modulating motivation (rather than just the ability) to exert cognitive control.

Metacognition in Psychology

How has the concept of metacognition been used within basic and applied psychological research? We begin our answer by presenting a broad definition of metacognition, a historical overview of its development and its presence in research databases. To assess which function and facets are most frequently addressed within each of the sub-disciplines, we present results from separate literature searches. We then review how metacognition has been defined and empirically explored within selected sub-disciplines in terms of typical research questions, conceptual definitions, how the concept has been measured, and examples of interesting findings and implications. We identify similarities, inconsistencies, and disagreements across fields and point out areas for future research. Our overall conclusion is that it is useful to consider metacognition as a broad umbrella concept across different domains and across basic and applied research. Nonetheless, we recommend that researchers be more specific and explicit about their approach and assumptions whenever using metacognition in their research.

Transcutaneous vagus nerve stimulation improves interoceptive accuracy

How can interoceptive accuracy, i.e. the objective ability to identify interoceptive signals, be improved? In the present study, we investigated whether non-invasive stimulation of the auricular branch of the vagus nerve (taVNS) modulates cardiac interoceptive accuracy, interoceptive sensibility, i.e. confidence in the identification of bodily signals, and interoceptive awareness, i.e. the capacity to evaluate one's ability in the objective task. Using a single-blind within-subjects design we compared participants' performance on the heartbeat counting task and on the heartbeat discrimination task during active and sham taVNS stimulation. Results revealed improved accuracy during active taVNS on the heartbeat discrimination task but not on the heartbeat counting task. Participants were also more confident during active stimulation, but interoceptive awareness was not modulated by taVNS. These findings show that taVNS can modulate interoceptive processing and suggest its potential as a tool to investigate body-brain interactions.

Distinct Roles of Dopamine and Noradrenaline in Incidental Memory

Episodic memory is sensitive to the influence of neuromodulators, such as dopamine and noradrenaline. These influences are considered important in the expression of several known memory biases, though their specific role in memory remains unclear. Using pharmacological agents with relatively high selectivity for either dopamine (400 mg amisulpride) or noradrenaline (40 mg propranolol) we examined their specific contribution to incidental memory. In a double-blind placebo-controlled human study (30 females, 30 males in total), we show that a memory selectivity bias was insensitive to propranolol but sensitive to amisulpride, consistent with a dominant influence from dopamine. By contrast, a putative arousal-induced memory boosting effect was insensitive to amisulpride but was sensitive to propranolol, consistent with a dominant noradrenaline effect. Thus, our findings highlight specific functional roles for dopamine and noradrenaline neurotransmission in the expression of incidental memory.

SIGNIFICANCE STATEMENT Why some information is preferentially encoded into memory while other information is not is a central question in cognitive neuroscience. The neurotransmitters dopamine and noradrenaline are often assumed critical in influencing this selectivity, but their specific contributions remain obscure. In this double-blind, placebo-controlled, between-subjects drug study, we investigate the contributions of noradrenaline and dopamine to episodic memory. Using an incidental memory task, we find that blocking dopamine (400 mg amisulpride) eliminates a neural-gain related memory selectivity bias. Blocking noradrenaline function (40 mg propranolol), in contrast, abolishes an arousal-related memory enhancement. In this assessment of dopamine and noradrenaline neuromodulatory effects we reveal their specific contributions to episodic memory.

Domain-general enhancements of metacognitive ability through adaptive training

The metacognitive ability to introspect about self-performance varies substantially across individuals. Given that effective monitoring of performance is deemed important for effective behavioral control, intervening to improve metacognition may have widespread benefits, for example in educational and clinical settings. However, it is unknown whether and how metacognition can be systematically improved through training independently of task performance, or whether metacognitive improvements generalize across different task domains. Across 8 sessions, here we provided feedback to two groups of participants in a perceptual discrimination task: an experimental group (n = 29) received feedback on their metacognitive judgments, while an active control group (n = 32) received feedback on their decision performance only. Relative to the control group, adaptive training led to increases in metacognitive calibration (as assessed by Brier scores), which generalized both to untrained stimuli and an untrained task (recognition memory). Leveraging signal detection modeling we found that metacognitive improvements were driven both by changes in metacognitive efficiency (meta-d′/d′) and confidence level, and that later increases in metacognitive efficiency were positively mediated by earlier shifts in confidence. Our results reveal a striking malleability of introspection and indicate the potential for a domain-general enhancement of metacognitive abilities.

Metacognition across sensory modalities: Vision, warmth, and nociceptive pain

The distinctive experience of pain, beyond mere processing of nociceptive inputs, is much debated in psychology and neuroscience. One aspect of perceptual experience is captured by metacognition—the ability to monitor and evaluate one’s own mental processes. We investigated confidence in judgements about nociceptive pain (i.e. pain that arises from the activation of nociceptors by a noxious stimulus) to determine whether metacognitive processes contribute to the distinctiveness of the pain experience. Our participants made intensity judgements about noxious heat, innocuous warmth, and visual contrast (first-order, perceptual decisions) and rated their confidence in those judgements (second-order, metacognitive decisions). First-order task performance between modalities was balanced using adaptive staircase procedures. For each modality, we quantified metacognitive efficiency (meta-d’/d’)—the degree to which participants’ confidence reports were informed by the same evidence that contributed to their perceptual judgements—and metacognitive bias (mean confidence)—the participant’s tendency to report higher or lower confidence overall. We found no overall differences in metacognitive efficiency or mean confidence between modalities. Mean confidence ratings were highly correlated between all three tasks, reflecting stable inter-individual variability in metacognitive bias. However, metacognitive efficiency for pain varied independently of metacognitive efficiency for warmth and visual perception. That is, those participants who had higher metacognitive efficiency in the visual task also tended to have higher metacognitive efficiency in the warmth task, but not necessarily in the pain task. We thus suggest that some distinctive and idiosyncratic aspects of the pain experience may stem from additional variability at a metacognitive level. We further speculate that this additional variability may arise from the affective or arousal aspects of pain.

Dopamine is a double-edged sword: dopaminergic modulation enhances memory retrieval performance but impairs metacognition

While memory encoding and consolidation processes have been linked with dopaminergic signaling for a long time, the role of dopamine in episodic memory retrieval remained mostly unexplored. Based on previous observations of striatal activity during memory retrieval, we used pharmacological functional magnetic resonance imaging to investigate the effects of dopamine on retrieval performance and metacognitive memory confidence in healthy humans. Dopaminergic modulation by the D2 antagonist haloperidol administered acutely during the retrieval phase improved recognition accuracy of previously learned pictures significantly and was associated with increased activity in the substantia nigra/ventral tegmental area, locus coeruleus, hippocampus, and amygdala during retrieval. In contrast, confidence for new decisions was impaired by unsystematically increased activity of the striatum across confidence levels and restricted range of responsiveness in frontostriatal networks under haloperidol. These findings offer new insights into the mechanisms underlying memory retrieval and metacognition and provide a broader perspective on the presence of memory problems in dopamine-related diseases and the treatment of memory disorders.

Neural correlates of social cognitive introspective accuracy in schizophrenia

Introspective accuracy (IA) refers to the ability to accurately assess one's own skills and capabilities. Recent work provides evidence of IA deficits in schizophrenia that are predictive of everyday functioning. Thus, IA deficits are an important target to understand mechanistically. The current study used fMRI to assess neural activation in 32 healthy controls and 31 individuals with schizophrenia as they completed IA and control versions of a social cognitive task (i.e., emotion recognition). Analyses revealed different areas of IA-specific neural activity between groups including activations of rostrolateral prefrontal cortex (rlPFC) and dorsal anterior cingulate cortex in healthy individuals that were absent in patients. Direct group comparisons revealed greater IA-specific activation for healthy individuals in right rlPFC, a region thought to be critical for successful IA. For healthy individuals only, activation in rlPFC was positively correlated with IA ability, but no association was observed for patients. Further, among individuals with schizophrenia, increased activation of rlPFC during judgments of IA was positively correlated with better informant-reported interpersonal functioning. These results suggest that reduced specialization of IA-related neural activation may contribute to impaired IA in schizophrenia and also highlight IA as a potential target for remediation programs aimed at improving real-world functioning.

Human metacognition across domains: insights from individual differences and neuroimaging

Metacognition is the capacity to evaluate and control one's own cognitive processes. Metacognition operates over a range of cognitive domains, such as perception and memory, but the neurocognitive architecture supporting this ability remains controversial. Is metacognition enabled by a common, domain-general resource that is recruited to evaluate performance on a variety of tasks? Or is metacognition reliant on domain-specific modules? This article reviews recent literature on the domain-generality of human metacognition, drawing on evidence from individual differences and neuroimaging. A meta-analysis of behavioral studies found that perceptual metacognitive ability was correlated across different sensory modalities, but found no correlation between metacognition of perception and memory. However, evidence for domain-generality from behavioral data may suffer from a lack of power to identify correlations across model parameters indexing metacognitive efficiency. Neuroimaging data provide a complementary perspective on the domain-generality of metacognition, revealing co-existence of neural signatures that are common and distinct across tasks. We suggest that such an architecture may be appropriate for "tagging" generic feelings of confidence with domain-specific information, in turn forming the basis for priors about self-ability and modulation of higher-order behavioral control.

Beta-Blocker Propranolol Modulates Decision Urgency During Sequential Information Gathering

Arbitrating between timely choice and extended information gathering is critical for effective decision making. Aberrant information gathering behavior is thought to be a feature of psychiatric disorders such as schizophrenia and obsessive-compulsive disorder, but we know little about the underlying neurocognitive control mechanisms. In a double-blind, placebo-controlled drug study involving 60 healthy human subjects (30 female), we examined the effects of noradrenaline and dopamine antagonism on information gathering during performance of an information sampling task. We show that modulating noradrenaline function with 40 mg of the β-blocker propranolol leads to decreased information gathering behavior. Modulating dopamine function via a single dose of 400 mg of amisulpride revealed some effects that were intermediate between those of propranolol and placebo. Using a Bayesian computational model, we show that sampling behavior is best explained by inclusion of a nonlinear urgency signal that promotes commitment to an early decision. Noradrenaline blockade promotes the expression of this decision-related urgency signal during information gathering. We discuss the findings with respect to psychopathological conditions that are linked to aberrant information gathering.SIGNIFICANCE STATEMENT Knowing when to stop gathering information and commit to a choice option is nontrivial. This is an important element in arbitrating between information gain and energy conservation. In this double-blind, placebo-controlled drug study, we investigated the role of catecholamines noradrenaline and dopamine on sequential information gathering. We found that blockade of noradrenaline led to a decrease in information gathering. Dopamine blockade showed an intermediate, but nonsignificant, effect. Using a Bayesian computational model, we show that this noradrenaline effect is driven by increased decision urgency, a signal that reflects an escalating subjective cost of sampling. The observation that noradrenaline modulates decision urgency suggests new avenues for treating patients that show information gathering deficits.

Noradrenaline Modulates Visual Perception and Late Visually Evoked Activity

An identical sensory stimulus may or may not be incorporated into perceptual experience, depending on the behavioral and cognitive state of the organism. What determines whether a sensory stimulus will be perceived? While different behavioral and cognitive states may share a similar profile of electrophysiology, metabolism, and early sensory responses, neuromodulation is often different and therefore may constitute a key mechanism enabling perceptual awareness. Specifically, noradrenaline improves sensory responses, correlates with orienting toward behaviorally relevant stimuli, and is markedly reduced during sleep, while experience is largely "disconnected" from external events. Despite correlative evidence hinting at a relationship between noradrenaline and perception, causal evidence remains absent. Here, we pharmacologically down- and upregulated noradrenaline signaling in healthy volunteers using clonidine and reboxetine in double-blind placebo-controlled experiments, testing the effects on perceptual abilities and visually evoked electroencephalography (EEG) and fMRI responses. We found that detection sensitivity, discrimination accuracy, and subjective visibility change in accordance with noradrenaline (NE) levels, whereas decision bias (criterion) is not affected. Similarly, noradrenaline increases the consistency of EEG visually evoked potentials, while lower noradrenaline levels delay response components around 200 ms. Furthermore, blood-oxygen-level-dependent (BOLD) fMRI activations in high-order visual cortex selectively vary along with noradrenaline signaling. Taken together, these results point to noradrenaline as a key factor causally linking visual awareness to external world events. VIDEO ABSTRACT.

Correlated individual differences suggest a common mechanism underlying metacognition in visual perception and visual short-term memory

Adaptive behaviour depends on the ability to introspect accurately about one's own performance. Whether this metacognitive ability is supported by the same mechanisms across different tasks is unclear. We investigated the relationship between metacognition of visual perception and metacognition of visual short-term memory (VSTM). Experiments 1 and 2 required subjects to estimate the perceived or remembered orientation of a grating stimulus and rate their confidence. We observed strong positive correlations between individual differences in metacognitive accuracy between the two tasks. This relationship was not accounted for by individual differences in task performance or average confidence, and was present across two different metrics of metacognition and in both experiments. A model-based analysis of data from a third experiment showed that a cross-domain correlation only emerged when both tasks shared the same task-relevant stimulus feature. That is, metacognition for perception and VSTM were correlated when both tasks required orientation judgements, but not when the perceptual task was switched to require contrast judgements. In contrast with previous results comparing perception and long-term memory, which have largely provided evidence for domain-specific metacognitive processes, the current findings suggest that metacognition of visual perception and VSTM is supported by a domain-general metacognitive architecture, but only when both domains share the same task-relevant stimulus feature.

Perceptual decisions based on previously learned information are independent of dopaminergic tone

Both cognitive and motor symptoms in people with Parkinson's disease (PD) arise from either too little or too much dopamine (DA). Akinesia stems from DA neuronal cell loss, and dyskinesia often stems from an overdose of DA medication. Cognitive behaviors typically associated with frontal cortical function, such as working memory and task switching, are also affected by too little or too much DA in PD. Whether motor and cognitive circuits overlap in PD is unknown. In this article, we show that whereas motor performance improves in people with PD when on dopaminergic medication compared with off medication, perceptual decision-making based on previously learned information (priors) remains impaired whether on or off medications. To rule out effects of long-term DA treatment and dopaminergic neuronal loss such as occur in PD, we also tested a group of people with dopa-unresponsive focal dystonia, a disease that involves the basal ganglia, like PD, but has motor symptoms that are insensitive to dopamine treatment and is not thought to involve frontal cortical DA circuits, unlike PD. We found that people with focal dystonia showed intact perceptual decision-making performance but impaired use of priors in perceptual decision-making, similar to people with PD. Together, the results show a dissociation between motor and cognitive performance in people with PD and reveal a novel cognitive impairment, independent of sensory and motor impairment, in people with focal dystonia. The combined results from people with PD and people with focal dystonia provide mechanistic insights into the role of basal ganglia non-dopaminergic circuits in perceptual decision-making based on priors.

Metacognitive impairments extend perceptual decision making weaknesses in compulsivity

Awareness of one's own abilities is of paramount importance in adaptive decision making. Psychotherapeutic theories assume such metacognitive insight is impaired in compulsivity, though this is supported by scant empirical evidence. In this study, we investigate metacognitive abilities in compulsive participants using computational models, where these enable a segregation between metacognitive and perceptual decision making impairments. We examined twenty low-compulsive and twenty high-compulsive participants, recruited from a large population-based sample, and matched for other psychiatric and cognitive dimensions. Hierarchical computational modelling of the participants' metacognitive abilities on a visual global motion detection paradigm revealed that high-compulsive participants had a reduced metacognitive ability. This impairment was accompanied by a perceptual decision making deficit whereby motion-related evidence was accumulated more slowly in high compulsive participants. Our study shows that the compulsivity spectrum is associated with a reduced ability to monitor one's own performance, over and above any perceptual decision making difficulties.