Cerebellar and cortico-striatal-midbrain contributions to reward-cognition processes and apathy within the psychosis continuum

Negative symptoms in the psychosis continuum are linked to impairments in reward processing and cognitive function. Processes at the interface of reward processing and cognition and their relation to negative symptoms remain little studied, despite evidence suggestive of integration in mechanisms and neural circuitry. Here, we investigated brain activation during reward-dependent modulation of working memory (WM) and their relationship to negative symptoms in subclinical and early stages of the psychosis continuum. We included 27 persons with high schizotypal personality traits and 23 patients with first episode psychosis as well as 27 healthy controls. Participants underwent functional magnetic resonance imaging while performing an established 2-back WM task with two reward levels (5 CHF vs. no reward), which allowed us to assess common reward-cognition regions through whole-brain conjunction analyses and to investigate relations with clinical scores of negative symptoms. As expected for behavior, reward facilitated performance while cognitive load diminished it. At the neural level, the conjunction of high reward and high cognitive load contrasts across the psychosis continuum showed increased hemodynamic activity in the thalamus and the cerebellar vermis. During high cognitive load, more severe apathy but not diminished expression in the psychosis continuum was associated with reduced activity in right lateral orbitofrontal cortex, midbrain, posterior vermal cerebellum, caudate and lateral parietal cortex. Our results suggest that hypoactivity in the cerebellar vermis and the cortical-striatal-midbrain-circuitry in the psychosis continuum relates to apathy possibly via impaired flexible cognitive resource allocation for effective goal pursuit

The Confidence Database

Understanding how people rate their confidence is critical for the characterization of a wide range of perceptual, memory, motor and cognitive processes. To enable the continued exploration of these processes, we created a large database of confidence studies spanning a broad set of paradigms, participant populations and fields of study. The data from each study are structured in a common, easy-to-use format that can be easily imported and analysed using multiple software packages. Each dataset is accompanied by an explanation regarding the nature of the collected data. At the time of publication, the Confidence Database (which is available at https://osf.io/s46pr/) contained 145 datasets with data from more than 8,700 participants and almost 4 million trials. The database will remain open for new submissions indefinitely and is expected to continue to grow. Here we show the usefulness of this large collection of datasets in four different analyses that provide precise estimations of several foundational confidence-related effects

From emotion processing to metacognition

Functional neurological disorder (FND) is the term used (DSM-5) to refer to a disabling neuropsychiatric condition that is frequently encountered in medical practice. It was previously known as conversion disorder (CD) and formerly described as hysteria. It is characterised by neuro­logical symptoms (e.g., weakness, numbness, tremor…) without evidence of any brain lesion. Early neurobiological accounts of this disorder were part of the foundation of psychiatry and neurology, but were then dominated by a purely psychodynamic perspective. The advent of neuroimaging in the past two decades has stimulated renewed interest in the “functional” brain underpinnings of these symptoms, with growing interest and ­increasing attempts to investigate them in a neuroscience perspective. In this brief review, I discuss recent evidence pointing to how top-down mechanisms may alter motor function in patients with motor FND/CD, through coupling with neural systems associated with internal self-monitoring, emotion regulation and memory, and thus lead to the emergence of functional symptoms. More research, however, is still needed to elucidate the causes of FND/CD (why they occur), in addition to their neuro­anatomical substrates (how they occur)

Pathophysiology of negative symptom dimensions of schizophrenia - Current developments and implications for treatment

Negative symptoms of schizophrenia comprise a group of severe symptoms contributing to high disease burden and poor long-term prognosis. Conceptual work has shown that these symptoms can be mapped onto, at least, two distinct dimensions: apathy including the domains avolition, asociality and anhedonia, and diminished expression including the domains blunted affect and alogia. Growing evidence suggest that these dimensions have partly distinct behavioral, cognitive and neural correlates. Nonetheless, modulation and treatment of specific processes and brain correlates related to these negative symptom dimensions through behavioral, pharmacological, and brain stimulation interventions remains poorly understood. Here, we address this question by employing an integrative approach and comprehensively synthesizing the current literature on neuroimaging, behavior and clinical studies of both negative symptom dimensions. While considerable progress has been made, it remains an open challenge to develop integrative mechanistic pathophysiological models for apathy and diminished expression. We conclude that such multi-level frameworks are key for the development of new biological and psychosocial treatments and may advance progress towards an individualized treatment of negative symptoms

Preserved metacognition for undetected visuomotor deviations

International audienceHumans can successfully correct deviations of movements without conscious detection of such deviations, suggesting limited awareness of movement details. We ask whether such limited awareness impairs confidence (metacognition). We recorded functional magnetic resonance imaging data while 31 human female and male participants detected cursor deviations during a visuomotor reaching task and rated their confidence retrospectively. We show that participants monitor a summary statistic of the unfolding visual feedback (the peak cursor error) to detect visuomotor deviations and adjust their confidence ratings, even when they report being unaware of a deviation. Crucially, confidence ratings were as metacognitively efficient for aware and unaware deviations. At the neural level, activity in the ventral striatum tracks high confidence, whereas a broad network encodes cursor error but not confidence. These findings challenge the notion of limited conscious action monitoring and uncover how humans monitor their movements as they unfold, even when unaware of ongoing deviations

Confidence of emotion expression recognition recruits brain regions outside the face perception network

Metacognitive beliefs about emotions expressed by others are crucial to social life, yet very little studied. To what extent does our confidence in emotion expression recognition depend on perceptual or other non-perceptual information? We obtained behavioral and magnetic resonance imaging measures while participants judged either the emotion in ambiguous faces or the size of two lines flanking these faces, and then rated their confidence on decision accuracy. Distinct behavioral and neural mechanisms were identified for confidence and perceptual decision in both tasks. Participants overestimated their emotion recognition (ER) accuracy, unlike visual size judgments. Whereas expression discrimination recruited several areas in the face-processing network, confidence for ER uniquely engaged the bilateral retrosplenial/posterior cingulate complex and left parahippocampal gyrus. Further, structural white matter connectivity of the former region predicted metacognitive sensitivity. These results highlight a key role for brain mechanisms integrating perception with contextual mnemonic information in the service of confidence during E

Autonomic, Endocrine, and Inflammation Profiles in Functional Neurological Disorder: A Systematic Review and Meta-Analysis

Functional neurological disorder (FND) is a core neuropsychiatric condition. To date, promising yet inconsistently identified neural circuit profiles have been observed in patients with FND, suggesting that gaps remain in our systems-level neurobiological understanding. As such, other important physiological variables, including autonomic, endocrine, and inflammation findings, need to be contextualized for a more complete mechanistic picture. The investigators conducted a systematicreview and meta-analysis of available case-control andcohort studies of FND. PubMed, PsycINFO, and Embasedatabases were searched for studies from January 1,1900, to September 1, 2020, that investigated autonomic,endocrine, and inflammation markers in patients withFND. Sixty-six of 2,056 screened records were included inthe review, representing 1,699 patients; data from 20articles were used in the meta-analysis