State dependent changes in error monitoring in schizophrenia

Moral learning and positive schizotypy: Social cognitive mechanisms in psychosis- proneness

BACKGROUND

Delusional thoughts such as paranoia and conspiratorial thinking reflect beliefs in others' intentions to do harm. Given the integral role of harm evaluation in moral cognition, a better understanding of how psychosis-prone individuals process others' moral characters may provide insights into social cognitive mechanisms of these types of delusions.

METHODS

An online sample of 293 participants was drawn from the general population, using Amazon Mechanical Turk. Participants performed a moral inference task, where they predicted and judged the binary choices of two fictitious agents ("good" or "bad") to impose harm under different levels of financial incentives. An investment game involving the same agents then examined participants' trust behavior. Psychosis-proneness was measured with the Multidimensional Schizotypy Scale Brief Edition.

RESULTS

A set of multiple regressions showed that positive schizotypy was associated with a lower yet more confident pre-experimental expectation of the agent's moral character, lower prediction accuracy of the agent's harm preferences, less belief revision, and undifferentiated perception of the good and bad agents' characters. Positive schizotypy was also related to higher expectations for reciprocity in the investment game, regardless of agent characters.

CONCLUSION

Our findings suggest that inflexible beliefs associated with psychosis-proneness extend beyond negative prior expectations, also reflecting difficulties in moral learning. The resulting undifferentiated moral impressions might contribute to undue suspicion of benevolent individuals and increased gullibility to malicious ones, potentially further strengthening conspiratorial beliefs.

Direct and indirect effects of error monitoring on social functioning in a cohort with high-risk and first-episode psychosis

Error monitoring plays a key role in people's adjustment to social life. This study aimed to examine the direct (DE) and indirect effects (IDE) of error monitoring, as indicated by error-related negativity (ERN), on social functioning in a clinical cohort from high-risk (APS) to first-episode psychosis (FEP). This study recruited 100 outpatients and 49 healthy controls (HC). ERN was recorded during a modified flanker task; social functioning was evaluated using the social scale of global functioning. The path analysis was executed using the "lavaan" package. When controlling for age and education, the clinical cohort had a smaller ERN than the HC group (F1, 145 = 19.58, p < 0.001, partial η2 = 0.12, 95%CI: 0.04-0.22). ERN demonstrated no substantial direct impact on current social functioning; however, it manifested indirect influences on social functioning via the disorganization factor of the Positive and Negative Syndrome Scale, both with (standardized IDE: -0.139, p = 0.009) and without (standardized IDE: -0.087, p = 0.018) accounting for the diagnosis, defined as a dummy variable (FEP = 1 and APS = 0) and included as a covariate. These findings suggest that error monitoring, as indicated by ERN, may serve as a potential prognostic indicator of social functioning in patients with psychosis.

Impaired insight and error-monitoring deficits among outpatients with attenuated psychosis syndrome and first-episode psychosis

We aimed to determine the relationship between electrophysiological signatures of error monitoring and clinical insight among outpatients with attenuated psychosis syndrome (APS) and first-episode psychosis (FEP). Error-related negativity (ERN), error positivity (Pe), and correct response negativity (CRN) were recorded during a modified flanker task for patients with FEP (n = 32), APS individuals (n = 58), and healthy controls (HC, n = 49). Clinical insight was measured using the Schedule of Assessment of Insight (SAI) and included awareness of illness (SAI-illness), relabeling of specific symptoms (SAI-symptoms), and treatment compliance (SAI-treatment). Compared with HC, patients with FEP showed smaller ERN (p < 0.001) and Pe (p = 0.011) amplitudes and individuals with APS showed smaller ERN amplitude (p = 0.009). No significant difference in CRN amplitude was observed among the groups. A smaller negative amplitude of ERN correlated with a lower score on SAI-symptoms (b = -0.032, 95% CI: 0.062 to -0.002, p = 0.035) and a decreased total score of SAI (b = -0.096, 95% CI: 0.182 to -0.010, p = 0.029). This links were adjusted for age, education, and diagnosis (a dummy variable with FEP = 1 and APS = 0), and was independent of positive symptoms. SAI-illness was predominantly influenced by diagnosis, whereas SAI-treatment was additionally affected by disorganized communications. Neither Pe nor CRN amplitude exhibited an association with clinical insight. Unconscious error detection, as indicated by ERN, may aid individuals at the preliminary stage of psychosis in recognizing the unusual symptoms.

Electrophysiological signature of the interplay between habits and inhibition in response to smoking-related cues in individuals with a smoking habit: An event-related potential study

The rigid, stimulus-bound nature of drug seeking that characterizes substance use disorder (SUD) has been related to a dysregulation of motivational and early attentional reflexive and inhibitory reflective systems. However, the mechanisms by which these systems are engaged by drug-paired conditioned stimuli (CSs) when they promote the enactment of seeking habits in individuals with a SUD have not been elucidated. The present study aimed behaviourally and electrophysiologically to characterize the nature of the interaction between the reflexive and reflective systems recruited by CSs in individuals with a smoking habit. We measured the behavioural performance and associated event-related potentials (ERPs) of 20 individuals with a smoking habit and 20 controls, who never smoked regularly, in a modified Go/NoGo task during which smoking-related CSs, appetitive and neutral pictures, presented either in first or third-person visual perspective were displayed 250 ms before the Go/NoGo cue. We show that smoking-related cues selectively influence early incentive motivation-related attention bias (N2 after picture onset), motor readiness and behavioural inhibition (Go-P3, NoGo-P3 and Pc) of individuals with a smoking habit only when presented from a first-person visual perspective. These data together identify the neural signature of the aberrant engagement of the reflexive and reflective systems during the recruitment of an incentive habit by CSs presented as if they had been response-produced, that is, as conditioned reinforcers.

Beyond a blunted ERN - Biobehavioral correlates of performance monitoring in schizophrenia

Cognitive deficits are well documented in schizophrenia. Here, we reviewed alterations in performance monitoring as potential marker of cognitive deficits in schizophrenia. We found that performance monitoring alterations in schizophrenia are specific to early (indexed by blunted error-related negativity (ERN)) and late (reflected in blunted error positivity (Pe)) internal error processing, while external performance feedback processing in simple response feedback tasks is relatively preserved. We propose, that these performance monitoring deficits may best be interpret as one aspect of disrupted theta band (4-8 Hz) oscillations over medial frontal recordings sites. Midfrontal theta dynamics are an increasingly established direct neural index of the recruitment of cognitive control and are impaired in several clinical populations. While theta-related ERPs (the ERN) may be an easy to assess marker of cognitive deficits in schizophrenia, further work investigating the trial-by-trial dynamics of theta in both the time and time-frequency domain is needed to parse cognitive deficits in schizophrenia into finer levels of detail and evaluate theta modulation as a therapeutic tool.

Pathways from performance monitoring to negative symptoms and functional outcomes in psychotic disorders

BACKGROUND

Performance monitoring entails rapid error detection to maintain task performance. Impaired performance monitoring is a candidate pathophysiological process in psychotic disorders, which may explain the broader deficit in executive function and its known associations with negative symptoms and poor functioning. The current study models cross-sectional pathways bridging neurophysiological measures of performance monitoring with executive function, symptoms, and functioning.

METHODS

Data were from the 20-year assessment of the Suffolk County Mental Health Project. Individuals with psychotic disorders (N = 181) were originally recruited from inpatient psychiatric facilities. Data were also collected from a geographically and demographically matched group with no psychosis history (N = 242). Neural measures were the error-related negativity (ERN) and error positivity (Pe). Structural equation modeling tested mediation pathways.

RESULTS

Blunted ERN and Pe in the clinical cohort related to impaired executive function (r = 0.26-0.35), negative symptom severity (r = 0.17-0.25), and poor real-world functioning (r = 0.17-0.19). Associations with executive function were consistent across groups. Multiple potential pathways were identified in the clinical cohort: reduced ERN to inexpressivity was mediated by executive function (β = 0.10); reduced Pe to global functioning was mediated by executive function and avolition (β = 0.10).

CONCLUSIONS

This supports a transdiagnostic model of psychotic disorders by which poor performance monitoring contributes to impaired executive function, which contributes to negative symptoms and poor real-world functioning. If supported by future longitudinal research, these pathways could inform the development of targeted interventions to address cognitive and functional deficits that are central to psychotic disorders.

Impaired error-related processing in patients with first-episode psychosis and subjects at clinical high risk for psychosis: An event-related potential study

AIM

Impaired event-related potential (ERP) indices reflecting performance-monitoring systems have been consistently reported in patients with schizophrenia. However, whether these impairments exist from the beginning of the early phase of psychosis, such as in first-episode psychosis (FEP) patients and individuals at clinical high risk (CHR) for psychosis, has not yet been clearly ascertained.

METHODS

Thirty-seven FEP patients, 22 CHR subjects, and 22 healthy controls (HC) performed a visual go/no-go task so that three ERP components associated with performance monitoring-error-related negativity (ERN), correct response negativity (CRN), and error positivity (Pe) -could be assessed. Repeated-measures analysis of variance (ANOVA) with age and sex as covariates was used to compare ERN, CRN, and Pe across the groups.

RESULTS

Repeated-measures ANOVA with age and sex as covariates revealed that compared with HC, FEP patients and CHR subjects showed significantly smaller ERN amplitudes at the Fz (F = 4.980, P = 0.009) and FCz (F = 3.453, P = 0.037) electrode sites. Neither CRN nor Pe amplitudes showed significant differences across the FEP, CHR, and HC groups.

CONCLUSION

These findings suggest that performance monitoring is already compromised during the early course of psychotic disorders, evident in FEP patients and CHR subjects, as reflected in the reduced ERN amplitude. Considering these findings, ERN could serve as a potential indicator of early-stage psychosis.

Test-Retest Reliability of Electroencephalographic Measures of Performance Monitoring in Children and Adults

This study examined the test-retest reliability of the error-related negativity (ERN) and error positivity (Pe) amplitudes using a Flanker task in 118 neurotypical children and 53 adults before and after latency jitter adjustments. The reliability of the ERN and Pe amplitudes was moderate for children and moderate to strong for adults. The latency variability adjustment did not improve the reliability of the ERN and Pe amplitudes for either group, suggesting that latency variability may be a trait-like measure. For comparison purposes, the reliability of the stimulus-locked ERPs was strong for correct trials, yet the reliability was weak for incorrect trials.

Effects of conflict and strategic processing on neural responses to errors in schizophrenia

The error-related negativity (ERN) and error-positivity (Pe) are commonly linked to error-detection and strategic processing. Studies have documented the influence of conflict probability on ERN amplitude. However, the influence of conflict probability on ERN/Pe in schizophrenia, where such components are reduced, is unknown. A modified flanker paradigm was used to examine how the probability of conflict modulates ERN and Pe amplitudes in patients with schizophrenia (n = 33) and healthy controls (n = 25). Increased ERN was observed in response to errors on low probability, incongruent trials. No such differences were observed in Pe. While ERN and Pe showed significantly reduced amplitudes in patients relative to controls, patients showed normal condition-dependent ERN and reaction-time modulation. This suggests that while the neural mechanisms generating the ERN and Pe are compromised in schizophrenia, those modulating task performance strategy and neurophysiological responses to errors based on conflict probability are intact.

ERP indices of performance monitoring and feedback processing in psychosis: A meta-analysis

BACKGROUND

Although individuals with, or at risk for, psychotic disorders often show difficulties with performance monitoring and feedback processing, findings from studies using event-related potentials (ERPs) to index these processes are not consistent. This meta-analytic review focused on studies of two different indexes of performance monitoring, the early error-related negativity (ERN; n = 25) and the later error positivity (Pe; n = 17), and one index of feedback processing, the feedback negativity (FN; n = 6).

METHODS

We evaluated whether individuals (1) with psychotic disorders, or (2) at heightened risk for these disorders differ from healthy controls in available studies of the ERN, Pe, and FN.

RESULTS

There was a significant, large ERN reduction in those with psychosis (g = -0.96) compared to controls, and a significant, moderate ERN reduction in those at-risk (g = -0.48). In contrast, there were uniformly non-significant, small between-group differences for Pe and FN (gs ≤ |0.16|).

CONCLUSIONS

The results reveal a differential pattern of impairment in psychosis. Early performance monitoring (ERN) impairments are substantial among those with psychotic disorders in general and may be a useful vulnerability indicator for these disorders. However, later performance monitoring (Pe) and basic feedback processing (FN) appear to be relatively spared in psychosis.

State-dependent microstructural white matter changes in drug-naïve patients with first-episode psychosis

BACKGROUND

Diffusion tensor imaging (DTI) studies have consistently shown white matter (WM) microstructural abnormalities in schizophrenia. Whether or not such alterations could vary depending on clinical status (i.e. acute psychosis v. remission) remains to be investigated.

METHODS

Twenty-five treatment-naïve first-episode psychosis (FEP) patients and 51 healthy-controls (HC) underwent MRI scanning at baseline. Twenty-one patients were re-scanned as soon as they achieved sustained remission of symptoms; 36 HC were also scanned twice. Rate-of-change maps of longitudinal DTI changes were calculated for in order to examine WM alterations associated with changes in clinical status. We conducted voxelwise analyses of fractional anisotropy (FA) and trace (TR) maps.

RESULTS

At baseline, FEP presented reductions of FA in comparison with HC [p < 0.05, false-discovery rate (FDR)-corrected] affecting fronto-limbic WM and associative, projective and commissural fasciculi. After symptom remission, patients showed FA increase over time (p < 0.001, uncorrected) in some of the above WM tracts, namely the right anterior thalamic radiation, right uncinate fasciculus/inferior fronto-occipital fasciculus, and left inferior fronto-occipital fasciculus/inferior longitudinal fasciculus. We also found significant correlations between reductions in PANSS scores and FA increases over time (p < 0.05, FDR-corrected).

CONCLUSIONS

WM changes affecting brain tracts critical to the integration of perceptual information, cognition and emotions are detectable soon after the onset of FEP and may partially reverse in direct relation to the remission of acute psychotic symptoms. Our findings reinforce the view that WM abnormalities in brain tracts are a key neurobiological feature of acute psychotic disorders, and recovery from such WM pathology can lead to amelioration of symptoms.

A trans-diagnostic perspective on obsessive-compulsive disorder

Progress in understanding the underlying neurobiology of obsessive-compulsive disorder (OCD) has stalled in part because of the considerable problem of heterogeneity within this diagnostic category, and homogeneity across other putatively discrete, diagnostic categories. As psychiatry begins to recognize the shortcomings of a purely symptom-based psychiatric nosology, new data-driven approaches have begun to be utilized with the goal of solving these problems: specifically, identifying trans-diagnostic aspects of clinical phenomenology based on their association with neurobiological processes. In this review, we describe key methodological approaches to understanding OCD from this perspective and highlight the candidate traits that have already been identified as a result of these early endeavours. We discuss how important inferences can be made from pre-existing case-control studies as well as showcasing newer methods that rely on large general population datasets to refine and validate psychiatric phenotypes. As exemplars, we take 'compulsivity' and 'anxiety', putatively trans-diagnostic symptom dimensions that are linked to well-defined neurobiological mechanisms, goal-directed learning and error-related negativity, respectively. We argue that the identification of biologically valid, more homogeneous, dimensions such as these provides renewed optimism for identifying reliable genetic contributions to OCD and other disorders, improving animal models and critically, provides a path towards a future of more targeted psychiatric treatments.

Impaired error processing in late-phase psychosis: Four-year stability and relationships with negative symptoms

Error processing is impaired in psychosis, and numerous event-related potential studies have found reductions in the error-related negativity (ERN) and, more recently, the error positivity (Pe). The stability of reduced ERN/Pe in psychosis, however, is unknown. In a previous cross-sectional report, reduced ERN was associated with negative symptom severity and reduced Pe with a diagnosis of schizophrenia versus other psychosis. Here, we test the stability of impaired error processing over a four-year follow-up and relationships with subdimensions of negative symptoms. The ERN and Pe were recorded from individuals with psychotic disorders twice: 79 individuals were assessed 15years after first hospitalization, and 69 were assessed at 19years; 59 (26 with schizophrenia, 33 with other psychotic disorders) had data at both assessments. At 19years the Pe was blunted in schizophrenia. The ERN and Pe exhibited temporal stability over the four years (r=0.59 and 0.60, respectively). Reduced ERN and Pe correlated with the negative symptom subdimensions of inexpressivity and avolition, respectively, and not with psychotic or disorganized symptoms. Moreover, 15-year ERN predicted an increase in inexpressivity by year 19. No evidence was found for the reverse: negative symptoms did not predict change in ERN/Pe. Similar to non-clinical samples, the ERN and Pe show impressive four-year stability in late-phase psychosis. The ERN and Pe are promising neural measures for capturing individual differences in psychotic disorders, particularly with regard to negative symptomatology. They may prove to be useful clinically for forecasting illness course and as treatment targets.

Neural Systems for Error Monitoring

Complex behavior requires a flexible system that maintains task performance in the context of specific goals, evaluating behavioral progress, adjusting behavior as needed, and adapting to changing contingencies. Generically referred to as performance monitoring, a key component concerns the identification and correction of differences between an intended and an executed response (i.e., an error). Brain mapping experiments have now identified the temporal and spatial components of a putative error-processing system in the large-scale networks of the human brain. Most of this work has focused on the medial frontal cortex and an associated electrophysiological component known as the error-related negativity (or error negativity). Although the precise role, or roles, of this region still remain unknown, investigations of error processing have identified a cluster of modules in the medial frontal cortex involved in monitoring/maintaining ongoing behavior and motivating task sets. Other regions include bilateral anterior insula/inferior operculum and lateral prefrontal cortex. Recent work has begun to uncover how individual differences might affect the modules recruited for a task, in addition to the identification of associations between pathological states and aberrant error signals, leading to insights about possible mechanisms of neuropsychiatric illness. NEUROSCIENTIST 13(2):160—172, 2007.

Neurophysiological evidence of impaired self-monitoring in schizotypal personality disorder and its reversal by dopaminergic antagonism

Background

Schizotypal personality disorder (SPD) is a schizophrenia-spectrum disorder characterized by odd or bizarre behavior, strange speech, magical thinking, unusual perceptual experiences, and social anhedonia. Schizophrenia proper has been associated with anomalies in dopaminergic neurotransmission and deficits in neurophysiological markers of self-monitoring, such as low amplitude in cognitive event-related brain potentials (ERPs) like the error-related negativity (ERN), and the error positivity (Pe). These components occur after performance errors, rely on adequate fronto-striatal function, and are sensitive to dopaminergic modulation. Here we postulated that analogous to observations in schizophrenia, SPD individuals would show deficits in self-monitoring, as measured by the ERN and the Pe. We also assessed the capacity of dopaminergic antagonists to reverse these postulated deficits.

Methods

We recorded the electroencephalogram (EEG) from 9 SPD individuals and 12 healthy controls in two separate experimental sessions while they performed the Eriksen Flanker Task, a classical task recruiting behavioral monitoring. Participants received a placebo or 1 mg risperidone according to a double-blind randomized design.

Results

After placebo, SPD individuals showed slower reaction times to hits, longer correction times following errors and reduced ERN and Pe amplitudes. While risperidone impaired performance and decreased ERN and Pe in the control group, it led to behavioral improvements and ERN amplitude increases in the SPD individuals.

Conclusions

These results indicate that SPD individuals show deficits in self-monitoring analogous to those in schizophrenia. These deficits can be evidenced by neurophysiological measures, suggest a dopaminergic imbalance, and can be reverted by dopaminergic antagonists.

Conflict adaptation in schizophrenia: reviewing past and previewing future efforts

INTRODUCTION

Cognitive control impairments have been suggested to be a critical component in the overall cognitive deficits observed in patients diagnosed with schizophrenia. Here, we zoom in on a specific function of cognitive control, conflict adaptation. Abnormal neural activity patterns have been observed for patients diagnosed with schizophrenia in core conflict adaptation areas such as anterior cingulate cortex and prefrontal cortex. On the one hand, this strongly indicates that conflict adaptation is affected. On the other hand, however, outcomes at the behavioural level are needed to create a window into a precise interpretation of this abnormal neural activity.

METHODS

We present a narrative review of behavioural work within the context of conflict adaptation in schizophrenia, focusing on various major conflict adaptation markers: congruency sequence effects, proportion congruency effects, and post-error and post-conflict slowing. The review emphasises both methodological and theoretical aspects that are relevant to the understanding of conflict adaptation in schizophrenia.

RESULTS

Based on the currently available set of behavioural studies on conflict adaptation, no clear-cut answer can be provided as to the precise conflict adaptation processes that are impaired (and to what extent) in schizophrenia populations.

CONCLUSIONS

Future work is needed in state-of-the-art designs in order to reach better insight into the specifics of conflict adaptation impairments associated with schizophrenia.

Neurophysiological evidence for diminished monitoring of own, but intact monitoring of other's errors in schizophrenia

Schizophrenia is characterized by social deficits. Correctly monitoring own and others' performance is crucial for efficient social behavior. Deficits in monitoring own performance as reflected in reduced error-related negativity (rERN) amplitudes, have been demonstrated repeatedly in schizophrenia. A similar ERP component (observed ERN; oERN) is elicited when observing others' mistakes. However, possible deficits in monitoring others' performance have never been investigated in schizophrenia. The current ERP-study compared a group of schizophrenia patients (N=22) and healthy controls (N=21) while performing a Simon task and the social Simon task, enabling the investigation of own (rERN) and others' (oERN) performance monitoring. Patients showed slower reaction times, but comparable accuracy and compatibility effects in both tasks. As expected, patients' rERN amplitudes were reduced. Importantly however, oERN amplitudes were comparable between both groups. While monitoring own performance is compromised in schizophrenia, monitoring others' performance seems intact. This divergence between internal and external performance monitoring in patients is in line with studies showing normal neurophysiological responses to negative feedback. The presently found dissociation may improve our understanding of cognitive and neural mechanisms underlying monitoring of own and others' performance and may stimulate treatment development aimed at learning from external rather than internal error information in schizophrenia.

Post-movement processing in visual oddball task - Evidence from intracerebral recording

OBJECTIVE

To identify intracerebral sites activated after correct motor response during cognitive task and to assess associations of this activity with mental processes.

METHODS

Intracerebral EEG was recorded from 205 sites of frontal, temporal and parietal lobes in 18 epileptic patients, who responded by button pressing together with mental counting to target stimuli in visual oddball task.

RESULTS

Post-movement event-related potentials (ERPs) with mean latency 295 ± 184 ms after movement were found in all subjects in 64% of sites investigated. Generators were consistently observed in mesiotemporal structures, anterior midcingulate, prefrontal, and temporal cortices. Task-variant nonspecific and target specific post-movement ERPs were identified, displaying no significant differences in distribution among generating structures. Both after correct and incorrect performances the post-performance ERPs were observed in frontal and temporal cortices with latency sensitive to error commission in several frontal regions.

CONCLUSION

Mesiotemporal structures and regions in anterior midcingulate, prefrontal and temporal cortices seem to represent integral parts of network activated after correct motor response in visual oddball task with mental counting. Our results imply equivalent involvement of these structures in task-variant nonspecific and target specific processes, and suggest existence of common nodes for correct and incorrect responses.

SIGNIFICANCE

Our results contribute to better understanding of neural mechanisms underlying goal-directed behavior.

Environmental Adaptations Improve Everyday Action in Schizophrenia

Cognitive functioning, particularly executive functioning, is a strong predictor of functional outcomes in people with schizophrenia. Cognitive remediation has been shown to improve specific cognitive processes, but adjunctive interventions are required for meaningful gains in adaptive functioning, particularly in people with chronic illness. This study examined whether (and how) environmental adaptations, used without training, may circumvent cognitive difficulties and facilitate everyday task performance in individuals with chronic schizophrenia. Forty-two individuals with chronic schizophrenia/schizoaffective disorder were administered cognitive measures and two versions of the Naturalistic Action Test (NAT)-a standard version (ST-NAT), and a user-centered version (UC-NAT) that incorporated environmental adaptations designed to facilitate task performance. The NAT conditions were counterbalanced across participants. Analyses compared performance between the NAT versions and examined the cognitive correlates of each NAT condition. Individuals with schizophrenia made fewer errors on the UC-NAT as compared to the ST-NAT; this between-group difference was significant for all error types. Compared to the ST-NAT, the UC-NAT performance was not significantly associated with an executive function measure of planning. Environmental adaptations may be implemented without extensive training to improve everyday action in individuals with chronic schizophrenia. Environmental adaptations that reduce planning demands may be most effective in this population.

Deficits in error-monitoring by college students with schizotypal traits: an event-related potential study

The present study used event-related potentials (ERPs) to investigate deficits in error-monitoring by college students with schizotypal traits. Scores on the Schizotypal Personality Questionnaire (SPQ) were used to categorize the participants into schizotypal-trait (n = 17) and normal control (n = 20) groups. The error-monitoring abilities of the participants were evaluated using the Simon task, which consists of congruent (locations of stimulus and response are the same) and incongruent (locations of stimulus and response are different) conditions. The schizotypal-trait group committed more errors on the Simon task and exhibited smaller error-related negativity (ERN) amplitudes than did the control group. Additionally, ERN amplitude measured at FCz was negatively correlated with the error rate on the Simon task in the schizotypal-trait group but not in the control group. The two groups did not differ in terms of correct-related potentials (CRN), error positivity (Pe) and correct-related positivity (Pc) amplitudes. The present results indicate that individuals with schizotypal traits have deficits in error-monitoring and that reduced ERN amplitudes may represent a biological marker of schizophrenia.

Error-related brain activity in the age of RDoC: A review of the literature

The ability to detect and respond to errors is critical to successful adaptation to a changing environment. The error-related negativity (ERN), an event-related potential (ERP) component, is a well-validated neural response to errors and reflects the error monitoring activity of the anterior cingulate cortex (ACC). Additionally, the ERN is implicated in several processes key to adaptive functioning. Abnormalities in error-related brain activity have been linked to multiple forms of psychopathology and individual differences. As such, the component is likely to be useful in NIMH's Research Domain Criteria (RDoC) initiative to establish biologically-meaningful dimensions of psychological dysfunction, and currently appears as a unit of measurement in three RDoC domains: Positive Valence Systems, Negative Valence Systems, and Cognitive Systems. In this review paper, we introduce the ERN and discuss evidence related to its psychometric properties, as well as important task differences. Following this, we discuss evidence linking the ERN to clinically diverse forms of psychopathology, as well as the implications of one unit of measurement appearing in multiple RDoC dimensions. And finally, we discuss important future directions, as well as research pathways by which the ERN might be leveraged to track the ways in which dysfunctions in multiple neural systems interact to influence psychological well-being.

Integrating frequency and magnitude information in decision-making in schizophrenia: An account of patient performance on the Iowa Gambling Task

BACKGROUND

The Iowa Gambling Task (IGT; Bechara et al., 1994) has frequently been used to assess risky decision making in clinical populations, including patients with schizophrenia (SZ). Poor performance on the IGT is often attributed to reduced sensitivity to punishment, which contrasts with recent findings from reinforcement learning studies in schizophrenia.

METHODS

In order to investigate possible sources of IGT performance deficits in SZ patients, we combined data from the IGT from 59 SZ patients and 43 demographically-matched controls with data from the Balloon Analog Risk Task (BART) in the same participants. Our analyses sought to specifically uncover the role of punishment sensitivity and delineate the capacity to integrate frequency and magnitude information in decision-making under risk.

RESULTS

Although SZ patients, on average, made more choices from disadvantageous decks than controls did on the IGT, they avoided decks with frequent punishments at a rate similar to controls. Patients also exhibited excessive loss-avoidance behavior on the BART.

CONCLUSIONS

We argue that, rather than stemming from reduced sensitivity to negative consequences, performance deficits on the IGT in SZ patients are more likely the result of a reinforcement learning deficit, specifically involving the integration of frequencies and magnitudes of rewards and punishments in the trial-by-trial estimation of expected value.

Electrophysiological (EEG) evidence for reduced performance monitoring in euthymic bipolar disorder

OBJECTIVES

Apart from mood episodes, many cognitive deficits are present in bipolar disorder (BD). Performance monitoring is an important aspect of executive functioning and involves continuous monitoring of behavior and making subsequent changes when an error is made. On a neurophysiological level, the error-related negativity (ERN), an event-related brain potential (ERP) generated in the anterior cingulate cortex (ACC), reflects this process of performance monitoring. Abnormal ERN amplitudes have been observed in many major psychiatric disorders. However, despite conflicting evidence regarding the role of the ACC in BD, no studies to date have investigated performance monitoring as reflected in the ERN in BD.

METHODS

Sixteen patients with BD in a euthymic state and 14 matched healthy controls performed a speeded two-choice reaction-time paradigm (Flankers Task) while electroencephalogram (EEG) measures were obtained. Behavioral and ERP measurements were analyzed for the two groups.

RESULTS

The patients with BD, although euthymic, scored higher on depressive symptoms than healthy controls. While no behavioral group differences were found, patients with BD displayed lower ERN amplitudes than healthy controls when controlling for effects of residual mood.

CONCLUSIONS

The lower ERN amplitudes in the BD group reflect reduced performance monitoring and extend current knowledge of executive functioning in BD. Importantly, these findings go a long way to resolving the contradictory results regarding ACC involvement in BD by showing that taking into account residual mood may greatly influence error-related ACC activations and is critically important in understanding cognitive deficits in BD.

Verbal self-monitoring in individuals with schizotypal personality traits: an exploratory ERP study

INTRODUCTION

Individuals with schizophrenia have deficits in verbal self-monitoring. This study aimed to assess whether individuals vulnerable to develop schizophrenia show similar difficulties.

METHODS

Fifteen individuals with schizotypal personality traits and 15 healthy controls participated. All participants underwent an event-related potential (ERP) paradigm using a phoneme monitoring Go/No-Go task.

RESULTS

Behavioural results showed that there was no significant difference between individuals with schizotypal personality traits and controls in post-error slowing, but schizotypal individuals had a significantly lower degree of error awareness and higher error rate. In the ERP data, when compared with controls, individuals with schizotypal personality traits showed similar error-related negativity (ERN) amplitude but significantly larger error positivity (Pe) amplitude.

CONCLUSIONS

Results of this study suggest that verbal error detection may be intact in individuals with schizotypal personality traits. However, it seems that this vulnerable population may have a greater emotional evaluation of errors.

Disrupted action monitoring in recent-onset psychosis patients with schizophrenia and bipolar disorder

Schizophrenia patients experience cognitive control disturbances, manifest in altered neural signatures during action monitoring. It remains unclear whether error- and conflict-monitoring disturbances co-occur, and whether they are observed in recent-onset psychosis patients with schizophrenia or bipolar disorder. We tested electrophysiological measures of action monitoring in these patients. Seventy-three schizophrenia patients (SZ), 26 bipolar disorder type I patients (BP), each within one year of psychosis onset, and 54 healthy control subjects (HC) underwent EEG during Stroop task performance. In the trial-averaged EEG at three midline scalp electrodes, the error-related negativity (ERN), error positivity (Pe) and conflict-related N450 were measured. Compared to HC (1) SZ exhibited an attenuated ERN and N450, and Pe unchanged and (2) BP exhibited an attenuated ERN but normal Pe and N450. Between patient groups, SZ showed an attenuated N450; ERN and Pe were not significantly different. A small (n=10) SZ subgroup that was not receiving antipsychotic medication showed normal ERPs. Altered error- and conflict-monitoring occur together in the first-episode schizophrenia patients, and these measures are comparable in patients with the first-episode bipolar disorder. Antipsychotic medication may be associated with altered measures of error-monitoring in schizophrenia.

Conflict and error processing in an extended cingulo-opercular and cerebellar network in schizophrenia

The loss of cognitive control is a prominent feature of schizophrenia. Relevant for adaptive control, individuals with schizophrenia often show impairments in their ability to monitor their ongoing behavior, and to adjust their responses based on advance information or feedback. By conducting a systematic examination of the behavioral adjustments after error and conflict and of activity within and between brain regions sensitive to the need to increase control (i.e. error commission, conflict presentation) in individuals with schizophrenia (n = 38) compared to healthy controls, we aimed to 1) shed light on the role of diverse brain regions previously associated with adaptive cognitive control, and 2) contribute to our understanding of the nature of the cognitive deficits present in individuals with schizophrenia. Our results show that error- and conflict-related behavioral adjustments are relatively intact during the performance of a change-signal task. Similarly, individuals with schizophrenia demonstrated intact error- and conflict-related effects in the dorsal anterior cingulate cortex, as well as in a number of other key regions including the bilateral anterior prefrontal cortex (PFC), bilateral insula, right inferior parietal lobule during error processing, and bilateral inferior parietal lobule and thalamus, right anterior PFC, left insula, and left lateral and inferior cerebellum during conflict processing. Given that a critical characteristic of our experimental design was the use of tasks that explicitly provide information about errors and conflict, we interpret our results as suggesting that the error- and conflict-detection systems are still somewhat functional in individuals with schizophrenia, but that a compromise in the ability to represent task relevant information that allow for the generation of an error representation may lead to the alterations in error- and conflict-processing documented in the schizophrenia literature.

Disruption of function-structure coupling in brain regions sub-serving self monitoring in schizophrenia

Deficits in self monitoring are a core feature of cognitive dysfunction in schizophrenia, and may be the basis for disturbances of self and lack of insight, ultimately impacting social functioning. However, the functional and structural neural correlates of such deficits in self monitoring are not well understood. We investigated this issue using measurements of neurophysiological and structural brain indices, i.e., error-related and correct-response negativity (ERN & CRN) of event-related potentials, and gray matter volume of the anterior cingulate cortex (ACC), and tested whether the association between these indices is altered in patients with schizophrenia. Participants consisted of 18 male patients with chronic schizophrenia and 18 healthy male controls. The 2 groups did not differ in ERN amplitude. In contrast, schizophrenia patients showed significantly larger CRN amplitudes than did healthy subjects. Although the 2 groups did not significantly differ in gray matter volume of the ACC subregions, a significant negative correlation was found between ERN amplitudes at the frontocentral electrodes and absolute gray matter volumes of the left cognitive region of ACC only in healthy controls. These results suggest a disruption of function-structure coupling of the brain regions sub-serving self monitoring in schizophrenia.

Beyond the broken error-related negativity: functional and diagnostic correlates of error processing in psychosis

BACKGROUND

Studies of event-related potentials have consistently shown that schizophrenia is associated with a blunted error-related negativity (ERN), indicating a deficit in error monitoring. It is unknown whether this deficit is unique to schizophrenia or is common to psychotic disorders more broadly, and its associations with clinical characteristics of the illness are not well understood.

METHODS

The ERN and the error positivity (Pe) were recorded from 33 individuals with schizophrenia, 45 individuals with other psychotic disorders, and 33 healthy control subjects. Patients were drawn from a cohort with psychotic disorders followed since first hospitalization and diagnosed by consensus based on 10 years of observation.

RESULTS

The ERN was profoundly blunted in the patient group, regardless of diagnosis, indicating that this deficit is not unique to schizophrenia. The Pe, meanwhile, was blunted only among individuals with schizophrenia, indicating that the ERN and Pe are differentially related to psychotic illnesses. A blunted ERN was associated with more severe negative symptoms and poorer real-world functioning, as indicated by unemployment and re-hospitalization over 10 years of illness. Although reduced compared with control subjects, ERN amplitude was greater in patients with higher neuroticism, indicating that error processing is moderated by personality differences in the same manner as in healthy populations.

CONCLUSIONS

The current study advances the literature by evaluating diagnostic specificity and functional correlates of impaired error processing in psychosis.

Increased orienting to unexpected action outcomes in schizophrenia

Although some recent research has indicated reduced performance monitoring in patients with schizophrenia, the literature on this topic shows some remarkable inconsistencies. While most studies suggest diminished error signals following error responses, some studies reported normal post-error slowing, while others reported reduced post-error slowing. Here we review these studies and highlight the most important discrepancies. Furthermore, we argue that overall error rates are a mostly neglected issue that can at least partly explain these discrepancies. It has been reported previously that post-error slowing depends on the error rates. Participants or patients that make more errors are likely to show decreased post-error slowing. Therefore, when a group of patients is compared to a group of controls, it is extremely important to match error rates. For this purpose, we developed a procedure where we matched individuals' error rates. In a task where subjects had to press a response key corresponding to one of four colors we manipulated the difficulty on an individual basis by varying the discriminability between the colors. Schizophrenic patients and a group of controls were tested with this procedure showing that differences in accuracy disappear. Interestingly, we can see that in patients, the color values that were needed to reach similar levels of accuracy correlate with the Positive and Negative Syndrome Scale (PANSS) scale, with higher PANSS requiring more color. Most important, we found that schizophrenic patients have increased rather than decreased post-error slowing when the inter-trial interval (ITI) is short. This result can be interpreted within the framework of the orienting account, as it has been demonstrated previously that schizophrenic patients show increased distractibility.

Error monitoring dysfunction across the illness course of schizophrenia

Response monitoring abnormalities have been reported in chronic schizophrenia patients, but it is unknown whether they predate the onset of psychosis, are present in early stages of illness, or are late-developing abnormalities associated with illness progression. Response-synchronized event-related potentials (ERP) recorded during a picture-word matching task yielded error-related negativity (ERN), correct-response negativity (CRN), and error positivity (Pe) from 84 schizophrenia patients (SZ), 48 clinical high risk patients (CHR), and their age-matched healthy controls (HC; n = 110 and 88, respectively). A sub-sample of 35 early illness schizophrenia patients (ESZ) was compared to 93 age-matched HC and the CHR patients (after statistically removing the effects of normal aging). Relative to HC, 1) SZ, ESZ, and CHR had smaller ERNs, and 2) SZ and ESZ had larger CRNs and smaller Pes. Within the SZ, longer illness duration was associated with larger CRNs but was unrelated to ERN or Pe. CHR and ESZ did not differ on ERN or CRN, although Pe was smaller in ESZ than CHR. These results indicate that while ERN, CRN, and Pe abnormalities are present early in the illness, only the ERN abnormality is evident prior to psychosis onset, and only the CRN abnormality appears to worsen progressively over the illness course. Brain regions subserving response monitoring may be compromised early in the illness and possibly during its clinical prodrome.

Dissociation of response and feedback negativity in schizophrenia: electrophysiological and computational evidence for a deficit in the representation of value

Contrasting theories of schizophrenia propose that the disorder is characterized by a deficit in phasic changes in dopamine activity in response to ongoing events or, alternatively, by a weakness in the representation of the value of responses. Schizophrenia patients have reliably reduced brain activity following incorrect responses but other research suggests that they may have intact feedback-related potentials, indicating that the impairment may be specifically response-related. We used event-related brain potentials and computational modeling to examine this issue by comparing the neural response to outcomes with the neural response to behaviors that predict outcomes in patients with schizophrenia and psychiatrically healthy comparison subjects. We recorded feedback-related activity in a passive gambling task and a time estimation task and error-related activity in a flanker task. Patients' brain activity following an erroneous response was reduced compared to comparison subjects but feedback-related activity did not differ between groups. To test hypotheses about the possible causes of this pattern of results, we used computational modeling of the electrophysiological data to simulate the effects of an overall reduction in patients' sensitivity to feedback, selective insensitivity to positive or negative feedback, reduced learning rate, and a decreased representation of the value of the response given the stimulus on each trial. The results of the computational modeling suggest that schizophrenia patients exhibit weakened representation of response values, possibly due to failure of the basal ganglia to strongly associate stimuli with appropriate response alternatives.

[Electrophysiology and schizophrenic vulnerability: the P300 component as endophenotype candidate?]

INTRODUCTION

Studies on early stages of schizophrenia imply the observation of stable markers of vulnerability. Among other research fields, these early and objective markers, or potential endophenotypes, can be described in event-related potential (ERP) paradigms.

LITERATURE FINDINGS

The P300 component, elicited during the allocation of attentional resources, is the most studied ERP among people with schizophrenia. In this review, we first develop the notion of endophenotypes in schizophrenia, notably in terms of stability, heritability and specificity. We also give a short account of the P300 component, its typical description, the classical paradigms which elicit it, and several interpretations of its significance.

DISCUSSION

After reviewing the main features of the schizophrenic alterations of P300 (their topography, amplitude and latency), we discuss the relevance of P300 when described as a potential schizophrenic endophenotype. In spite of an important number of studies, results remain controversial and incomplete. First, P300 in schizophrenia shows complex patterns of temporal evolution, and thus can be described as either a stable trait or a state marker. Second, its heritability is still discussed among high-risk participants with genetic, schizotypal or clinical vulnerability. Third, the issue of its specificity is the less studied criteria. In line with the debate of its specificity, only little is known about specific alterations of P300 among unipolar or bipolar disorders. In the discussion, we describe a few possible origins of such controversial results in both empirical and conceptual perspectives, and we provide several experimental propositions in order to develop a more systematic exploration of P300 alterations.

Executive control in schizophrenia in task involving semantic inhibition and working memory

Executive dysfunctions have been consistently demonstrated in patients with schizophrenia. This study aimed to investigate deficits in specific executive functioning components, namely working memory and inhibition, in schizophrenia. In study 1, a set of neurocognitive function tests was administered to 41 patients with schizophrenia and 25 healthy controls to capture specific components of executive functioning, including semantic inhibition (the Stroop-like paradigm and the Chinese Version of the Hayling Sentence Completion Test (HSC)), working memory (the spatial n-back), and response inhibition (the stop signal task (SST)). Results showed that schizophrenia patients did significantly worse than controls under both working memory and inhibition demands in the Stroop-like paradigm. In particular, patients were impaired when inhibiting a semantically associated response; and performance was correlated with negative symptoms. In study 2, we employed a modified semantic inhibitory error monitoring paradigm to examine whether patients with schizophrenia (n=11) were impaired in semantic inhibitory error monitoring or not as compared to 11 healthy controls. The results suggested that patients with schizophrenia in this study remained intact in semantic inhibition error monitoring. There was no difference in the semantic inhibitory monitoring performance between healthy controls and patients with schizophrenia. Taken together, these results suggested impaired working memory context maintenance and semantic inhibition in schizophrenia patients, and these impairments were related to clinical symptoms of schizophrenia.

Impaired Error Monitoring and Correction Function in Autism

INTRODUCTION: Error monitoring and correction is one of the executive functions and is important for effective goal directed behavior. Deficient executive functioning, including reduced error monitoring ability, is one of the typical features of such neurodevelopmental disorders as autism, probably related to perseverative responding, stereotyped repetitive behaviors, and an inability to accurately monitor ongoing behavior. Our prior studies of behavioral and event-related potential (ERP) measures during performance on visual oddball tasks in high-functioning autistic (HFA) children showed that despite only minor differences in reaction times HFA children committed significantly more errors. METHODS: This study investigated error monitoring in children with autism spectrum disorder (ASD) with response-locked event-related potentials - the Error-related Negativity (ERN) and Error-related Positivity (Pe) recorded at fronto-central sites. The ERN reflects early error detection processes, while the Pe has been associated with later conscious error evaluation and attention re-allocation. Reaction times (RT) in correct trials and post-error slowing in reaction times were measured. In this study fourteen subjects with ASD and 14 age- and IQ- matched controls received a three-category visual oddball task with novel distracters. RESULTS: ERN had a lower amplitude and longer latency in the ASD group but was localized in the caudal part of anterior cingulate cortex (ACC) in both groups. The Pe component was significantly prolonged in the ASD group but did not reach significance in amplitude differences compared to controls. We found significant post-error slowing in RTs in controls, and post-error acceleration in RTs in the ASD group. CONCLUSIONS: The reduced ERN and altered Pe along with a lack of post-error RT slowing in autism might be interpreted as insensitivity in the detection and monitoring of response errors and a reduced ability of execute corrective actions. This might result in reduced error awareness and failure in adjustment when dealing with situations where erroneous responses may occur. This deficit might be manifested in the perseverative behaviors often seen in individuals with ASD. The results are discussed in terms of a general impairment in self-monitoring and other executive functions underlying behavioral and social disturbances in ASD.

Error-related processing dysfunction in children aged 9 to 12 years presenting putative antecedents of schizophrenia

BACKGROUND

Intervention aimed at preventing schizophrenia may be most effective if targeted at specific, but modifiable, functional impairments that present during childhood. We have developed a novel method of screening community samples aged 9 to 12 years to identify children who present a triad of putative antecedents of schizophrenia (ASz), defined as 1) speech and/or motor development lags/problems; 2) internalizing, externalizing, and/or peer-relationship problems in the clinical range; and 3) psychotic-like experiences. This study examined whether ASz children display brain function abnormalities during error processing that are similar to those exhibited by adults with schizophrenia.

METHODS

Twenty-two ASz children and 26 typically developing (TD) children with no antecedents of schizophrenia completed an error-inducing Go/NoGo task during event-related potential recording. Group differences were examined in the amplitude and latency of four event-related potential components: the initial error-related negativity (ERN) and later error-positivity (Pe) elicited on false-alarm responses to NoGo trials, and the corresponding initial correct response negativity (CRN) and later correct response positivity (Pc) elicited during processing of correct responses to Go trials.

RESULTS

Relative to TD children, ASz children were characterized by reduced ERN amplitude but unaffected CRN, Pe, and Pc amplitudes. No group differences were observed in the latency of any component.

CONCLUSIONS

Children presenting a triad of putative antecedents of schizophrenia show error-processing dysfunction mimicking that observed in adults with schizophrenia using the same Go/NoGo paradigm. The ASz children displayed specific early error-processing deficits rather than a generalized deficit in self-monitoring.

Low-frequency EEG oscillations associated with information processing in schizophrenia

Numerous studies have described attenuated event-related potential (ERP) component amplitudes in schizophrenia (e.g., P300, Mismatch Negativity (MMN), Error Negativity/Error-Related Negativity (Ne/ERN)). Functional magnetic resonance imaging (fMRI) studies have typically shown decreased recruitment of diverse brain areas during performance of tasks that elicit the above ERP components. Recent research suggests that phase-resetting of slow-oscillations (e.g., in the delta and theta bands) underlies the potentials observed in ERP averages. Several studies have reported that slow-oscillations are increased in amplitude in people with schizophrenia at rest. Few studies have examined event-related low-frequency oscillations in schizophrenia. We examined event-related evoked and induced delta and theta activity in 17 people with schizophrenia and 17 healthy controls in two go/no-go task variants. We analyzed stimulus-related and response-related oscillations associated with correct-hits, correct-rejects and false-alarms. Our results reveal a pattern of reduced delta and theta activity for task-relevant events in schizophrenia. The findings indicate that while low-frequency oscillations are increased in amplitude at rest, they are not coordinated effectively in schizophrenia during various information processing tasks including target-detection, response-inhibition and error-detection. This slow-oscillation coordination abnormality may help explain the decreased recruitment of brain areas seen in fMRI studies.

Positive affect modulates flexibility and evaluative control

The ability to interact with a constantly changing environment requires a balance between maintaining the currently relevant working memory content and being sensitive to potentially relevant new information that should be given priority access to working memory. Mesocortical dopamine projections to frontal brain areas modulate working memory maintenance and flexibility. Recent neurocognitive and neurocomputational work suggests that dopamine release is transiently enhanced by induced positive affect. This ERP study investigated the role of positive affect in different aspects of information processing: in proactive control (context maintenance and updating), reactive control (flexible adaptation to incoming task-relevant information), and evaluative control in an AX-CPT task. Subjects responded to a target probe if it was preceded by a specific cue. Induced positive affect influenced the reactive and evaluative components of control (indexed by the N2 elicited by the target and by the error-related negativity elicited after incorrect responses, respectively), whereas cue-induced proactive preparation and maintenance processes remained largely unaffected (as reflected in the P3b and the contingent negative variation components of the ERP).