A Machine Learning Study of Anxiety-related Symptoms and Error-related Brain Activity.

Changes in error processing are observable in a range of anxiety-related disorders. Numerous studies, however, have reported contradictory and nonreplicating findings, thus the exact mapping of brain response to errors (i.e., error-related negativity [ERN]; error-related positivity [Pe]) onto specific anxiety symptoms remains unclear. In this study, we collected 16 self-reported scores of anxiety dimensions and obtained spatial features of EEG recordings from 171 individuals. We then used machine learning to (1) identify symptoms that are central for elevated ERN/Pe and (2) estimate the generalizability of traditional statistical approaches. ERN was associated with rumination, threat overestimation, and inhibitory intolerance of uncertainty. Pe was associated with rumination, prospective intolerance of uncertainty, and behavioral inhibition. Our findings emphasize that not only the amplitude of ERN but also other sources of brain signal variance encode information relevant to individual differences in error processing. The results of the generalizability check reveal the need for a change in result-validation methods to move toward robust findings that reflect stable individual differences and clinically useful biomarkers. Our study benefits from the use of machine learning to improve the generalizability of results.

Don't Stop Me Now: Neural Underpinnings of Increased Impulsivity to Temporally Predictable Events.

Although the benefit of temporal predictability for behavior is long-established, recent studies provide evidence that knowing when an important event will occur comes at the cost of greater impulsivity. Here, we investigated the neural basis of inhibiting actions to temporally predictable targets using an EEG-EMG method. In our temporally cued version of the stop-signal paradigm (two-choice task), participants used temporal information delivered by a symbolic cue to speed their responses to the target. In a quarter of the trials, an auditory signal indicated that participants had to inhibit their actions. Behavioral results showed that although temporal cues speeded RTs, they also impaired the ability to stop actions as indexed by longer stop-signal reaction time. In line with behavioral benefits of temporal predictability, EEG data demonstrated that acting at temporally predictable moments facilitated response selection at the cortical level (reduced frontocentral negativity just before the response). Likewise, activity of the motor cortex involved in suppression of incorrect response hand was stronger for temporally predictable events. Thus, by keeping an incorrect response in check, temporal predictability likely enabled faster implementation of the correct response. Importantly, there was no effect of temporal cues on the EMG-derived index of online, within-trial inhibition of subthreshold impulses. This result shows that although participants were more prone to execute a fast response to temporally predictable targets, their inhibitory control was, in fact, unaffected by temporal cues. Altogether, our results demonstrate that greater impulsivity when responding to temporally predictable events is paralleled by enhanced neural motor processes involved in response selection and implementation rather than impaired inhibitory control.

Emotional enhancement of error detection-The role of perceptual processing and inhibition monitoring in failed auditory stop trials.

The first aim of the present study was to test whether arousing, aversive sounds can influence inhibitory task performance and lead to increased error monitoring relative to a neutral task condition. The second aim was to examine whether the enhancement of error monitoring in an affective context (if present) could be predicted from stop-signal-related brain activity. Participants performed an emotional stop-signal task that required response inhibition to aversive and neutral auditory stimuli. The behavioral data revealed that unpleasant sounds facilitated inhibitory processing by decreasing the stop-signal reaction time and increasing the inhibitory rate relative to neutral tones. Aversive sounds evoked larger N1, P3, and Pe components, indicating improvements in perceptual processing, inhibition, and conscious error monitoring. A first regression analysis, conducted regardless of the category of the stop signal, revealed that both selected indexes of stop-signal-related brain activity-the N1 and P3 amplitudes recorded in the unsuccessfully inhibited trials-significantly accounted for the Pe component variance, explaining a large amount of the observed variation (66%). A second regression model, focused on difference measures (emotional minus neutral), revealed that the affective increase in the P3 amplitude on failed stop trials was the only factor that significantly accounted for the emotional enhancement effect in the Pe amplitude. This suggests that, in general (regardless of stop-signal condition), error processing is stronger if the erroneous response directly follows the stimulus, which was effectively processed on both the perceptual and action-monitoring levels. However, only inhibition-monitoring evidence accounts for the emotional increase in conscious error detection.

Machine learning reveals differential effects of depression and anxiety on reward and punishment processing.

Recent studies suggest that depression and anxiety are associated with unique aspects of EEG responses to reward and punishment, respectively; also, abnormal responses to punishment in depressed individuals are related to anxiety, the symptoms of which are comorbid with depression. In a non-clinical sample, we aimed to investigate the relationships between reward processing and anxiety, between punishment processing and anxiety, between reward processing and depression, and between punishment processing and depression. Towards this aim, we separated feedback-related brain activity into delta and theta bands to isolate activity that indexes functionally distinct processes. Based on the delta/theta frequency and feedback valence, we then used machine learning (ML) to classify individuals with high severity of depressive symptoms and individuals with high severity of anxiety symptoms versus controls. The significant difference between the depression and control groups was driven mainly by delta activity; there were no differences between reward- and punishment-theta activities. The high severity of anxiety symptoms was marginally more strongly associated with the punishment- than the reward-theta feedback processing. The findings provide new insights into the differences in the impacts of anxiety and depression on reward and punishment processing; our study shows the utility of ML in testing brain-behavior hypotheses and emphasizes the joint effect of theta-RewP/FRN and delta frequency on feedback-related brain activity.

Cognitive functions in patients with liver cirrhosis: a tendency to commit more memory errors.

BACKGROUND: Minimal hepatic encephalopathy (MHE) is the mildest form of hepatic encephalopathy (HE). For diagnostic purposes, 2 alternative batteries of psychometric screening tests are recommended. They differ from each other in terms of the cognitive domains assessed. The research was designed to provide a profile of cognitive functioning in patients with liver cirrhosis, using an assessment that covers a wider range of cognitive functions than the usual screening battery. MATERIAL AND METHODS: We examined 138 persons, including 88 with liver cirrhosis and 50 healthy volunteers. The Mini Mental State Examination (MMSE) was used for screening and excluding advanced cognitive impairment. Then, to assess cognitive functions in more detail, the following tests were used: Auditory Verbal Learning Test (AVLT), Letter and Semantic Fluency Tests (LF and SF), Trail Making Test (TMT A&B), Digit Symbol Test (DST), Block Design Test (BDT), and Mental Rotation Test (MRT). The MRT task has not been used in MHE diagnosis so far. Finally, 57 patients and 48 controls took part in the entire study. RESULTS: Patients with liver cirrhosis commit significantly more errors of intrusions in the AVLT during the delayed free recall trial. Results significantly deviating from the norm in at least 2 tests were found only in 7 cirrhosis patients. CONCLUSIONS: The results do not provide any specific profile of cognitive disturbances in MHE, but suggest that cirrhosis patients have a tendency to commit more memory errors, probably due to subtle impairments of executive function.

Bilingualism caught in a net: A new approach to understanding the complexity of bilingual experience.

The growing importance of research on bilingualism in psychology and neuroscience motivates the need for a psychometric model that can be used to understand and quantify this phenomenon. This research is the first to meet this need. We reanalyzed two data sets (N = 171 and N = 112) from relatively young adult language-unbalanced bilinguals and asked whether bilingualism is best described by the factor structure or by the network structure. The factor and network models were established on one data set and then validated on the other data set in a fully confirmatory manner. The network model provided the best fit to the data. This implies that bilingualism should be conceptualized as an emergent phenomenon arising from direct and idiosyncratic dependencies among the history of language acquisition, diverse language skills, and language-use practices. These dependencies can be reduced to neither a single universal quotient nor to some more general factors. Additional in-depth network analyses showed that the subjective perception of proficiency along with language entropy and language mixing were the most central indices of bilingualism, thus indicating that these measures can be especially sensitive to variation in the overall bilingual experience. Overall, this work highlights the great potential of psychometric network modeling to gain a more accurate description and understanding of complex (psycho)linguistic and cognitive phenomena. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Does magnetic resonance spectroscopy identify patients with minimal hepatic encephalopathy?

BACKGROUND AND PURPOSE: The results of a few studies suggest that magnetic resonance spectroscopy of the brain could allow detection of minimal hepatic encephalopathy. The goal of this study was to assess the ability of magnetic resonance spectroscopy to differentiate between cirrhotic patients with and without minimal hepatic encephalopathy. MATERIAL AND METHODS: Localized magnetic resonance spectroscopy was performed in the basal ganglia, occipital gray matter and frontal white matter in 46 patients with liver cirrhosis without overt encephalopathy and in 45 controls. Neurological and neuropsychological examination was performed in each participant. RESULTS: The patients with liver cirrhosis had a decreased ratio of myoinositol to creatine in occipital gray matter and frontal white matter (mean: 0.17 ± 0.05 vs. 0.20 ± 0.04, p = 0.01 and 0.15 ± 0.05 vs. 0.19 ± 0.04, p < 0.01, respectively) and a decreased ratio of choline to creatine in occipital gray matter (mean: 0.32 ± 0.07 vs. 0.36 ± 0.08, p = 0.03). Minimal hepatic encephalopathy was diagnosed in 7 patients. Metabolite ratios did not differ significantly between patients with and without minimal hepatic encephalopathy. Metabolite ratios did not differ significantly between patients with Child-Pugh A and those with Child-Pugh B. CONCLUSIONS: Magnetic resonance spectroscopy does not allow accurate diagnosis of minimal hepatic encephalopathy. A similar profile of metabolites in the brain is observed in cirrhotic patients without cognitive impairment.

Socially Induced Negative Emotions Elicit Neural Activity in the Mentalizing Network in a Subsequent Inhibitory Task.

Despite the growing emphasis on embedding interactive social paradigms in the field of cognitive and affective neuroscience, the impact of socially induced emotions on cognition remains widely unknown. The aim of the present study was to fill this gap by testing whether facial stimuli whose emotional valence was acquired through social learning in an economic trust game may influence cognitive performance in a subsequent stop-signal task. The study was designed as a conceptual replication of previous event-related potential experiments, extending them to more naturalistic settings. We hypothesized that response inhibition to briefly presented faces of negative and positive game partners would be enhanced on the behavioral and neural levels as compared to trials with a neutral player. The results revealed that the trust game was an effective paradigm for the induction of differently valenced emotions towards players; however, behavioral inhibitory performance was comparable in all stop-signal conditions. On the neural level, we found decreased P3 amplitude in negative trials due to significantly stronger activation in the right frontoparietal control network, which is involved in theory-of-mind operations and underlies social abilities in humans, especially memory-guided inference of others' mental states. Our findings make an important contribution to the cognition-emotion literature by showing that social interactions that take place during an economic game may influence brain activity within the mentalizing network in a subsequent cognitive task.

Socially induced negative affective knowledge modulates early face perception but not gaze cueing of attention.

Prior affective and social knowledge about other individuals has been shown to modulate perception of their faces and gaze-related attentional processes. However, it remains unclear whether emotionally charged knowledge acquired through interactive social learning also modulates face processing and attentional control. Thus, the aim of this study was to test whether affective knowledge induced through social interactions in a naturalistic exchange game can influence early stages of face processing and attentional shifts in a subsequent gaze-cueing task. As indicated by self-reported ratings, the game was successful in inducing valenced affective knowledge towards positive and negative players. In the subsequent task, in which the locations of future targets were cued by the gaze of the game players, we observed enhanced early neural activity (larger amplitude of the P1 component) in response to a photograph of the negative player. This indicates that negative affective knowledge about an individual indeed modulates very early stages of the processing of this individual's face. Our study contributes to the existing literature by providing further evidence for the saliency of interactive social exchange paradigms that are used to induce affective knowledge. Moreover, it extends the previous research by presenting a very early modulation of perception by socially learned affective knowledge. Importantly, it also offers increased ecological validity of the findings due to the use of naturalistic social exchange in the study design.

#EEGManyLabs: Investigating the replicability of influential EEG experiments.

There is growing awareness across the neuroscience community that the replicability of findings about the relationship between brain activity and cognitive phenomena can be improved by conducting studies with high statistical power that adhere to well-defined and standardised analysis pipelines. Inspired by recent efforts from the psychological sciences, and with the desire to examine some of the foundational findings using electroencephalography (EEG), we have launched #EEGManyLabs, a large-scale international collaborative replication effort. Since its discovery in the early 20th century, EEG has had a profound influence on our understanding of human cognition, but there is limited evidence on the replicability of some of the most highly cited discoveries. After a systematic search and selection process, we have identified 27 of the most influential and continually cited studies in the field. We plan to directly test the replicability of key findings from 20 of these studies in teams of at least three independent laboratories. The design and protocol of each replication effort will be submitted as a Registered Report and peer-reviewed prior to data collection. Prediction markets, open to all EEG researchers, will be used as a forecasting tool to examine which findings the community expects to replicate. This project will update our confidence in some of the most influential EEG findings and generate a large open access database that can be used to inform future research practices. Finally, through this international effort, we hope to create a cultural shift towards inclusive, high-powered multi-laboratory collaborations.

Patterns of bilingual language use and response inhibition: A test of the adaptive control hypothesis.

Given prior studies that provided inconsistent results, there is an ongoing debate on the issue of whether bilingualism benefits cognitive control. We tested the Adaptive Control Hypothesis, according to which only the intense use of different languages in the same situation without mixing them in single utterances (called dual-language context) confers a bilingual advantage in response inhibition. In a large-scale correlational study, we attempted to circumvent several pitfalls of previous research on the bilingual advantage by testing a relatively large sample of participants and employing a more reliable and valid measurement of constructs (i.e., latent variable approach accompanied by Bayesian estimation). Our results do not support the Adaptive Control Hypothesis' prediction: the intensity of the dual-language context experience was unrelated to the efficiency of response inhibition in bilinguals. The results suggest that the Adaptive Control Hypothesis is not likely to account for the inconsistent results regarding the bilingual advantage hypothesis, at least in the case of the response-inhibition mechanism. At the same time, the study points to the problem of measuring the response-inhibition construct at the behavioral level. No evidence for a robust response-inhibition construct adds to the growing skepticism on this issue in the literature.

Religious fundamentalism is associated with hyperactive performance monitoring: ERP evidence from correct and erroneous responses.

The aim of the current study was to examine whether action monitoring is associated with religious fundamentalism. Participants performed a stop-signal task that required response inhibition to a simple auditory tone. The level of their religious fundamentalism was measured on a scale. Analysis with mixed-effects linear models revealed significantly larger error-related negativity, correct-related negativity, and post-error positivity components in individuals scoring higher on religious fundamentalism, pointing to their increased engagement in response monitoring. However, it was not accompanied by improved behavioral performance. The electrophysiological results of our study suggest that individuals high in religious fundamentalism engage more in monitoring for conflict between outcomes of their actions and standards of correct behavior. Our findings also point to a possible association between a fundamentalist mindset and higher levels of negative affect, uncertainty, anxiety, and distress, as measured by response-related brain activity.

Flanker task with equiprobable congruent and incongruent conditions does not elicit the conflict N2.

In many published studies, various modifications of the flanker task have been used. Regardless of the flanker task version, the conflict N2 component has been consistently reported and interpreted as evidence for the resolution of conflict introduced by incongruent flankers. However, ERP studies that used the most basic flanker task (i.e., a version with equiprobable congruent and incongruent conditions in which only congruency between the target and flankers is manipulated) have not provided compelling evidence for the conflict N2 component. We report the results of a large-sample ERP study employing a basic flanker task that allowed us to revisit the mechanism underlying the resolution of conflict introduced by incongruent flankers. In the behavioral data, we observed the classic effect of congruency. In the ERP data, we found three conflict-sensitive components: (a) an early frontal component, presumably corresponding to P2, (b) P300 for congruent trials, followed by (c) P300 for incongruent trials. We did not find evidence for the conflict N2 component. Based on a review of literature, we propose that the conflict N2 component observed in a basic flanker task might be a frontal aspect of the P300 component. Given previous attempts to attribute the functional role of the ERP components, the absence of the conflict N2 in the basic flanker task suggests that response inhibition may not be crucial for the resolution of conflict induced by incongruent flankers. Instead, the P2 component appears to indicate that selective attention might play an important role in resolving the flanker conflict.

Post-error Brain Activity Correlates With Incidental Memory for Negative Words.

The present study had three main objectives. First, we aimed to evaluate whether short-duration affective states induced by negative and positive words can lead to increased error-monitoring activity relative to a neutral task condition. Second, we intended to determine whether such an enhancement is limited to words of specific valence or is a general response to arousing material. Third, we wanted to assess whether post-error brain activity is associated with incidental memory for negative and/or positive words. Participants performed an emotional stop-signal task that required response inhibition to negative, positive or neutral nouns while EEG was recorded. Immediately after the completion of the task, they were instructed to recall as many of the presented words as they could in an unexpected free recall test. We observed significantly greater brain activity in the error-positivity (Pe) time window in both negative and positive trials. The error-related negativity amplitudes were comparable in both the neutral and emotional arousing trials, regardless of their valence. Regarding behavior, increased processing of emotional words was reflected in better incidental recall. Importantly, the memory performance for negative words was positively correlated with the Pe amplitude, particularly in the negative condition. The source localization analysis revealed that the subsequent memory recall for negative words was associated with widespread bilateral brain activity in the dorsal anterior cingulate cortex and in the medial frontal gyrus, which was registered in the Pe time window during negative trials. The present study has several important conclusions. First, it indicates that the emotional enhancement of error monitoring, as reflected by the Pe amplitude, may be induced by stimuli with symbolic, ontogenetically learned emotional significance. Second, it indicates that the emotion-related enhancement of the Pe occurs across both negative and positive conditions, thus it is preferentially driven by the arousal content of an affective stimuli. Third, our findings suggest that enhanced error monitoring and facilitated recall of negative words may both reflect responsivity to negative events. More speculatively, they can also indicate that post-error activity of the medial prefrontal cortex may selectively support encoding for negative stimuli and contribute to their privileged access to memory.

Individual differences in decisiveness: ERP correlates of response inhibition and error monitoring.

The aim of the current study was to examine whether and how self-reported decisiveness is associated with response inhibition and performance monitoring. We hypothesized that these two cognitive control mechanisms, both of which are often associated with decision making, would differ in individuals varying in decisiveness. We focused on ERP correlates and behavioral measures of inhibition and error processing in the stop-signal task. We expected a negative relationship between decisiveness and behavioral measures of inhibitory control. We also hypothesized that stop-signal-locked N1 and P3 components and response-locked error-related negativity (ERN) would be less pronounced when participants self-reported higher levels of decisiveness. Correlation analysis identified an association between high decisiveness, long stop-signal reaction time, and low inhibition rate. Analysis with mixed-effects linear models revealed that stop signals evoked less pronounced N1 and P3 in individuals scoring higher on decisiveness in both successfully and unsuccessfully inhibited trials. Additionally, high decisiveness was linked to reduced error monitoring, as indicated by decreased ERNs. Importantly, we also found positive association between P3 onset latency and decisiveness, suggesting that individuals scoring higher on this measure have relatively less ability to rapidly engage the stopping process. Thus, our findings primarily indicate that decisiveness is negatively associated with the efficiency of both response inhibition and error monitoring. They also suggest that highly decisive people may share some characteristics of diminished cognitive control with impulsive individuals.

Threatening visual stimuli influence response inhibition and error monitoring: An event-related potential study.

The present study investigated the effect of emotion on response inhibition and error monitoring using event-related potentials. Participants performed an emotional stop-signal task that required response inhibition to briefly presented threatening and neutral visual stimuli. Negative, arousing pictures improved behavioral performance by decreasing the stop-signal reaction time and increasing the inhibitory rate, but had no enhancing effect on inhibitory processing at the electrophysiological level (N2-P3 complex). The perceptual processing of threatening stop-signals resulted in a larger and earlier N1 component. The Pe component, associated with conscious evaluation or affective processing of an error, was stronger in negative than in neutral trials. The stronger Pe correlated with superior task performance in the emotional condition. Prioritized perceptual processing of the stop-signal was associated with better conscious error monitoring. These results support the hypothesis that threatening, arousing stimuli improve behavioral inhibitory performance and error monitoring due to the enhancement of perceptual processing.

ERP correlates of the conflict level in the multi-response Stroop task.

This EEG study (N=33) examined event-related potentials associated with conflict between activated responses in the Stroop task, in order to examine the conflict monitoring theory of cognitive control, which predicts the strength of exerted control to be proportional to the detected level of conflict. However, existing research manipulated the sole presence/absence of conflict, but not its exact level. Here, by using a modified color-word task that allowed multiple correct responses for target colors, as well as multiple incorrect responses for distractor words, we manipulated the level of conflict among activated responses (and not only its presence). We expected that a larger number of activated incorrect responses (i.e., a presumably higher conflict) would entail more pronounced conflict-related potentials. Indeed, two components of the N450 wave, parietal negativity and medial frontal negativity, were more negatively deflected when conflict was higher, than when it was lower, visibly responding to the level of conflict. Slow potential weakly responded to the sheer presence of conflict, but not to its level. These results can be plausibly explained by the conflict monitoring theory with a modified conflict evaluation formula, whereas they are at odds with several alternative theories of cognitive control.

Event-related potentials in children with attention deficit hyperactivity disorder: an investigation using an auditory oddball task.

The aim of the study was to investigate differences in electrophysiological brain activity between children diagnosed with attention deficit hyperactivity disorder combined type (ADHD-Com) and normally developing children, using the auditory 2-tone oddball paradigm. Forty right-handed subjects aged between 6.9 and 12.3 years participated in the present study, with 16 boys and 4 girls in each of the control and ADHD-Com groups. Children were individually age- and gender-matched. The auditory oddball task consisted of 155 standards (1 KHz, p=.66) and 80 targets (1.5 KHz, p=.34), presented randomly one at a time. Subjects were instructed to listen to the sounds and count the rare tones. Task performance in ADHD children did not differ compared to that in the control group. Event-related potentials (ERPs) elicited to target and standard stimuli were analyzed for between-group differences. The ADHD group showed enhanced P2 and reduced N2 component to both oddball stimuli, followed by reduced P3 component to attended targets compared with controls. The difference in the P3 amplitude between targets and standards was smaller in the ADHD group, particularly over the right hemisphere. These results suggest deficiencies in both automatic and controlled processing in children with ADHD. Enhanced amplitude of the P2 in ADHD children may reflect an early orienting deficit which affects later processing stages in the oddball task. Reduced amplitude of the N2 in the clinical group may be associated with stimulus discrimination impairment and inappropriate conflict monitoring. Reduced amplitude of target P3 and its asymmetrical distribution in ADHD children may reflect a deficit in higher-level executive functions, such as attention allocation and stimulus evaluation, accompanied by an impairment of global aspects of attentional processing that are under right hemisphere control.

Response inhibition of children with ADHD in the stop-signal task: an event-related potential study.

The Stop-Signal Task (SST) is a procedure that can provide a measure of inhibitory control of an ongoing motor response. We used the stop-signal paradigm to determine whether deficient inhibitory control distinguishes children with a diagnosis of attention deficit hyperactivity disorder combined type (ADHD-Com) from normally developing children, matched on age and sex. Participants performed a standard visual two-choice task with an auditory stop-signal stimulus, while an EEG was recorded. The behavioral results indicated that the ADHD group had significantly impaired inhibitory control compared to the performance of normal children. Relative to controls, the go stimulus reaction time (RT) and the stop-signal reaction time (SSRT) were prolonged in children with ADHD. The amplitudes of P2 and P3 components to the auditory stop-signal were more pronounced for successful than for unsuccessful stop-signal trials in both groups. However, the successful-unsuccessful difference was larger in control subjects. In contrast, the amplitude of the N2 component to auditory stop-signal was more pronounced for unsuccessful than for successful stop-signal trials in both groups. The comparison of the N2 component between control and ADHD groups revealed a greater amplitude and longer latency in the latter group, in successful stop-signal trials only. Additionally, the amplitude of response-locked ERPs, containing the ERN-Pe complex related to error-detection, was smaller in ADHD children. These results support the hypothesis of a complex deficit of inhibitory control, conflict monitoring, and error recognition mechanisms in ADHD and corroborate the utility of the stop-signal task in distinguishing hyperactive from normal children.