Individual differences in combat experiences and error-related brain activity in OEF/OIF/OND veterans

Associations between lifetime stress exposure and the error-related negativity (ERN) differ based on stressor characteristics and exposure timing in young adults

Life stress increases risk for multiple forms of psychopathology, in part by altering neural processes involved in performance monitoring. However, the ways in which these stress-cognition effects are influenced by the specific timing and types of life stressors experienced remains poorly understood. To address this gap, we examined how different social-psychological characteristics and developmental timing of stressors are related to the error-related negativity (ERN), a negative-going deflection in the event-related potential (ERP) waveform that is observed from 0 to 100 ms following error commission. A sample of 203 emerging adults performed an ERN-eliciting arrow flanker task and completed an interview-based measure of lifetime stress exposure. Adjusting for stress severity during other developmental periods, there was a small-to-medium effect of stress on performance monitoring, such that more severe total stress exposure, as well as more severe social-evaluative stress in particular, experienced during early adolescence significantly predicted an enhanced ERN. These results suggest that early adolescence may be a sensitive developmental period during which stress exposure may result in lasting adaptations to neural networks implicated in performance monitoring.

Predictors of posttraumatic stress symptom severity and meaning made in treatment-seeking veterans

OBJECTIVE

Combat-exposed veterans risk encountering events that disrupt beliefs. To facilitate reduced discrepancy between prior beliefs and current trauma appraisals, veterans may engage in a process of meaning-making. Meaning-making can lead to positive outcomes, such as integrating the traumatic event into one's life narrative or adapting global meaning (meaning made) or elicit distress. Given these potentially different outcomes, this study examined potential correlates of posttraumatic stress symptom (PTSS) severity and meaning made, including relationship attachment dimensions of anxiety and avoidance, and difficulties with emotion regulation, while controlling for combat exposure.

METHOD

Veterans receiving mental health services at a Veterans Affairs (VA) Medical Center and a VA community-based outpatient clinic (N = 130) completed measures through a paper-and-pencil survey. Almost all participants (92%) were male, with a mean age of 55.92 years.

RESULTS

In terms of meaning made, lower levels of attachment anxiety and emotional clarity (an aspect of emotion regulation) predicted higher meaning made. In terms of PTSS severity, higher attachment avoidance, attachment anxiety, and difficulties engaging in goal-directed behavior (an aspect of emotion regulation) significantly predicted higher PTSS severity.

CONCLUSION

Aspects of both attachment style and emotion regulation difficulties affect meaning made and PTSS severity. These constructs may be especially relevant for clinicians working with veterans to help PTSS and support meaning made postcombat.

EEG correlates of attentional control in anxiety disorders: A systematic review of error-related negativity and correct-response negativity findings

BACKGROUND

Anxiety disorders are highly prevalent and cause substantial personal, social and economic burden. Altered attentional control has been shown to be present across anxiety disorders and is associated with specific changes in brain activity which can be recorded by electroencephalogram (EEG). These include changes in the EEG markers of error-related negativity (ERN) and correct-response negativity (CRN), both believed to reflect response monitoring and attentional control pathophysiology in anxiety. The aim of this review was to systematically assess the research on ERN and CRN in attentional control in individuals with clinical anxiety and healthy controls, across emotional and non-emotional attentional control.

METHODS

A comprehensive literature search was conducted for studies published prior to October 22^nd, 2020. Details of the protocol for this systematic review were registered on PROSPERO (CRD42019144885).

RESULTS

66 studies had their data extracted. All 66 studies measured ERN, with 85% finding significantly increased ERN amplitudes associated with clinical anxiety. Only 44 of the extracted studies analysed CRN and only ~20% of these found significant changes in CRN amplitude associated with individuals with clinical anxiety.

LIMITATIONS

There were several anxiety disorders that had either limited literature (i.e. specific phobia, separation anxiety disorder or agoraphobia) or nil literature (i.e. selective mutism) available. No extracted studies included samples of older adults (i.e. aged 60+ years), and only six extracted studies included measures of emotional attentional control.

CONCLUSIONS

Findings indicate the promising utility of ERN of attentional control as a robust, transdiagnostic trait marker of clinical anxiety.

The effect of static and dynamic visual stimulations on error-evoked brain responses

Error-related potentials (ErrPs) can reflect the brain's response to errors. Recently, it has been used in the studies on neural mechanisms of human cognition, such as error detection and conflict monitoring. Moreover, ErrPs have provided technical support for the development of brain-computer interface (BCI). However, the different effects of visual stimulation modes (dynamic or static) on ErrPs have not been revealed. This may seriously affect the recognition accuracy of the ErrPs in practical applications. Therefore, the aim of this study was to investigate how people respond to different types of visual stimulations. Nineteen participants were recruited in the ErrPs-based tasks with two visual stimulation modes (dynamic and static). The ErrPs were analyzed and the feature values (N1, P2, P3, N6 and P8, named by the occurrence time) were statistically compared. The results showed that the difference between correctness and error was reflected in P3, N6, P8 in dynamic stimulation; and N1, P3, N6 and P8 in static stimulation. In the event-related potential based on error, the differences between dynamic and static tasks were reflected in N1 and P2. In conclusion, this study found that the features with later occurrence were significantly affected by correctness and error in both cases, while the error-related change in N1 only existed under the static stimulation. We also found that the recognition of stimulation modes came earlier within about 300 ms after the start of visual stimulation.

The error-related negativity (ERN) moderates the association between interpersonal stress and anxiety symptoms six months later

Anxiety disorders are often preceded by interpersonal stress; however, most individuals who experience stress do not develop anxiety, making it difficult to predict who is most susceptible to stress. One proposed trans-diagnostic neural risk marker for anxiety is the error-related negativity (ERN), a negative deflection in the event-related potential waveform occurring within 100 ms of error commission. The present study sought to investigate whether interpersonal stress experienced over the course of a year interacts with ERN magnitude to prospectively predict anxiety symptoms. A sample of 57 emerging adults performed an arrow flanker task to elicit the ERN at the start of the academic school year (time one). Toward the end of the academic year (time two), participants reported on past-year interpersonal stress and anxiety symptoms. Stress interacted with ERN magnitude to predict anxiety symptoms, whereby, for individuals with an enhanced ERN at time one, greater interpersonal stress over the course of a year was significantly associated with increased anxiety symptoms at time two, even controlling for anxiety symptoms at time one. These findings suggest that enhanced performance monitoring may render individuals more susceptible to the adverse effects of interpersonal stress, thereby increasing risk for heightened anxiety.

Punishment has a persistent effect on error-related brain activity in highly anxious individuals twenty-four hours after conditioning

The ability to detect and respond to errors, and to subsequently recruit cognitive control to remediate those errors, is critical to successful adaptation in a changing environment. However, there is also evidence that, for anxious individuals, this error signal is enhanced, highlighting affective and motivational influences on error monitoring. These individual differences arise as a function of both genetic influences and learning experiences. In this study, we examined punishment-based modulation of the error-related negativity (ERN) in high and low anxious individuals across two days. Twenty-two low- and 25 high-anxious participants performed a Flanker task in a standard and punishment condition in three phases (Day one: acquisition and extinction 1, Day two: extinction 2). During the acquisition phase, errors in one condition were punished by a loud noise. This was followed by an immediate extinction phase (extinction 1), during which errors were no longer punished, and an identical extinction phase 24 h later (extinction 2). Only high anxious individuals showed increased ERN amplitudes in the punishment compared to the standard condition. This effect was not modulated by phase and was observed across acquisition and both extinction phases, such that anxious individuals appeared not to learn that the threat value of formerly-punished errors had changed in the course of the experiment. These data suggest that environmental factors (i.e., punishment) can have a persistent effect on the magnitude of the ERN, particularly for anxious individuals. This may point to a pathogenic mechanism linking learning experiences with the development of overactive error-monitoring in anxiety.

The Electrical Aftermath: Brain Signals of Posttraumatic Stress Disorder Filtered Through a Clinical Lens

This review aims to identify patterns of electrical signals identified using electroencephalography (EEG) linked to posttraumatic stress disorder (PTSD) diagnosis and symptom dimensions. We filter EEG findings through a clinical lens, evaluating nuances in findings according to study criteria and participant characteristics. Within the EEG frequency domain, greater right than left parietal asymmetry in alpha band power is the most promising marker of PTSD symptoms and is linked to exaggerated physiological arousal that may impair filtering of environmental distractors. The most consistent findings within the EEG time domain focused on event related potentials (ERPs) include: 1) exaggerated frontocentral responses (contingent negative variation, mismatch negativity, and P3a amplitudes) to task-irrelevant distractors, and 2) attenuated parietal responses (P3b amplitudes) to task-relevant target stimuli. These findings suggest that some individuals with PTSD suffer from attention dysregulation, which could contribute to problems concentrating on daily tasks and goals in lieu of threatening distractors. Future research investigating the utility of alpha asymmetry and frontoparietal ERPs as diagnostic and predictive biomarkers or intervention targets are recommended.