Anna Weinberg

Event‐related potential activity in the basal ganglia differentiates rewards from nonrewards: Temporospatial principal components analysis and source localization of the feedback negativity

Event‐related potential studies of reward processing have consistently identified the feedback negativity (FN), an early neural response that differentiates feedback indicating unfavorable versus favorable outcomes. Several important questions remain, however, about the nature of this response. In this study, the FN was recorded in response to monetary gains and losses during a laboratory gambling task, and temporospatial principal components analysis was used to separate the FN from overlapping responses. The FN was identified as a positive deflection at frontocentral recording sites that was enhanced for rewards compared with nonrewards. Furthermore, source localization techniques identified the striatum as a likely neural generator. These data indicate that this apparent FN reflects increased striatal activation in response to favorable outcomes that is reduced or absent for unfavorable outcomes, thereby providing unique information about the timing and nature of basal ganglia activity related to reward processing. Hum Brain Mapp, 2011.

Beyond Good and Evil: The Time-Course of Neural Activity Elicited by Specific Picture Content

The present study examined electrocortical evidence for a negativity bias, focusing on the impact of specific picture content on a range of event-related potentials (ERPs). To this end, ERPs were recorded while 67 participants viewed a variety of pictures from the International Affective Picture System. Examination of broad categories (i.e., pleasant, neutral, unpleasant) found no evidence for a negativity bias in two early components, the N1 and the Early Posterior Negativity (EPN), but revealed that unpleasant images did elicit a larger late positive potential (LPP) than pleasant pictures. However, images of erotica and mutilation elicited comparable LPP responses, as did affiliative and threatening images. Exciting (i.e., sports) images and disgusting images elicited smaller LPPs than other emotional images, similar to neutral images containing people-which were associated with the largest LPPs among neutral pictures. When these three anomalous categories (exciting, disgusting, and scenes with people) were excluded, unpleasant images no longer elicited a larger LPP than pleasant images. Thus, including exciting images in pleasant ERP averages disproportionately reduces the LPP. The present findings are discussed in light of the motivational significance of specific picture subtypes.

Measurement of Emotion Dysregulation in Adolescents

The construct of emotion dysregulation increasingly has been used to explain diverse psychopathologies across the lifespan. The Difficulties in Emotion Regulation Scale (DERS; K. L. Gratz & L. Roemer, 2004) represents the most comprehensive measure of the construct to date and exhibits good reliability and validity in adults; however, the measure has yet to be tested in adolescents. The present study examined the psychometric properties of the DERS in a community sample of 428 adolescents (ages 13-17 years). Exploratory factor analysis supported a 6-factor structure consistent with the 6 DERS subscales. Internal consistencies for the subscales were good to excellent (alphas ranged from .76 to .89). In support of the measures construct validity, the DERS exhibited robust correlations with psychological problems reflecting emotion dysregulation, specifically depression, anxiety, suicidal ideation, eating disorders, alcohol use, and drug use. Intercorrelations among the DERS subscales ranged from negligible to high (range: r = .04 to r = .68), and potential problems with discriminant validity were noted. In general, results support the reliability and validity of the DERS as a measure of emotion dysregulation in adolescents.

Increased error-related brain activity in generalized anxiety disorder

The error-related negativity (ERN) is a negative deflection approximately 50ms following an erroneous response, and is thought to reflect activity of the anterior cingulate cortex (ACC), a region of the medial prefrontal cortex implicated in the pathophysiology of a number of affective disorders, including generalized anxiety disorder (GAD). Pathological worry, the hallmark of GAD, has been linked to increased error-related brain activity, although no studies to date have examined the ERN among a clinical GAD sample. The present study measured electrocortical indices of error monitoring in a well-characterized, medication-free GAD sample. Brain activity was recorded in 17 GAD and 24 control subjects. The GAD group was characterized by a larger ERN and an increased difference between error and correct trials; a larger ERN was associated with increased self-reported anxiety and depression symptoms. Individuals with GAD have exaggerated early neural responses to errors, consistent with fMRI work implicating ACC abnormalities in GAD.

The development of the error-related negativity (ERN) and its relationship with anxiety: evidence from 8 to 13 year-olds.

Because anxiety disorders appear to follow developmental trajectories that begin early in development, it may be useful to examine the neurodevelopmental correlates of specific cognitive processes that have been linked to anxiety. For instance, the error-related negativity (ERN) is a negative deflection in the event-related potential that is maximal approximately 50 ms following the commission of errors at fronto-central electrode sites,and has consistently been found to be more negative among anxious adults. Much less,however, is known about anxiety and the ERN in children—especially when this relationship develops. We recorded event-related potentials (ERPs) while 55 children aged 8–13 performed an arrow version of the flankers task. Parents and children both reported on childrens anxiety. Results suggest that the relationship between the ERN and anxiety changes as a function of age. Among older children, a larger (i.e., more negative) ERN was significantly related to increased anxiety based on parent report. Although the relationship was less robust, the relationship between ERN and anxiety was opposite among younger children.These results are discussed in terms of existing work on anxiety and the ERN, and the need for longitudinal and developmental studies on the relationship between ERN andanxiety

The late positive potential predicts subsequent interference with target processing

The current study investigated the association between neural engagement with task-irrelevant images and subsequent interference with target processing using the Emotional Interrupt paradigm [Mitchell, D., Richell, R., Leonard, A., & Blair, R. Emotion at the expense of cognition: Psychopathic individuals outperform controls on an operant response task. Journal of Abnormal Psychology, 115, 559, 2006]. Consistent with previous studies, PCA-derived factors corresponding to the early posterior negativity, P300, and late positive potential (LPP) were enhanced for emotional (i.e., both unpleasant and pleasant) compared with neutral distracters, and the P300 elicited by targets was smaller following emotional compared with neutral pictures. In addition, RTs were increased to targets that followed emotional pictures. Within-subject analyses demonstrated that slow trials were characterized by a smaller P300 and were preceded by pictures with a larger LPP. Additionally, between-subject analyses indicate that individuals with a larger LPP also demonstrated slower RTs to targets and reduced target-elicited P300s. All results were specific to the LPP and were not observed for either the early posterior negativity or the P300 elicited by task-irrelevant pictures. By relating the LPP to subsequent behavioral and ERP interference in both within- and between-subject analyses, the current study provides direct support for the notion that LPP indexes attentional engagement with visual stimuli that is uniquely associated with subsequent interference in terms of both RT slowing and P300 reduction to targets.

The ERN is the ERN is the ERN? Convergent validity of error-related brain activity across different tasks

Error-processing is increasingly examined using the error-related negativity (ERN) and error positivity (Pe) - event-related potentials (ERPs) that demonstrate trait-like properties and excellent reliability. The current study focuses on construct validity by applying a multitrait-multimethod approach, treating error-related ERPs (i.e., ERN, Pe and the difference between error minus correct, referred to as ΔERN and ΔPe, respectively) as traits measured across multiple tasks (i.e., Flanker, Stroop, and Go/NoGo). Results suggest convergent validity of these ERPs ranging between .62 and .64 for ΔERN. Values were somewhat smaller for ERN (range .33-.43), Pe (range .37-.49) and ΔPe (range .30-.37). Further, the correlations for ERN and Pe are higher within components across tasks than between different components suggesting discriminant validity. In conclusion, the present study revealed evidence for convergent and discriminant validity of error-related ERPs, further supporting the use of these components as psychophysiological trait markers.

Longer term test-retest reliability of error-related brain activity

The error-related negativity (ERN) is a negative deflection in the event-related potential (ERP) following an erroneous response and is thought to reflect activity of the anterior cingulate cortex. There is accumulating evidence that the component has trait-like properties; prior evidence further suggests test-retest reliability estimates ranging from .40 to .82 over a period of 2 to 6 weeks. The present study examined temporal stability over a longer time period. Error-related brain activity was recorded from 26 subjects during an arrow version of the flankers task on two occasions separated by 1.5 to 2.5 years. Depending on the scoring method, test-retest reliability of the ERN ranged from .56 to .67. These data are consistent with previous suggestions that the ERN is a moderately stable, trait-like neural measure.

Punishment has a lasting impact on error‐related brain activity

The current study examined whether punishment has direct and lasting effects on error-related brain activity, and whether this effect is larger with increasing trait anxiety. Participants were told that errors on a flanker task would be punished in some blocks but not others. Punishment was applied following 50% of errors in punished blocks during the first half of the experiment (i.e., acquisition), but never in the second half (i.e., extinction). The ERN was enhanced in the punished blocks in both experimental phases--this enhancement remained stable throughout the extinction phase. More anxious individuals were characterized by larger punishment-related modulations in the ERN. The study reveals evidence for lasting, punishment-based modulations of the ERN that increase with anxiety. These data suggest avenues for research to examine more specific learning-related mechanisms that link anxiety to overactive error monitoring.

Electrocortical evidence for vigilance‐avoidance in Generalized Anxiety Disorder

Both exaggerated and attenuated responses to emotional stimuli have been documented in Generalized Anxiety Disorder (GAD). Event-related potentials are well-suited for examining the time-course of neural activity during emotional processing; early components (e.g., the P1) appear to index relatively automatic attention to emotional stimuli, whereas later positivities (e.g., the late positive potential or LPP) index dynamic allocation of attention to emotional stimuli. Twenty-one individuals with GAD and 25 healthy controls (HC) passively viewed emotional and neutral images while ERPs were recorded. An enhanced P1 for unpleasant compared to neutral images was larger in GAD. In addition, the increased LPP to unpleasant compared to neutral images was diminished in the GAD group. These data provide evidence for early hypervigilance for emotional stimuli, followed by failure to engage in elaborative processing, in GAD.