Reinforcement learning and the reward positivity with aversive outcomes

The reinforcement learning (RL) theory of the reward positivity (RewP), an event-related potential (ERP) component that measures reward responsivity, suggests that the RewP should be largest when positive outcomes are unexpected and has been supported by work using appetitive outcomes (e.g., money). However, the RewP can also be elicited by the absence of aversive outcomes (e.g., shock). The limited work to-date that has manipulated expectancy while using aversive outcomes has not supported the predictions of RL theory. Nonetheless, this work has been difficult to reconcile with the appetitive literature because the RewP was not observed as a reward signal in these studies, which used passive tasks that did not involve participant choice. Here, we tested the predictions of the RL theory by manipulating expectancy in an active/choice-based threat-of-shock doors task that was previously found to elicit the RewP as a reward signal. Moreover, we used principal components analysis to isolate the RewP from overlapping ERP components. Eighty participants viewed pairs of doors surrounded by a red or green border; shock delivery was expected (80%) following red-bordered doors and unexpected (20%) following green-bordered doors. The RewP was observed as a reward signal (i.e., no shock > shock) that was not potentiated for unexpected feedback. In addition, the RewP was larger overall for unexpected (vs expected) feedback. Therefore, the RewP appears to reflect the additive (not interactive) effects of reward and expectancy, challenging the RL theory of the RewP, at least when reward is defined as the absence of an aversive outcome.

Generalization of savoring to novel positive stimuli

Savoring is a positive emotion up-regulation technique that can increase electrocortical and self-reported valence and arousal to positive and neutral pictures, with effects persisting to increase response to the same stimuli when encountered later. Outside of the lab, emotion regulation techniques that persist to affect not just encounters with the same stimuli but also encounters with similar, but previously unencountered stimuli should save individuals time and effort. Here, we used event-related potentials and picture ratings to test whether savoring would generalize to similar, but previously unseen positive pictures. To this end, 89 participants (56 female; M age = 18.96 years, SD = 1.87) were asked to savor positive pictures from one category (e.g., happy people) and to view positive pictures from another category (e.g., cute animals), as well as to view neutral pictures (e.g., plants). In a subsequent passive picture viewing task, participants viewed novel pictures from all three categories (i.e., happy people, cute animals, plants). In the first task, savoring was effective for pictures of animals throughout picture presentation, but only for pictures of people during the later part of picture presentation. In the second task, savoring generalized to novel pictures of animals, though this was only evident in the early portion of picture processing (and for self-reported ratings). Therefore, savoring holds promise as a useful technique for increasing positive emotion in everyday life, though more work is needed to understand whether effects may vary depending on different types of picture content.

Positive emotion up-regulation is resistant to working memory load: An electrocortical investigation of reappraisal and savoring

Studies of emotion regulation to-date have mostly focused on negative emotion down-regulation, leaving positive emotion up-regulation poorly understood, particularly regarding factors that may modulate its success. While reappraisal and savoring have been shown to be effective at increasing electrocortical and subjective response to pictures in controlled laboratory settings, it remains unclear whether individuals can effectively enact these techniques to willfully increase positive emotions in everyday life when faced with other concurrent distractions/demands. Here, we used the late positive potential (LPP), an electrocortical measure that is larger for emotional compared to neutral stimuli, to assess the effect of working memory (WM) load on individuals' ability to reappraise or savor positive pictures. Seventy-six participants were randomly assigned to use either reappraisal or savoring to up-regulate positive emotion to pictures. Following training, participants engaged in a positive emotion up-regulation task interspersed with high and low WM load trials, while EEG was recorded. Frequentist and Bayesian statistics showed that although high WM load seemed to consume resources and reduced picture processing overall, it did not interfere with the enhancement of the LPP via positive emotion up-regulation. Nonetheless, WM performance (especially on high-load trials) was worse when participants were engaged in positive emotion up-regulation. Therefore, while both techniques appear to be effective under concurrent WM load, positive emotion up-regulation may interfere with other ongoing tasks.

Transdiagnostic Fear and Anxiety: Prospective Prediction Using the No-Threat, Predictable Threat, and Unpredictable Threat Task

Background

Fear and anxiety are distinct dimensions of psychopathology that may be characterized by differences in dimensional threat reactivity. Heightened response to predictable threat is hypothesized to underlie fear symptomatology, whereas increased response to unpredictable threat may underlie anxiety. Despite widespread acceptance of this model, these purported associations have rarely been tested, and the prognostic value of predictable and unpredictable threat responding is unclear. Here we examined multilevel indicators of predictable and unpredictable threat response as cross-sectional correlates and prospective predictors of transdiagnostic fear and anxiety.

Methods

Fifty-two individuals with varying levels of internalizing psychopathology (31 female) performed the no-threat, predictable threat, and unpredictable threat task. Transdiagnostic fear and anxiety were assessed at baseline (time 1) and approximately 1.5 years later (time 2). We used event-related potential, the stimulus-preceding negativity, as a measure of threat anticipation and startle eyeblink as a measure of defensive reactivity during the no-threat, predictable threat, and unpredictable threat task. These probes were assessed as cross-sectional correlates and prospective predictors of fear and anxiety.

Results

Participants with larger time 1 stimulus-preceding negativities to predictable threat were characterized by greater time 1 fear. Larger time 1 stimulus-preceding negativities to unpredictable threat were associated with greater increases in time 2 anxiety. Heightened time 1 startle to predictable threat predicted larger increases in time 2 fear.

Conclusions

Results validate predictable and unpredictable threat responding as dimensional correlates of transdiagnostic fear versus anxiety and suggest that psychophysiological measures of predictable and unpredictable threat response hold promise as prospective predictors of trajectories of fear and anxiety.

Triarchic psychopathy and affective picture processing: An event-related potential study

Psychopathy and its precursors appear to be associated with abnormal affective response. For example, individuals high in psychopathy show reduced psychophysiological response to unpleasant stimuli, which might explain low levels of empathy in psychopathic individuals, and their pursuit of individual goals without regard for others' wellbeing. In keeping with the notion that psychopathology is best represented on a continuum, the triarchic model suggests that psychopathy is characterized by elevations on three traits: boldness, meanness and disinhibition. Understanding how these traits relate to psychophysiological response to emotional stimuli would help validate the triarchic model, while also bridging to other psychopathological spectra (e.g., internalizing psychopathology, which is characterized by low boldness). Here, N = 123 young adults passively viewed unpleasant, pleasant and neutral pictures while subjective and electrocortical response were recorded. Controlling for the other triarchic traits, individuals with higher self-reported meanness had smaller late positive potentials (LPPs) to both pleasant and unpleasant pictures, whereas individuals higher in boldness had larger LPPs to unpleasant pictures. In addition, those higher in meanness rated unpleasant pictures as more pleasant and less emotionally arousing. Disinhibition was not associated with the LPP or ratings. Meanness appears to drive blunted response to unpleasant pictures that has previously been observed among those high on psychopathy, and may also be associated with reduced engagement with generic pleasant stimuli. Moreover, results converge with prior work on other traits of transdiagnostic relevance (e.g., extraversion), as well as internalizing symptoms, providing a bridge between psychopathy and other forms of psychopathology.

A Neurobiological Profile Underlying Comorbidity Load and Prospective Increases in Dysphoria in a Focal Fear Sample

BACKGROUND

Knowledge of the neural mechanisms underlying increased disease burden in anxiety disorders that is unaccounted for by individual categorical diagnoses could lead to improved clinical care. Here, we tested the utility of a joint functional magnetic resonance imaging-electroencephalography neurobiological profile characterized by overvaluation of negative stimuli (amygdala) in combination with blunted elaborated processing of these same stimuli (the late positive potential [LPP], an event-related potential) in predicting increased psychopathology across a 2-year period in people with anxiety disorders.

METHODS

One hundred ten participants (64 female, 45 male, 1 other) including 78 participants with phobias who varied in the extent of their internalizing comorbidity and 32 participants who were free from psychopathology viewed negative and neutral pictures during separate functional magnetic resonance imaging blood oxygen level-dependent and electroencephalogram recordings. Dysphoria was assessed at baseline and 2 years later.

RESULTS

Participants with both heightened amygdala activation and blunted LPPs to negative pictures showed the greatest increases in dysphoria 2 years later. Cross-sectionally, participants with higher comorbidity load (≥2 additional diagnoses, n = 34) showed increased amygdala activation to negative pictures compared with participants with lower comorbidity load (≤1 additional diagnosis, n = 44) and compared with participants free from psychopathology. In addition, high comorbid participants showed reduced LPPs to negative pictures compared with low comorbid participants.

CONCLUSIONS

Heightened amygdala in response to negative stimuli in combination with blunted LPPs could indicate overvaluation of threatening stimuli in the absence of elaborated processing that might otherwise help regulate threat responding. This brain profile could underlie the worsening and maintenance of internalizing psychopathology over time.

Neural reactivity to affective stimuli and internalizing symptom dimensions in a transdiagnostic patient sample

BACKGROUND

Internalizing psychopathologies (IPs) are highly comorbid and exhibit substantial overlap, such as aberrant affective reactivity. Neural reactivity to emotional images, measured via the late positive potential (LPP) event-related potential (ERP) component, has been utilized to index affective reactivity in IPs. The LPP is often examined in isolation with a specific disorder, ignoring overlap between IPs. The current study examined how transdiagnostic IP symptom dimensions relate to neural affective reactivity in a highly comorbid patient sample.

METHODS

Participants (N = 99) completed a battery of IP symptom assessments as well as a target categorization task while viewing pleasant, unpleasant, and neutral images during electroencephalography recording. ERPs to each image valence were averaged from 400 to 1000 ms following picture onset at pooled centroparietal and occipital electrodes to calculate the LPP. A principal components analysis performed on the IP symptom measures resulted in two factors: affective distress/misery and fear-based anxiety.

RESULTS

Fear-based anxiety was associated with enhanced LPP reactivity to unpleasant, but not pleasant, images. Distress/misery was related to attenuated average LPP reactivity across images.

CONCLUSIONS

Results revealed a dissociable effect of IP symptom factors in a transdiagnostic sample such that enhanced reactivity to negative images was specific to enhanced fear-based anxiety symptoms while distress/misery symptoms predicted blunted affective reactivity. Neural affective reactivity may serve as an objective biological marker to elucidate the nature of psychological concerns in individuals with comorbid IPs.

Group differences in agency modulate error monitoring

Mistakes can lead to aversive outcomes. Error monitoring may help prevent mistakes, but it might be maladaptive for individuals who lack control over aversive outcomes, as it consumes cognitive processing resources that could be allocated elsewhere. Here, we examined the effect of agency (i.e., control over punishment) on error monitoring using the error-related negativity (ERN), an event-related potential measure of error monitoring and error rate. Ninety unselected participants performed a flanker task in which they were shocked according to their own errors (controllable punishment, n = 47) or were shocked in accordance with another participant's errors (uncontrollable punishment, n = 43). Participants without agency over punishment showed smaller ERNs and higher error rates compared with participants with agency. Furthermore, punishment only reduced error rates for participants with agency. Together, these results provide the first experimental evidence that agency modulates error monitoring and suggest an adaptive process in which error monitoring is increased/decreased depending on its utility.

Generalization of reappraisal to novel negative stimuli as evidenced by the LPP

Cognitive reappraisal is a well-studied emotion regulation technique that involves changing the meaning of stimuli. To be useful in everyday life, reappraisal's effects would ideally generalize from previously reappraised stimuli to novel, but similar stimuli, saving individuals from needing to generate novel interpretations for similar stimuli. Here, 41 participants were asked to use reappraisal to down-regulate their response to negative pictures from one category (e.g., snakes), and to view negative pictures from another category (e.g., guns) as well as neutral pictures (e.g., plants). In a subsequent task, participants passively viewed novel pictures from all three categories (e.g., snakes, guns, and plants). EEG and subjective ratings of valence and arousal were collected in both tasks. In the reappraisal task, we did not find an effect of reappraisal on the LPP or arousal ratings, but reappraisal reduced ratings of picture unpleasantness. In the second task, negative pictures from the previously reappraised category elicited smaller LPPs than negative pictures from the previously viewed category, though there was no evidence that reappraisal generalized to subjective ratings of pictures. Therefore, at the electrocortical level, cognitive reappraisal may generalize to similar but novel stimuli encountered outside of the reappraisal context. Moreover, meaning change might be more effective in modulating electrocortical response following a delay and in the absence of deliberate attempts to down-regulate emotional response. Nonetheless, reappraisal's effects appear to differ across levels of affective response when similar stimuli are encountered in the absence of willful attempts at reappraisal.

Modulation of threat extinction by working memory load: An event-related potential study

Distraction is typically discouraged during exposure therapy for anxiety, because it is thought to interfere with extinction learning by diverting attention away from anxiety-provoking stimuli. Working memory load is one form of distraction that might interfere with extinction learning. Alternatively, working memory load might reduce threat responding and benefit extinction learning by engaging prefrontal brain regions that have a reciprocal relationship with brain circuits involved in threat detection and processing. Prior work examining the effect of working memory load on threat extinction has been limited and has found mixed results. Here, we used the late positive potential (LPP), an event-related potential that is larger for threatening compared to non-threatening stimuli to assess the effect of working memory load on threat extinction. After acquisition, 38 participants performed three blocks of an extinction task interspersed with low and high working memory load trials. Results showed that overall, the LPP was reduced under high compared to low working memory load, and that working memory load slowed extinction learning. Results provide empirical evidence in support of limiting distraction during exposure therapy in order to optimize extinction learning efficiency.

Neural mechanisms and predictors of SSRI and CBT treatment of anxiety: A randomized trial focused on emotion and cognitive processing

Anxiety disorders (ADs) are common and difficult to treat. While research suggests ADs are characterized by an imbalance between bottom-up and top-down attention processes and that effective treatments work by correcting this dysfunction, there is insufficient data to explain how and for whom treatments work. The late positive potential (LPP), an event-related potential reflecting elaborative processing of motivationally salient stimuli, is sensitive to both bottom-up and top-down processes. The present study examines the LPP in healthy controls (HC) and patients with ADs under low and high working memory (WM) load to assess its utility as a predictor and index of symptom reduction in patients who underwent cognitive behavioral therapy (CBT) or selective serotonin reuptake inhibitor (SSRI) treatment. The LPP when viewing negative and neutral distractor images and WM performance were assessed in 96 participants (40 HC, 32 CBT, 24 SSRI) during a letter recall task at Week 0 and in a subset of the study sample (23 CBT, 16 SSRI) at Week 12. Patients were randomly assigned to twelve weeks of CBT or SSRI treatment. Participants completed self-reported symptom measures at each time point. Greater Week 0 LPP to negative images under low WM load predicted greater symptom reduction in the SSRI, but not the CBT, group. Regression analyses examining the LPP to negative images as an index of symptom reduction revealed a smaller decrease in the LPP to negative images under low WM load was associated with less anxiety reduction across treatment modalities. Findings suggest the LPP during low WM load may serve as a cost-effective predictor and index of treatment outcome in ADs. Clinical Trials Registration: ClinicalTrials.gov (Identifier: NCT01903447).

Comorbid anxiety and depression: Opposing effects on the electrocortical processing of negative imagery in a focal fear sample

BACKGROUND

Anxiety and depression are highly comorbid and share clinical characteristics, such as high levels of negative emotion. Attention toward negative stimuli in anxiety and depression has been studied primarily using negative pictures. Yet, negative mental imagery-that is, mental representations of imagined negative events or stimuli-might more closely mirror patient experience.

METHODS

The current study presents the first examination of neural response to negative imagery in 57 adults (39 female) who all shared a common "focal fear" diagnosis (i.e., specific phobia or performance-only social anxiety disorder), but varied in levels of comorbid anxiety and depression. After listening to standardized descriptions of negative and neutral scenes, participants imagined these scenes as vividly as possible. Associations between categorical and continuous measures of depression, generalized anxiety disorder (GAD), and social anxiety disorder with electrocortical and subjective responses to negative imagery were assessed.

RESULTS

Individuals who were more depressed showed reduced electrocortical processing of negative imagery, whereas those with GAD showed increased electrocortical processing of negative imagery-but only when controlling for depression. Furthermore, participants with higher levels of depression rated negative imagery as less negative and those with greater social anxiety symptoms rated negative imagery more negatively.

CONCLUSIONS

Depression and GAD are characterized by opposing electrocortical response to negative imagery; moreover, depression may suppress GAD-related increases in the electrocortical processing of negative imagery. Results highlight distinctions between different dimensions of distress-based psychopathology, and reveal the unique and complex contribution of comorbid depression to affective response in anxiety.

#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.

The controllability of aversive and neutral pictures: an event-related potential study

Control over physically aversive stimuli may reduce stress, arousal and physiological responses to these stimuli. Nonetheless, avoidance of emotionally aversive stimuli/excessive attempts to control negative emotion might alternatively increase the salience of these stimuli. Here, we used a novel paradigm to examine the effect of controllability on the processing of aversive and neutral pictures (using the late positive potential, LPP) and response uncertainty (using the post-imperative negative variation, PINV). Participants (n = 48) were told that they could press a button to terminate the presentation of an aversive or neutral picture, but this was only true during some blocks of the experiment and not others. Results showed that the LPP was larger for control compared to no control blocks and that this was driven by larger LPPs to aversive pictures during the first control block, but only for participants who had started the task in a no control block. Therefore, knowing that aversive stimuli might not always be controllable (i.e., a prior experience of uncontrollability) appears to increase the motivational salience of these stimuli once control becomes possible. In addition, uncontrollability increased both the early and late PINV, and the late PINV was larger for the second compared to the first control block. As such, the current study provides the first evidence that the PINV can be elicited using aversive and neutral pictures and suggests functional differentiation between the early and late portions of the PINV. Results support the utility of this novel paradigm for examining control over emotional stimuli.

Authors' reply to the commentary on "Establishing norms for error-related brain activity during the arrow Flanker task among young adults"

In their commentary on our article, "Establishing norms for error-related brain activity during the arrow Flanker task among young adults" (Imburgio et al., 2020), Clayson and colleagues (2021) voiced their concerns about our development of norms for an event-related potential measure of error monitoring, the error-related negativity (ERN). The central flaw in their commentary is the idea that because we don't know all the factors that can affect the ERN, it should not be normed. We respond to this idea, while also reiterating points made in our original manuscript: a) at present, the reported norms are not intended to be used for individual clinical assessment and b) our norms should be considered specific to the procedures (i.e., recording and processing parameters) and task used (i.e., arrow Flanker). Contrary to Clayson and colleagues' claims, we believe that information about the distribution of the ERN (i.e., our norms) in a large sample representative of those used in much of the ERN literature (i.e., unselected young adults) will be useful to the field and that this information stands to increase, not decrease, understanding of the ERN.

Savor the moment: Willful increase in positive emotion and the persistence of this effect across time

Savoring is an emotion regulation technique that aims to increase, sustain, and deepen positive emotion. It has been incorporated into several novel, "positive affect" interventions for anxiety, depression, and chronic pain, but has not been studied in a laboratory setting. As such, it is unknown whether savoring can modulate subjective and neural correlates of emotion-processing and whether savoring might exert a persistent effect on stimulus processing (i.e., modulating response at subsequent encounter). Here, 49 participants savored or viewed positive and neutral pictures, before seeing the same pictures again approximately 20 min later without instructions to savor (or view) pictures. Subjective valence and arousal ratings and the picture-elicited late positive potential (LPP) were assessed during both tasks. Results showed that savoring increased participant ratings of picture pleasantness and arousal as well as a picture-elicited LPP. Moreover, pictures that had previously been savored continued to elicit higher ratings during the subsequent picture viewing task. A larger LPP was observed for previously savored positive and neutral pictures during an early portion of picture viewing; later on during picture viewing, this effect was limited to positive pictures only (i.e., it was not evident for neutral pictures). Results validate savoring as an effective and durable means of increasing positive emotion and are discussed in the context of a broader emotion regulation literature, which has primarily examined the downregulation of negative picture processing.

Establishing norms for error-related brain activity during the arrow Flanker task among young adults

Psychological assessments typically rely on self-report and behavioral measures. Augmenting these with neurophysiological measures of the construct in question may increase the accuracy and predictive power of these assessments. Moreover, thinking about neurophysiological measures from an assessment perspective may facilitate under-utilized research approaches (e.g., brain-based recruitment of participants). However, the lack of normative data for most neurophysiological measures has prevented the comparison of individual responses to the general population, precluding these approaches. The current work examines the distributions of two event-related potentials (ERPs) commonly used in individual differences research: the error-related negativity (ERN) and error positivity (Pe). Across three lab sites, 800 unselected participants between the ages of 18 and 30 performed the arrow version of a Flanker task while EEG was recorded. Percentile scores and distributions for ERPs on error trials, correct trials, and the difference (ΔERN, ΔPe; error minus correct) at Fz, Cz and Pz are reported. The 25th, 50th, and 75th percentile values for the ΔERN at Cz were -2.37 ​μV, -5.41 ​μV, and -8.65 ​μV, respectively. The same values for ΔPe at Cz were 7.51 ​μV, 11.18 ​μV, and 15.55 ​μV. Females displayed significantly larger ΔPe magnitudes and smaller ΔERN magnitudes than males. Additionally, normative data for behavioral performance (accuracy, post-error slowing, and reaction time) on the Flanker task is reported. Results provide a means by which ERN and Pe amplitudes of young adults elicited by the arrow Flanker task can be benchmarked, facilitating the classification of neural responses as 'large,' 'medium,' or 'small'. The ability to classify responses in this manner is a necessary step towards expanded use of these measures in assessment and research settings. These norms may not apply to ERPs elicited by other tasks, and future work should establish similar norms using other tasks.

Intolerance of uncertainty, depression and the error-related negativity

Prior work has yielded contradictory findings regarding the association between depression and the error-related negativity (ERN), an event-related potential thought to reflect individual variation in sensitivity to internal threat (i.e., errors), and the error positivity (Pe), which is thought to reflect more elaborative, conscious processing of errors. One possibility is that variation in transdiagnostic dimensional constructs related to threat processing might help explain inconsistencies in the relationship between depression and the ERN and Pe. Here, we used a large, unselected sample (N = 100) to determine whether variation in intolerance of uncertainty (IU), a transdiagnostic trait dimension that is implicated in both depression and anxiety, might moderate associations between depressive symptomatology and error processing. Results showed that greater levels of depressive symptomatology were associated with larger ΔERNs (error minus correct trials) when IU was low, but were unrelated to ΔERN when IU was high; main effects of depression and IU on ΔERN were not observed. The Pe was not associated with IU or depression. Additionally, IU, but not depression, was associated with faster response times on error and correct trials. Overall, results suggest that error processing may differ for individuals with elevated depression with versus without elevated IU. Moreover, prior failures to observe associations between depression and the ERN might stem from failure to account for related transdiagnostic constructs.

Intolerance of uncertainty and threat generalization: A replication and extension

Intolerance of uncertainty (IU) is a transdiagnostic risk factor for internalizing disorders. Prior work has found that IU may be associated with either increased reactivity to threat or, alternatively, with decreased differential responding between threat and nonthreat/safety cues (i.e., threat generalization). For example, work by Morriss, Macdonald, & van Reekum  (2016) found that higher IU was associated with increased threat generalization during acquisition (using skin conductance response (SCR)), as well as less differentiation between acquisition and extinction (using subjective uneasiness ratings). Here, three labs attempted direct and conceptual replications of Morriss, Macdonald, et al. (2016). Results showed that the direct replication failed, despite being conducted at the same lab site as the original study; moreover, in contrast to Morriss, Macdonald, et al. (2016), the direct replication found that higher IU was associated with greater SCR discrimination between threat and safety cues (across acquisition and extinction), as well as greater differences in uneasiness ratings between acquisition and extinction. Nonetheless, in the conceptual replications, higher IU was associated with greater threat generalization, as well as less discrimination between acquisition and extinction, as measured using SCR. Higher IU was also associated with larger late positive potentials to threat versus safety cues during extinction-results that mirror those observed by Morriss, Macdonald, et al. (2016) using SCR. Results are discussed with regards to the challenge involved in defining a successful replication attempt, the benefits of collaborative replication and the use and reliability of multiple measures.

Maternal Neural Reactivity During Pregnancy Predicts Infant Temperament

Maternal biological systems impact infant temperament as early as the prenatal period, though the mechanisms of this association are unknown. Using a prospective, longitudinal design, we found that maternal (N = 89) amplitudes of the late positive potential (LPP) in response to negative stimuli during the second, but not the third, trimester of pregnancy predicted observed and physiological indices of temperamental reactivity in infants at age 4 months. Maternal LPP was positively associated with observed infant fear and negatively associated with frontal EEG asymmetry and cortisol reactivity in infants at age 4 months. Results identify a putative mechanism, early in pregnancy, for the intergenerational transmission of emotional reactivity from mother to infant.

Event-related potentials to threat of predictable and unpredictable shock

Cognitive affective neuroscience tasks that are straightforward to administer, measure key constructs of interest, and can be used in different lab settings and with multiple psychophysiological methods can lead to a more complete understanding of experimental effects. The no-threat, predictable threat, unpredictable threat (NPU-threat) task assesses constructs of interest to both clinical and basic affective science literatures, is relatively brief to administer, and has been used across labs with a number of different measurements (e.g., startle eyeblink, fMRI, corrugator response, subjective ratings). ERPs provide another means of assessing neurobiological reactivity during the NPU-threat task, but to date such measures have been underutilized. That is, no study has yet evaluated cue-elicited ERPs in the NPU-threat task. Here, cue-elicited ERPs were assessed in 78 participants who completed a version of the NPU-threat task previously shown to reliably moderate startle eyeblink amplitudes. Results showed larger P2 amplitudes for unpredictable versus predictable trials, increased P3s and late positive potentials for threatening versus no-threat trials, as well as larger stimulus preceding negativities for threatening versus no-threat trials (driven primarily by predictable threat cues). In line with prior work, we observed enhanced startle eyeblink for threatening versus no-threat trials and for unpredictable compared to predictable threat interstimulus intervals. In addition, the probe-elicited P3 was suppressed for predictable and unpredictable compared to no-threat trials. Therefore, cue-elicited ERPs, which can be recorded alongside other measures in the NPU-threat task (e.g., startle), may provide useful indices of temporally distinct stages of predictable and unpredictable threat processing.

Working Memory Load and Negative Picture Processing: Neural and Behavioral Associations With Panic, Social Anxiety, and Positive Affect

BACKGROUND

Internalizing disorders such as anxiety may be characterized by an imbalance between bottom-up (stimulus-driven) and top-down (goal-directed) attention. The late positive potential (LPP) can be used to assess these processes when task-irrelevant negative and neutral pictures are presented within a working memory paradigm. Prior work using this paradigm has found that working memory load reduces the picture-elicited LPP across participants; however, anxious individuals showed a reduced effect of working memory load on the LPP, suggesting increased distractibility.

METHODS

The current study assessed transdiagnostic associations between specific symptom dimensions of anxiety, the LPP, and behavior in a clinically representative, heterogeneous group of 76 treatment-seeking patients with internalizing disorders, who performed a working memory task interspersed with negative and neutral pictures.

RESULTS

As expected, negative pictures enhanced the LPP, and working memory load reduced the LPP. Participants with higher social anxiety showed increased LPPs to negative stimuli during early and late portions of picture presentation. Panic symptoms were associated with reduced LPPs to negative pictures compared with neutral pictures as well as a reduced effect of working memory load on the LPP during the late time window. Reduced positive affect was associated with greater behavioral interference from negative pictures.

CONCLUSIONS

Hypervigilance for negative stimuli was uniquely explained by social anxiety symptoms, whereas panic symptoms were associated with the opposing effect-blunted processing/avoidance of these stimuli. Panic symptoms were uniquely associated with reduced top-down control. Results reveal distinct associations between neural reactivity and anxiety symptom dimensions that transcend traditional diagnostic boundaries.

What do clinicians treat: Diagnoses or symptoms? The incremental validity of a symptom-based, dimensional characterization of emotional disorders in predicting medication prescription patterns

BACKGROUND

Although practice guidelines are based on disorders specified in diagnostic manuals, such as the DSM, practitioners appear to follow symptoms when making treatment decisions. Psychiatric medication is generally prescribed in a transdiagnostic manner, further highlighting how symptoms, not diagnoses, often guide clinical practice. A quantitative approach to nosology promises to provide better guidance as it describes psychopathology dimensionally and its organization reflects patterns of covariation among symptoms.

AIM

To investigate whether a quantitative classification of emotional disorders can account for naturalistic medication prescription patterns better than traditional diagnoses.

METHODS

Symptom dimensions and DSM diagnoses of emotional disorders, as well as prescribed medications, were assessed using interviews in a psychiatric outpatient sample (N=318, mean age 42.5years old, 59% female, 81% Caucasian).

RESULTS

Each diagnosis was associated with prescription of multiple medication classes, and most medications were associated with multiple disorders. This was largely due to heterogeneity of clinical diagnoses, with narrow, homogenous dimensions underpinning diagnoses showing different medication profiles. Symptom dimensions predicted medication prescription better than DSM diagnoses, irrespective of whether this was examined broadly across all conditions, or focused on a specific disorder and medication indicated for it.

CONCLUSIONS

Psychiatric medication was prescribed in line with symptoms rather than DSM diagnoses. A quantitative approach to nosology may better reflect treatment planning and be a more effective guide to pharmacotherapy than traditional diagnoses. This adds to a diverse body of evidence about superiority of the quantitative system in practical applications and highlights its potential to improve psychiatric care.

In the mind's eye: The late positive potential to negative and neutral mental imagery and intolerance of uncertainty

There are many advantages to human beings' ability to generate and sustain mental imagery in the absence of exteroceptive stimuli; however, this ability may also underlie emotional disorders characterized by worry, rumination, or excessive concern about the future. For instance, fear-based disorders may be characterized by heightened ERPs to negative imagery. On the other hand, distress disorders may be characterized by attempts to avoid engaging with negative mental imagery, and therefore reduced electrocortical response. Prior ERP work has used negative and neutral pictorial stimuli to establish the parameters of response in healthy individuals, before taking these paradigms to clinical samples to assess aberrant emotion processing. Yet despite its clinical relevance, no study to date has elicited a late positive potential (LPP), a robust measure of emotion processing, to standardized negative imagined scenes. Here, participants listened to audio descriptions of negative and neutral scenes, and were asked to imagine these scenes as vividly as possible. Results showed that negative imagined scenes elicited an increased LPP, lasting approximately 10 s after audio description offset, as well as heightened ratings of arousal and unpleasantness. Moreover, participants with greater self-reported cognitive concerns about uncertain future events (higher prospective intolerance of uncertainty) showed reduced emotional modulation of the LPP. These data provide the first evidence of sustained electrocortical processing of standardized negative imagery elicited in the absence of salient visual cues, and suggest that cognitive risk for anxiety in an unselected sample may be represented phenotypically by blunted LPPs to negative imagery.

Convergence of fMRI and ERP measures of emotional face processing in combat-exposed U. S. military veterans

The late positive potential (LPP) and fMRI blood-oxygen-level dependent (BOLD) activity can provide complementary measures of the processing of affective and social stimuli. Separate lines of research using these measures have often employed the same stimuli, paradigms, and samples; however, there remains relatively little understanding of the way in which individual differences in one of these measures relates to the other, and all prior research has been conducted in psychiatrically healthy samples and using emotional scenes (not faces). Here, 32 combat-exposed U. S. military veterans with varying levels of posttraumatic stress symptomatology viewed affective social stimuli (angry, fearful, and happy faces) and geometric shapes during separate EEG and fMRI BOLD recordings. Temporospatial principal component analysis was used to quantify the face-elicited LPP in a data-driven manner, prior to conducting whole-brain correlations between resulting positivities and fMRI BOLD elicited by faces. Participants with larger positivities to fearful faces (> shapes) showed increased activation in the amygdala; larger positivities to angry and happy faces (> shapes) were associated with increased BOLD activation in the posterior fusiform gyrus and inferior temporal gyrus, respectively. Across all face types, larger positivities were associated with increased activation in the fusiform "face" area. Correlations using mean area amplitude LPPs showed an association with increased activation in the anterior insula for angry faces (> shapes). LPP-BOLD associations were not moderated by PTSD. Findings provide the first evidence of correspondence between face-elicited LPP and BOLD activation across a range of (normal to disordered) psychiatric health.

Transdiagnostic neural correlates of affective face processing in anxiety and depression

BACKGROUND

It is unknown whether there are neurobiologic differences between various anxiety and depressive disorders, or whether they are characterized by shared neurobiologic variation that cuts across diagnostic boundaries. For instance, multiple anxiety disorders and depression may be characterized by abnormalities in blood oxygen-level dependent (BOLD) response during the processing of affective scenes and faces. To interrogate the shared or unique nature of these aberrations, research that examines the influence of transdiagnostic, dimensional predictors across multiple diagnoses is needed.

METHODS

One hundred ninety-nine individuals, 142 with primary diagnoses of social anxiety disorder (SAD), generalized anxiety disorder (GAD), or major depressive disorder (MDD) and 57 free from psychiatric diagnoses (healthy controls, HCs), performed a face-matching task involving fearful, angry, and happy faces (and geometric shapes) while undergoing functional magnetic resonance imaging.

RESULTS

Across the three primary diagnoses, anxiety symptom scores were associated with increased Angry > Shapes activation in the bilateral insula, anterior/midcingulate, and dorsolateral prefrontal cortex (dlPFC), while depressive symptoms were associated with reduced dlPFC activation for Angry > Shapes. Patient > HC differences were limited to non a priori regions, and no differences in BOLD activation were observed between diagnostic groups.

CONCLUSIONS

(1) Activation in paralimbic, cingulate, and lateral prefrontal regions in response to angry faces is associated with transdiagnostic anxiety and depressive symptomatology. (2) Anxiety and depressive symptoms may exert opposing influences on lateral prefrontal activation. (3) Abnormal threat processing in GAD, SAD, and MDD may reflect shared neural dysfunction that varies with symptom load.

Brain-behavioral adaptability predicts response to cognitive behavioral therapy for emotional disorders: A person-centered event-related potential study

Single-trial-level analyses afford the ability to link neural indices of elaborative attention (such as the late positive potential [LPP], an event-related potential) with downstream markers of attentional processing (such as reaction time [RT]). This approach can provide useful information about individual differences in information processing, such as the ability to adapt behavior based on attentional demands ("brain-behavioral adaptability"). Anxiety and depression are associated with maladaptive information processing implicating aberrant cognition-emotion interactions, but whether brain-behavioral adaptability predicts response to psychotherapy is not known. We used a novel person-centered, trial-level analysis approach to link neural indices of stimulus processing to behavioral responses and to predict treatment outcome. Thirty-nine patients with anxiety and/or depression received 12 weeks of cognitive behavioral therapy (CBT). Prior to treatment, patients performed a speeded reaction-time task involving briefly-presented pairs of aversive and neutral pictures while electroencephalography was recorded. Multilevel modeling demonstrated that larger LPPs predicted slower responses on subsequent trials, suggesting that increased attention to the task-irrelevant nature of pictures interfered with reaction time on subsequent trials. Whereas using LPP and RT averages did not distinguish CBT responders from nonresponders, in trial-level analyses individuals who demonstrated greater ability to benefit behaviorally (i.e., faster RT) from smaller LPPs on the previous trial (greater brain-behavioral adaptability) were more likely to respond to treatment and showed greater improvements in depressive symptoms. These results highlight the utility of trial-level analyses to elucidate variability in within-subjects, brain-behavioral attentional coupling in the context of emotion processing, in predicting response to CBT for emotional disorders.

Individual differences in cognitive reappraisal use and emotion regulatory brain function in combat-exposed veterans with and without PTSD

BACKGROUND

Veterans with posttraumatic stress disorder (PTSD) exhibit marked deficits in emotion regulation. Past research has demonstrated underengagement of the prefrontal cortex during regulation of negative affect in those with PTSD, but has been unable to find evidence of impaired downregulation of the amygdala. One possibility is that there exists variability in amygdala reactivity that cuts across diagnostic status and which can be characterized using a continuous measure of individual differences. In healthy/nontraumatized volunteers, individual variability in amygdala engagement during emotion processing and regulation has been shown to relate to habitual use of regulation strategies.

METHODS

The current study examined whether self-reported use of cognitive reappraisal and expressive suppression regulation strategies correlated with brain activation during cognitive reappraisal in combat-exposed veterans with (n = 28) and without PTSD (combat-exposed controls, CEC; n = 20).

RESULTS

Results showed that greater self-reported use of cognitive reappraisal was associated with less activation in the right amygdala during volitional attempts to attenuate negative affect using reappraisal, irrespective of PTSD diagnosis.

CONCLUSIONS

This finding is in line with prior work and extends evidence of an association between habitual use of regulation strategies and amygdala engagement during emotion regulation to a trauma-exposed sample of individuals both with and without PTSD. Furthermore, by providing evidence of individual differences in regulation-related amygdala response in a traumatized sample, this result may increase understanding of the neural mechanisms that support variability in symptom manifestation observed across individuals with PTSD.

Resting-state theta band connectivity and graph analysis in generalized social anxiety disorder

BACKGROUND

Functional magnetic resonance imaging (fMRI) resting-state studies show generalized social anxiety disorder (gSAD) is associated with disturbances in networks involved in emotion regulation, emotion processing, and perceptual functions, suggesting a network framework is integral to elucidating the pathophysiology of gSAD. However, fMRI does not measure the fast dynamic interconnections of functional networks. Therefore, we examined whole-brain functional connectomics with electroencephalogram (EEG) during resting-state.

METHODS

Resting-state EEG data was recorded for 32 patients with gSAD and 32 demographically-matched healthy controls (HC). Sensor-level connectivity analysis was applied on EEG data by using Weighted Phase Lag Index (WPLI) and graph analysis based on WPLI was used to determine clustering coefficient and characteristic path length to estimate local integration and global segregation of networks.

RESULTS

WPLI results showed increased oscillatory midline coherence in the theta frequency band indicating higher connectivity in the gSAD relative to HC group during rest. Additionally, WPLI values positively correlated with state anxiety levels within the gSAD group but not the HC group. Our graph theory based connectomics analysis demonstrated increased clustering coefficient and decreased characteristic path length in theta-based whole brain functional organization in subjects with gSAD compared to HC.

CONCLUSIONS

Theta-dependent interconnectivity was associated with state anxiety in gSAD and an increase in information processing efficiency in gSAD (compared to controls). Results may represent enhanced baseline self-focused attention, which is consistent with cognitive models of gSAD and fMRI studies implicating emotion dysregulation and disturbances in task negative networks (e.g., default mode network) in gSAD.

Impact of alcohol use disorder comorbidity on defensive reactivity to errors in veterans with posttraumatic stress disorder

Converging lines of evidence suggest that individuals with comorbid posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) may be characterized by heightened defensive reactivity, which serves to maintain drinking behaviors and anxiety/hyperarousal symptoms. However, it is important to note that very few studies have directly tested whether individuals with PTSD and AUD exhibit greater defensive reactivity compared with individuals with PTSD without AUD. Therefore, the aim of the current study was to test this emerging hypothesis by examining individual differences in error-related negativity (ERN), an event-related component that is larger among anxious individuals and is thought to reflect defensive reactivity to errors. Participants were 66 military veterans who completed a well-validated flanker task known to robustly elicit the ERN. Veterans were comprised of 3 groups: controls (i.e., no PTSD or AUD), PTSD-AUD (i.e., current PTSD but no AUD), and PTSD + AUD (i.e., current comorbid PTSD and AUD). Results indicated that individuals with PTSD and controls generally did not differ in ERN amplitude. However, among individuals with PTSD, those with comorbid AUD had significantly larger ERNs than those without AUD. These findings suggest that PTSD + AUD is a neurobiologically unique subtype of PTSD, and the comorbidity of AUD may enhance defensive reactivity to errors in individuals with PTSD. (PsycINFO Database Record

Neural markers of attention to aversive pictures predict response to cognitive behavioral therapy in anxiety and depression

Excessive attention toward aversive information may be a core mechanism underlying emotional disorders, but little is known about whether this is predictive of response to treatments. We evaluated whether enhanced attention toward aversive stimuli, as indexed by an event-related potential component, the late positive potential (LPP), would predict response to cognitive behavioral therapy (CBT) in patients with social anxiety disorder and/or major depressive disorder. Thirty-two patients receiving 12 weeks of CBT responded to briefly-presented pairs of aversive and neutral pictures that served as targets or distracters while electroencephaolography was recorded. Patients with larger pre-treatment LPPs to aversive relative to neutral distracters (when targets were aversive) were more likely to respond to CBT, and demonstrated larger reductions in symptoms of depression and anxiety following treatment. Increased attention toward irrelevant aversive stimuli may signal attenuated top-down control, so treatments like CBT that improve this control could be beneficial for these individuals.

Enhanced Neural Reactivity to Threatening Faces in Anxious Youth: Evidence from Event-Related Potentials

Anxiety disorders are characterized by enhanced reactivity to threat, and event-related potentials (ERPs) are useful neural measures of the dynamics of threat processing. In particular, the late positive potential (LPP) is an ERP component that reflects sustained attention towards motivationally salient information. Previous studies in adults suggest that the LPP is enhanced to threatening stimuli in anxiety but blunted in depression; however, very little work has evaluated the LPP to threat in anxious youth. We measured the LPP during an emotional face-matching task in youth (age 7-19) with current anxiety disorders (n = 53) and healthy controls with no history of psychopathology (n = 37). We evaluated group differences, as well as the effect of depressive symptoms on the LPP. Youth with anxiety disorders exhibited enhanced LPPs to angry and fearful faces 1000-2000 ms after stimulus onset. Higher depressive symptoms were associated with reduced LPPs to angry faces across both groups. Enhanced LPPs to threatening faces were most apparent for social anxiety disorder, as opposed to generalized anxiety disorder or separation anxiety disorder. Results suggest the LPP may be a useful neural measure of threat reactivity in youth with anxiety disorders and highlight the importance of accounting for symptoms of both depression and anxiety when examining emotional processing.

Psychobiological operationalization of RDoC constructs: Methodological and conceptual opportunities and challenges

NIMH's Research Domain Criteria (RDoC) project seeks to advance the diagnosis, prevention, and treatment of mental disorders by promoting psychobiological research on dimensional constructs that might cut across traditional diagnostic boundaries (Kozak & Cuthbert, ). At the core of this approach is the notion that these dimensional constructs can be assessed across different units of analysis (e.g., genes, physiology, behavior), enriching the constructs and providing more complete explanations of clinical problems. While the conceptual aspects of RDoC have been discussed in several prior papers, its methodological aspects have received comparatively less attention. For example, how to integrate data from different units of analysis has been relatively unclear. Here, we discuss one means of psychobiologically operationalizing RDoC constructs across different units of analysis (the psychoneurometric approach; Yancey et al., ), highlighting ways in which this approach might be refined in future iterations. We conclude that there is much to be learned from this technique; however, greater attention to scale-development methods and to psychometrics will likely benefit this and other methodological approaches to combining measurements across multiple units of analysis.

Aberrant Spontaneous and Task-Dependent Functional Connections in the Anxious Brain

A number of brain regions have been implicated in the anxiety disorders, yet none of these regions in isolation has been distinguished as the sole or discrete site responsible for anxiety disorder pathology. Therefore, the identification of dysfunctional neural networks as represented by alterations in the temporal correlation of blood-oxygen level dependent (BOLD) signal across several brain regions in anxiety disorders has been increasingly pursued in the past decade. Here, we review task-independent (e.g., resting state) and task-induced functional connectivity magnetic resonance imaging (fcMRI) studies in the adult anxiety disorders (including trauma- and stressor-related and obsessive compulsive disorders). The results of this review suggest that anxiety disorder pathophysiology involves aberrant connectivity between amygdala-frontal and frontal-striatal regions, as well as within and between canonical "intrinsic" brain networks - the default mode and salience networks, and that evidence of these aberrations may help inform findings of regional activation abnormalities observed in the anxiety disorders. Nonetheless, significant challenges remain, including the need to better understand mixed findings observed using different methods (e.g., resting state and task-based approaches); the need for more developmental work; the need to delineate disorder-specific and transdiagnostic fcMRI aberrations in the anxiety disorders; and the need to better understand the clinical significance of fcMRI abnormalities. In meeting these challenges, future work has the potential to elucidate aberrant neural networks as intermediate, brain-based phenotypes to predict disease onset and progression, refine diagnostic nosology, and ascertain treatment mechanisms and predictors of treatment response across anxiety, trauma-related and obsessive compulsive disorders.

An electrocortical investigation of voluntary emotion regulation in combat-related posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) - a debilitating disorder characterized by severe deficits in emotion regulation - is prevalent among U.S. military veterans. Research into the pathophysiology of PTSD has focused primarily on emotional reactivity, showing evidence of heightened neural response during negative affect provocation. By comparison, studies of brain functioning during the voluntary regulation of negative affect are limited. In the current study, combat-exposed U.S. military veterans with (n=25) and without (n=25) PTSD performed an emotion regulation task during electroencephalographic (EEG) recording. The late positive potential (LPP) was used as a measure of sustained attention toward, and processing of, negative and neutral pictures, and was scored prior to and after instructions to either maintain or down-regulate emotional response using the strategy of cognitive reappraisal. Results showed that groups did not differ in picture-elicited LPP amplitude either prior to or during cognitive reappraisal; reappraisal reduced the LPP in both groups over time. Time-dependent increases in LPP amplitude as a function of emotional reactivity maintenance were evident in the non-PTSD group only. This latter finding may signal PTSD-related deficits in sustained engagement with emotion-processing over the course of several seconds.

Emotion Regulatory Brain Function and SSRI Treatment in PTSD: Neural Correlates and Predictors of Change

Posttraumatic stress disorder (PTSD)-a chronic, debilitating condition, broadly characterized by emotion dysregulation-is prevalent among US military personnel who have returned from Operations Enduring Freedom (OEF) and Iraqi Freedom (OIF). Selective serotonin reuptake inhibitors (SSRIs) are a first-line treatment for PTSD, but treatment mechanisms are unknown and patient response varies. SSRIs may exert their effects by remediating emotion regulatory brain activity and individual differences in patient response might be explained, in part, by pre-treatment differences in neural systems supporting the downregulation of negative affect. Thirty-four OEF/OIF veterans, 17 with PTSD and 17 without PTSD underwent 2 functional magnetic resonance imaging scans 12 weeks apart. At each scan, they performed an emotion regulation task; in the interim, veterans with PTSD were treated with the SSRI, paroxetine. SSRI treatment increased activation in both the left dorsolateral prefrontal cortex (PFC) and supplementary motor area (SMA) during emotion regulation, although only change in the SMA over time occurred in veterans with PTSD and not those without PTSD. Less activation of the right ventrolateral PFC/inferior frontal gyrus during pre-treatment emotion regulation was associated with greater reduction in PTSD symptoms with SSRI treatment, irrespective of pre-treatment severity. Patients with the least recruitment of prefrontal emotion regulatory brain regions may benefit most from treatment with SSRIs, which appear to augment activity in these regions.

Diagnostic and symptom-based predictors of emotional processing in generalized anxiety disorder and major depressive disorder: An event-related potential study

The delineation of specific versus overlapping mechanisms in GAD and MDD could shed light on the integrity of these diagnostic categories. For example, negative emotion generation is one mechanism that may be especially relevant to both disorders. Emotional processing abnormalities were examined among 97 outpatients with generalized anxiety disorder (GAD) or major depressive disorder (MDD) and 25 healthy adults, using the late positive potential (LPP), an event-related potential that is larger for emotional versus neutral stimuli. GAD and MDD were also assessed dimensionally across all participants. Both MDD diagnosis and dimensional depression scores were associated with reduced ΔLPP. When controlling for MDD diagnosis/dimension, both the diagnosis and dimension of GAD were associated with increased ΔLPP. Both MDD and GAD dimensions, but not diagnoses, were associated with increased ΔRT to targets that followed emotional pictures. Therefore, MDD and GAD have distinguishable and opposing features evident in neural measures of emotion processing.

Age-related changes in emotional face processing across childhood and into young adulthood: Evidence from event-related potentials

Socio-emotional processing is an essential part of development, and age-related changes in its neural correlates can be observed. The late positive potential (LPP) is a measure of motivated attention that can be used to assess emotional processing; however, changes in the LPP elicited by emotional faces have not been assessed across a wide age range in childhood and young adulthood. We used an emotional face matching task to examine behavior and event-related potentials (ERPs) in 33 youth aged 7-19 years old. Younger children were slower when performing the matching task. The LPP elicited by emotional faces but not control stimuli (geometric shapes) decreased with age; by contrast, an earlier ERP (the P1) decreased with age for both faces and shapes, suggesting increased efficiency of early visual processing. Results indicate age-related attenuation in emotional processing that may stem from greater efficiency and regulatory control when performing a socio-emotional task.

Focal and aberrant prefrontal engagement during emotion regulation in veterans with posttraumatic stress disorder

BACKGROUND

Collectively, functional neuroimaging studies implicate frontal-limbic dysfunction in the pathophysiology of posttraumatic stress disorder (PTSD), as reflected by altered amygdala reactivity and deficient prefrontal responses. These neural patterns are often elicited by social signals of threat (fearful/angry faces) and traumatic reminders (combat sounds, script-driven imagery). Although PTSD can be conceptualized as a disorder of emotion dysregulation, few studies to date have directly investigated the neural correlates of volitional attempts at regulating negative affect in PTSD.

METHODS

Using functional magnetic resonance imaging and a well-validated task involving cognitive regulation of negative affect via reappraisal and known to engage prefrontal cortical regions, the authors compared brain activation in veterans with PTSD (n = 21) and without PTSD (n = 21, combat-exposed controls/CEC), following military combat trauma experience during deployments in Afghanistan or Iraq. The primary outcome measure was brain activation during cognitive reappraisal (i.e., decrease negative affect) as compared to passive viewing (i.e., maintain negative affect) of emotionally evocative content of aversive images

RESULTS

The subjects in both groups reported similar successful reduction in negative affect following reappraisal. The PTSD group engaged the dorsolateral prefrontal cortex (dlPFC) during cognitive reappraisal, albeit to a lesser extent than the CEC group. Although the amygdala was engaged in both groups during passive viewing of aversive images, neither group exhibited attenuation of amygdala activation during cognitive reappraisal.

CONCLUSIONS

Veterans with combat-related PTSD showed less recruitment of the dlPFC involved in cognitive reappraisal, suggesting focal and aberrant neural activation during volitional, self-regulation of negative affective states.

Electrocortical evidence for rapid allocation of attention to threat in the dot-probe task

Threatening stimuli have been shown to preferentially capture attention using a range of tasks and measures. However, attentional bias to threat has not typically been found in unselected individuals using behavioral measures in the dot-probe task, one of the most common ways of examining attention to threat. The present study leveraged event-related potentials (ERPs) in conjunction with behavioral measures in the dot-probe task to examine whether more direct measures of attention might reveal an attentional bias to threat in unselected individuals. As in previous dot-probe studies, we found no evidence of an attentional bias to threat using reaction time; additionally, this measure exhibited poor internal reliability. In contrast, ERPs revealed an initial shift of attention to threat-related stimuli, reflected by the N2pc, which showed moderate internal reliability. However, there was no evidence of sustained engagement with the threat-related stimuli, as measured by the late positive potential (LPP). Together, these results demonstrate that unselected individuals do initially allocate attention to threat in the dot-probe task, and further, that this bias is better characterized by neural measures of attention than traditional behavioral measures. These results have implications for the study of attention to threat in both unselected and anxious populations.

Cognitive load and emotional processing in generalized anxiety disorder: electrocortical evidence for increased distractibility

Generalized anxiety disorder (GAD) may be characterized by emotion regulation deficits attributable to an imbalance between top-down (i.e., goal-driven) and bottom-up (i.e., stimulus-driven) attention. In prior work, these attentional processes were examined by presenting unpleasant and neutral pictures within a working memory paradigm. The late positive potential (LPP) measured attention toward task-irrelevant pictures. Results from this prior work showed that working memory load reduced the LPP across participants; however, this effect was attenuated for individuals with greater self-reported state anxiety, suggesting reduced top-down control. In the current study, the same paradigm was used with 106 medication-free female participants-71 with GAD and 35 without GAD. Unpleasant pictures elicited larger LPPs, and working memory load reduced the picture-elicited LPP. Compared with healthy controls, participants with GAD showed large LPPs to unpleasant pictures presented under high working memory load. Self-reported symptoms of anhedonic depression were related to a reduced effect of working memory load on the LPP elicited by neutral pictures. These results indicate that individuals with GAD show less flexible modulation of attention when confronted with unpleasant stimuli. Furthermore, among those with GAD, anhedonic depression may broaden attentional deficits to neutral distracters.

More target features in visual working memory leads to poorer search guidance: evidence from contralateral delay activity

The visual-search literature has assumed that the top-down target representation used to guide search resides in visual working memory (VWM). We directly tested this assumption using contralateral delay activity (CDA) to estimate the VWM load imposed by the target representation. In Experiment 1, observers previewed four photorealistic objects and were cued to remember the two objects appearing to the left or right of central fixation; Experiment 2 was identical except that observers previewed two photorealistic objects and were cued to remember one. CDA was measured during a delay following preview offset but before onset of a four-object search array. One of the targets was always present, and observers were asked to make an eye movement to it and press a button. We found lower magnitude CDA on trials when the initial search saccade was directed to the target (strong guidance) compared to when it was not (weak guidance). This difference also tended to be larger shortly before search-display onset and was largely unaffected by VWM item-capacity limits or number of previews. Moreover, the difference between mean strong- and weak-guidance CDA was proportional to the increase in search time between mean strong-and weak-guidance trials (as measured by time-to-target and reaction-time difference scores). Contrary to most search models, our data suggest that trials resulting in the maintenance of more target features results in poor search guidance to a target. We interpret these counterintuitive findings as evidence for strong search guidance using a small set of highly discriminative target features that remain after pruning from a larger set of features, with the load imposed on VWM varying with this feature-consolidation process.

Electrocortical processing of social signals of threat in combat-related post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is characterized by avoidance, emotional numbing, increased arousal and hypervigilance for threat following a trauma. Thirty-three veterans (19 with PTSD, 14 without PTSD) who had experienced combat trauma while on deployment in Iraq and/or Afghanistan completed an emotional faces matching task while electroencephalography was recorded. Vertex positive potentials (VPPs) elicited by happy, angry and fearful faces were smaller in veterans with versus without PTSD. In addition, veterans with PTSD exhibited smaller late positive potentials (LPPs) to angry faces and greater intrusive symptoms predicted smaller LPPs to fearful faces in the PTSD group. Veterans with PTSD were also less accurate at identifying angry faces, and accuracy decreased in the PTSD group as hyperarousal symptoms increased. These findings show reduced early processing of emotional faces, irrespective of valence, and blunted prolonged processing of social signals of threat in conjunction with impaired perception for angry faces in PTSD.

Electrocortical and ocular indices of attention to fearful and neutral faces presented under high and low working memory load

Working memory load reduces the late positive potential (LPP), consistent with the notion that functional activation of the DLPFC attenuates neural indices of sustained attention. Visual attention also modulates the LPP. In the present study, we sought to determine whether working memory load might exert its influence on ERPs by reducing fixations to arousing picture regions. We simultaneously recorded eye-tracking and EEG while participants performed a working memory task interspersed with the presentation of task-irrelevant fearful and neutral faces. As expected, fearful compared to neutral faces elicited larger N170 and LPP amplitudes; in addition, working memory load reduced the N170 and the LPP. Participants made more fixations to arousing regions of neutral faces and faces presented under high working memory load. Therefore, working memory load did not induce avoidance of arousing picture regions and visual attention cannot explain load effects on the N170 and LPP.

Event-related potentials, emotion, and emotion regulation: an integrative review

Progress in the study of emotion and emotion regulation has increasingly been informed by neuroscientific methods. This article focuses on two components of the event-related potential (ERP)--the P300 and the late positive potential (LPP)--and how they can be used to understand the interaction between the more automatic and controlled processing of emotional stimuli. Research is reviewed exploring: the dynamics of emotional response as indexed at early and late latencies; neurobiological correlates of emotional response; individual and developmental differences; ways in which the LPP can be utilized as a measure of emotion regulation. Future directions for the application of ERP/electroencephalogram (EEG) in achieving a more complete understanding of emotional processing and its regulation are presented.