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.

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.

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.

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.

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.

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.

Event-related potential studies of emotion regulation: A review of recent progress and future directions.

Event-related potentials (ERPs) bring many strengths to the study of emotion regulation, including: direct measurement of neural activity, high temporal resolution, affordability and suitability to a wide range of participants. Research using ERPs to study emotion regulation began approximately two decades ago, but has grown exponentially over the last 10 years. Here, we highlight progress in this body of work throughout the past decade, as well as emerging themes, novel approaches and paradigms that will likely shape the field in the coming years. While standardized picture sets are still the most commonly used stimuli in these studies, new types of stimuli (e.g., mental imagery, autobiographical memories) have become increasingly common throughout the past decade, with the potential for improved ecological validity. Cognitive reappraisal is still seen by many as the gold standard of emotion regulation, yet mixed findings suggest that its utility might be better understood by taking into account the type of stimuli and context to which it is applied. Moreover, other emotion regulation techniques, particularly for the upregulation of positive emotion (e.g., savoring), have been relatively unexamined in the ERP literature to-date, as have associations between controlled, lab-based measures of emotion generation and regulation in everyday life (e.g., as assessed using ambulatory techniques). In sum, the past decade has seen progress in a more granular understanding of emotion regulation, with ongoing and future work aimed at increasing understanding of the boundary conditions of emotion regulation; novel techniques and emotion regulation's application to everyday life.

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.

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).

#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.

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.

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.

Working memory load reduces the electrocortical processing of positive pictures.

To date, the emotion regulation literature has focused primarily on the down-regulation of negative emotion, with far fewer studies interrogating the mechanisms at work in positive emotion regulation. This body of work has suggested that nonaffective mechanisms, such as cognitive load have a role to play in reducing emotional response. For example, the late positive potential (LPP), which tracks attention to salient stimuli, is reduced when task-irrelevant negative and neutral stimuli are presented under high compared with low working memory load. Using positive stimuli, working memory load has been shown to reduce the LPP elicited by positive words and faces but has not previously been shown to modulate the LPP elicited by positive scenes. Emotional scenes are the predominant type of stimuli used in the broader emotion regulation literature, are more arousing than faces, and have been shown to more strongly modulate the LPP. Here, 41 participants performed a working memory task interspersed with the presentation of positive and neutral scenes, while electroencephalography was recorded. Results showed that the LPP was increased for positive compared with neutral pictures and reduced on high-load compared to low-load trials. Working memory performance was worse on high-load compared with low-load trials, although it was not significantly correlated with the LPP, and picture type did not affect working memory performance. Results bridge to the willful emotion regulation literature to increase understanding of the mechanisms underlying positive emotion regulation, which has been relatively unexamined.

Using item response theory to select emotional pictures for psychophysiological experiments.

Standardized picture databases such as the International Affective Picture System (IAPS; Lang et al., 2008) and Emotional Picture Set (EmoPicS; Wessa et al., 2010) facilitate the study of emotional scene perception, and have the potential to increase replicability and comparability of results within and across labs. However, with the availability of large numbers of pictures comes the challenge of selecting subsets of pictures for inclusion in experimental paradigms. Typically, researchers rely on expert consensus or normed ratings to select emotional pictures, but these methods may favor pictures with high agreement over those that provide the most information or best differentiate individuals. Here, in n = 297 individuals, we demonstrate how item response theory (IRT), which provides information on psychometric functioning at both the item and test level, can be used to select negative and positive pictures for eliciting the late positive potential (LPP), a measure of emotional attention. We present results for 50 negative and 50 positive pictures, and show how pictures with higher discrimination values improve differentiation between individuals with different levels of emotional attention. Moreover, "strong" modulators of the LPP - i.e., erotic and mutilation pictures - provided the most information about individuals with low levels of emotional attention, whereas, "weak" modulators of the LPP - i.e., affiliative and exciting pictures - provided the most information about individuals with high levels of emotional attention. Results demonstrate how IRT can inform emotional picture selection and improve the psychometrics of psychophysiological tasks, which can ultimately increase the replicability of findings based on standardized pictures.

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.