Effects of attentional deployment training for relieving negative emotion in individuals with subthreshold depression

OBJECTIVE

As a prodromal stage to major depressive disorder (MDD), subthreshold depression (StD) has a higher prevalence in the population, resulting in a greater healthcare burden. StD individuals' current negative emotion could be moderated by attentional deployment. However, it remains unclear whether attentional deployment training can mitigate subsequent negative emotion in StD individuals.

METHODS

Based on 160 participants, we combined decision task (Experiment 1, N = 69), eye-tracking (Experiment 2, N = 40), and EEG (Experiment 3, N = 51) techniques to investigate how one-week attentional deployment (gain-focus, GF) training modulated the emotional processing of negative stimulus and its underlying neural correlates in StD individuals.

RESULTS

After one-week GF training, StD individuals significantly reduced the first fixation time and total fixation time on the negative part (missed opportunities) of decision outcome and showed a decrease in emotional sensitivity to missed opportunities. An increase in N1 and decrease in P3 and LPP (late positive potentials) amplitudes, as well as a decrease in alpha oscillation, were observed when StD individuals faced missed opportunities after training. Additionally, the extent of reduction in StD individuals' emotional sensitivity to missed opportunities could be significantly predicted by the degree of decrease in alpha oscillation.

CONCLUSION

One-week attentional deployment training could modulate negative emotion in StD individuals and the degree of change in alpha oscillation might act as an objective indicator for the effectiveness of training.

SIGNIFICANCE

Our study provides a convenient and effective approach to alleviate the negative emotion of StD individuals.

Acquisition and generalization of emotional and neural responses to faces associated with negative and positive feedback behaviours

Faces can acquire emotional meaning by learning to associate individuals with specific behaviors. Here, we investigated emotional evaluation and brain activations toward faces of persons who had given negative or positive evaluations to others. Furthermore, we investigated how emotional evaluations and brain activation generalize to perceptually similar faces. Valence ratings indicated learning and generalization effects for both positive and negative faces. Brain activation, measured with functional magnetic resonance imaging (fMRI), showed significantly increased activation in the fusiform gyrus (FG) to negatively associated faces but not positively associated ones. Remarkably, brain activation in FG to faces to which emotional meaning (negative and positive) was successfully generalized was decreased compared to neutral faces. This suggests that the emotional relevance of faces is not simply associated with increased brain activation in visual areas. While, at least for negative conditions, faces paired with negative feedback behavior are related to potentiated brain responses, the opposite is seen for perceptually very similar faces despite generalized emotional responses.

Robust memory of face moral values is encoded in the human caudate tail: a simultaneous EEG-fMRI study

Moral judgements about people based on their actions is a key component that guides social decision making. It is currently unknown how positive or negative moral judgments associated with a person's face are processed and stored in the brain for a long time. Here, we investigate the long-term memory of moral values associated with human faces using simultaneous EEG-fMRI data acquisition. Results show that only a few exposures to morally charged stories of people are enough to form long-term memories a day later for a relatively large number of new faces. Event related potentials (ERPs) showed a significant differentiation of remembered good vs bad faces over centerofrontal electrode sites (value ERP). EEG-informed fMRI analysis revealed a subcortical cluster centered on the left caudate tail (CDt) as a correlate of the face value ERP. Importantly neither this analysis nor a conventional whole-brain analysis revealed any significant coding of face values in cortical areas, in particular the fusiform face area (FFA). Conversely an fMRI-informed EEG source localization using accurate subject-specific EEG head models also revealed activation in the left caudate tail. Nevertheless, the detected caudate tail region was found to be functionally connected to the FFA, suggesting FFA to be the source of face-specific information to CDt. A further psycho-physiological interaction analysis also revealed task-dependent coupling between CDt and dorsomedial prefrontal cortex (dmPFC), a region previously identified as retaining emotional working memories. These results identify CDt as a main site for encoding the long-term value memories of faces in humans suggesting that moral value of faces activates the same subcortical basal ganglia circuitry involved in processing reward value memory for objects in primates.

Morality or competence is more important? The effect of evaluation dimensions on ERP responses to neutral faces depends on contextual valence and self-relevance

Recent studies have shown that the processing of neutral facial expressions could be modulated by the valence and self-relevance of preceding verbal evaluations. However, these studies have not distinguished the dimension (i.e., morality and competence) from verbal evaluations. In fact, there is a hot controversy about whether morality or competence receives more weight. Therefore, using the ERP technique, the current study aimed to address this issue by comparing the influence of morality and competence evaluations on behavioral and neural responses to neutral facial expressions when these evaluations varied with contextual valence and self-relevance. Our ERP results revealed that the early EPN amplitudes were larger for neutral faces after receiving evaluations about self relative to evaluations about senders. Moreover, the EPN was more negative after a competence evaluation relative to a morality evaluation when these evaluations were positive, while this effect was absent when these evaluations were negative. The late LPP was larger after a morality evaluation compared to a competence evaluation when these evaluations were negative and directed to self. However, no significant LPP effect between morality and competence evaluations was observed when these evaluations were positive. The present study extended previous studies by showing that early and late processing stages of faces are affected by the evaluation dimension in a top-down manner and further modulated by contextual valence and self-relevance.

Art perception is affected by negative knowledge about famous and unknown artists

The biographies of some celebrated artists are marked by accounts that paint a far from beautiful portrait. Does this negative-social knowledge influence the aesthetic experience of an artwork? Does an artist's fame protect their paintings from such an influence? We present two preregistered experiments examining the effect of social-emotional biographical knowledge about famous and unknown artists on the reception and perception of their paintings, using aesthetic ratings and neurocognitive measures. In Experiment 1, paintings attributed to artists characterised by negative biographical information were liked less, evoked greater feelings of arousal and were judged lower in terms of quality, than paintings by artists associated with neutral information. No modulation of artist renown was found. Experiment 2 fully replicated these behavioural results and revealed that paintings by artists associated with negative social-emotional knowledge also elicited enhanced early brain activity related to visual perception (P1) and early emotional arousal (early posterior negativity; EPN). Together, the findings suggest that negative knowledge about famous artists can shape not only explicit aesthetic evaluations, but may also penetrate the perception of the artwork itself.

Comparison with others influences encoding and recognition of their faces: Behavioural and ERP evidence

In daily life, faces are often memorized within contexts involving interpersonal interactions. However, little is known about whether interpersonal interaction-related contexts influence face memory. The present study aimed to understand this question by investigating how social comparison-related context affects face encoding and recognition. To address this issue, 40 participants were informed that they and another player each played a monetary game and were then presented with both of their outcomes (either monetary gain or loss). Subsequently, participants were shown the face of the player whom they were just paired with. After all the faces had been encoded, participants were asked to perform a sudden old/new recognition task involving these faces. The results showed that, during the encoding phase, another player's monetary gain, compared to loss, resulted in more negative responses in the N170 and early posterior negativity (EPN)/N250 to relevant players' faces when participants encountered monetary loss and a smaller late positive potential (LPP) response irrespective of self-related outcomes. In the subsequent recognition phase, preceding another player's monetary gain as compared to loss led to better recognition performance and stronger EPN/N250 and LPP responses to the faces of relevant players when participants had lost some amount of money. These findings suggest that the social comparison-related context, particularly self-disadvantageous outcomes in the context, influences the memory of comparators' faces.

Distrust before first sight? Examining knowledge- and appearance-based effects of trustworthiness on the visual consciousness of faces

The present EEG study with 32 healthy participants investigated whether affective knowledge about a person influences the visual awareness of their face, additionally considering the impact of facial appearance. Faces differing in perceived trustworthiness based on appearance were associated with negative or neutral social information and shown as target stimuli in an attentional blink task. As expected, participants showed enhanced awareness of faces associated with negative compared to neutral social information. On the neurophysiological level, this effect was connected to differences in the time range of the early posterior negativity (EPN)-a component associated with enhanced attention and facilitated processing of emotional stimuli. The findings indicate that the social-affective relevance of a face based on emotional knowledge is accessed during a phase of attentional enhancement for conscious perception and can affect prioritization for awareness. In contrast, no clear evidence for influences of facial trustworthiness during the attentional blink was found.

Gender congruence and emotion effects in cross-modal associative learning: Insights from ERPs and pupillary responses

Social and emotional cues from faces and voices are highly relevant and have been reliably demonstrated to attract attention involuntarily. However, there are mixed findings as to which degree associating emotional valence to faces occurs automatically. In the present study, we tested whether inherently neutral faces gain additional relevance by being conditioned with either positive, negative, or neutral vocal affect bursts. During learning, participants performed a gender-matching task on face-voice pairs without explicit emotion judgments of the voices. In the test session on a subsequent day, only the previously associated faces were presented and had to be categorized regarding gender. We analyzed event-related potentials (ERPs), pupil diameter, and response times (RTs) of N = 32 subjects. Emotion effects were found in auditory ERPs and RTs during the learning session, suggesting that task-irrelevant emotion was automatically processed. However, ERPs time-locked to the conditioned faces were mainly modulated by the task-relevant information, that is, the gender congruence of the face and voice, but not by emotion. Importantly, these ERP and RT effects of learned congruence were not limited to learning but extended to the test session, that is, after removing the auditory stimuli. These findings indicate successful associative learning in our paradigm, but it did not extend to the task-irrelevant dimension of emotional relevance. Therefore, cross-modal associations of emotional relevance may not be completely automatic, even though the emotion was processed in the voice.

Beyond facial expressions: A systematic review on effects of emotional relevance of faces on the N170

The N170 is the most prominent electrophysiological signature of face processing. While facial expressions reliably modulate the N170, there is considerable variance in N170 modulations by other sources of emotional relevance. Therefore, we systematically review and discuss this research area using different methods to manipulate the emotional relevance of inherently neutral faces. These methods were categorized into (1) existing pre-experimental affective person knowledge (e.g., negative attitudes towards outgroup faces), (2) experimentally instructed affective person knowledge (e.g., negative person information), (3) contingency-based affective learning (e.g., fear-conditioning), or (4) the immediate affective context (e.g., emotional information directly preceding the face presentation). For all categories except the immediate affective context category, the majority of studies reported significantly increased N170 amplitudes depending on the emotional relevance of faces. Furthermore, the potentiated N170 was observed across different attention conditions, supporting the role of the emotional relevance of faces on the early prioritized processing of configural facial information, regardless of low-level differences. However, we identified several open research questions and suggest venues for further research.

Motivated attention and task relevance in the processing of cross-modally associated faces: Behavioral and electrophysiological evidence

It has repeatedly been shown that visually presented stimuli can gain additional relevance by their association with affective stimuli. Studies have shown effects of associated affect in event-related potentials (ERP) like the early posterior negativity (EPN), late positive complex (LPC), and even earlier components as the P1 or N170. However, findings are mixed as to the extent associated affect requires directed attention to the emotional quality of a stimulus and which ERP components are sensitive to task instructions during retrieval. In this preregistered study ( https://osf.io/ts4pb ), we tested cross-modal associations of vocal affect-bursts (positive, negative, neutral) to faces displaying neutral expressions in a flash-card-like learning task, in which participants studied face-voice pairs and learned to correctly assign them to each other. In the subsequent EEG test session, we applied both an implicit ("old-new") and explicit ("valence-classification") task to investigate whether the behavior at retrieval and neurophysiological activation of the affect-based associations were dependent on the type of motivated attention. We collected behavioral and neurophysiological data from 40 participants who reached the preregistered learning criterium. Results showed EPN effects of associated negative valence after learning and independent of the task. In contrast, modulations of later stages (LPC) by positive and negative associated valence were restricted to the explicit, i.e., valence-classification, task. These findings highlight the importance of the task at different processing stages and show that cross-modal affect can successfully be associated to faces.

Early neural potentiation to centrally and peripherally presented fear-conditioned faces

For humans, it is vitally important to rapidly detect and process threatening signals regardless of whether stimuli occur at fixation or in the periphery. However, it is unknown whether eccentricity affects early neuronal electrophysiological responses to fear-conditioned stimuli. We examined early event-related potentials (ERPs) of the electroencephalogram (EEG) to fear-conditioned faces to address this question. Participants (N = 80) were presented with faces, either paired with an aversive (CS+) or neutral sound (CS-), at central or peripheral positions. We ensured constant central fixation using online eye-tracking but directed attention to either centrally or peripherally presented faces. Manipulation checks showed successful fear-conditioning (i.e., on average lower ratings in valence and higher ratings in arousal and perceived threat) and successful shifts of visuospatial attention indexed by high task performance and pre-stimulus alpha lateralization of the EEG spectra. We observed a generally increased P1 to fear-conditioned faces regardless of presentation location. An N170 difference between fear-conditioned and neutral stimuli was found but was restricted to the central location and depended on the effectivity of fear-conditioning. A similar effect was observed for the early posterior negativity (EPN). Trait anxiety was not related to differential ERP responses to CS+ versus CS- faces for any ERP component. These findings suggest that the P1 indexes early responses to centrally and peripherally presented fear-conditioned faces. Subsequent stages are modulated by the spatial location of the stimuli. This suggests different stages of neural processing of fear-conditioned faces depending on their spatial location. Finally, our results question the hypothesis that trait anxiety in healthy participants is related to altered visual processing of fear-conditioned faces.

Potentiated early neural responses to fearful faces are not driven by specific face parts

Prioritized processing of fearful compared to neutral faces is reflected in increased amplitudes of components of the event-related potential (ERP). It is unknown whether specific face parts drive these modulations. Here, we investigated the contributions of face parts on ERPs to task-irrelevant fearful and neutral faces using an ERP-dependent facial decoding technique and a large sample of participants (N = 83). Classical ERP analyses showed typical and robust increases of N170 and EPN amplitudes by fearful relative to neutral faces. Facial decoding further showed that the absolute amplitude of these components, as well as the P1, was driven by the low-frequency contrast of specific face parts. However, the difference between fearful and neutral faces was not driven by any specific face part, as supported by Bayesian statistics. Furthermore, there were no correlations between trait anxiety and main effects or interactions. These results suggest that increased N170 and EPN amplitudes to task-irrelevant fearful compared to neutral faces are not driven by specific facial regions but represent a holistic face processing effect.

Testing stimulus exposure time as the critical factor of increased EPN and LPP amplitudes for fearful faces during perceptual distraction tasks

Fearful facial expressions are prioritized across different information processing stages, as evident in early, intermediate, and late components of event-related brain potentials (ERPs). Recent studies showed that, in contrast to early N170 modulations, mid-latency (Early Posterior Negativity, EPN) and late (Late Positive Potential, LPP) emotional modulations depend on the attended perceptual feature. Nevertheless, several studies reported significant differences between emotional and neutral faces for the EPN or LPP components during distraction tasks. One cause for these conflicting findings might be that when faces are presented sufficiently long, participants attend to task-irrelevant features of the faces. In this registered report, we tested whether the presentation duration of faces is the critical factor for differences between reported emotional modulations during perceptual distraction tasks. To this end, 48 participants were required to discriminate the orientation of lines overlaid onto fearful or neutral faces, while face presentation varied (100 msec, 300 msec, 1,000 msec, 2,000 msec). While participants did not need to pay attention to the faces, we observed main effects of emotion for the EPN and LPP, but no interaction between emotion and presentation duration. Of note, unregistered exploratory tests per presentation duration showed no significant EPN and LPP emotion differences during short durations (100 and 300 msec) but significant differences with longer durations. While the presentation duration seems not to be a critical factor for EPN and LPP emotion effects, future studies are needed to investigate the role of threshold effects and the applied analytic designs to explain conflicting findings in the literature.

Influence of affective verbal context on emotional facial expression perception of social anxiety

Previous studies have shown that the perception of ambiguous facial expressions for individuals with social anxiety was influenced by the affective verbal context. However, it is still unknown how emotional facial expressions are perceived by individuals with social anxiety in the context of the verbal context. In this study, we used event-related potentials (ERPs) technology to examine how individuals with social anxiety perceive emotional facial expressions in positive and negative contexts. The results showed that: (1) Within the negative verbal contexts, the amplitude of P1 induced by facial expressions in the social anxiety group was significantly higher than that induced by the healthy control group; The N170 amplitude induced by facial expressions in social anxiety group was less negative than that in the healthy control group, and was not affected by the context. (2) The social anxiety group had significantly higher LPP in negative contexts elicited by angry expressions than by happy expressions. This study proved that the perception of emotional facial expressions was influenced by top-down information in the early and late stages of visual perception for individuals with social anxiety.

Auditory and cross-modal attentional bias toward positive natural sounds: Behavioral and ERP evidence

Recently, researchers have expanded the investigation into attentional biases toward positive stimuli; however, few studies have examined attentional biases toward positive auditory information. In three experiments, the present study employed an emotional spatial cueing task using emotional sounds as cues and auditory stimuli (Experiment 1) or visual stimuli (Experiment 2 and Experiment 3) as targets to explore whether auditory or visual spatial attention could be modulated by positive auditory cues. Experiment 3 also examined the temporal dynamics of cross-modal auditory bias toward positive natural sounds using event-related potentials (ERPs). The behavioral results of the three experiments consistently demonstrated that response times to targets were faster after positive auditory cues than they were after neutral auditory cues in the valid condition, indicating that healthy participants showed a selective auditory attentional bias (Experiment 1) and cross-modal attentional bias (Experiment 2 and Experiment 3) toward positive natural sounds. The results of Experiment 3 showed that N1 amplitudes were more negative after positive sounds than they were after neutral sounds, which further provided electrophysiological evidence that positive auditory information enhances attention at early stages in healthy adults. The results of the experiments performed in the present study suggest that humans exhibit an attentional bias toward positive natural sounds.

Negative news dominates fast and slow brain responses and social judgments even after source credibility evaluation

Remedies to counter the impact of misinformation are in high demand, but little is known about the neuro-cognitive consequences of untrustworthy information and how they can be mitigated. In this preregistered study, we investigated the effects of social-emotional headline contents on social judgments and brain responses and whether they can be modulated by explicit evaluations of the trustworthiness of the media source. Participants (N = 30) evaluated -and clearly discerned- the trustworthiness of news sources before they were exposed to person-related news headlines. Despite this intervention, social judgments and brain responses were dominated largely by emotional headline contents. Results suggest differential effects of source credibility might depend on headline valence. Electrophysiological indexes of fast emotional and arousal-related brain responses, as well as correlates of slow evaluative processing were enhanced for persons associated with positive headline contents from trusted sources, but not when positive headlines stemmed from distrusted sources. In contrast, negative headlines dominated fast and slow brain responses unaffected by explicit source credibility evaluations. These results provide novel insights into the brain mechanisms underlying the "success" of emotional news from untrustworthy sources, suggesting a pronounced susceptibility to negative information even from distrusted sources that is reduced for positive contents. The differential pattern of responses to misinformation in mind and brain sheds light on the cognitive mechanisms underlying the processing of misinformation and possible strategies to avoid their potentially detrimental effects.

Increased early and late neuronal responses to aversively conditioned faces across different attentional conditions

Faces with emotional information-by virtue of their expression or their history of affective learning-are prioritized during neuronal processing as compared to neutral faces. Classical conditioning studies have shown that aversively conditioned (CS+) faces potentiate different face processing stages as evidenced by increased early and late event-related potential (ERPs) components. However, it is unknown whether and how ERP modulations depend on certain attentional conditions. To examine this question, this preregistered study investigated ERPs to faces paired with aversive screams or neutral sounds under three tasks with increasing attention to CS + relevant features of the face: Participants (N = 40) had to discriminate either the orientation of superimposed lines, perceived gender, or the CS association. We found potentiation of the N170, the Early Posterior Negativity (EPN), and, most remarkably, the Late Positive Potential (LPP) to CS + faces regardless of task condition. This finding suggests that, in contrast to other types of emotional information and learning, classical conditioning boosts early and late processing stages, even if no explicit attention to the face information or the CS association is required.

Electrophysiological responses to negative evaluative person-knowledge: Effects of individual differences

Faces transmit rich information about a unique personal identity. Recent studies examined how negative evaluative information affects event-related potentials (ERPs), the relevance of individual differences, such as trait anxiety, neuroticism, or agreeableness, for these effects is unclear. In this preregistered study, participants (N = 80) were presented with neutral faces, either associated with highly negative or neutral biographical information. Faces were shown under three different task conditions that varied the attentional focus on face-unrelated features, perceptual face information, or emotional information. Results showed a task-independent increase of the N170 component for faces associated with negative information, while interactions occurred for the Early Posterior Negativity (EPN) and the Late Positive Potential (LPP), showing ERP differences only when paying attention to the evaluative information. Trait anxiety and neuroticism did not influence ERP differences. Low agreeableness increased EPN differences during perceptual distraction. Thus, we observed that low agreeableness leads to early increased processing of potentially hostile faces, although participants were required to attend to a face-unrelated feature.