A neuromarker of clinical outcome in attention bias modification therapy for social anxiety disorder

Research hotspots and trends of neuroimaging in social anxiety: a CiteSpace bibliometric analysis based on Web of Science and Scopus database

Background

This study focused on the research hotspots and development trends of the neuroimaging of social anxiety (SA) in the past 25 years.

Methods

We selected 1,305 studies on SA neuroimaging from the Web of Science and Scopus from January 1998 to December 2023. CiteSpace was used to analyze the number of published articles visually, cited references, cooperation among authors and institutions, co-occurrence of keywords, clustering of keywords, burst of keywords, and time zone of co-occurring keywords.

Results

A total of 1,305 articles were included, and the annual number of articles published over nearly 25 years showed the overall trend is on the rise. The analysis of author and institutional collaboration reveals that most authors collaborate closely. Among them, the team led by Pine, Daniel S published 59 articles, making it the most central team. Harvard University is identified as the most central institution in this network. The research hotspots can be categorized into four areas: research techniques, cognitive processing research areas, core brain regions and brain networks, and the neural predictors of treatment outcomes in SA. The most recent burst keywords are "cognitive behavioral therapy," "systematic review," "machine learning," "major clinical study," "transcranial direct current stimulation," "depression," and "outcome assessment," which provided clues on research frontiers. Based on the burst map and keyword time zone map, it appears that exploring the activity of brain regions involved in cognitive processing, such as face processing and attentional bias, as well as the comorbidity of SA and depression, through brain imaging technology, using brain signals as predictors of treatment outcomes in SA.

Conclusion

This study conducted a comprehensive, objective, and visual analysis of publications, and revealed hot topics and trends concerning the study of the brain mechanism of SA from 1998 to 2023. This work might assist researchers in identifying new insights on potential collaborators and institutions, hot topics, and research directions.

Neurophysiological effects of cognitive behavioral therapy in social anxiety: An ERP study using a dot-probe task

BACKGROUND

Social anxious individuals show attention bias towards emotional stimuli, this phenomenon is considered to be an important cause of anxiety generation and maintenance. Cognitive-behavioral therapy (CBT) is a standard psychotherapy for social anxiety disorder. CBT decreases attention biases by correcting the maladaptive beliefs of socially anxious individuals, but it is not clear whether CBT alters neurophysiological features of socially anxious individuals at early automatic and/or late cognitive strategy stage of attentional processing.

METHOD

To address this knowledge gap, we collected pre-treatment event-related potential data of 22 socially anxious individuals while they performed a dot-probe task. These participants then received eight weeks of CBT, and post-treatment ERP data were collected after completion of CBT treatment. We also included 29 healthy controls and compared them with individuals with social anxiety to determine the neural mechanisms underlying the effectiveness of CBT.

RESULTS

Participants' social anxiety level was significantly alleviated with CBT. ERP results revealed that (1) compared to pre-treatment phase, P1 amplitudes induced by probes significantly decreased at post-treatment phase, whereas P3 amplitudes increased at post-treatment phase; the P1 amplitudes induced by probes following happy-neutral face pairs in socially anxious individuals after treatment was significantly different with that in healthy controls; (2) amplitude of components elicited by face pairs did not change significantly between pre-treatment and post-treatment phases; (3) changes of Liebowitz Social Anxiety Scale were positively correlated with changes of P1 amplitude, and negatively correlated with changes of N1 amplitude.

LIMITATIONS

Our sample was university students and lacked randomization, which limits the generalizability of the results.

CONCLUSION

The present results demonstrated that CBT may adjust cognitive strategies in the later stage of attentional processing, indicating by changed ERPs appeared in probe-presenting stage for social anxiety.

Event-related alpha power in early stage of facial expression processing in social anxiety: Influence of language context

Accurate interpretation of the emotional information conveyed by others' facial expressions is crucial for social interactions. Event-related alpha power, measured by time-frequency analysis, is a frequently used EEG index of emotional information processing. However, it is still unclear how event-related alpha power varies in emotional information processing in social anxiety groups. In the present study, we recorded event-related potentials (ERPs) while participants from the social anxiety and healthy control groups viewed facial expressions (angry, happy, neutral) preceded by contextual sentences conveying either a positive or negative evaluation of the subject. The impact of context on facial expression processing in both groups of participants was explored by assessing behavioral ratings and event-related alpha power (0-200 ms after expression presentation). In comparison to the healthy control group, the social anxiety group exhibited significantly lower occipital alpha power in response to angry facial expressions in negative contexts and neutral facial expressions in positive contexts. The influence of language context on facial expression processing in individuals with social anxiety may occur at an early stage of processing.

Positive attention bias in high socially anxious individuals: Evidence from an ERP study

The Bivalent Fear of Evaluation (BFEO) model posits that the fear of positive evaluation (FPE) is a core feature of social anxiety. As such, high socially anxious individuals may show attention bias when faced with positive stimuli. However, most of the previous studies focused on the negative attention bias of social anxiety, and less on the attention bias of positive stimuli. Meanwhile, the effect of stimulus presentation time on the attention bias pattern was unclear. In order to investigate this question, we used a dot-probe paradigm with facial expressions (happy, fearful, angry, neutral) presented for 100 ms and 500 ms. The ERP results showed: (1) For high socially anxious group, happy faces elicited a larger N1 for valid than for invalid cued probes, whereas for healthy control group, angry faces elicited a larger N1 for valid than for invalid cued probes. (2) When valid cues following happy faces presented for 500 ms, the N1 amplitude was larger than that of invalid cues. However, when valid cues following angry and fear faces presented for 100 ms, the N1 amplitude was larger than that of invalid cues. The results showed difficulty in attention disengagement of high socially anxious individuals from positive stimuli, as reflected by N1, illustrating the positive attention bias in social anxiety. These results prove that FPE may contribute to maintaining social anxiety.

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.

Does attention bias modification reduce anxiety in socially anxious college students? An experimental study of potential moderators and considerations for implementation

According to cognitive models, preferential attention to social threat contributes to maintenance of social anxiety. Socially anxious individuals are known to show attention biases to threatening stimuli, although there is inconsistency in the literature with regards to the type of attentional biases they present. This study examines the effect of attention bias modification (ABM) for social anxiety in non-treatment-seeking college students meeting social anxiety disorder criteria, taking into consideration previous mixed results regarding its effectiveness. Attention bias levels and types (i.e. vigilance vs avoidance) at baseline were examined and considered as potential moderators of ABM effects. Sixty-eight socially anxious individuals were randomly allocated to ABM vs placebo groups. A structured interview and self-report assessment were completed at pre-treatment and post-treatment. Results showed half of the participants presented few attention biases at baseline, and the rest presented either vigilance or avoidance. Participants with low attention biases scored higher in social anxiety than those showing avoidance and there was no difference between those showing vigilance vs avoidance. No significant effects from pre to post treatment were observed in attention biases, self-report or structured interview of anxiety in the ABM group. Baseline attention biases did not moderate these effects. Results are discussed with regards to implications for future research towards the creation of more effective protocols, based on the needs of heterogeneous social anxiety sub-groups.

A systematic review of event-related potentials as outcome measures of attention bias modification

Attention bias modification (ABM) was initially developed with the goal of reducing attentional bias to threat-and subsequently anxious symptoms-in individuals with heightened anxiety. Although controversial, ABM appears to be generally effective in achieving this goal. Yet, the primary outcome measure of ABM (i.e., the reaction time-based differences score) has poor reliability and temporal resolution, which limits the inferences that can be drawn. In contrast, event-related potentials (ERPs) have superior reliability as well as temporal resolution and may therefore be better outcome measures of ABM. In this review, I systematically assess the research using ERPs as outcome measures in ABM protocols. I focus on the extent to which the ERPs modified by ABM represent earlier or later stages of information processing. In addition, I explore the extent to which ABM produces near and/or far transfer of learning effects on ERP measures. The reviewed literature suggests that ERPs are promising outcome measures of ABM. ABM modulates the effects of affective stimuli on posterior visually evoked ERPs (i.e., P1) as well as ERPs at anterior electrodes (i.e., P2, N2, and ERN). Based on the state of the field, several directions for future research are identified.

Automatic detection advantage of problematic Internet users for Wi-Fi signal cues and the moderating effect of negative affect: An event-related potential study

Cognitive bias toward Internet-related cues is an important factor of the formation and maintenance of the addictive behavior of problematic Internet users (PIUs). The development of fiber-optic communication and smartphones has ushered human society into the era of wireless networks. The Wi-Fi signal, the symbol of wireless network connection, represents not only network access but also a channel for communication with others anywhere at any time. Therefore, the Wi-Fi signal cues should be an effective inducer of the addictive behaviors of PIUs. We used images of Wi-Fi signal as Internet-related cues to explore the automatic detection advantage of PIUs for these cues and to determine whether negative affect, another predisposing factor for addiction, can enhance this advantage. We utilized an intergroup design in this study. The PIU and control groups each comprised 30 participants and were randomly assigned to negative or neutral affect priming group. Mismatch negativity (MMN) was induced through the deviant-standard reverse oddball paradigm. Wi-Fi signal cues and neutral cues were used as standard and deviant stimuli, respectively. Results show that the MMN induced by Wi-Fi signal cues in the PIU group was larger than that in the control group. Meanwhile, the MMN induced by Wi-Fi signal cues was considerably enhanced in the PIU group under negative affect priming relative to that in the PIU group under neutral affect priming. Overall, PIUs have an automatic detection advantage for Wi-Fi signal cues, and negative affect can enhance this advantage. Our results suggest that the MMN elicited by Wi-Fi signal cues function as a sensitive neurobiological marker tracing the change of addiction motivation for PIUs.

Automatic detection advantage of problematic Internet users for Wi-Fi signal cues and the moderating effect of negative affect: An event-related potential study

Cognitive bias toward Internet-related cues is an important factor of the formation and maintenance of the addictive behavior of problematic Internet users (PIUs). The development of fiber-optic communication and smartphones has ushered human society into the era of wireless networks. The Wi-Fi signal, the symbol of wireless network connection, represents not only network access but also a channel for communication with others anywhere at any time. Therefore, the Wi-Fi signal cues should be an effective inducer of the addictive behaviors of PIUs. We used images of Wi-Fi signal as Internet-related cues to explore the automatic detection advantage of PIUs for these cues and to determine whether negative affect, another predisposing factor for addiction, can enhance this advantage. We utilized an intergroup design in this study. The PIU and control groups each comprised 30 participants and were randomly assigned to negative or neutral affect priming group. Mismatch negativity (MMN) was induced through the deviant-standard reverse oddball paradigm. Wi-Fi signal cues and neutral cues were used as standard and deviant stimuli, respectively. Results show that the MMN induced by Wi-Fi signal cues in the PIU group was larger than that in the control group. Meanwhile, the MMN induced by Wi-Fi signal cues was considerably enhanced in the PIU group under negative affect priming relative to that in the PIU group under neutral affect priming. Overall, PIUs have an automatic detection advantage for Wi-Fi signal cues, and negative affect can enhance this advantage. Our results suggest that the MMN elicited by Wi-Fi signal cues function as a sensitive neurobiological marker tracing the change of addiction motivation for PIUs.

Brain structure changes induced by attention bias modification training

Attention bias modification (ABM) therapy aims to reduce anxiety by changing threat-related attention patterns using computerized training tasks. We examined changes in brain microstructure following ABM training. Thirty-two participants were randomly assigned to one of two training conditions: active ABM training shifting attention away from threat or attention control training involving no attention modification. Participants completed six lab visits, including five training sessions and three diffusion tensor imaging scans: immediately before and after the first training session, and at the end of the training series. Indices of local and global changes in microstructure and connectivity were measured. Significant longitudinal differences in fractional anisotropy (FA) between the active and control training regimens occurred in inferior temporal cortex. Changes in FA occurred across groups within ventromedial prefrontal cortex and middle occipital gyrus. These results indicate specific effects of active ABM on brain structure. Such changes could relate to clinical effects of ABM.