Subliminal attention bias modification training in socially anxious individuals

Advancing the treatment of anxiety disorders in transition-age youth: a review of the therapeutic effects of unconscious exposure

BACKGROUND

The real-world effectiveness of exposure-based therapies for youth depends on the willingness and ability of young people to tolerate confronting their fears, which can be experienced as highly aversive and create problems with treatment engagement and acceptance. Recently, neuroscientific research on the nonconscious basis of fear has been translated into novel exposure interventions that bypass conscious processing of feared stimuli and that thus do not cause phobic youth to experience distress. We present a review of these unconscious exposure interventions.

METHODS

A PRISMA-based search yielded 20 controlled experiments based on three paradigms that tested if fear-related responses could be reduced without conscious awareness in highly phobic, transition-age youth: 14 randomized controlled trials (RCTs), 5 fMRI studies (1 was also an RCT), 4 psychophysiological studies (3 were also RCTs), and 1 ERP study. We conducted meta-analyses of outcomes where feasible.

RESULTS

Unconscious exposure interventions significantly (1) reduced avoidance behavior (range of Cohen's d = 0.51-0.95) and self-reported fear (d = 0.45-1.25) during in vivo exposure to the feared situation; (2) reduced neurobiological indicators of fear (d = 0.54-0.62) and concomitant physiological arousal (d = 0.55-0.64); (3) activated neural systems supporting fear regulation more strongly than visible exposure to the same stimuli (d = 1.2-1.5); (4) activated regions supporting fear regulation that mediated the reduction of avoidance behavior (d = 0.70); (5) evoked ERPs suggesting encoding of extinction memories (d = 2.13); and (6) had these effects without inducing autonomic arousal or subjective fear.

CONCLUSIONS

Unconscious exposure interventions significantly reduce a variety of symptomatic behaviors with mostly moderate effect sizes in transition-age youth with specific phobias. fMRI and physiological findings establish a neurophysiological basis for this efficacy, and suggest it occurs through extinction learning. Unconscious exposure was well tolerated, entirely unassociated with drop out, and is highly scalable for clinical practice. However, a number of limitations must be addressed to assess potential clinical impacts, including combining unconscious exposure with exposure therapy to boost treatment acceptance and efficacy.

Application of attentional bias modification to reduce attentional bias and emotional reactivity to stress in mildly depressed individuals

This study aims to verify the effectiveness of attentional bias modification (ABM) in reducing attentional bias related to depression, particularly in the later stages of attention as a pattern of difficulty in disengagement from depression-relevant stimuli, and to assess its effects on emotional reactivity to stress. A total of 78 participants were separated into four groups based on their levels of depression (minimal and mild) and the types of ABM. The positive ABM (pABM) trained participants to disengage their attention from depression-relevant stimuli and directed their attention toward more positive stimuli, whereas the neutral ABM (nABM) was designed to have no effect. The participants underwent a free-viewing task by eye tracker both before and after ABM to observe changes in attentional bias. Subsequently, they reported their emotional response after a stress-inducing task. The group of mildly depressed participants receiving pABM showed significantly less attention to depression-relevant negative affective stimuli and reported significantly decreased negative emotional reactivity to stress compared to the other groups. pABM had an effect on decreasing difficulty in disengaging from depression-relevant negative affective words (DW). However, it did not increase the dwell time on positive affective words (PW) in the current study. This might be due to the short duration of the application of ABM. The current study conducted ABM twice in 1 day, and this might not be enough to increase the dwell time on PA. This study verified that the ABM effectively decreased the attentional bias of depression and its relevant symptom, emotional reactivity to stress.

Subliminal attentional bias modification training for itch

Introduction

Itch is unpleasant and induces the urge to scratch. This is adaptive to remove the itch-inducing stimulus from the skin. Accordingly, itch draws attention to protect our bodily integrity. Recent studies investigated whether attention is preferentially drawn towards its location, i.e., attentional bias (AB), and also whether this bias could be changed in healthy individuals. So far, results are mixed concerning the existance of an attentional bias towards itch stimuli in healthy individuals as well as the impact of modifications. However, available studies have typically focused on conscious processing and might miss preconscious aspects of attention and potential biases at these stages.

Methods

This study included 117 healthy individuals who underwent a subliminal Attentional Bias Modification (ABM)- training for itch based on a dot-probe paradigm with itch- related pictures. Participants were randomly assigned to a training towards itch group, a training away from itch group and a control group. This was done by manipulating the itch-target congruency of the dot-probe task during a training block. Pre- and post-training assessments were regular dot-probe tasks. Exploratorily, also attentional inhibition, cognitive flexibility and itch-related cognitions were assessed. Lastly, participants received an itchy stimulus on the inner forearm before and after the ABM-training to assess potential effects on itch sensitivity.

Results

Results showed no AB towards itch across groups at baseline, i.e., pre-training, but an AB away from itch, hence, avoidance of itch, post-training. Further analyses showed that this effect was driven by an attentional bias away from itch in the control group, while there were no significant effects in the experimental groups. There was no effect on itch sensitivity.

Conclusion

These findings are in line with recent studies on conscious ABM-training for itch and pain that also did not find significant training effects. Therefore, it is suggested that the field of AB might need to reconsider the current assessment of AB. Moreover, AB is probably a dynamic process that is highly dependent on current itch-related goals and relevance of itch in a specific situation. This suggests that processes probably differ in patients with chronic itch and that also ABM-training might work differently in these populations.

Clinical trial registration

https://trialsearch.who.int/Trial2.aspx?TrialID=NTR7561, identifier NTR7561.

Attention and interpretation cognitive bias change: A systematic review and meta-analysis of bias modification paradigms

This systematic review and meta-analysis examines the effect of Cognitive Bias Modification for attention (CBM-A) and interpretation (CBM-I) on reducing the targeted biases and investigates moderators of each approach. PsycINFO, PsychArticles, and PubMED databases were searched for randomized-controlled studies published before March 2020 with pre- and post-CBM cognitive bias outcome measures, resulting in 91 CBM-A (n = 5914 individuals) and 70 CBM-I samples (n = 4802 individuals). Random-effects models and Hedge's g calculation showed significant medium overall effects of bias reduction with moderate to high heterogeneity (CBM-A g = 0.49 [0.36, 0.64], I² = 85.19%; CBM-I g = 0.58 [0.48, 0.68], I² = 70.92%). Effect sizes did not differ between approaches and remained significant after trim-and-fill adjustment for possible publication bias. Moderator variables were investigated with meta-regression and subgroup analyses. Participant age, symptom type, control condition and number of trials moderated CBM-A; student and clinical status moderated CBM-I effect size. Results support attention and interpretation modification in controlled laboratory and variable (online) training settings for non-clinical and clinical samples across various symptom types (anxiety, depression, substance use, eating disorders). Further empirical evidence is necessary to determine optimal sample and methodological combinations most strongly associated with adaptive behavioral outcomes.

Promoting helpful attention and interpretation patterns to reduce anxiety and depression in young people: weaving scientific data with young peoples' lived experiences

BACKGROUND

Anxiety and depression are common, disabling and frequently start in youth, underscoring the need for effective, accessible early interventions. Empirical data and consultations with lived experience youth representatives suggest that maladaptive cognitive patterns contribute to and maintain anxiety and depression in daily life. Promoting adaptive cognitive patterns could therefore reflect "active ingredients" in the treatment and/or prevention of youth anxiety and depression. Here, we described and compared different therapeutic techniques that equipped young people with a more flexible capacity to use attention and/or promoted a tendency to positive/benign (over threatening/negative) interpretations of uncertain situations.

METHODS

We searched electronic databases (PubMed, PsycINFO, EMBASE, and PsycARTICLES) for studies containing words relating to: intervention; youth; anxiety and/or depression and attention and/or interpretation, and selected studies which sought to reduce self-reported anxiety/depression in youth by explicitly altering attention and/or interpretation patterns. Ten young people with lived experiences of anxiety and depression and from diverse backgrounds were consulted on the relevance of these strategies in managing emotions in their daily lives and also whether there were additional strategies that could be targeted to promote adaptive thinking styles.

RESULTS

Two sets of techniques, each targeting different levels of responding with different strengths and weaknesses were identified. Cognitive bias modification training (CBM) tasks were largely able to alter attention and interpretation biases but the effects of training on clinical symptoms was more mixed. In contrast, guided instructions that teach young people to regulate their attention or to evaluate alternative explanations of personally-salient events, reduced symptoms but there was little experimental data establishing the intervention mechanism. Lived experience representatives suggested that strategies such as deliberately recalling positive past experiences or positive aspects of oneself to counteract negative thinking.

DISCUSSION

CBM techniques target clear hypothesised mechanisms but require further co-design with young people to make them more engaging and augment their clinical effects. Guided instructions benefit from being embedded in clinical interventions, but lack empirical data to support their intervention mechanism, underscoring the need for more experimental work. Feedback from young people suggest that combining complimentary techniques within multi-pronged "toolboxes" to develop resilient thinking patterns in youth is empowering.

Pinpointing mechanisms of a mechanistic treatment: Dissociable roles for overt and covert attentional processes in acute and long-term outcomes following Attention Bias Modification

Biased patterns of attention towards threat are implicated as key mechanisms in anxiety which can be modified through automated intervention (Attention Bias Modification; ABM). Intervention refinement and personalized dissemination efforts are substantially hindered by gaps in understanding the precise attentional components that underlie ABM's effects on symptoms-particularly with respect to longer-term outcomes. Seventy adults with transdiagnostic anxiety were randomized to receive 8 sessions of active ABM (n=49) or sham training (n=21). Reaction time and eyetracking data, collected at baseline, post-training, and 1-month follow-up, dissociated multiple core attentional processes, spanning overt and covert processes of engagement and disengagement. Self-reported symptoms were collected out to 1-year follow-up. Covert disengagement bias was specifically reduced by ABM, unlike all other indices. Overt disengagement bias at baseline predicted acute post-ABM outcomes, while covert engagement bias was non-specifically predictive of symptom trajectories out to 1-year follow-up. Results suggest unique and dissociable roles for each discrete mechanism.

Less is more: Patient-level meta-analysis reveals paradoxical dose-response effects of a computer-based social anxiety intervention targeting attentional bias

BACKGROUND

The past decade of research has seen considerable interest in computer-based approaches designed to directly target cognitive mechanisms of anxiety, such as attention bias modification (ABM).

METHODS

By pooling patient-level datasets from randomized controlled trials of ABM that utilized a dot-probe training procedure, we assessed the impact of training "dose" on relevant outcomes among a pooled sample of 693 socially anxious adults.

RESULTS

A paradoxical effect of the number of training trials administered was observed for both posttraining social anxiety symptoms and behavioral attentional bias (AB) toward threat (the target mechanism of ABM). Studies administering a large (>1,280) number of training trials showed no benefit of ABM over control conditions, while those administering fewer training trials showed significant benefit for ABM in reducing social anxiety (P = .02). These moderating effects of dose were not better explained by other examined variables and previously identified moderators, including patient age, training setting (laboratory vs. home), or type of anxiety assessment (clinician vs. self-report).

CONCLUSIONS

Findings inform the optimal dosing for future dot-probe style ABM applications in both research and clinical settings, and suggest several novel avenues for further research.

Attention Bias Modification (ABM): Review of Effects of Multisession ABM Training on Anxiety and Threat-Related Attention in High-Anxious Individuals

Attention bias modification (ABM) aims to reduce anxiety by reducing attention bias (AB) to threat; however, effects on anxiety and AB are variable. This review examines 34 studies assessing effects of multisession-ABM on both anxiety and AB in high-anxious individuals. Methods include ABM-threat-avoidance (promoting attention-orienting away from threat), ABM-positive-search (promoting explicit, goal-directed attention-search for positive/nonthreat targets among negative/threat distractors), and comparison conditions (e.g., control-attention training combining threat-cue exposure and attention-task practice without AB-modification). Findings indicate anxiety reduction often occurs during both ABM-threat-avoidance and control-attention training; anxiety reduction is not consistently accompanied by AB reduction; anxious individuals often show no pretraining AB in orienting toward threat; and ABM-positive-search training appears promising in reducing anxiety. Methodological and theoretical issues are discussed concerning ABM paradigms, comparison conditions, and AB assessment. ABM methods combining explicit goal-directed attention-search for nonthreat/positive information and effortful threat-distractor inhibition (promoting top-down cognitive control during threat-cue exposure) warrant further evaluation.

Effects of cognitive bias modification on social anxiety: A meta-analysis

Background

Cognitive bias modification (CBM), a set of techniques for modifying bias in information processing—is considered a novel intervention for social anxiety disorder (SAD), which has drawn considerable interest from researchers. However, the effects of CBM on SAD are not consistent. Some studies have demonstrated significant positive effects compared to control groups, while others have found no such effects.

Aims

We conducted a meta-analysis aimed at quantitatively assessing the effects of CBM on SAD at post-test.

Method

Through a systematic literature search by two independent raters, 34 articles (36 randomized studies) including 2,550 participants were identified. A multilevel modeling approach was employed to assess the effects of CBM on SAD, and to explore the potentially crucial procedures and sample characteristics that enhance the effectiveness of benign training.

Results

In general, there were small but significant effects of CBM on the primary symptoms of SAD (g = 0.17), cognitive bias (CB) toward threat (g = 0.32), and reactivity in stressful situations (g = 0.25), but non-significant effects on secondary symptoms. However, the interpretation modification program was more effective than was attentional bias modification in reducing SAD primary symptoms and negative CB. Laboratory training procedures produced larger primary symptom reductions compared to Internet-based training, whereas the percentage of contingency and feedback about training performance boosted cognitive effects only. Finally, the following groups were more likely to benefit from CBM: younger participants (primary symptoms and cognitive effects), women (primary symptom effects), and samples with stronger CB (stressor effects). The quality of the randomized controlled trials was less than desirable, as there was some indication of publication bias in our study.

Conclusions

Current findings broadly supported cognitive theories of SAD that consider a bidirectional or mutually reinforcing relationship between symptoms and CBs. However, the small therapeutic effect observed here indicates that it is necessary to develop more reliable and efficient CBM interventions that are specific to SAD.

Asymmetrical transfer effects of cognitive bias modification: Modifying attention to threat influences interpretation of emotional ambiguity, but not vice versa

BACKGROUND AND OBJECTIVES

It is well established that attention bias and interpretation bias each have a key role in the development and continuation of anxiety. How the biases may interact with one another in anxiety is, however, poorly understood. Using cognitive bias modification techniques, the present study examined whether training a more positive interpretation bias or attention bias resulted in transfer of effects to the untrained cognitive domain. Differences in anxiety reactivity to a real-world stressor were also assessed.

METHODS

Ninety-seven first year undergraduates who had self-reported anxiety were allocated to one of four groups: attention bias training (n = 24), interpretation bias training (n = 26), control task training (n = 25) and no training (n = 22). Training was computer-based and comprised eight sessions over four weeks. Baseline and follow-up measures of attention and interpretation bias, anxiety and depression were taken.

RESULTS

A significant reduction in threat-related attention bias and an increase in positive interpretation bias occurred in the attention bias training group. The interpretation bias training group did not exhibit a significant change in attention bias, only interpretation bias. The effect of attention bias training on interpretation bias was significant as compared with the two control groups. There were no effects on self-report measures.

LIMITATIONS

The extent to which interpretive training can modify attentional processing remains unclear.

CONCLUSIONS

Findings support the idea that attentional training might have broad cognitive consequences, impacting downstream on interpretive bias. However, they do not fully support a common mechanism hypothesis, as interpretive training did not impact on attentional bias.

Attention bias modification for youth with social anxiety disorder

BACKGROUND

Attention bias modification treatment (ABMT) targets threat-related attention biases in anxiety disorders. Most clinical trials of ABMT have focused on adults or small samples of youth. The current randomized controlled trial (RCT) examines ABMT efficacy in youth with social anxiety disorder (SAD) and tests possible moderators of treatment outcomes.

METHOD

Sixty-seven youth with SAD were randomly assigned to ABMT or attention control training (ACT) conditions. Anxiety severity was measured at baseline, posttreatment, and 3-month follow-up. ClinicalTrials.gov name and identifier: Attention bias modification treatment for children with social anxiety, NCT01397032; http://www.clinicaltrials.gov.

RESULTS

Both ABMT and ACT induced significant reductions in clinician and self-rated social anxiety (ps < .001). An additional reduction was observed at the 3-month follow-up in clinician-rated anxiety symptoms (p = .03). Moderation effects were nonsignificant for the clinician-rated anxiety outcome, but age moderated self-reported anxiety. Older but not younger children, showed significant reduction in anxiety following ABMT relative to ACT (p < .001). Individual differences in attention control also moderated ABMT's effect on self-reported anxiety (p = .05). Children rated by their parents as lower on attention control benefited more from ABMT than those rated higher on attention control. Baseline attention bias did not moderate anxiety (p = .17).

CONCLUSIONS

Despite significant reductions in social anxiety, no specific evidence for ABMT was found relative to a control condition. Age and attention control moderated ABMT effects on self-reported SAD symptoms, with clinical effects for older relative to younger children and for those with lower attention control. These results highlight the need to consider developmental influences in the implementation of ABMT protocols.

Pooled patient-level meta-analysis of children and adults completing a computer-based anxiety intervention targeting attentional bias

Computer-based approaches, such as Attention Bias Modification (ABM), could help improve access to care for anxiety. Study-level meta-analyses of ABM have produced conflicting findings and leave critical questions unresolved regarding ABM's mechanisms of action and clinical potential. We pooled patient-level datasets from randomized controlled trials of children and adults with high-anxiety. Attentional bias (AB) towards threat, the target mechanism of ABM, was tested as an outcome and a mechanistic mediator and moderator of anxiety reduction. Diagnostic remission and Liebowitz Social Anxiety Scale (LSAS) were clinical outcomes available in enough studies to enable pooling. Per-patient data were obtained on at least one outcome from 13/16 eligible studies [86% of eligible participants; n=778]. Significant main effects of ABM on diagnostic remission (ABM-22.6%, control-10.8%; OR=2.57; p=0.006) and AB (β* (95%CI)=-0.63 (-0.83, -0.42); p<0.00005) were observed. There was no main effect of ABM on LSAS. However, moderator analyses suggested ABM was effective for patients who were younger (≤37y), trained in the lab, and/or assessed by clinicians. Under the same conditions where ABM was effective, mechanistic links between AB and anxiety reduction were supported. Under these specific circumstances, ABM reduces anxiety and acts through its target mechanism, supporting ABM's theoretical basis while simultaneously suggesting clinical indications and refinements to improve its currently limited clinical potential.

Impact of Anodal and Cathodal Transcranial Direct Current Stimulation over the Left Dorsolateral Prefrontal Cortex during Attention Bias Modification: An Eye-Tracking Study

People with anxiety disorders show an attentional bias for threat (AB), and Attention Bias Modification (ABM) procedures have been found to reduce this bias. However, the underlying processes accounting for this effect remain poorly understood. One explanation suggests that ABM requires the modification of attention control, driven by the recruitment of the dorsolateral prefrontal cortex (DLPFC). In the present double-blind study, we examined whether modifying left DLPFC activation influences the effect of ABM on AB. We used transcranial direct current stimulation (tDCS) to directly modulate cortical excitability of the left DLPFC during an ABM procedure designed to reduce AB to threat. Anodal tDCS increases excitability, whereas cathodal tDCS decreases it. We randomly assigned highly trait-anxious individuals to one of three conditions: 1) ABM combined with cathodal tDCS, 2) ABM combined with anodal tDCS, or 3) ABM combined with sham tDCS. We assessed the effects of these manipulations on both reaction times and eye-movements on a task indexing AB. Results indicate that combining ABM and anodal tDCS over the left DLPFC reduces the total duration that participants' gaze remains fixated on threat, as assessed using eye-tracking measurement. However, in contrast to previous studies, there were no changes in AB from baseline to post-training for participants that received ABM without tDCS. As the tendency to maintain attention to threat is known to play an important role in the maintenance of anxiety, the present findings suggest that anodal tDCS over the left DLPFC may be considered as a promising tool to reduce the maintenance of gaze to threat. Implications for future translational research combining ABM and tDCS are discussed.

Reliability, validity and sensitivity of a computerized visual analog scale measuring state anxiety

BACKGROUND AND OBJECTIVES

Assessment of state anxiety is frequently required in clinical and research settings, but its measurement using standard multi-item inventories entails practical challenges. Such inventories are increasingly complemented by paper-and-pencil, single-item visual analog scales measuring state anxiety (VAS-A), which allow rapid assessment of current anxiety states. Computerized versions of VAS-A offer additional advantages, including facilitated and accurate data collection and analysis, and applicability to computer-based protocols. Here, we establish the psychometric properties of a computerized VAS-A.

METHODS

Experiment 1 assessed the reliability, convergent validity, and discriminant validity of the computerized VAS-A in a non-selected sample. Experiment 2 assessed its sensitivity to increase in state anxiety following social stress induction, in participants with high levels of social anxiety.

RESULTS

Experiment 1 demonstrated the computerized VAS-A's test-retest reliability (r = .44, p < .001); convergent validity with the State-Trait Anxiety Inventory's state subscale (STAI-State; r = .60, p < .001); and discriminant validity as indicated by significantly lower correlations between VAS-A and different psychological measures relative to the correlation between VAS-A and STAI-State. Experiment 2 demonstrated the VAS-A's sensitivity to changes in state anxiety via a significant pre- to during-stressor rise in VAS-A scores (F(1,48) = 25.13, p < .001).

LIMITATIONS

Set-order administration of measures, absence of clinically-anxious population, and gender-unbalanced samples.

CONCLUSIONS

The adequate psychometric characteristics, combined with simple and rapid administration, make the computerized VAS-A a valuable self-rating tool for state anxiety. It may prove particularly useful for clinical and research settings where multi-item inventories are less applicable, including computer-based treatment and assessment protocols. The VAS-A is freely available: http://people.socsci.tau.ac.il/mu/anxietytrauma/visual-analog-scale/.