Effects of attention bias modification for anxiety: Neurophysiological indices and moderation by symptom severity

Abstract

Objective: Attention bias modification (ABM) aims to decrease anxiety symptom severity through the reduction of threat-related attention bias (AB). Individual differences in treatment response and poor measurement reliability of AB have called its clinical promise into question. The current study examined whether individual differences in anxiety severity at baseline moderated treatment response, and employed both behavioral and neurophysiological metrics of AB.

Methods: Participants (N = 99) were randomly assigned to four weeks of ABM or placebo control training (PT). Self-reported anxiety symptom severity, and AB metrics and ERPs generated during the dot probe task were collected at baseline (Time 1), one-week post-intervention (Time 5), and at a three-month follow-up (Time 6).

Results: ABM, relative to PT, reduced ERPs indexing attention discrimination (N170) and increased ERPs indexing salience tracking (P3). Increases in P3 were associated with ABM-related reductions in anxiety. Anxiety severity was reduced following ABM, but only among those with higher baseline anxiety symptom severity.

Conclusions: ABM effectively reduced symptom severity among those with higher levels of anxiety, and modulated neurophysiological indices of AB.

Significance: Results provide evidence for attention-relevant ERPs as outcomes of ABM treatment responsivity and suggest that ABM may be most beneficial for those with more severe anxiety symptoms.

Keywords: Anxiety; Attention bias modification; Event-related potentials; Individual differences.

Figure 1.

Consolidated Standards of Reporting Trials (CONSORT) Flow Diagram. * For the Generalized Estimating Equations (GEE) analysis, as it accounts for missing data, we used dataset that includes those who underwent intervention, which is N = 99.

Figure 2.

Topographic maps and waveforms of the analyzed, entire sample averaged across both ABM and PT for P1, N170, N2, and P3 are presented (Left). (a.) N170 to threat faces significantly decreased (became less negative) from T1 to T6 for the ABM group. (b.) For the ABM group, P3 to threat faces significantly increased from T1 to T5, and from T1 to T6. No significant changes over time were detected for the PT group. (c.) N2 to threat faces significantly increased (became more negative over time). (d.) In the high baseline anxiety group, N2 significantly increased from T1 to T5 and T1 to T6 (Right). Note. *Difference is significant at the .05 level, **Difference is significant at the .01 level. ***Difference is significant at the < .001 level. T1 = Time 1, T5 = Time 5, T6 = Time 6, ABM = attention bias modification training, PT = placebo control training, TLBS = trial-level bias score, DASS = Depression Anxiety Stress Scales.

Figure 3.

(a.) Anxiety symptom severity decreased over time in the sample as a whole. (b.) Anxiety decreased from T1 to T6, and from T5 to T6 among the high baseline anxiety group who received ABM. (c.) Among those with low baseline anxiety, anxiety decreased from T1 to T6 in the PT group. (d., e.) Peak difference TLBS significantly decreased over time, particularly for those starting with low baseline anxiety who received ABM. Note. *Difference is significant at the .05 level, **Difference is significant at the .01 level. ***Difference is significant at the < .001 level. T1 = Time 1, T5 = Time 5, T6 = Time 6, ABM = attention bias modification training, PT = placebo control training, TLBS = trial-level bias score, DASS = Depression Anxiety Stress Scales, HAM-A = Hamilton Anxiety Rating Scale.