Brain structure changes induced by attention bias modification training

Abstract

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.

Trial registration: ClinicalTrials.gov NCT00018057.

Keywords: Anxiety; Attention bias; Connectivity; DTI; Dot probe; Structure; Temporal cortex.

Conflict of interest statement

Declarations of interest: none.

Published by Elsevier B.V.

Figures

Figure 1.

Trial sequence and experimental design. (A) A single trial of the dot-probe task: fixation cross (500 ms), faces pair (500 ms), probe (until response). (B) Study design for the ABM and ACT groups: Participants in the ABM and ACT conditions underwent DTI scans immediately before and after the first training session (visit 1); over the following two weeks, four additional training sessions were held on different days (visits 2–5), followed by a final DTI scan (visit 6). Note: ABM = attention bias modification, ACT = attention control training, DTI = diffusion tensor imaging.

Figure 2.

Structural changes induced by training. Left panels show locations of significant clusters (FDR-corrected, whole-brain); right panels delineate effects in terms of mean FA values normalized to Scan 1 values. (A) Significant Group × Time interaction in the inferior temporal cortex. (B) Significant main effect of Time in the ventromedial prefrontal cortex (top) and the middle occipital gyrus (bottom). Note: FA = fractional anisotropy, ABM = attention bias modification, ACT = attention control training. *, p<.05, **, p<.01, t-tests for dependent-samples for mean changes between scans. Error bars signify standard error of the mean.