Neuroplasticity in an Extended Amygdala Network as a Target Mechanism for Attention Bias Modification Outcome

Study Summary

Anxiety disorders are one of the most common psychological disorders. Underlying anxiety is an increased attentional bias to threat, which has been identified as a causal contributor in the development of anxiety. Given this causal relationship, attention bias modification was introduced as a treatment option where anxiety is reduced by training individuals to direct their attention away from threat and thereby decreasing anxiety. Over a decade of research using this approach, called attention bias modification (ABM), suggests that overall the approach is effective in reducing anxiety. Although ABM appears to be a very promising treatment option for anxiety, there are several factors limiting the effectiveness of ABM. These include the recognition of individual-level needs and a known underlying mechanism of action by which ABM is effective. Neuroimaging evidence suggests that attentional bias to visual threat is associated with a network of brain regions including the amygdala, anterior cingulate cortex, and visual cortex. In human participants, experience-dependent neuroplasticity is visible in voxel-based morphometry based measures of gray matter volume following training. Recently, voxel-based morphometry measures of gray matter volume have been linked to dendritic spine density-a known cellular mechanism for learning-related neuroplasticity. Thus, voxel-based morphometry measures are ideally suited to measure learning-related neuroplasticity following attention bias modification. In this proposal participants' level of attentional bias, anxiety, and gray matter volume will be measured before and after completing six weeks of attention bias modification training (N = 50) or attention control training (N= 50). The proposal aims to (1) establish that pre-treatment bias predicts variability in gray matter volume in the extended amygdala and anterior cingulate cortex, (2) assess the extent to which reduced extended amygdala and anterior cingulate cortex gray matter

Primary Outcome

Reaction time difference to congruent and incongruent trials in the dot-probe task, which measure heightened attentional bias to threat.

Conditions Studied

Interventions

• BEHAVIORAL Attention Control
• BEHAVIORAL Attention Bias Modification

Study Locations (1)