A new study has identified neuroplastic changes in brain structure that accompany attention bias modification training in highly anxious individuals. The findings, which appear in the journal Biological Psychology, shed light on the mechanisms underlying the efficacy of the treatment.
Research has demonstrated that the brain prioritizes threating information over non-threatening information. But in highly anxious individuals, this attentional bias can become exaggerated and detrimental. The authors of the new study sought to better understand the changes in brain structure that result from attention bias modification, an intervention that seeks to systematically train attention away from threatening stimuli and toward neutral stimuli.
“Our lab has had a longstanding interest in understanding the behavioral and neural mechanisms of affective attention and attentional bias to affective information,” said study authors Josh Carlson and Lin Fang of the Cognitive x Affective Behavior & Integrated Neuroscience (CABIN) Lab at Northern Michigan University.
“We are interested in attentional bias to affective information from both an adaptive (e.g., detecting and attending to threat in the environment) and maladaptive (e.g., exaggerated attentional bias to threat, which is characteristic of anxiety disorders) perspective.”
In the new study, 61 right-handed women (aged 18 to 38) were randomly assigned to complete 6 weeks of attention bias modification or a control treatment using their smart phone.
“Attention bias modification is intended to reduce maladaptive attentional biases to threat, which in turn reduce anxious symptoms,” the researchers explained. “Although the effectiveness of attention bias modification interventions has been mixed in the literature, our goal was to determine how the brain changes following attention bias modification training and how these changes in the brain relate to symptom reduction following attention bias modification.”
Previous research has indicated that attention bias modification is most effective among anxious individuals who exhibit a heightened attentional bias to threat. With this in mind, the researchers screened participants to have high levels of anxiety and some level of attentional bias.
Using magnetic resonance imaging, the researchers observed differences in brain structure and function between those who completed attention bias modification treatment and those who completed the control treatment. In particular, those who completed attention bias modification treatment displayed increases in gray matter volume in the anterior cingulate cortex, a region of the brain linked to anxiety and mood disorders. They also found increases in functional connectivity between the superior frontal gyrus and the anterior cingulate cortex as well as the insula.
Importantly, increased levels of anterior cingulate cortex gray matter volume were linked to decreased anxiety following attention bias modification treatment.
“We think the three main take-aways from our data are (1) interventions such as attention bias modification that are used to target symptoms of psychopathology appear to ‘rewire’ (or change) brain structure and function, (2) these changes appear to be linked to regions traditionally involved in emotional responding and cognitive control, and (3) individuals with the largest changes in brain structure are those with the largest decrease in anxious symptoms (i.e., the degree to which brain structure changes is linked to the efficacy of the attention bias modification intervention),” Carlson and Fang told PsyPost.
But the study, like all research, includes some caveats. The participants in the study had a high levels of trait anxiety, which captures the general tendency to experience anxiety. However, this is different than a diagnosis of an anxiety disorder. “Therefore, although our results suggest that changes in brain structure and function accompany attention bias modification in high trait anxious individuals, it is unclear if these findings generalize to clinically anxious samples,” the researchers explained.
“In addition, the attention bias modification intervention did not reduce anxiety across the entire sample,” Carlson and Fang noted. “That is, not everyone appeared to benefit from the training. As mentioned above, however, our data suggest that those with greater changes in brain structure are most likely to experience reductions in symptoms of anxiety. We are currently utilizing this dataset to assess whether pre-training MRI-based biomarkers can predict who is most likely to benefit from the attention bias modification intervention.”
The new research was funded by a National Institute of Mental Health Academic Research Enhancement Award.
The study, “Neuroplastic changes in anterior cingulate cortex gray matter volume and functional connectivity following attention bias modification in high trait anxious individuals“, was authored by Joshua M.Carlson, Lin Fang, Ernst H. W. Koster, Jeremy A. Andrzejewski, Hayley Gilbertson, Katherine A.Elwell, and Taylor R.Zuidema.
