In our recent study, Strengthened Hippocampal Circuits Underlie Enhanced Retrieval of Extinguished Fear Memories Following Mindfulness Training, published by Biological Psychiatry, we found mindfulness meditation helps extinguish fearful associations.

A common way to treat anxiety disorders is to expose patients to the anxiety provoking stimulus in a safe environment until it no longer elicits fear, a process termed exposure therapy. This exposure provides an opportunity to learn that these stimuli are not threatening and thereby facilitate adaptive regulation of emotional responses. To be successful, a new memory must be created between the stimulus and a feeling of safety, then the ‘safety’ memory must be recalled when the stimulus is presented again in a new environment, rather than the original fearful memory. 

Mindfulness meditation has been proposed to provide an optimal condition for exposure therapy because it involves experiencing the present moment with an open, curious and non-reactive mindset. Numerous studies have documented that mindfulness meditation programs are useful for reducing anxiety, however the mechanisms were unknown. Our current study investigated enhanced learning of the ‘safety’ signal as one mechanism through which mindfulness can help individuals learn to have a less reactive and more adaptive response to anxiety provoking stimuli. 

We used MRI brain scans and a fear-conditioning task to examine changes in neural networks associated with attention and memory following mindfulness meditation training. In the study, 42 participants completed an 8-week mindfulness-based stress reduction program where they learned formal meditation and yoga practices. Another 25 participants were randomly placed into an 8-week exercise-based stress management control group, in which they were taught about the impact of stress and performed light aerobic exercise. We found changes in the hippocampus after mindfulness training were associated with enhanced ability to recall the safety memory, and thus respond in a more adaptive way.

Future studies need to be done with clinical samples and use threatening stimuli relevant to their anxiety, such as, spiders, cues that trigger panic or PTSD, etc., to determine if similar changes in brain activation occur in these conditions. Furthermore, some of the findings were observed in both the mindfulness and control groups, suggesting that some of the changes are not unique to mindfulness training, or might be due to some other component of the program, such as social support. 

The study was authored by Gunes Sevinc, Britta Hölzel, Jonathan Greenberg, Tim Gard, Vincent Brunsch, Javaria Hashmi, Mark Vangel, Scott Orr, Mohammed Milad and Sara Lazar.  The work was supported by the National Institutes of Health.