Summary: Daily training with a mindfulness app produces lasting improvements in extinction learning and reduces threat-related arousal.
Source: University of Southern Denmark
Overview: Mindfulness training has repeatedly been shown to reduce negative emotions in both healthy people and those with psychological disorders. Clinical studies report benefits for anxiety, depression, stress, and trauma-related conditions, but the underlying biological mechanisms remain incompletely understood. Neuroimaging research has linked mindfulness practice with changes in brain regions involved in extinction learning, suggesting extinction retention as a plausible mechanism. Until now, however, direct experimental evidence that mindfulness enhances extinction retention has not been available.
In a collaborative study conducted by researchers from the University of Southern Denmark, Uppsala University, Lund University, Peking University and the Icahn School of Medicine at Mount Sinai, investigators tested whether a short, app-delivered mindfulness intervention would influence the formation and retention of extinction memories. The findings show that four weeks of daily mindfulness practice delivered via the Headspace app improved extinction retention and produced lasting reductions in physiological responses to threat.
Study design: Healthy volunteers were randomly assigned to one of two groups: a mindfulness training group that completed a four-week daily program using the Headspace mindfulness app (n = 14), or a waitlist control group (n = 15). After the intervention period, all participants underwent a two-day laboratory protocol based on classical Pavlovian aversive conditioning.
On day 1, participants first learned conditioned fear responses by viewing neutral images on a computer screen, some of which were paired with a mild electric shock to the hand. Repeated pairings produced conditioned responses: participants showed increased autonomic arousal to the images that had signaled the shock. Researchers measured these reactions using skin conductance, an objective index of sympathetic arousal and a marker of the human fight-or-flight response.
After conditioning, the team carried out extinction training by repeatedly presenting the previously shock-paired images while omitting the shocks. Over the course of extinction, autonomic arousal to those images fell substantially, indicating that participants had learned that the cues no longer predicted an aversive outcome.
On day 2, participants returned to the lab to test extinction retention. They were reconnected to the shock equipment and shown the same images from the previous day, but no shocks were delivered. This test probes spontaneous recovery: extinction learning is often fragile, and conditioned fear can return after a delay even when initial extinction appeared successful.
Key results: The group that completed mindfulness training showed significantly lower fear-related arousal on day 2 compared with the waitlist control group. For mindfulness-trained participants, physiological responses remained at the low level achieved at the end of extinction on day 1, demonstrating improved retention of extinction memory. In contrast, the control group showed a notable increase in arousal from the end of extinction on day 1 to the test on day 2, consistent with spontaneous recovery.
Importantly, there were no differences between groups during the initial conditioning or during extinction on day 1. Both groups acquired and extinguished conditioned responses to a similar degree, indicating that mindfulness specifically enhanced the retention of extinction rather than influencing conditioning or immediate extinction learning.
Implications: According to study first author Johannes Björkstrand, these results extend previous findings by showing that a relatively brief period of mindfulness practice can produce measurable changes in autonomic physiological responses—not only shifts in subjective emotion. “We can show that mindfulness does not only affect subjective experiences of negative emotion, as prior work has shown, but also produces clear effects on autonomic arousal, even after limited training,” Björkstrand says. “The specificity of the effect on extinction retention fits with earlier neuroimaging studies and suggests potential clinical applications for anxiety-related problems.”
Clinical relevance: Exposure therapy relies on extinction learning and is a cornerstone treatment for anxiety and trauma-related disorders. However, many patients fail to achieve lasting benefit, and one contributing factor may be difficulty forming durable extinction memories. The present findings raise the possibility that combining mindfulness training with exposure therapy could enhance treatment durability by targeting an underlying vulnerability in extinction retention. The authors stress, however, that clinical trials in patient populations are required before drawing treatment recommendations.
Next steps: The research team is expanding the work to uncover the neurobiological processes that underlie the observed behavioral effects. Senior author Ulrich Kirk explains that they are replicating the experiment with a larger sample while collecting high-resolution fMRI data to track brain activity throughout conditioning, extinction and retention. “We hope to demonstrate the robustness of the behavioral effect, replicate these findings, and identify the neural mechanisms that drive the improved extinction retention,” says Kirk. Data collection is complete, and analysis is ongoing.
Source:
University of Southern Denmark
Media Contacts:
Ulrich Kirk – University of Southern Denmark
Image Source:
Image in the public domain.
Original Research: Open access
“The effect of mindfulness training on extinction retention.” Johannes Björkstrand, Daniela Schiller, Jian Li, Per Davidson, Jörgen Rosén, Johan Mårtensson & Ulrich Kirk. Scientific Reports. DOI: 10.1038/s41598-019-56167-7.
Abstract
The effect of mindfulness training on extinction retention
Anxiety and trauma-related disorders are widespread and costly. Existing treatments produce only moderate effect sizes in some cases, highlighting the need to understand mechanisms and improve interventions. Emerging evidence indicates mindfulness training (MFT) can help treat fear and anxiety, but the mechanisms are unclear. Based on prior neuroimaging findings, one hypothesis is that MFT enhances extinction retention. To test this, healthy subjects completed either a four-week MFT program via a smartphone app (n = 14) or were assigned to a waitlist (n = 15). Participants then completed a two-day aversive conditioning protocol assessing acquisition and extinction on day 1 and extinction retention on day 2. Results showed the MFT group demonstrated reduced spontaneous recovery of threat-related arousal on day 2 compared with controls. MFT did not affect acquisition or extinction on day 1. These findings clarify a potential mechanism by which mindfulness improves emotional functioning and could inform treatment approaches for anxiety and trauma-related disorders.