Posted 05.17.2018 | by AMRA

Mindfulness-Based Stress Reduction (MBSR) and Relaxation Response (RR) training are both well-established mind-body interventions designed to reduce stress. While there is some overlap between these modalities—both involve meditative attention to bodily sensations—there are also significant differences. MBSR emphasizes non-judgmental awareness to increase acceptance of the present moment, while RR employs muscle relaxation to induce a parasympathetic state that interferes with the fight-or-flight response.

To understand the ways in which these two programs function, Sevinc et al. [Psychosomatic Medicine] tested for commonalties and differences in terms of psychological effects and brain correlates.

The researchers randomly assigned 50 volunteers (64% female, average age = 38 years) to either MBSR or RR with 40 of the volunteers completing the programs. Both programs involved 8 weekly 2-hour group sessions with 20 minutes of daily home practice. RR included a body scan meditation emphasizing muscle relaxation along with breath-focused and mantra-focused meditations.

Participants were assessed at baseline and after the intervention on self-report measures of mindfulness (using the Five Facet Mindfulness Questionnaire or FFMQ), perceived stress, self-compassion, and rumination.

After the intervention, participants underwent fMRI brain scanning while at rest and while engaging in the body scan meditation specific to each program: the RR body scan emphasized relaxing various muscle groups, whereas the MBSR body scan emphasized mindful awareness of body sensations.

The researchers were interested in exploring changes in functional connectivity in specific brain regions of interest. Brain regions exhibiting simultaneous increases and decreases in activity are said to be functionally connected. Usable fMRI data was obtained from 34 participants.

The results showed that both programs significantly reduced perceived stress (RR Cohen’s d=0.5; MBSR d=1.0). After the intervention, RR participants showed significant FFMQ increases on the Describing, Acting with Awareness, Observing, and Non-reactivity sub-scales, while MBSR participants showed significant increases on the Observing and Non-reactivity sub-scales. MBSR participants also showed a significant increase in self-compassion and a decrease in rumination, but these group differences did not reach statistical significance.

The fMRI results showed that the MBSR and RR body scans both induced a common increased functional connectivity between the brain’s ventromedial prefrontal cortex, which plays a role in attention, and the brain’s supplementary motor areas, which play a role in voluntary muscle control.

Brain differences by group were also identified. RR practice produced stronger functional connectivity between the right inferior parietal gyrus and the supplementary motor areas, reflecting greater intentional inhibition and control of muscle relaxation. MBSR practice significantly increased functional connectivity between the anterior insula and the Anterior Cingulate Cortex (ACC), reflecting enhanced bodily awareness and regulation of limbic-mediated emotionality. This did not significantly differentiate the MBSR practice from the RR practice, which may be attributed to their shared emphasis on enhanced bodily awareness.

This is one of the first head-to-head comparisons of mind-body practices using both self-report and brain imaging data. Both MBSR and RR reduce stress levels and increase aspects of mindfulness. Their unique pattern of brain commonalties and differences makes sense given that MBSR emphasizes non-judgmental awareness, while RR emphasizes parasympathetic relaxation along with attention to muscular sensations.

The results also support the idea that mindfulness is not identical to relaxation: the two have their own unique neurological signatures. The study is limited by its small sample size and lack of an attention-only control.

Reference:

Sevinc, G., Hölzel, B. K., Hashmi, J., Greenberg, J., McCallister, A., Treadway, M., . . . Lazar, S. W. (2018). Common and dissociable neural activity following mindfulness-based stress reduction and relaxation response programs. Psychosomatic Medicine.

[Link to abstract]