Mindfulness related changes in grey matter: a systematic review and meta-analysis

Author: Cyril R Pernet1, Nikolai Belov2, Arnaud Delorme3,4, Alison Zammit5
Affiliation: <sup>1</sup> Centre for Clinical Brain Sciences, Edinburgh Imaging, The University of Edinburgh, Edinburgh, UK. cyril.pernet@ed.ac.uk. <sup>2</sup> Department of Psychology, Otto von Guericke University Magdeburg, Magdeburg, Germany. <sup>3</sup> CerCo, CNRS, Paul Sabatier University, Toulouse, France. <sup>4</sup> SCCN, INC, University of California San Diego, La Jolla, CA, USA. <sup>5</sup> Centre for Clinical Brain Sciences, Edinburgh Imaging, The University of Edinburgh, Edinburgh, UK.
Conference/Journal: Brain Imaging Behav
Date published: 2021 Feb 24
Other: Special Notes: doi: 10.1007/s11682-021-00453-4. , Word Count: 179

Knowing target regions undergoing strfuncti changes caused by behavioural interventions is paramount in evaluating the effectiveness of such practices. Here, using a systematic review approach, we identified 25 peer-reviewed magnetic resonance imaging (MRI) studies demonstrating grey matter changes related to mindfulness meditation. An activation likelihood estimation (ALE) analysis (n = 16) revealed the right anterior ventral insula as the only significant region with consistent effect across studies, whilst an additional functional connectivity analysis indicates that both left and right insulae, and the anterior cingulate gyrus with adjacent paracingulate gyri should also be considered in future studies. Statistical meta-analyses suggest medium to strong effect sizes from Cohen's d ~ 0.8 in the right insula to ~ 1 using maxima across the whole brain. The systematic review revealed design issues with selection, information, attrition and confirmation biases, in addition to weak statistical power. In conclusion, our analyses show that mindfulness meditation practice does induce grey matter changes but also that improvements in methodology are needed to establish mindfulness as a therapeutic intervention.

Keywords: Grey matter; MRI; Meta‚Äźanalysis; Mindfulness meditation; Systematic review.

PMID: 33624219 DOI: 10.1007/s11682-021-00453-4