Common and Dissociable Neural Activity Following Mindfulness-Based Stress Reduction and Relaxation Response Programs. Author: Sevinc G1, Hölzel BK1,2, Hashmi J3, Greenberg J1, McCallister A1,4, Treadway M5, Schneider ML1, Dusek JA6,7, Carmody J8, Lazar SW1 Affiliation: <sup>1</sup>Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA. <sup>2</sup>Department of Neuroradiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany. <sup>3</sup>Department of Anesthesia, Pain Management &amp; Perioperative Medicine, Dalhousie University, Dalhousie University, Canada. <sup>4</sup>Department of Osteopathic Manipulative Medicine, Berkshire Medical Center, Pittsfield, MA, USA. <sup>5</sup>Department of Psychology, Emory University, Atlanta, GA, USA. <sup>6</sup>Kripalu Center for Yoga and Health, Stockbridge, MA, USA. <sup>7</sup>Benson-Henry Institute for Mind Body Medicine, Massachusetts General Hospital, Boston, MA, USA. <sup>8</sup>University of Massachusetts Medical School, Worcester, MA, USA. Conference/Journal: Psychosom Med. Date published: 2018 Apr 10 Other: Special Notes: doi: 10.1097/PSY.0000000000000590. [Epub ahead of print] , Word Count: 297 OBJECTIVE: We investigated common and dissociable neural and psychological correlates of two widely used meditation-based stress-reduction programs. METHODS: Participants were randomized to the Relaxation Response (RR; n=18; 56% female) or the Mindfulness-Based Stress Reduction (MBSR; n=16, 56% female) programs. Both programs utilize a 'bodyscan' meditation, however the RR program explicitly emphasizes physical relaxation during this practice, while the MBSR program emphasizes mindful awareness with no explicit relaxation instructions. Following the programs, neural activity during the respective meditation was investigated using fMRI. RESULTS: Both programs were associated with reduced stress (for RR, from 14.1±6.6 to11.3± 5.5; Cohen's d=0.50; for MBSR, from 17.7±5.7 to 11.9±5.0; Cohen's d= 1.02). Conjunction analyses revealed functional coupling between ventromedial prefrontal regions and supplementary motor areas (p<0.001). The disjunction analysis indicated that the RR bodyscan was associated with stronger functional connectivity of the right inferior frontal gyrus - an important hub of intentional inhibition and control- with supplementary motor areas (p<0.001, FWE corrected). The MBSR program was uniquely associated with improvements in self-compassion and rumination and the within group analysis of MBSR bodyscan revealed significant functional connectivity of the right anterior insula - an important hub of sensory awareness and salience- with pregenual anterior cingulate during bodyscan meditation compared to rest (p=0.03, FWE corrected). CONCLUSIONS: The bodyscan exercises in each program were associated with both overlapping and differential functional coupling patterns, which were consistent with each program's theoretical foundation. These results may have implications for the differential effects of these programs for the treatment of diverse conditions.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. PMID: 29642115 DOI: 10.1097/PSY.0000000000000590