Meditation attenuates Default-mode activity: a pilot study using ultra-high field 7 Tesla MRI


Author: Saampras Ganesan1, Bradford Moffat2, Nicholas T Van Dam3, Valentina Lorenzetti4, Andrew Zalesky5

Affiliation: <sup>1</sup> Melbourne Neuropsychiatry Centre, Carlton, Victoria 3053, Australia; Department of Biomedical Engineering, The University of Melbourne, Carlton, Victoria 3053, Australia; Contemplative Studies Centre, Melbourne School of Psychological Sciences, The University of Melbourne, Melbourne, Victoria 3010, Australia. Electronic address: saamprasg@student.unimelb.edu.au.

<sup>2</sup> Melbourne Brain Centre Imaging Unit, Department of Radiology, The University of Melbourne, Parkville, Victoria 3052, Australia.

<sup>3</sup> Contemplative Studies Centre, Melbourne School of Psychological Sciences, The University of Melbourne, Melbourne, Victoria 3010, Australia.

<sup>4</sup> Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioral and Health Sciences, Faculty of Health, Australian Catholic University, Fitzroy, Victoria 3065, Australia.

<sup>5</sup> Melbourne Neuropsychiatry Centre, Carlton, Victoria 3053, Australia; Department of Biomedical Engineering, The University of Melbourne, Carlton, Victoria 3053, Australia.
Conference/Journal: Brain Res Bull
Date published: 2023 Sep 19
Other:
  Special Notes: doi: 10.1016/j.brainresbull.2023.110766.   ,  Word Count: 271  
    Objectives:

Mapping the neurobiology of meditation has been bolstered by functional MRI (fMRI) research, with advancements in ultra-high field 7 Tesla fMRI further enhancing signal quality and neuroanatomical resolution. Here, we utilize 7 Tesla fMRI to examine the neural substrates of meditation and replicate existing widespread findings, after accounting for relevant physiological confounds.



Methods:

In this feasibility study, we scanned 10 beginner meditators (N=10) while they either attended to breathing (focused attention meditation) or engaged in restful thinking (non-focused rest). We also measured and adjusted the fMRI signal for key physiological differences between meditation and rest. Finally, we explored changes in state mindfulness, state anxiety and focused attention attributes for up to 2 weeks following the single fMRI meditation session.



Results:

Group-level task fMRI analyses revealed significant reductions in activity during meditation relative to rest in Default-mode network hubs, i.e., antero-medial prefrontal and posterior cingulate cortices, precuneus, as well as visual and thalamic regions. These findings survived stringent statistical corrections for fluctuations in physiological responses which demonstrated significant differences (p < 0.05/n, Bonferroni controlled) between meditation and rest. Compared to baseline, State Mindfulness Scale (SMS) scores were significantly elevated (F(3,9) = 8.16, p<0.05/n, Bonferroni controlled) following the fMRI meditation session, and were closely maintained at 2-week follow up.



Conclusions:

This pilot study establishes the feasibility and utility of investigating focused attention meditation using ultra-high field (7 Tesla) fMRI, by supporting widespread evidence that focused attention meditation attenuates Default-mode activity responsible for self-referential processing. Future functional neuroimaging studies of meditation should control for physiological confounds and include behavioural assessments.



Keywords: 7 Tesla; Default-mode network; beginner meditators; focused attention meditation; functional MRI; pilot study.



PMID: 37734622 DOI: 10.1016/j.brainresbull.2023.110766