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Matthew D. Sacchet

Massachusetts General Hospital

14 papers in the library · 358 citations · publishing 2013-2026

Papers

Mindfulness starts with the body: somatosensory attention and top-down modulation of cortical alpha rhythms in mindfulness meditation

Frontiers in Human Neuroscience January 1, 2013 Catherine E. Kerr, Matthew D. Sacchet, Sara W. Lazar et al. 329 citations

Standardized mindfulness practices that focus attention on breath and body sensations may work by training the brain to better regulate alpha rhythms (7-14 Hz) in the primary somatosensory cortex. These alpha rhythms filter sensory information entering the neocortex. The framework suggests that in chronic pain, somatic attention in mindfulness reduces pain-focused attentional resources by altering alpha activity. In depression relapse prevention, somatic attention competes with rumination, as internal cognitive processes rely on alpha filtering. A computational model predicts enhanced top-down modulation of alpha through precise timing changes in thalamocortical inputs. The theory aligns with Buddhist teachings that mindfulness begins with mindfulness of the body, proposing that enhanced alpha regulation improves detection and regulation of mind-wandering.

Facilitating Meditation with Focused Ultrasound Neuromodulation: A First Investigation in Experienced Practitioners

January 31, 2024 Joshua Cain, Tracy Brandmeyer, Ninette Simonian et al. 9 citations preprint

Focused ultrasound stimulation of the caudate nucleus significantly improves self-reported meditative depth and mood in experienced vipassana meditators, and is accompanied by reduced heart rate and increased heart rate variability. These physiological changes strongly correlate with reported depth, suggesting a mechanistic link between reduced arousal and successful meditation. Stimulation of the posterior cingulate cortex or insula did not produce similar effects. The findings indicate that targeted neuromodulation may help lower the barrier to consistent meditation practice for novice or intermediate meditators.

Endogenous suspension and reset of consciousness: 7T fMRI brain mapping of the extended cessation meditative endpoint

bioRxiv Preprint Server September 6, 2025 Winson F.z. Yang, Akila Kadambi, Kilian Abellaneda-Pérez et al. 4 citations preprint

An advanced meditative state called extended cessation (EC), where consciousness is voluntarily suspended and later resumes with heightened clarity and equanimity, provides a natural model for studying consciousness. Using ultra-high-resolution 7T fMRI with dense sampling of three individuals, the research mapped whole-brain activity, connectivity, gradients, and eigenmodes during EC, linking them to brain chemistry and cognitive maps. EC increased activity in sensory regions, reduced activity in higher-order association areas, subcortex, and brainstem, expanded the principal cortical gradient, and decreased low-order global eigenmodes.

Integrated phenomenology and brain connectivity demonstrate changes in nonlinear processing in jhana advanced meditation

bioRxiv (Cold Spring Harbor Laboratory) Ruby M. Potash, Sean D. Van Mil, Mar Estarellas et al. 4 citations preprint

During a deep meditative state called jhana, the brain's non-oscillatory, nonlinear neural activity—rather than oscillatory synchrony—best distinguishes the state from ordinary waking consciousness. In a single highly experienced meditator (over 20,000 hours of practice) studied across 29 sessions, EEG recordings showed that combining subjective ratings of attention with a nonlinear connectivity metric improved the ability to decode the meditative state compared to using neural measures alone. Deeper jhana states were marked by a balance between feedback and feedforward neural processes, indicating an equalization of internally and externally directed information processing. These findings suggest that refined conscious states involve distinct large-scale neural dynamics not captured by traditional oscillatory measures.

Neuroelectrophysiological correlates of extended cessation of consciousness in advanced meditators: A multimodal EEG and MEG study

bioRxiv Preprint Server September 19, 2025 Kenneth Shinozuka, Winson F.z. Yang, Ruby M. Potash et al. 3 citations preprint

Advanced meditators can enter a state called extended cessation (EC) in which they intentionally suppress consciousness and later emerge with clarity and equanimity. In the first electrophysiological study of EC, five meditators were recorded with EEG and MEG. EC markedly reduced alpha power and tended to increase neural complexity, unlike sleep, anesthesia, or disorders of consciousness. The findings indicate that the neural correlates of EC are distinct from other unconscious states and that complexity alone is not sufficient for consciousness, offering new insights into advanced meditation and human flourishing.

High-precision neurofeedback-guided meditation training optimises real-world self-guided meditation practice for well-being

bioRxiv (Cold Spring Harbor Laboratory) October 26, 2024 Saampras Ganesan, Nicholas T. van Dam, Sunjeev K. Kamboj et al. 3 citations preprint

Personalized high-precision neurofeedback (NF) can help novice meditators better disengage from mental activity during meditation, improving emotional well-being and mindful awareness. In a single-blind, controlled study, 40 novices received two days of meditation training with feedback from either their own or a matched participant's posterior cingulate cortex (PCC) activity, measured using 7 Tesla fMRI. The experimental group showed stronger functional decoupling of PCC from dorsolateral prefrontal cortex, indicating improved control over disengagement. This led to greater improvements in emotional well-being and mindful awareness during a week of real-world self-guided meditation, supporting the utility of NF-guided meditation training.

Ketamine pharmacotherapy for major depressive disorder: A narrative review

Progress in Neuro-Psychopharmacology and Biological Psychiatry February 27, 2026 Chris H. Miller, Angela Hickman, Caitlin Baten et al. 2 citations

Ketamine, originally developed as an anesthetic, has emerged as a novel treatment for major depressive disorder (MDD) and treatment-resistant depression (TRD). Its antidepressant properties were discovered serendipitously, leading to FDA approval for TRD and MDD with suicidal ideation. The drug acts primarily as an NMDA receptor antagonist, triggering a paradoxical AMPA-mediated glutamate surge that promotes synaptogenesis and neuroplasticity. Intravenous ketamine and intranasal esketamine differ in dosing, bioavailability, and onset. Common adverse effects include dissociation, sedation, and hypertension. Efficacy studies show mixed-to-positive results, with non-inferiority to established treatments like electroconvulsive therapy. Future research aims to develop predictive markers for personalized medicine.

Toward a neuroscience of consciousness using advanced meditation.

Neuroscience and biobehavioral reviews February 1, 2026 Jonathan M. Lieberman, Matthew D. Sacchet 2 citations

Advanced meditation, cultivated through long-term expertise, provides a unique experimental window into the core mechanisms of consciousness. Two classes of meditative phenomena are highlighted: advanced concentrative absorption (related to jhāna), where highly abstract awareness persists while typical features of consciousness fade, and meditative endpoints (related to nirodha), involving a temporary suspension of consciousness. These states serve as precise, replicable anchors for a minimal model framework that aims to identify the simplest possible form of conscious experience. Integrating advanced meditation into neuroscience offers a promising path toward isolating the neural mechanisms supporting consciousness in its most reduced and fundamental forms.

ENIGMA-Meditation: Worldwide consortium for neuroscientific investigations of meditation practices

April 8, 2024 Saampras Ganesan, Aki Tsuchiyagaito, Greg J. Siegle et al. 2 citations preprint

Meditation practices, which have been adapted into manualized interventions for conditions like depression, pain, addiction, and anxiety, show therapeutic promise, but their neuroscientific basis remains unclear. Current neuroimaging studies rely on small, heterogeneous datasets that vary in practice types, participant experience, clinical targets, and imaging methods, limiting generalizability and replicability. To address this, the ENIGMA-Meditation consortium was formed as a global collaboration to conduct systematic meta- and mega-analyses of distributed neuroimaging data using standardized methods. This framework aims to improve statistical power and rigorously characterize the neural mechanisms underlying meditation's effects on psychological and cognitive attributes, advancing the field of contemplative neuroscience.

EEG brain reconfiguration during meditation-induced extended cessation of consciousness: A dense-sampling multi-participant microstate study

bioRxiv Preprint Server February 10, 2026 David Zarka, Winson F.z. Yang, Abel Rassat et al. preprint

Extended cessation (EC) is a rare meditative state in which conscious experience temporarily stops, followed by heightened perception and emotional balance. In five highly trained meditators, electroencephalographic microstate analysis revealed that EC altered brain activity patterns linked to self-referential processing. Specifically, microstate B occurred less often and for shorter durations, while microstate C occurred more often and for longer durations. Transition probabilities also shifted, with more transitions from A and B to C and fewer from A to B. These changes appeared across delta, theta, and beta frequency bands, with additional band-specific effects for microstates A and D. The findings suggest EC involves a reweighting of self-referential and sensory processes.

Meditation and neurofeedback: A systematic scoping review, synthesis, and future directions

Imaging Neuroscience January 1, 2026 Hagar Tal, Winson F. Z. Yang, Matthew D. Sacchet

Neurofeedback (NF) has been proposed as a tool to support meditation practice, but a systematic review mapping the field across clinical and non-clinical contexts reveals that most studies are proof-of-concept and vary widely in design, implementation, and outcome measures. While NF consistently modulates neural activity, evidence for corresponding improvements in behavior, phenomenology, or transferable meditative skills remains limited. The review concludes that additional research is essential to determine whether NF can help practitioners overcome common meditative barriers, such as anxiety and self-doubt, and accelerate meditative development from novice to advanced meditators.

Enhancing Meditative Development with Transcranial Focused Ultrasound: A Mixed-Methods Phenomenological Study of Neuromodulation in Experienced Meditators During a Ten-Day Retreat

October 8, 2025 Sebastian Ehmann, Brian Lord, Erica Cook et al. preprint

Inhibiting the posterior cingulate cortex with transcranial focused ultrasound during a ten-day silent retreat enhanced meditative qualities such as equanimity, concentration, and sensory clarity. Twenty-eight meditators received two stimulation sessions and reported significant increases in trait mindfulness, nondual awareness, and interoceptive body listening. Qualitative reports showed consistent differences between stimulation and non-stimulation days, including shifts in self-perception and cathartic emotional release. The effects often interacted with participants' ongoing psychological challenges, suggesting tFUS may increase baseline equanimity and support meditative development. Implementation was feasible but required logistical planning; limitations include the quasi-experimental design and reliance on self-reports.

Development of a Digital Intervention for Psychedelic Preparation (DIPP): a theory- and person-centred approach

November 22, 2023 Rosalind McAlpine, Katarina Krajnović, Maisha M. Khan et al. preprint

A self-directed, 21-day digital course (Digital Intervention for Psychedelic Preparation, DIPP) was developed to help people prepare for psychedelic experiences. The course is based on a four-factor model of psychedelic preparedness: Knowledge-Expectation, Psychophysical-Readiness, Safety-Planning, and Intention-Preparation. It includes daily meditation, weekly exercises, and mood tracking. Development followed the UK Medical Research Council framework for complex interventions and used a person-centred, co-design approach. Interviews with 19 past retreat attendees and co-design workshops with 28 current retreat attendees shaped the intervention. DIPP offers a scalable, digital solution to enhance preparedness, aiming to limit adverse reactions and improve therapeutic benefits.

The Effects of Serotonergic Psychedelics on Neural Activity: A Meta-Analysis of Task-Based Functional Neuroimaging Studies

European Psychiatry March 1, 2023 J. H. Shepherd, C.t.m. Baten, A. C. Klassen et al.

Serotonergic psychedelics such as LSD, psilocybin, and MDMA significantly alter neural activation in several regions of the cerebral cortex and basal ganglia. Some effects are common across these drugs, while others are unique to each substance. This meta-analysis combined functional MRI studies of both clinical and healthy participants, using multilevel kernel density analysis with ensemble thresholding. The findings clarify the functional neuroanatomy associated with these drugs and may guide future research into their therapeutic and adverse effects, particularly for emerging psychiatric treatments.