Progress in brain research
January 1, 2019
Tracy Brandmeyer, Arnaud Delorme, Helané Wahbeh
143 citations
Meditation research has grown substantially over the last 30 years, emerging from contemplative and spiritual traditions. This chapter reviews meditation classifications, which remain varied and subjective, and suggests broader multidimensional models for future improvement. Phenomenological studies, though few, are increasing and link subjective experience to neurophysiology. EEG oscillatory studies are inconclusive due to heterogeneity in meditation styles and practitioners. Neuroimaging reveals common patterns during meditation and in long-term practitioners, reflecting general similarities, but most patterns differ across traditions. Research on attention and emotion regulation mechanisms is discussed. Evidence shows positive benefits for stress reduction, anxiety, depression, and pain in some clinical populations, though methodological and conceptual issues remain.
Biological Psychiatry Global Open Science
October 17, 2024
Nicco Reggente, Christian Kothe, Tracy Brandmeyer et al.
15 citations
Decoding self-reported meditative depth from EEG recordings is feasible. Expert Vipassana meditators (34 people) reported their depth on a 1–5 scale during two sessions, using either traditional probing or a novel spontaneous emergence method. Machine learning models fused spatial, spectral, and connectivity information from theta, alpha, and gamma bands to predict depth across unseen sessions. The spontaneous emergence method produced more frequent reports and correlated better with post-session outcomes than probing. No single EEG channel or default mode network region captured the complex neural dynamics; multivariate patterns were necessary. The findings suggest potential improvements for neurofeedback in meditation.
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.
January 31, 2024
Nicco Reggente, Christian Kothe, Tracy Brandmeyer et al.
4 citations
preprint
Meditation depth can be decoded from brain activity measured by EEG in expert Vipassana meditators. A novel 'spontaneous emergence' method, where meditators report their depth on a 1-5 scale only when they feel a shift, outperformed traditional periodic probing and correlated more strongly with post-session outcomes. A new machine learning approach that fuses spatial, spectral, and connectivity information achieved the best accuracy in predicting self-reported depth across separate sessions. Conventional EEG channel-level methods and default mode network regions were insufficient to capture the complex neural dynamics. The findings demonstrate the feasibility of decoding personally defined meditative depth and suggest that 'spontaneous emergence' is a less obtrusive, ecologically valid sampling method.
February 17, 2017
Tracy Brandmeyer
Expert meditation practice is associated with a reduced frequency of spontaneous thought, and meditation training reduces the mind's tendency to wander, leading to longer periods of meditative absorption. Increases in theta activity (4-7 Hz) over frontal midline regions and alpha activity (9-12 Hz) focused on the somatosensory cortex appear to be markers of sustained meditative states compared to mind wandering. A neurofeedback protocol training frontal midline theta activity (3.5-6.5 Hz) showed that subjects receiving real neurofeedback could significantly modulate their theta activity over eight sessions compared to controls, with additional modulations in alpha and beta bands and improvements in executive function measures.