arXiv subjects

Michael Lifshitz

Publications and source records attributed to Michael Lifshitz.

4 recordsLinked to original sources

arXiv2026

The Complex Brain Hypothesis: Resolving the Entropy-Content Conundrum in Minimal Phenomenal Experience

Minimal Phenomenal Experiences (MPEs) are states of consciousness in which wakefulness is preserved but phenomenal content is low or absent. The Entropic Brain Hypothesis (EBH) is a model of conscious processes that regards the entropy of spontaneous brain activity as a marker of 'phenomenal richness', exemplified by high-content psychedelic experiences (HCPEs). Yet recent human neuroimaging studies of MPEs induced by meditation -- and possibly 5-MeO-DMT -- suggest that these states, defined by their phenomenological simplicity, also show signs of increased neurophysiological entropy. This presents a conundrum for the EBH: brain entropy is elevated with increased and decreased richness of the phenomenal experience. Here, we put forward the Complex Brain Hypothesis (CBH), which proposes that the richness of experience differentiating MPEs from HCPEs is better indexed by complexity than by entropy. We argue that brain complexity is modulated by the grain of inference through which the brain resolves uncertainty: some HCPEs exemplify a fine-grained regime, in which loosened constraints amplify fluctuations into proliferating content, whereas some MPEs exemplify a coarse-grained regime, in which a simpler model dissolves variety into an experience of 'contentless' awareness. Both regimes can be associated with elevated brain entropy, but they diverge in phenomenology and perturbational signatures. By resolving the entropy-content conundrum, the CBH refines the EBH and highlights MPEs as an important test case for computational theories of consciousness.

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arXiv2025

Meditative absorption shifts brain dynamics toward criticality

Criticality describes a regime between order and chaos that supports flexible yet stable information processing. Here we examine whether neural dynamics can be volitionally shifted toward criticality through the self-regulation of attention. We examined ten experienced practitioners of meditation during a 10-day retreat, comparing refined states of meditative absorption, called the jhanas, to regular mindfulness of breathing. We collected electroencephalography (EEG) and physiological data during these practices and quantified the signal's dynamical properties using Lempel-Ziv complexity, signal entropy, chaoticity and long-range temporal correlations. In addition, we estimated perturbational sensitivity using a global auditory oddball mismatch negativity (MMN) during meditation. Relative to mindfulness, jhana was associated with pronounced self-reported sensory fading, slower respiration, higher neural signal diversity across multiple measures, reduced chaoticity, and enhanced MMN amplitude over frontocentral sites. Spectral analyses showed a flatter aperiodic one over f component and a frequency-specific reorganization of long-range temporal correlations. Together, increased diversity with reduced chaoticity and heightened deviance detection indicate a shift toward a metastable, near-critical regime during jhana. We propose an overlap of the phenomenology of jhana with minimal phenomenal experiences in terms of progressive attenuation of sensory content with preserved tonic alertness. Accordingly, our findings suggest that criticality is a candidate neurophysiological marker of the absorptive, minimal-content dimension of the minimal phenomenal experience.

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arXiv2016

Increasing cognitive-emotional flexibility with meditation and hypnosis: The cognitive neuroscience of de-automatization

Meditation and hypnosis both aim to facilitate cognitive-emotional flexibility, i.e., the "de-automatization" of thought and behavior. However, little research or theory has addressed how internal thought patterns might change after such interventions, even though alterations in the internal flow of consciousness may precede externally observable changes in behavior. This chapter outlines three mechanisms by which meditation or hypnosis might alter or reduce automatic associations and elaborations of spontaneous thought: by an overall reduction of the chaining of thoughts into an associative stream; by de-automatizing and diversifying the content of thought chains (i.e., increasing thought flexibility or variety); and, finally, by re-automatizing chains of thought along desired or valued paths (i.e., forming new, voluntarily chosen mental habits). The authors discuss behavioral and cognitive neuroscientific evidence demonstrating the influence of hypnosis and meditation on internal cognition and highlight the putative neurobiological basis, as well as potential benefits, of these forms of de-automatization.

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arXiv2016

Functional neuroanatomy of meditation: A review and meta-analysis of 78 functional neuroimaging investigations

Meditation is a family of mental practices that encompasses a wide array of techniques employing distinctive mental strategies. We systematically reviewed 78 functional neuroimaging (fMRI and PET) studies of meditation, and used activation likelihood estimation to meta-analyze 257 peak foci from 31 experiments involving 527 participants. We found reliably dissociable patterns of brain activation and deactivation for four common styles of meditation (focused attention, mantra recitation, open monitoring, and compassion/loving-kindness), and suggestive differences for three others (visualization, sense-withdrawal, and non-dual awareness practices). Overall, dissociable activation patterns are congruent with the psychological and behavioral aims of each practice. Some brain areas are recruited consistently across multiple techniques - including insula, pre/supplementary motor cortices, dorsal anterior cingulate cortex, and frontopolar cortex - but convergence is the exception rather than the rule. A preliminary effect-size meta-analysis found medium effects for both activations (d = .59) and deactivations (d = -.74), suggesting potential practical significance. Our meta-analysis supports the neurophysiological dissociability of meditation practices, but also raises many methodological concerns and suggests avenues for future research.

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