Cross-Scale Dynamicity of Entropy and Connectivity in the Sleeping Brain

Kung, Yi-Chia; Li, Chia-Wei; Hsiao, Fan-Chi; Tsai, Pei-Jung; Chen, Shuo; Li, Mingkang; Lee, Hsin Chien; Chang, Chun‐Yen; Wu, Changwei; Lin, Ching-Po

doi:10.1089/brain.2021.0174

Cited by 4 publications

(6 citation statements)

References 64 publications

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“…Firstly, there is now substantial evidence to support the entropy brain principle, in terms of increased brain entropy in relation to the psychedelic state (Carhart-Harris et al, 2014), and other flexible mental states such as Rapid Eyes Movement Sleep (Lee et al, 2013) and dreaming (Nardelli et al, 2019), jazz improvisation (Simon, 2005), and deep meditation (Kumar et al, 2022;Li, Hu, Zhang and Zhang, 2011) -and reduced brain entropy under states of reduced consciousness such as deep sleep (Kung et al, 2022), the anaesthetized state (Fuentes et al, 2022) and disorders of consciousness (Visani et al, 2022). More specific support for REBUS can be found in perceptual changes under psychedelics (Kaiser and Gold, 1973), altered beliefs under (Safron, 2020) and after psychedelics (McGovern et al, 2022;Timmermann et al, 2021) as well as other trait changes (Aday et al, 2021) as well as decreased top-down processing seen through such metrics as travelling waves (Alamia et al, 2020), dynamic causal modelling (Muthukumaraswamy et al, 2013), and transfer entropy (Wang, Chen and Chen, 2022;Vicente et al, 2011) reduced hierarchical organisation under psychedelics (Girn et al 2022) and the flattening of the brain's energy landscape under (Singleton et al 2021) and after (Daws et al 2022) psychedelics.…”

Section: Neuroscience Of Psychedelics: Psychedelics As Destabilisers ...mentioning

confidence: 99%

Pattern Breaking: A Complex Systems Approach to Psychedelic Medicine

Hipólito¹,

Mago²,

Rosas³

et al. 2022

Preprint

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There is growing evidence for the safety and efficacy of psychedelic therapy in mental health care. What is less understood however, is how psychedelics act to yield therapeutic results. In this paper we propose that psychedelics act as destabilisers — both in a psychological and a neurophysiological sense. Our proposed framework builds on the ‘entropic brain’ hypothesis, according to which psychedelics increase the entropy of spontaneous cortical activity and, in parallel, the richness or depth of content of psychological experience. The so-called ‘RElaxed Beliefs Under pSychedelics’ (REBUS) model is a predictive-coding inspired extension to this hypothesis, which states that psychedelics’ entropic action is paralleled by a relaxation of prior assumptions. Here we adopt a complex systems theory (CST) perspective, proposing that psychedelics act as destabilisers of excessively reinforced fixed points — or ‘attractors’ — which translates as the breaking of excessively reinforced or overweighted patterns of thinking or behaving. Our CST approach explains how psychedelic-induced increases in brain entropy destabilise neurophysiological set-points that are synonymous with overweighted priors, thereby augmenting and enriching the account given by REBUS. We believe that this perspective helps inspire conceptualisations of psychedelic psychotherapy — bearing relevance both to the peak psychedelic experience and subsequent sub-acute period of potential recovery. We discuss implications for risk mitigation and treatment optimization in psychedelic medicine.

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Section: Neuroscience Of Psychedelics: Psychedelics As Destabilisers ...mentioning

confidence: 99%

Pattern Breaking: A Complex Systems Approach to Psychedelic Medicine

Hipólito¹,

Mago²,

Rosas³

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…2011 , Kumar et al. 2021 )—and reduced brain entropy under states of reduced consciousness such as deep sleep ( Kung et al 2022 ), the anaesthetized state ( Fuentes et al 2022 ) and disorders of consciousness ( Visani et al 2022 ). More specific support for REBUS can be found in perceptual changes under psychedelics ( Kaiser and Gold 1973 ), altered beliefs under ( Safron 2020 ) and after psychedelics ( Timmermann et al.…”

Section: Shaking Up the Brain: How Psychedelics Act As Neurological D...mentioning

confidence: 99%

Pattern breaking: a complex systems approach to psychedelic medicine

Hipólito

Mago

Rosas

et al. 2023

Neuroscience of Consciousness

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Recent research has demonstrated the potential of psychedelic therapy for mental health care. However, the psychological experience underlying its therapeutic effects remains poorly understood. This paper proposes a framework that suggests psychedelics act as destabilizers, both psychologically and neurophysiologically. Drawing on the ‘entropic brain’ hypothesis and the ‘RElaxed Beliefs Under pSychedelics’ model, this paper focuses on the richness of psychological experience. Through a complex systems theory perspective, we suggest that psychedelics destabilize fixed points or attractors, breaking reinforced patterns of thinking and behaving. Our approach explains how psychedelic-induced increases in brain entropy destabilize neurophysiological set points and lead to new conceptualizations of psychedelic psychotherapy. These insights have important implications for risk mitigation and treatment optimization in psychedelic medicine, both during the peak psychedelic experience and during the subacute period of potential recovery.

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“…See Supplementary Table S1 for more details about the previous studies. Previous fMRI studies have reported reduced brain entropy in other states of “reduced consciousness”, including NREM sleep 37 , minimal-consciousness 38 , and anaesthesia 39 , whereas other studies have shown increased brain entropy following caffeine 40 and Salvinorin A intake 41 .…”

Section: Introductionmentioning

confidence: 96%

“…*Investigates persisting effects at 1 week and 1 month post-psilocybin administration † at thresholds producing a mean degree of[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] …”

mentioning

confidence: 99%

Navigating the chaos of psychedelic fMRI brain-entropy via multi-metric evaluations of acute psilocybin effects

McCulloch

Olsen

Ozenne

et al. 2023

Preprint

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Investigations into the acute effects of psychedelics on brain imaging have emphasised increased 'brain entropy' as a potential neural correlate. To date, 12 previous studies have reported brain entropy effects, each reporting a single and unique metric, none of which have been examined in an independent cohort. Here we evaluated acute psilocybin effects on these 12 brain entropy metrics in an independent cohort of 28 healthy participants. Following a single psilocybin dose, participants completed pre/post resting-state BOLD fMRI scans (28 pre-drug, 93 post-drug scans during the acute drug effects). Each scan was accompanied by a plasma sample to quantify plasma drug levels and estimate brain serotonin 2A receptor occupancy, as well as a rating of subjective drug intensity. We assessed relations between brain entropy and these measures with linear mixed-effects models. There was a significantly positive association for Shannon entropy of path-length and instantaneous correlation distributions and divergent associations of network-wise sample entropy at varying time-scales. We did not observe significant psilocybin effects for seven of 12 brain-entropy metrics. Whole-brain entropy metrics showed limited correlations between each other. Our observations suggest a nuanced acute effect of psychedelics on brain entropy, underscoring the need for reproducing effects. The variable effects and limited inter-metric correlation undermines the generalisability of 'brain entropy' as a singular construct. Future studies in clinical cohorts are crucial to elucidate the link between these metrics and therapeutic effects of psychedelics.

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Cross-Scale Dynamicity of Entropy and Connectivity in the Sleeping Brain

Cited by 4 publications

References 64 publications

Pattern Breaking: A Complex Systems Approach to Psychedelic Medicine

Pattern Breaking: A Complex Systems Approach to Psychedelic Medicine

Pattern breaking: a complex systems approach to psychedelic medicine

Navigating the chaos of psychedelic fMRI brain-entropy via multi-metric evaluations of acute psilocybin effects

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