Imperial College London
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DrLeorRoseman

Faculty of Medicine, Department of Brain Sciences

Honorary Senior Lecturer
 
 
 
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Contact

 

leor.roseman13

 
 
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Location

 

Commonwealth BuildingHammersmith Campus

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Summary

 

Publications

Citation

BibTex format

@article{Mediano:2020:10.1101/2020.11.01.356071,
author = {Mediano, PAM and Rosas, FE and Timmermann, C and Roseman, L and Nutt, DJ and Feilding, A and Kaelen, M and Kringelbach, ML and Barrett, AB and Seth, AK and Muthukumaraswamy, S and Bor, D and Carhart-Harris, RL},
doi = {10.1101/2020.11.01.356071},
title = {Effects of external stimulation on psychedelic state neurodynamics},
url = {http://dx.doi.org/10.1101/2020.11.01.356071},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - <jats:p>Recent findings have shown that psychedelics reliably enhance brain entropy (understood as neural signal diversity), and this effect has been associated with both acute and long-term psychological outcomes such as personality changes. These findings are particularly intriguing given that a decrease of brain entropy is a robust indicator of loss of consciousness (e.g. from wakefulness to sleep). However, little is known about how context impacts the entropy-enhancing effect of psychedelics, which carries important implications for how it can be exploited in, for example, psychedelic psychotherapy. This article investigates how brain entropy is modulated by stimulus manipulation during a psychedelic experience, by studying participants under the effects of LSD or placebo, either with gross state changes (eyes closed vs. open) or different stimulus (no stimulus vs. music vs. video). Results show that while brain entropy increases with LSD in all the experimental conditions, it exhibits largest changes when subjects have their eyes closed. Furthermore, brain entropy changes are consistently associated with subjective ratings of the psychedelic experience, but this relationship is disrupted when participants are viewing video — potentially due to a “competition” between external stimuli and endogenous LSD-induced imagery. Taken together, our findings provide strong quantitative evidence for the role of context in modulating neural dynamics during a psychedelic experience, underlining the importance of performing psychedelic psychotherapy in a suitable environment. Additionally, our findings put into question simplistic interpretations of brain entropy as a direct neural correlate of conscious level.</jats:p><jats:sec><jats:title>Significance Statement</jats:title><jats:p>The effects of psychedelic substances on conscious experience can be substantially affected by contextual factors, which play a critical role
AU  - Mediano,PAM
AU  - Rosas,FE
AU  - Timmermann,C
AU  - Roseman,L
AU  - Nutt,DJ
AU  - Feilding,A
AU  - Kaelen,M
AU  - Kringelbach,ML
AU  - Barrett,AB
AU  - Seth,AK
AU  - Muthukumaraswamy,S
AU  - Bor,D
AU  - Carhart-Harris,RL
DO  - 10.1101/2020.11.01.356071
PY  - 2020///
TI  - Effects of external stimulation on psychedelic state neurodynamics
UR  - http://dx.doi.org/10.1101/2020.11.01.356071
ER  -
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