Shannon entropy of brain functional complex networks under the influence of the psychedelic Ayahuasca
Aline Viol, Fernanda Palhano-Fontes, Heloisa Onias, Draulio B. de Araujo, G. M. Viswanathan
arXiv Preprint Archive November 1, 2016 preprint
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort |
|---|---|
| Population | Human subjects |
| Intervention | Ayahuasca |
| Topics | Ayahuasca |
| Keywords | Psychedelics Neuroscience q-bio.nc Consciousness research Brain networks |
| Citations | 154 |
| Key findings | Ayahuasca ingestion increases the Shannon entropy of the brain's functional connectivity degree distribution, along with increased local and decreased global network integration. |
Abstract
The entropic brain hypothesis holds that the key facts concerning psychedelics are partially explained in terms of increased entropy of the brain's functional connectivity. Ayahuasca is a psychedelic beverage of Amazonian indigenous origin with legal status in Brazil in religious and scientific settings. In this context, we use tools and concepts from the theory of complex networks to analyze resting state fMRI data of the brains of human subjects under two distinct conditions: (i) under ordinary waking state and (ii) in an altered state of consciousness induced by ingestion of Ayahuasca. We report an increase in the Shannon entropy of the degree distribution of the networks subsequent to Ayahuasca ingestion. We also find increased local and decreased global network integration. Our results are broadly consistent with the entropic brain hypothesis. Finally, we discuss our findings in the context of descriptions of "mind-expansion" frequently seen in self-reports of users of psychedelic drugs.