Brain Imaging Of Psychedelic State Shows Resemblance To REM Sleep

Dr. Enzo Tagliazucchi: Goethe University,  Interview with:
Dr. Enzo Tagliazucchi:
Goethe University, Germany


MedicalResearch: What are the main findings of the study?

Dr. Tagliazucchi: The main finding of the study is the objective discovery of an “expanded mind” and a more “unpredictable mind” after the ingestion of a psychedelic (in this case psilocybin, a compound found in “magic mushrooms”). We say that this discovery is objective since it comes from a brain imaging experiment (using magnetic resonance imaging) instead from reports of drug users, which could be unreliable or exaggerated.

Also, comparing our results with those obtained in brain imaging experiments of REM sleep (the phase of sleep when we dream), we found a remarkable resemblance between both brain states. Thus, the psychedelic state perhaps has more to do with a “dream-like” state than with normal, resting wakefulness.

MedicalResearch: Were any of the findings unexpected?

Dr. Tagliazucchi: In part, yes. The psychedelic state is strongly associated with visual and auditory hallucinations and distortions (such as geometric patterns, for instance) and other sensory alterations (such as mixing of the senses or synesthesia). However, all our results point to “high-level” alterations in brain activity, this is, not alterations in the way we perceive the world around us, but deeper alterations in the way we put our thoughts together over time. Thus, psychedelics allow us not only to see or hear differently but also to “think differently”.

MedicalResearch: What should clinicians and patients take away from your report?

Dr. Tagliazucchi: Psilocybin is currently being explored as a treatment for depression, anxiety and other related disorders. Our results reveal a general effect of psilocybin on brain activity during rest (which is perhaps shared by other psychedelics). By understanding better the influence of psilocybin on the functional architecture of the human brain, we will be closer to revealing the specific effects involved in its role as anti-depressant. 

MedicalResearch: What recommendations do you have for future research as a result of this study?

Dr. Tagliazucchi: It is necessary to study the human brain as a dynamic entity continuously evolving over time. Most studies to date treat the brain as a static object whose properties (such as connectivity) remain unchanged over several minutes. It is only by defining “brain states” and studying the temporal succession of states (a “train of thought”) that we can reveal some specific effects of psilocybin on the human brain. Otherwise, the effects would remain hidden.


Enhanced Repertoire of Brain Dynamical States During the Psychedelic Experience
Tagliazucchi, E. et al.

Tagliazucchi, E., Carhart-Harris, R., Leech, R., Nutt, D. and Chialvo, D. R. (2014), Enhanced repertoire of brain dynamical states during the psychedelic experience. Hum. Brain Mapp.. doi: 10.1002/hbm.22562