Using three different neuroimaging techniques (ASL, BOLD, MEG), this single-blind, placebo-controlled study highlighted the neurological underpinnings of the LSD/psychedelic (75μg) experience.
Abstract of Neural correlates of the LSD experience revealed by multimodal neuroimaging
“Lysergic acid diethylamide (LSD) is the prototypical psychedelic drug, but its effects on the human brain have never been studied before with modern neuroimaging. Here, three complementary neuroimaging techniques: arterial spin labeling (ASL), blood oxygen level-dependent (BOLD) measures, and magnetoencephalography (MEG), implemented during resting state conditions, revealed marked changes in brain activity after LSD that correlated strongly with its characteristic psychological effects. Increased visual cortex cerebral blood flow (CBF), decreased visual cortex alpha power, and a greatly expanded primary visual cortex (V1) functional connectivity profile correlated strongly with ratings of visual hallucinations, implying that intrinsic brain activity exerts a greater influence on visual processing in the psychedelic state, thereby defining its hallucinatory quality. LSD’s marked effects on the visual cortex did not significantly correlate with the drug’s other characteristic effects on consciousness. Rather, decreased connectivity between the parahippocampus and retrosplenial cortex (RSC) correlated strongly with ratings of “ego-dissolution” and “altered meaning,” implying the importance of this particular circuit for the maintenance of “self” or “ego” and its processing of “meaning.” Strong relationships were also found between the different imaging metrics, enabling firmer inferences to be made about their functional significance. This uniquely comprehensive examination of the LSD state represents an important advance in scientific research with psychedelic drugs at a time of growing interest in their scientific and therapeutic value. The present results contribute important new insights into the characteristic hallucinatory and consciousness-altering properties of psychedelics that inform on how they can model certain pathological states and potentially treat others.”
Authors: Robin L. Carhart-Harris, Suresh Muthukumaraswamy, Leor Roseman, Mendel Kaelen, Wouter Droog, Kevin Murphy, Enzo Tagliazucchi, Eduardo E. Schenberg, Timothy Nest, Csaba Orban, Robert Leech, Luke T. Williams, Tim M. Williams, Mark Bolstridge, Ben Sessa, John McGonigle, Martin I. Sereno, David E. Nichols, Peter J. Hellyer, Peter Hobden, John Evans, Krish D. Singh, Richard G. Wise, H. Valerie Curran, Amanda Feilding & David J. Nutt
Notes on Neural correlates of the LSD experience revealed by multimodal neuroimaging
This study was sponsored, in part, by the Beckley Foundation.
The same participants were also included in Timmermann et al. (2017) which used MEG and an auditory test further study brain connectivity under LSD.
Summary of Neural correlates of the LSD experience revealed by multimodal neuroimaging
Lysergic acid diethylamide (LSD), the prototypical “psychedelic,” alters brain activity and produces profound, sometimes life-changing experiences. The results have implications for the neurobiology of consciousness and potential applications of LSD in psychological research.
Three complementary neuroimaging techniques were implemented during resting state conditions to study the effects of LSD on the human brain. The results revealed that increased visual cortex cerebral blood flow, decreased visual cortex alpha power, and a greatly expanded primary visual cortex functional connectivity profile correlated strongly with ratings of visual hallucinations.
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Neural correlates of the LSD experience revealed by multimodal neuroimaging
https://doi.org/10.1073/pnas.1518377113
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Cite this paper (APA)
Carhart-Harris, R. L., Muthukumaraswamy, S., Roseman, L., Kaelen, M., Droog, W., Murphy, K., ... & Nutt, D. J. (2016). Neural correlates of the LSD experience revealed by multimodal neuroimaging. Proceedings of the National Academy of Sciences, 113(17), 4853-4858.
Study details
Compounds studied
LSD
Topics studied
Neuroscience
Study characteristics
Placebo-Controlled
Single-Blind
Within-Subject
Bio/Neuro
Participants
15
Humans
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