This double-blind placebo-controlled study (n=25) assessed whether a change in anticorrelated networks (default mode network (DMN)/salience network (SN)) underlies the peak effects of LSD (100μg) using fMRI. Inhibitory effective connectivity from the SN to DMN became excitatory, and inhibitory effective connectivity from DMN to DAN decreased under the peak effect of LSD suggesting that diminution of the functional anticorrelation between resting state networks that may be a key neural mechanism of LSD and underlie ego dissolution.
“Background Classic psychedelic-induced ego dissolution involves a shift in the sense of self and blurring of boundary between the self and the world. A similar phenomenon is identified in psychopathology and is associated to the balance of anticorrelated activity between the default mode network (DMN) – which directs attention inwards – and the salience network (SN) – which recruits the dorsal attention network (DAN) to direct attention outward.
Methods To test whether change in anticorrelated networks underlie the peak effects of LSD, we applied dynamic causal modeling to infer effective connectivity of resting state functional MRI scans from a study of 25 healthy adults who were administered 100μg of LSD, or placebo.
Results We found that inhibitory effective connectivity from the SN to DMN became excitatory, and inhibitory effective connectivity from DMN to DAN decreased under the peak effect of LSD.
Conclusions The effective connectivity changes we identify may reflect diminution of the functional anticorrelation between resting state networks that may be a key neural mechanism of LSD and underlie ego dissolution. Our findings suggest changes to sense of self and subject-object boundaries across different states of consciousness may depend upon the organised balance of effective connectivity of resting state networks.”
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August 6, 2022
Authors associated with this publication with profiles on BlossomFranz Vollenweider
Franz X. Vollenweider is one of the pioneering psychedelics researchers, currently at the University of Zurich. He is also the director of the Heffter (sponsored) Research Center Zürich for Consciousness Studies (HRC-ZH).
Katrin Preller is one of the upcoming researchers, currently at the University of Zurich and Yale University, and is focused on the neurobiology and pharmacology of psychedelics.
Institutes associated with this publicationMonash University
The Clinical Psychedelic Research Lab at Monash University is Australia's first research group dedicated to the study of psychedelics.
University of Zurich
Within the Department of Psychiatry, Psychotherapy and Psychosomatics at the University of Zurich, Dr Mialn Scheidegger is leading team conducting psychedelic research and therapy development.