In this section
@article{Girn:2020:10.1101/2020.05.01.072314,
author = {Girn, M and Roseman, L and Bernhardt, B and Smallwood, J and Carhart-Harris, R and Spreng, RN},
doi = {10.1101/2020.05.01.072314},
title = {Serotonergic psychedelic drugs LSD and psilocybin reduce the hierarchical differentiation of unimodal and transmodal cortex},
url = {http://dx.doi.org/10.1101/2020.05.01.072314},
year = {2020}
}
TY - JOUR
AB - <jats:title>Abstract</jats:title><jats:p>LSD and psilocybin are serotonergic psychedelic compounds with potential in the treatment of mental health disorders. Past neuroimaging investigations have revealed that both compounds can elicit significant changes to whole-brain functional organization and dynamics. A recent proposal linked past findings into a unified model and hypothesized reduced whole-brain hierarchical organization as a key mechanism underlying the psychedelic state, but this has yet to be directly tested. We applied a non-linear dimensionality reduction technique previously used to map hierarchical connectivity gradients to pharmacological resting-state fMRI data to assess cortical organization in the LSD and psilocybin state. Results supported our primary hypothesis: The principal gradient of cortical connectivity, describing a hierarchy from unimodal to transmodal cortex, was significantly flattened under both drugs relative to their respective placebo conditions. Between-condition contrasts revealed that this was driven by a reduction of functional differentiation at both hierarchical extremes – default and frontoparietal networks at the upper end, and somatomotor at the lower. Gradient-based connectivity mapping confirmed that this was underpinned by increased unimodal-transmodal crosstalk. In addition, LSD-dependent principal gradient changes tracked changes in self-reported ego-dissolution. Results involving the second and third gradient, which respectively represent axes of sensory and executive differentiation, also showed significant alterations across both drugs. These findings provide support for a recent mechanistic model of the psychedelic state relevant to therapeutic applications of psychedelics. More fundamentally, we provide the first evidence that macroscale connectivity gradients are sensitive to a pharmacological manipulation, specifically highlighting an important relationship between cortical organization
AU - Girn,M
AU - Roseman,L
AU - Bernhardt,B
AU - Smallwood,J
AU - Carhart-Harris,R
AU - Spreng,RN
DO - 10.1101/2020.05.01.072314
PY - 2020///
TI - Serotonergic psychedelic drugs LSD and psilocybin reduce the hierarchical differentiation of unimodal and transmodal cortex
UR - http://dx.doi.org/10.1101/2020.05.01.072314
UR - https://doi.org/10.1101/2020.05.01.072314
ER -
