Imperial College London

Professor Robin Carhart-Harris

Faculty of MedicineDepartment of Brain Sciences

Visiting Professor
 
 
 
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Contact

 

+44 (0)20 7594 7992r.carhart-harris

 
 
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Assistant

 

Miss Bruna Cunha +44 (0)20 7594 7992

 
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Location

 

Burlington DanesHammersmith Campus

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Summary

 

Publications

Citation

BibTex format

@unpublished{Ruffini:2022:10.1101/2022.08.27.505518,
author = {Ruffini, G and Damiani, G and Lozano-Soldevilla, D and Deco, N and Rosas, FE and Kiani, NA and Ponce-Alvarez, A and Kringelbach, ML and Carhart-Harris, R and Deco, G},
doi = {10.1101/2022.08.27.505518},
title = {LSD-induced increase of Ising temperature and algorithmic complexity of brain dynamics},
url = {http://dx.doi.org/10.1101/2022.08.27.505518},
year = {2022}
}

RIS format (EndNote, RefMan)

TY  - UNPB
AB - <jats:title>Abstract</jats:title><jats:p>A topic of growing interest in computational neuroscience is the discovery of fundamental principles underlying global dynamics and the self-organization of the brain. In particular, the notion that the brain operates near criticality has gained considerable support, and recent work has shown that the dynamics of different brain states may be modeled by pairwise maximum entropy Ising models at various distances from a phase transition, i.e., from criticality. Here we aim to characterize two brain states (psychedelics-induced and placebo) as captured by functional magnetic resonance imaging (fMRI), with features derived from the Ising spin model formalism (system temperature, critical point, susceptibility) and from algorithmic complexity. We hypothesized, along the lines of the entropic brain hypothesis, that psychedelics drive brain dynamics into a more disordered state at a higher Ising temperature and increased complexity. We analyze resting state blood-oxygen-level-dependent (BOLD) fMRI data collected in an earlier study from fifteen subjects in a control condition (placebo) and during ingestion of lysergic acid diethylamide (LSD). Working with the automated anatomical labeling (AAL) brain parcellation, we first create “archetype” Ising models representative of the entire dataset (global) and of the data in each condition. Remarkably, we find that such archetypes exhibit a strong correlation with an average structural connectome template obtained from dMRI (<jats:italic>r</jats:italic>= 0.6). We compare the archetypes from the two conditions and find that the Ising connectivity in the LSD condition is lower than the placebo one, especially at homotopic links (interhemispheric connectivity), reflecting a significant decrease of homotopic functional connectivity in the LSD condition. The global archetype is then personalized for each individual and condition by adjusting the system
AU - Ruffini,G
AU - Damiani,G
AU - Lozano-Soldevilla,D
AU - Deco,N
AU - Rosas,FE
AU - Kiani,NA
AU - Ponce-Alvarez,A
AU - Kringelbach,ML
AU - Carhart-Harris,R
AU - Deco,G
DO - 10.1101/2022.08.27.505518
PY - 2022///
TI - LSD-induced increase of Ising temperature and algorithmic complexity of brain dynamics
UR - http://dx.doi.org/10.1101/2022.08.27.505518
ER -