Characterizing Complex Networks Using Entropy-Degree Diagrams: Unveiling Changes in Functional Brain Connectivity Induced by Ayahuasca
Aline Viol, Fernanda Palhano-Fontes, Heloisa Onias, Dráulio Barros de Araújo, Philipp Hövel, G. M. Viswanathan
Entropy January 30, 2019 DOI: 10.3390/e21020128 via OpenAlex
Summary
AI-generated from the abstractA new network metric, geodesic entropy, measures the Shannon entropy of distances from one node to all others in a network, characterizing how much influence a node has based on the overall network structure. Applied to resting-state functional brain networks of humans, the metric differentiates ordinary consciousness from the altered state induced by Ayahuasca ingestion. On average, functional networks from subjects in the altered state show larger geodesic entropy than those in the ordinary state, suggesting the metric can reveal differences in brain network organization across states of consciousness.
Study at a glance
| Characteristics | Observational study Peer reviewed |
|---|---|
| Population | Human subjects in resting state |
| Topics | Ayahuasca |
| Keywords | Functional connectivity Statistical physics Degree music Computer science |
| Citations | 37 |
| Key finding | Functional brain networks from subjects in the Ayahuasca-altered state have, on average, a larger geodesic entropy compared to the ordinary state. |
Abstract
With the aim of further advancing the understanding of the human brain’s functional connectivity, we propose a network metric which we term the geodesic entropy. This metric quantifies the Shannon entropy of the distance distribution to a specific node from all other nodes. It allows to characterize the influence exerted on a specific node considering statistics of the overall network structure. The measurement and characterization of this structural information has the potential to greatly improve our understanding of sustained activity and other emergent behaviors in networks. We apply this method to study how the psychedelic infusion Ayahuasca affects the functional connectivity of the human brain in resting state. We show that the geodesic entropy is able to differentiate functional networks of the human brain associated with two different states of consciousness in the awaking resting state: (i) the ordinary state and (ii) a state altered by ingestion of the Ayahuasca. The functional brain networks from subjects in the altered state have, on average, a larger geodesic entropy compared to the ordinary state. Finally, we discuss why the geodesic entropy may bring even further valuable insights into the study of the human brain and other empirical networks.