An implementation of integrated information theory in resting-state fMRI.
Communications Biology July 5, 2023 Idan E Nemirovsky, Nicholas J M Popiel, Jorge Rudas et al.
Integrated Information Theory aims to explain and measure consciousness by quantifying how integrated a system's causal properties are. This work implemented version 3.0 of the theory on functional MRI data from 17 healthy volunteers sedated with propofol. Using the PyPhi software, the measure Φmax was computed and compared with other proposed consciousness metrics: an earlier integrated information version, Granger causality, and correlation-based functional connectivity. Φmax showed varied responses to sedation across different brain networks. Changes in Φmax closely tracked changes in conscious level within the frontoparietal and dorsal attention networks, which support higher-order cognition. The findings offer guidance for future use of these measures in neuroimaging.