Human electromagnetic and haemodynamic networks systematically converge in unimodal cortex and diverge in transmodal cortex

Author: Golia Shafiei1, Sylvain Baillet1, Bratislav Misic1
1 McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, Canada.
Conference/Journal: PLoS Biol
Date published: 2022 Aug 1
Other: Volume ID: 20 , Issue ID: 8 , Pages: e3001735 , Special Notes: doi: 10.1371/journal.pbio.3001735. , Word Count: 188

Whole-brain neural communication is typically estimated from statistical associations among electromagnetic or haemodynamic time-series. The relationship between functional network architectures recovered from these 2 types of neural activity remains unknown. Here, we map electromagnetic networks (measured using magnetoencephalography (MEG)) to haemodynamic networks (measured using functional magnetic resonance imaging (fMRI)). We find that the relationship between the 2 modalities is regionally heterogeneous and systematically follows the cortical hierarchy, with close correspondence in unimodal cortex and poor correspondence in transmodal cortex. Comparison with the BigBrain histological atlas reveals that electromagnetic-haemodynamic coupling is driven by laminar differentiation and neuron density, suggesting that the mapping between the 2 modalities can be explained by cytoarchitectural variation. Importantly, haemodynamic connectivity cannot be explained by electromagnetic activity in a single frequency band, but rather arises from the mixing of multiple neurophysiological rhythms. Correspondence between the two is largely driven by MEG functional connectivity at the beta (15 to 29 Hz) frequency band. Collectively, these findings demonstrate highly organized but only partly overlapping patterns of connectivity in MEG and fMRI functional networks, opening fundamentally new avenues for studying the relationship between cortical microarchitecture and multimodal connectivity patterns.

PMID: 35914002 DOI: 10.1371/journal.pbio.3001735