Comparing structure–function relationships in brain networks using EEG and fNIRS

Rosmary Blanco, Maria Giulia Preti, Cemal Koba,  Dimitri Van De Ville, Alessandro Crimi 

Understanding how structural and functional brain networks interact is key to uncovering the principles behind large-scale brain organization. While techniques like functional near-infrared spectroscopy (fNIRS) hold promise for studying these relationships, their full potential remains largely untapped. In this research, we analyzed data from 18 participants using simultaneous EEG and fNIRS recordings to examine how structural and functional connectivity align at different timescales, both at rest and during motor imagery tasks—an area still not fully explored. By applying graph signal processing methods, we evaluated differences in structure–function coupling between hemodynamic (fNIRS) and electrical (EEG) signals under varying brain states. TO: We evaluated differences in the structure–function relationship between hemodynamic (fNIRS) and electrical (EEG) networks by applying graph signal processing. Results show that fNIRS structure–function coupling resembles slower-frequency EEG coupling at rest, with variations across brain states and oscillations. Locally, the relationship is heterogeneous, following the unimodal to transmodal gradient. Discrepancies between EEG and fNIRS are noted, particularly in the frontoparietal network. Cross-band representations of neural activity revealed lower correspondence between electrical and hemodynamic activity in the transmodal cortex, irrespective of brain state, while showing specificity for the somatomotor network during a motor imagery task. Overall, these findings initiate a multimodal comprehension of structure–function relationship and brain organization when using affordable functional brain imaging. 

Autors: Rosmary Blanco, Maria Giulia Preti, Cemal Koba,  Dimitri Van De Ville, Alessandro Crimi 

DOI: 10.1038/s41598-024-79817-x