title: Tracking Dynamic Interactions Between Structural and Functional Connectivity: A TMS/EEG-dMRI Study.
abstract: Transcranial magnetic stimulation (TMS) in combination with neuroimaging techniques allows to measure the effects of a direct perturbation of the brain. When coupled with high-density electroencephalography (TMS/hd-EEG), TMS pulses revealed electrophysiological signatures of different cortical modules in health and disease. However, the neural underpinnings of these signatures remain unclear. Here, by applying multimodal analyses of cortical response to TMS recordings and diffusion magnetic resonance imaging (dMRI) tractography, we investigated the relationship between functional and structural features of different cortical modules in a cohort of awake healthy volunteers. For each subject, we computed directed functional connectivity interactions between cortical areas from the source-reconstructed TMS/hd-EEG recordings and correlated them with the correspondent structural connectivity matrix extracted from dMRI tractography, in three different frequency bands (α, β, γ) and two sites of stimulation (left precuneus and left premotor). Each stimulated area appeared to mainly respond to TMS by being functionally elicited in specific frequency bands, that is, β for precuneus and γ for premotor. We also observed a temporary decrease in the whole-brain correlation between directed functional connectivity and structural connectivity after TMS in all frequency bands. Notably, when focusing on the stimulated areas only, we found that the structure-function correlation significantly increases over time in the premotor area controlateral to TMS. Our study points out the importance of taking into account the major role played by different cortical oscillations when investigating the mechanisms for integration and segregation of information in the human brain.
authors.affiliation: 1 Coma Science Group, Cyclotron Research Center & GIGA Research Center, University and University Hospital of Liège , Liège, Belgium .|2 Department of Data-Analysis, University of Ghent , Ghent, Belgium .
authors.forename: Enrico
authors.initials: E
authors.lastname: Amico
authors.affiliation: 1 Coma Science Group, Cyclotron Research Center & GIGA Research Center, University and University Hospital of Liège , Liège, Belgium .
authors.forename: Olivier
authors.initials: O
authors.lastname: Bodart
authors.affiliation: 3 Department of Biomedical and Clinical Sciences "Luigi Sacco, " University of Milan , Milan, Italy .
authors.forename: Mario
authors.initials: M
authors.lastname: Rosanova
authors.affiliation: 1 Coma Science Group, Cyclotron Research Center & GIGA Research Center, University and University Hospital of Liège , Liège, Belgium .|4 Department of Psychiatry, University of Wisconsin , Madison, Wisconsin.
authors.forename: Olivia
authors.initials: O
authors.lastname: Gosseries
authors.affiliation: 1 Coma Science Group, Cyclotron Research Center & GIGA Research Center, University and University Hospital of Liège , Liège, Belgium .
authors.forename: Lizette
authors.initials: L
authors.lastname: Heine
authors.affiliation: 5 Medical Image and Signal Processing Group, Department of Electronics and Information Systems, Ghent University-IBBT , Ghent, Belgium .
authors.forename: Pieter
authors.initials: P
authors.lastname: Van Mierlo
authors.affiliation: 1 Coma Science Group, Cyclotron Research Center & GIGA Research Center, University and University Hospital of Liège , Liège, Belgium .
authors.forename: Charlotte
authors.initials: C
authors.lastname: Martial
authors.affiliation: 3 Department of Biomedical and Clinical Sciences "Luigi Sacco, " University of Milan , Milan, Italy .
authors.forename: Marcello
authors.initials: M
authors.lastname: Massimini
authors.affiliation: 2 Department of Data-Analysis, University of Ghent , Ghent, Belgium .
authors.forename: Daniele
authors.initials: D
authors.lastname: Marinazzo
authors.affiliation: 1 Coma Science Group, Cyclotron Research Center & GIGA Research Center, University and University Hospital of Liège , Liège, Belgium .
authors.forename: Steven
authors.initials: S
authors.lastname: Laureys
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging* / Q000502:physiology*; D001931:Brain Mapping; D015331:Cohort Studies; D038524:Diffusion Magnetic Resonance Imaging; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D017711:Nonlinear Dynamics; D050781:Transcranial Magnetic Stimulation; D014851:Wakefulness; D055815:Young Adult
keywords: DTI; TMS/EEG; brain-directed functional connectivity; directed functional connectivity; structural connectivity; structure–function