Brain Structural and Functional Connectivity: A Review of Combined Works of Diffusion Magnetic Resonance Imaging and Electro-Encephalography

Abstract

Implications of structural connections within and between brain regions for their functional counterpart are timely points of discussion. White matter microstructural organization and functional activity can be assessed in unison. At first glance, however, the corresponding findings appear variable, both in the healthy brain and in numerous neuro-pathologies. To identify consistent associations between structural and functional connectivity and possible impacts for the clinic, we reviewed the literature of combined recordings of electro-encephalography (EEG) and diffusion-based magnetic resonance imaging (MRI). It appears that the strength of event-related EEG activity increases with increased integrity of structural connectivity, while latency drops. This agrees with a simple mechanistic perspective: the nature of microstructural white matter influences the transfer of activity. The EEG, however, is often assessed for its spectral content. Spectral power shows associations with structural connectivity that can be negative or positive often dependent on the frequencies under study. Functional connectivity shows even more variations, which are difficult to rank. This might be caused by the diversity of paradigms being investigated, from sleep and resting state to cognitive and motor tasks, from healthy participants to patients. More challenging, though, is the potential dependency of findings on the kind of analysis applied. While this does not diminish the principal capacity of EEG and diffusion-based MRI co-registration, it highlights the urgency to standardize especially EEG analysis.

Graph-generative neural network for EEG-based epileptic seizure detection via discovery of dynamic brain functional connectivity

“…Our testing results complement other detection methods based on fMRI and clinical factors 54,56,57 . The GGN approach helps brain specialists to detect early seizure attacks with more accurate results.…”

“…In addition to detection or classification tasks, brain functional connectivity has been a very hot research topic for many years 54 . Revealing accurate connectivity within very small-time windows is critical to modeling the brain activity associated with neurological disorders.…”

Multimodal data fusion of cortical-subcortical morphology and functional network connectivity in psychotic spectrum disorder

“…Further, there are multiple studies reporting altered subcortical-to-cortical connectivity in SZ and BPI, but these are typically reported across thalamocortical connections ( Sui et al, 2011 ). Previous work in a large-scale multi-site study noted alterations in similar networks in individuals on the schizophrenia portion of the psychotic spectrum ( Skåtun et al, 2017 ) and it has been argued by multiple research groups that individuals with schizophrenia may display alterations within the striatal-thalamo-cortical loop ( Sui et al, 2011 , Skåtun et al, 2017 , Sui et al, 2015 , Sui et al, 2018 , Ellison-Wright and Bullmore, 2009 , Skudlarski et al, 2013 , Heng et al, 2010 , Babaeeghazvini et al, 2021 ). This loop is a key mechanism in inhibitory control, which has been proposed to interplay with working memory ( Lustig et al, 2005 ).…”

Exploring Neural Heterogeneity in Inattention and Hyperactivity

“…The fact that the inattentive and hyperactive clusters were not found to differ on any behavioural measures could be attributable to the fact that functional connectivity is typically better-associated with behaviour than structural connectivity (Jia et al, 2014; Fjell et al, 2017). In addition, structural brain connectivity has been linked robustly to cognitive ability (Ponsoda et al, 2017; Babaeeghazvini et al, 2021; Amunts et al, 2022). This coupling of structure-cognition and function-behaviour relationships could explain why cognitive differences, rather than behavioural differences, were found to exist between two different profiles of structural brain connectivity.…”