MRI Study on the Functional and Spatial Consistency of Resting State-Related Independent Components of the Brain Network

Abstract

ObjectiveResting-state networks (RSNs), including the default mode network (DMN), have been considered as markers of brain status such as consciousness, developmental change, and treatment effects. The consistency of functional connectivity among RSNs has not been fully explored, especially among resting-state-related independent components (RSICs).Materials and MethodsThis resting-state fMRI study addressed the consistency of functional connectivity among RSICs as well as their spatial consistency between 'at day 1' and 'after 4 weeks' in 13 healthy volunteers.ResultsWe found that most RSICs, especially the DMN, are reproducible across time, whereas some RSICs were variable in either their spatial characteristics or their functional connectivity. Relatively low spatial consistency was found in the basal ganglia, a parietal region of left frontoparietal network, and the supplementary motor area. The functional connectivity between two independent components, the bilateral angular/supramarginal gyri/intraparietal lobule and bilateral middle temporal/occipital gyri, was decreased across time regardless of the correlation analysis method employed, (Pearson's or partial correlation).ConclusionRSICs showing variable consistency are different between spatial characteristics and functional connectivity. To understand the brain as a dynamic network, we recommend further investigation of both changes in the activation of specific regions and the modulation of functional connectivity in the brain network.

Similarity analysis of functional connectivity with functional near-infrared spectroscopy

“…16 However, most of these studies have ignored the temporal and/or interindividual variability of functional connectivity. 6 Results found in the present study are consistent with these previous studies in the literature. Although temporal variability of FC has emerged as an important topic recently, the studies have used fMRI as an imaging tool so far.…”

“…3 Conventionally, FC is computed by correlating a time series signal from one area [functional magnetic resonance imaging (fMRI) voxel or electroencephalography (EEG) electrode] with a signal from another area. 5,6 Several studies have shown that FC vary due to differences in mental tasks and changes in FC are observed even in the same imaging session. Usually the whole time series are used to compute these correlation matrices, which inherently come with the assumption that the initial condition of the brain remains constant throughout the task; hence, neuroimaging data are stationary [i.e., n H ðtÞ ≈nðtÞ].…”

Aberrant Development of Functional Connectivity among Resting State-Related Functional Networks in Medication-Naïve ADHD Children

“…Results from a functional connectivity study using simulated fMRI data showed that partial correlation (PC) analysis was more reliable than cross correlation (CC) analysis [31]. We also reported that the functional connectivity among RSFNs was more consistent using PC than CC [32]. A possible indirect effect of functional connectivity among other RSFNs, on the functional connectivity of a certain RSFN pair, can be controlled-for using PC analysis.…”

Modelo de conectividad de la circunvolución angular en el lenguaje: metaanálisis de neuroimágenes funcionales

“…En segundo lugar, la técnica que correlaciona la señal de activación BOLD de un conglo-merado (vóxel) o cluster durante el reposo (conectividad funcional basada en estado de reposo) demuestra la conectividad funcional de áreas cerebrales a través de vías directas o indirectas. En tercer lugar, está la conectividad funcional durante una tarea específica, que no necesariamente coincide con la conectividad de reposo y que es un proceso dinámico que cambia de una tarea a otra [40,41]. La metodología utilizada en el presente trabajo permite deducir la conectividad de la circunvolución angular basándose en la probabilidad de que otras áreas cerebrales conectadas con la región angular se activen simultáneamente cuando el sujeto esté realizando una tarea lingüística.…”