How reliable are the functional connectivity networks of MEG in resting states?

2011 ◽  
Vol 106 (6) ◽  
pp. 2888-2895 ◽  
Author(s):  
Seung-Hyun Jin ◽  
Jaeho Seol ◽  
June Sic Kim ◽  
Chun Kee Chung
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
High Reliability ◽  
Intraclass Correlation ◽  
Alpha Band ◽  
Eyes Closed ◽  
Gamma Frequency ◽  
Centrality Metrics ◽  
Eyes Open ◽  
Network Metrics

We investigated the reliability of nodal network metrics of functional connectivity (FC) networks of magnetoencephalography (MEG) covering the whole brain at the sensor level in the eyes-closed (EC) and eyes-open (EO) resting states. Mutual information (MI) was employed as a measure of FC between sensors in theta, alpha, beta, and gamma frequency bands of MEG signals. MI matrices were assessed with three nodal network metrics, i.e., nodal degree (Dnodal), nodal efficiency (Enodal), and betweenness centrality (normBC). Intraclass correlation (ICC) values were calculated as a measure of reliability. We observed that the test-retest reliabilities of the resting states ranged from a poor to good level depending on the bands and metrics used for defining the nodal centrality. The dominant alpha-band FC network changes were the salient features of the state-related FC changes. The FC networks in the EO resting state showed greater reliability when assessed by Dnodal (maximum mean ICC = 0.655) and Enodal (maximum mean ICC = 0.604) metrics. The gamma-band FC network was less reliable than the theta, alpha, and beta networks across the nodal network metrics. However, the sensor-wise ICC values for the nodal centrality metrics were not uniformly distributed, that is, some sensors had high reliability. This study provides a sense of how the nodal centralities of the human resting state MEG are distributed at the sensor level and how reliable they are. It also provides a fundamental scientific background for continued examination of the resting state of human MEG.

scholarly journals The effect of congenital blindness on resting-state functional connectivity revisited

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria J. S. Guerreiro ◽  
Madita Linke ◽  
Sunitha Lingareddy ◽  
Ramesh Kekunnaya ◽  
Brigitte Röder
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Visual Experience ◽  
Brain Regions ◽  
State Condition ◽  
Resting State Functional Connectivity ◽  
Congenital Blindness ◽  
Eyes Closed ◽  
Congenitally Blind ◽  
Eyes Open

AbstractLower resting-state functional connectivity (RSFC) between ‘visual’ and non-‘visual’ neural circuits has been reported as a hallmark of congenital blindness. In sighted individuals, RSFC between visual and non-visual brain regions has been shown to increase during rest with eyes closed relative to rest with eyes open. To determine the role of visual experience on the modulation of RSFC by resting state condition—as well as to evaluate the effect of resting state condition on group differences in RSFC—, we compared RSFC between visual and somatosensory/auditory regions in congenitally blind individuals (n = 9) and sighted participants (n = 9) during eyes open and eyes closed conditions. In the sighted group, we replicated the increase of RSFC between visual and non-visual areas during rest with eyes closed relative to rest with eyes open. This was not the case in the congenitally blind group, resulting in a lower RSFC between ‘visual’ and non-‘visual’ circuits relative to sighted controls only in the eyes closed condition. These results indicate that visual experience is necessary for the modulation of RSFC by resting state condition and highlight the importance of considering whether sighted controls should be tested with eyes open or closed in studies of functional brain reorganization as a consequence of blindness.

scholarly journals The Difference of Brain Functional Connectivity between Eyes-Closed and Eyes-Open Using Graph Theoretical Analysis

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Bo Tan ◽  
Xianxian Kong ◽  
Ping Yang ◽  
Zhenlan Jin ◽  
Ling Li
Keyword(s):  
Functional Connectivity ◽  
Alpha Band ◽  
Topological Parameters ◽  
Eyes Closed ◽  
Synchronization Likelihood ◽  
Functional Brain Networks ◽  
Eyes Open ◽  
The Difference ◽  
Path Lengths ◽  
Brain Functional Connectivity

To study the differences in functional brain networks between eyes-closed (EC) and eyes-open (EO) at resting state, electroencephalographic (EEG) activity was recorded in 21 normal adults during EC and EO states. The synchronization likelihood (SL) was applied to measure correlations between all pairwise EEG channels, and then the SL matrices were converted to graphs by thresholding. Graphs were measured by topological parameters in theta (4–7 Hz), alpha (8–13 Hz), and beta (14–30 Hz) bands. By changing from EC to EO states, mean cluster coefficients decreased in both theta and alpha bands, but mean shortest path lengths became shorter only in the alpha band. In addition, local efficiencies decreased in both theta and alpha bands, while global efficiencies in the alpha band increased inversely. Opening the eyes decreased both nodes and connections in frontal area in the theta band, and also decreased those in bilateral posterior areas in the alpha band. These results suggested that a combination of the SL and graph theory methods may be a useful tool for distinguishing states of EC and EO. The differences in functional connectivity between EC and EO states may reflect the difference of information communication in human brain.

scholarly journals Reduced Functional Connectivity in Children With Congenital Cataracts Using Resting-State Electroencephalography Measurement

2021 ◽  
Vol 15 ◽  
Author(s):  
Wan Chen ◽  
Liping Lan ◽  
Wei Xiao ◽  
Jiahong Li ◽  
Jiahao Liu ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Resting State ◽  
Functional Improvement ◽  
Control Group ◽  
Salience Network ◽  
Alpha Band ◽  
Congenital Cataracts ◽  
Eyes Closed ◽  
Parietal Cortices

ObjectivesNumerous task-based functional magnetic resonance imaging studies indicate the presence of compensatory functional improvement in patients with congenital cataracts. However, there is neuroimaging evidence that shows decreased sensory perception or cognition information processing related to visual dysfunction, which favors a general loss hypothesis. This study explored the functional connectivity between visual and other networks in children with congenital cataracts using resting state electroencephalography.MethodsTwenty-one children with congenital cataracts (age: 8.02 ± 2.03 years) and thirty-five sex- and age-matched normal sighted controls were enrolled to investigate functional connectivity between the visual cortex and the default mode network, the salience network, and the cerebellum network during resting state electroencephalography (eyes closed) recordings.ResultThe congenital cataract group was less active, than the control group, in the occipital, temporal, frontal and limbic lobes in the theta, alpha, beta1 and beta2 frequency bands. Additionally, there was reduced alpha-band connectivity between the visual and somatosensory cortices and between regions of the frontal and parietal cortices associated with cognitive and attentive control.ConclusionThe results indicate abnormalities in sensory, cognition, motion and execution functional connectivity across the developing brains of children with congenital cataracts when compared with normal controls. Reduced frontal alpha activity and alpha-band connectivity between the visual cortex and salience network might reflect attenuated inhibitory information flow, leading to higher attentional states, which could contribute to adaptation of environmental change in this group of patients.

scholarly journals EEG resting-state functional connectivity: evidence for an imbalance of external/ internal information integration in Autism

2021 ◽  
Author(s):  
Prany Wantzen ◽  
Patrice Clochon ◽  
Franck Doidy ◽  
Fabrice Wallois ◽  
Mahdi Mahmoudzadeh ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Information Integration ◽  
Resting State ◽  
Phase Synchronization ◽  
Current Source ◽  
Autism Spectrum ◽  
High Temporal Resolution ◽  
Alpha Band ◽  
Eyes Closed ◽  
Internal Information

Abstract Background Autism spectrum disorder (ASD) is associated with atypical neural activity in resting-state. Most of the studies have focused on abnormalities in alpha-frequency, as a marker of ASD dysfunctions. However, few have explored alpha synchronization, with a specific interest in resting-state networks: the default mode network (DMN), the sensorimotor network (SMN), and the dorsal attention network (DAN). These functional connectivity analyses provide relevant insight into the neurophysiological correlates of multimodal integration in ASD. Methods Using the high temporal resolution of EEG, the present study investigates the functional connectivity in the alpha band within and between the DMN, SMN, and the DAN. We examined eyes-closed EEG alpha lagged phase synchronization, using standardized Low-Resolution Brain Electromagnetic Tomography (sLORETA) in 29 participants with ASD and 38 age,- sex- and IQ-matched typically developing (TD) controls. Results We observed reduced functional connectivity in the ASD group relative to TD controls, within and between the DMN, the SMN, and the DAN. We identified three hubs of dysconnectivity in ASD: the posterior cingulate cortex, the precuneus, and the medial frontal gyrus. These three regions also presented decreased current source density in the alpha band. Conclusion These results may account for impairments in multimodal - sensory and internal information - integration frequently observed in ASD. Underconnectivity potentially involves difficulties switching between this externally oriented attention and internally oriented thoughts and, more broadly, may impact embodied cognition.

Eyes closed or Eyes open? Exploring the alpha desynchronization hypothesis in resting state functional connectivity networks with intracranial EEG

2017 ◽  
Author(s):  
Jaime Gómez-Ramírez ◽  
Shelagh Freedman ◽  
Diego Mateos ◽  
José Luis Pérez-Velázquez ◽  
Taufik Valiante
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Connectivity Pattern ◽  
Cost Calculation ◽  
Resting State Functional Connectivity ◽  
Eyes Closed ◽  
Regional Specificity ◽  
Eyes Open ◽  
First Time ◽  
Intracranial Recordings

AbstractThis paper addresses a fundamental question, are eyes closed and eyes open resting states equivalent baseline conditions, or do they have consistently different electrophysiological signatures? We compare the functional connectivity patterns in an eyes closed resting state with an eyes open resting state, and show that functional connectivity in the alpha band decreases in the eyes open condition compared to eyes closed. This "alpha desynchronization " or reduction in the number of connections from eyes closed to eyes open, is here, for the first time, studied with intracranial recordings. We provide two calculations of the wiring cost, local and mesoscopic, defined in terms of the distance between the electrodes and the likelihood that they are functionally connected. We find that, in agreement with the "alpha desynchronization" hypothesis, the local wiring cost decreases going from eyes closed to eyes open. However, when the wiring cost calculation takes into account the connectivity pattern, the wiring cost variation from eyes closed to eyes open is not as consistent and shows regional specificity. The wiring cost measure defined here, provides a new avenue for understanding the electrophysiology of resting state.

scholarly journals Functional connectivity between the thalamus and visual cortex under eyes closed and eyes open conditions: A resting-state fMRI study

2009 ◽  
Vol 30 (9) ◽  
pp. 3066-3078 ◽  
Author(s):  
Qihong Zou ◽  
Xiangyu Long ◽  
Xinian Zuo ◽  
Chaogan Yan ◽  
Chaozhe Zhu ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Resting State ◽  
Resting State Fmri ◽  
Eyes Closed ◽  
Fmri Study ◽  
Eyes Open

scholarly journals A Pilot Study Investigating a Novel Non-Linear Measure of Eyes Open versus Eyes Closed EEG Synchronization in People with Alzheimer’s Disease and Healthy Controls

2018 ◽  
Vol 8 (7) ◽  
pp. 134 ◽  
Author(s):  
Daniel Blackburn ◽  
Yifan Zhao ◽  
Matteo De Marco ◽  
Simon Bell ◽  
Fei He ◽  
...  
Keyword(s):  
Pilot Study ◽  
Resting State ◽  
Low Cost ◽  
Linear Measure ◽  
Ageing Population ◽  
Healthy Controls ◽  
Causality Test ◽  
Non Invasive ◽  
Eyes Closed ◽  
Eyes Open

Background: The incidence of Alzheimer disease (AD) is increasing with the ageing population. The development of low cost non-invasive diagnostic aids for AD is a research priority. This pilot study investigated whether an approach based on a novel dynamic quantitative parametric EEG method could detect abnormalities in people with AD. Methods: 20 patients with probable AD, 20 matched healthy controls (HC) and 4 patients with probable fronto temporal dementia (FTD) were included. All had detailed neuropsychology along with structural, resting state fMRI and EEG. EEG data were analyzed using the Error Reduction Ratio-causality (ERR-causality) test that can capture both linear and nonlinear interactions between different EEG recording areas. The 95% confidence intervals of EEG levels of bi-centroparietal synchronization were estimated for eyes open (EO) and eyes closed (EC) states. Results: In the EC state, AD patients and HC had very similar levels of bi-centro parietal synchronization; but in the EO resting state, patients with AD had significantly higher levels of synchronization (AD = 0.44; interquartile range (IQR) 0.41 vs. HC = 0.15; IQR 0.17, p < 0.0001). The EO/EC synchronization ratio, a measure of the dynamic changes between the two states, also showed significant differences between these two groups (AD ratio 0.78 versus HC ratio 0.37 p < 0.0001). EO synchronization was also significantly different between AD and FTD (FTD = 0.075; IQR 0.03, p < 0.0001). However, the EO/EC ratio was not informative in the FTD group due to very low levels of synchronization in both states (EO and EC). Conclusion: In this pilot work, resting state quantitative EEG shows significant differences between healthy controls and patients with AD. This approach has the potential to develop into a useful non-invasive and economical diagnostic aid in AD.

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