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.

Relation between EEG source functional connectivity and the negative symptom severity in schizophrenia: a preliminary report from a multicentre study

2016 ◽  
Vol 33 (S1) ◽  
pp. s246-s246
Author(s):  
G. Di Lorenzo ◽  
A. Mucci ◽  
A. Daverio ◽  
F. Ferrentino ◽  
A. Vignapiano ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Multicentre Study ◽  
Negative Symptom ◽  
Resting State ◽  
Symptom Severity ◽  
Negative Symptoms ◽  
Phase Synchronization ◽  
Lower Quartile ◽  
Eyes Closed ◽  
Significant Difference

IntroductionNeural dysconnectivity is hypothesized to be a key element in pathophysiology of schizophrenia. However, the relation of disordered connectivity with the different clinical characteristics of the syndrome is not fully elucidated.ObjectivesThe current research investigated the relations between resting-state EEG Source Functional Connectivity (EEG-SFC) and the two main clusters of negative symptoms derived from the Brief Negative Symptom Scale, the Expressive Deficit (ED) and the Avolition (AV), in subjects with schizophrenia (SCZ) enrolled to the multicentre study of the Italian Network for Research on Psychoses.MethodsOut of 97 chronic, stabilized SCZ included, we selected subjects according the lower and the upper quartile of the ED and AV value distribution: 25 were in upper and 24 in the lower quartile of ED (respectively, HIGH-ED and LOW-ED); 27 were in upper and 24 in the lower quartile of AV (respectively, HIGH-AV and LOW-AV). Fifty-five healthy controls (HC) were included, comparable to SCZ for gender, age and educational level. EEG-SFC analysis was based on the lagged phase synchronization (LPS) computed by eLORETA from 5 minutes resting-state EEG recordings in eyes closed condition. LPS indices were determined for each spectrum band and between all 28 regions of interest (ROI) pairs. Group differences were significant for corrected P-value < 0.05.ResultsSCZ had higher theta band LPS than HC. Respect to LOW-ED, HIGH-ED showed significant increased alpha LPS in fronto-cingulate, para-hippocampal and insular inter-hemispheric ROI pairs. No significant difference emerged between HIGH-AV and LOW-AV.ConclusionsSubgrouping SCZ according to negative symptom severity reveals heterogeneous patterns of resting-state LPS connectivity.Disclosure of interestThe authors have not supplied their declaration of competing interest.

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 Ketamine Alters Functional Gamma and Theta Resting-State Connectivity in Healthy Humans: Implications for Schizophrenia Treatment Targeting the Glutamate System

2021 ◽  
Vol 12 ◽  
Author(s):  
Stjepan Curic ◽  
Christina Andreou ◽  
Guido Nolte ◽  
Saskia Steinmann ◽  
Stephanie Thiebes ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Rating Scale ◽  
Current Source ◽  
Gamma Band ◽  
Neurocognitive Deficits ◽  
Theta Band ◽  
Healthy Humans ◽  
Eyes Closed ◽  
Glutamate System

Disturbed functional connectivity is assumed to cause neurocognitive deficits in patients suffering from schizophrenia. A Glutamate N-methyl-D-aspartate receptor (NMDAR) dysfunction has been suggested as a possible mechanism underlying altered connectivity in schizophrenia, especially in the gamma- and theta-frequency range. The present study aimed to investigate the effects of the NMDAR-antagonist ketamine on resting-state power, functional connectivity, and schizophrenia-like psychopathological changes in healthy volunteers. In a placebo-controlled crossover design, 25 healthy subjects were recorded using resting-state 64-channel-electroencephalography (EEG) (eyes closed). The imaginary coherence-based Multivariate Interaction Measure (MIM) was used to measure gamma and theta connectivity across 80 cortical regions. The network-based statistic was applied to identify involved networks under ketamine. Psychopathology was assessed with the Positive and Negative Syndrome Scale (PANSS) and the 5-Dimensional Altered States of Consciousness Rating Scale (5D-ASC). Ketamine caused an increase in all PANSS (p &lt; 0.001) as well as 5D-ASC scores (p &lt; 0.01). Significant increases in resting-state gamma and theta power were observed under ketamine compared to placebo (p &lt; 0.05). The source-space analysis revealed two distinct networks with an increased mean functional gamma- or theta-band connectivity during the ketamine session. The gamma-network consisted of midline regions, the cuneus, the precuneus, and the bilateral posterior cingulate cortices, while the theta-band network involved the Heschl gyrus, midline regions, the insula, and the middle cingulate cortex. The current source density (CSD) within the gamma-band correlated negatively with the PANSS negative symptom score, and the activity within the gamma-band network correlated negatively with the subjective changed meaning of percepts subscale of the 5D-ASC. These results are in line with resting-state patterns seen in people who have schizophrenia and argue for a crucial role of the glutamate system in mediating dysfunctional gamma- and theta-band-connectivity in schizophrenia. Resting-state networks could serve as biomarkers for the response to glutamatergic drugs or drug development efforts within the glutamate system.

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 Increased Functional Connectivity Between Subcortical and Cortical Resting-State Networks in Autism Spectrum Disorder

2015 ◽  
Vol 72 (8) ◽  
pp. 767 ◽  
Author(s):  
Leonardo Cerliani ◽  
Maarten Mennes ◽  
Rajat M. Thomas ◽  
Adriana Di Martino ◽  
Marc Thioux ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Functional Connectivity ◽  
Resting State ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Resting State Networks

Inter-Hemispherical Investigations on the Functional Connectivity in Controls and Autism Spectrum Using Resting State fMRI

2020 ◽  
pp. 169-186
Author(s):  
S. Vidhusha ◽  
A. Kavitha
Keyword(s):  
Functional Connectivity ◽  
Granger Causality ◽  
Resting State ◽  
Cognitive Task ◽  
Resting State Fmri ◽  
Autism Spectrum ◽  
Control Group ◽  
Neural Connectivity ◽  
Activation Patterns ◽  
The Brain

Autism spectrum disorders are connected with disturbances of neural connectivity. Functional connectivity is typically examined during a cognitive task, but also exists in the absence of a task. While a number of studies have performed functional connectivity analysis to differentiate controls and autism individuals, this work focuses on analyzing the brain activation patterns not only between controls and autistic subjects, but also analyses the brain behaviour present within autism spectrum. This can bring out more intuitive ways to understand that autism individuals differ individually. This has been performed between autism group relative to the control group using inter-hemispherical analysis. Indications of under connectivity were exhibited by the Granger Causality (GC) and Conditional Granger Causality (CGC) in autistic group. Results show that as connectivity decreases, the GC and CGC values also get decreased. Further, to demark the differences present within the spectrum of autistic individuals, GC and CGC values have been calculated.

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