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 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 Altered functional connectivity of the nucleus accumbens subdivisions in amphetamine-type stimulant abusers: a resting-state fMRI study

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Yun Wang ◽  
Kai-Juan Yan ◽  
Chen-Xiao Fan ◽  
Xiao-Nian Luo ◽  
Yuan Zhou
Keyword(s):  
Nucleus Accumbens ◽  
Functional Connectivity ◽  
Resting State ◽  
Inferior Frontal Gyrus ◽  
Resting State Fmri ◽  
Resting State Functional Connectivity ◽  
Functional Architecture ◽  
Superior Frontal Gyrus ◽  
Eyes Closed ◽  
Orbital Part

Abstract Background The growing abuse of amphetamine-type stimulants leads to new challenges to human health. A possible addiction mechanism has been proposed by altered functional architecture of the nucleus accumbens (NAc) during resting state. NAc contains different subdivisions and they may play different roles in addiction. The aim of the present study was to examine whether there are common or distinct patterns of functional connectivity of the NAc subdivisions in amphetamine-type stimulant abusers (ATSAs). Methods The present study recruited 17 male ATSAs and 22 healthy male controls. All the subjects underwent resting-state functional magnetic resonance imaging (fMRI) with their eyes closed. The NAc was divided into core-like and shell-like subdivisions. We used seed-based resting-state functional connectivity (RSFC) analyses to identify differences in brain functional architecture between ATSAs and healthy controls (HCs). Results ATSAs had lower positive RSFCs with all of the NAc subdivisions over the left orbital part of superior frontal gyrus and higher positive RSFCs with the NAc subdivisions over the left opercular part of inferior frontal gyrus than HCs, which indicates common abnormalities across the NAc subdivisions in ATSAs. In addition, the RSFCs between the NAc subdivisions and the left orbital part of superior frontal gyrus were negatively correlated with the addiction severity in ATSAs. Conclusion These results provide evidence that there are common RSFC patterns of the NAc subdivisions in ATSAs. The abnormality indicated by disrupted functional connectivity between the NAc subdivisions and prefrontal cortex suggests abnormal interaction between the rewarding process and cognitive control in ATSAs. Our results shed insight on the neurobiological mechanisms of ATSA and suggest potential novel therapeutic targets for treatment and intervention of ATSAs.

scholarly journals High-amplitude cofluctuations in cortical activity drive functional connectivity

2020 ◽  
Vol 117 (45) ◽  
pp. 28393-28401
Author(s):  
Farnaz Zamani Esfahlani ◽  
Youngheun Jo ◽  
Joshua Faskowitz ◽  
Lisa Byrge ◽  
Daniel P. Kennedy ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Temporal Structure ◽  
Activity Patterns ◽  
High Amplitude ◽  
Network Activity ◽  
Connectivity Pattern ◽  
Future Research ◽  
Resting State Functional Connectivity ◽  
Brain Organization

Resting-state functional connectivity is used throughout neuroscience to study brain organization and to generate biomarkers of development, disease, and cognition. The processes that give rise to correlated activity are, however, poorly understood. Here we decompose resting-state functional connectivity using a temporal unwrapping procedure to assess the contributions of moment-to-moment activity cofluctuations to the overall connectivity pattern. This approach temporally resolves functional connectivity at a timescale of single frames, which enables us to make direct comparisons of cofluctuations of network organization with fluctuations in the blood oxygen level-dependent (BOLD) time series. We show that surprisingly, only a small fraction of frames exhibiting the strongest cofluctuation amplitude are required to explain a significant fraction of variance in the overall pattern of connection weights as well as the network’s modular structure. These frames coincide with frames of high BOLD activity amplitude, corresponding to activity patterns that are remarkably consistent across individuals and identify fluctuations in default mode and control network activity as the primary driver of resting-state functional connectivity. Finally, we demonstrate that cofluctuation amplitude synchronizes across subjects during movie watching and that high-amplitude frames carry detailed information about individual subjects (whereas low-amplitude frames carry little). Our approach reveals fine-scale temporal structure of resting-state functional connectivity and discloses that frame-wise contributions vary across time. These observations illuminate the relation of brain activity to functional connectivity and open a number of directions for future research.

scholarly journals Resting-State Functional Connectivity of the Ageing Female Brain—Differences Between Young and Elderly Female Adults on Multislice Short TR rs-fMRI

2021 ◽  
Vol 12 ◽  
Author(s):  
Przemysław Podgórski ◽  
Marta Waliszewska-Prosół ◽  
Anna Zimny ◽  
Marek Sąsiadek ◽  
Joanna Bladowska
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Large Scale ◽  
World Health ◽  
Resting State Functional Connectivity ◽  
Default Mode ◽  
Young Females ◽  
Eyes Closed ◽  
Age Related ◽  
Healthy Female

Introduction: Age-related brain changes are one of the most important world health problems due to the rising lifespan and size of the elderly populations. The aim of the study was to assess the effect of ageing in women on coordinated brain activity between eight resting-state networks.Material and Methods: The study group comprised 60 healthy female volunteers who were divided into two age groups: younger women (aged 20–30 n = 30) and older women (aged 55–80 n = 30). Resting-state data were collected during a 15 min scan in the eyes-closed condition using a 3T MR scanner. Data were preprocessed and analysed using the CONN toolbox version 19.c. The large-scale network analysis included a priori selected regions of interest of the default mode, the sensorimotor, the visual, the salience, the dorsal attention, the fronto-parietal, the language, and the cerebellar network.Results: Within the visual, the default mode, the salience, and the sensorimotor network, the intra-network resting-state functional connectivity (RSFC) was significantly higher with increasing age. There was also a significant increase in the inter-network RSFC in older females compared to young females found in the following networks: sensorimotor lateral and salience, salience and language, salience and fronto-parietal, cerebellar anterior and default mode, cerebellar posterior and default mode, visual and sensorimotor lateral, visual and sensorimotor, visual lateral and default mode, language and cerebellar anterior, language and cerebellar posterior, fronto-parietal and cerebellar anterior, dorsal attention and sensorimotor, dorsal attention and default mode, sensorimotor superior, and salience. Compared to young females, elderly women presented bilaterally significantly lower inter-network RSFC of the salience supramarginal gyrus and cerebellar posterior, sensorimotor lateral, and cerebellar anterior network, and sensorimotor lateral and cerebellar posterior as well as sensorimotor superior and cerebellar posterior network.Conclusion: Increased RSFC between some brain networks including the visual, the default mode, the salience, the sensorimotor, the language, the fronto-parietal, the dorsal attention, and the cerebellar networks in elderly females may function as a compensation mechanism during the ageing process of the brain. To the best of our knowledge, this study is the first to report the importance of increase of cerebellar networks RSFC during healthy female ageing.

Commonalties and differences of two psychotic phenotypes using connectivity fMRI

2011 ◽  
Vol 26 (S2) ◽  
pp. 925-925
Author(s):  
J.R. Foucher ◽  
B.-T. Pham ◽  
D. Gounot ◽  
G. Stöber
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Multiple Testing ◽  
Permutation Test ◽  
Paranoid Schizophrenia ◽  
Resting State Fmri ◽  
Resting State Functional Connectivity ◽  
Residual Symptoms ◽  
Eyes Closed ◽  
Psychosis Proneness

The ICD/DSM schizophrenia diagnosis is a ill-defined phenotype. The Wernicke-Kleist-Leonhard school distinguish 35 major phenotypes in the psychotic spectrum. Among them, the cycloid psychoses (CP, remitting forms) and affect laden paraphrenia (ALP, the core of paranoid schizophrenia) appear promising. We used a resting state functional connectivity analysis to find commonalities and differences between these 2 groups.Seventeen patients with CP and 17 with ALP all fulfilling DSM-IV defined schizophrenia were recruited together with 57 controls. Participants took part to a 20 min resting state fMRI scan keeping eyes closed but remaining awake. The signal from the 78 Brodman areas was averaged and a correlation coefficient was the metric for functional connectivity between them. Groups were compared using permutation test corrected for multiple testing.CP and ALP commonly differed from controls by a disconnection of their temporal regions (internal temporal, the temporal pole, the inferior temporal - in black). But CP had an increase of connectivity between the same temporal regions relative to both ALP and controls. Conversely ALP had a much larger disconnectivity pattern relative to both CP and controls including the cingulate and the orbito-frontal regions as a whole (in white).CP and ALP share temporal disconnectivity which could be correlated with psychosis proneness. However the reasons for it appear different in the two groups: an excess of intra-temporal connectivity in CP, a more global and widespread decrease of connectivity in ALP which correlate with the type of residual symptoms observed in this group.

scholarly journals High-amplitude co-fluctuations in cortical activity drive functional connectivity

2019 ◽  
Author(s):  
Farnaz Zamani Esfahlani ◽  
Youngheun Jo ◽  
Joshua Faskowitz ◽  
Lisa Byrge ◽  
Daniel P. Kennedy ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Temporal Structure ◽  
High Amplitude ◽  
Network Activity ◽  
Connectivity Pattern ◽  
Future Research ◽  
Resting State Functional Connectivity ◽  
Brain Organization ◽  
Fluctuation Amplitude

Resting-state functional connectivity is used throughout neuroscience to study brain organization and to generate biomarkers of development, disease, and cognition. The processes that give rise to correlated activity are, however, poorly understood. Here, we decompose resting-state functional connectivity using a “temporal unwrapping” procedure to assess the contributions of moment-to-moment activity co-fluctuations to the overall connectivity pattern. This approach temporally resolves functional connectivity at a timescale of single frames, which enables us to make direct comparisons of co-fluctuations of network organization with fluctuations in the BOLD time series. We show that, surprisingly, only a small fraction of frames exhibiting the strongest co-fluctuation amplitude are required to explain a significant fraction of variance in the overall pattern of connection weights as well as the network’s modular structure. These frames coincide with frames of high BOLD activity amplitude, corresponding to activity patterns that are remarkably consistent across individuals and identify fluctuations in default mode and control network activity as the primary driver of resting-state functional connectivity. Finally, we demonstrate that co-fluctuation amplitude synchronizes across subjects during movie-watching and that high-amplitude frames carry detailed information about individual subjects (whereas low-amplitude frames carry little). Our approach reveals fine-scale temporal structure of resting-state functional connectivity, and discloses that frame-wise contributions vary across time. These observations illuminate the relation of brain activity to functional connectivity and open a number of new directions for future research.

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