Impact of Alzheimers Disease on the Functional Connectivity of Spontaneous Brain Activity

2009 ◽  
Vol 6 (6) ◽  
pp. 541-553 ◽  
Author(s):  
Christian Sorg ◽  
Valentin Riedl ◽  
Robert Perneczky ◽  
Alexander Kurz ◽  
Afra Wohlschlager
Keyword(s):  
Functional Connectivity ◽  
Brain Activity ◽  
Alzheimers Disease ◽  
Spontaneous Brain Activity

Brain activity at rest: a multiscale hierarchical functional organization

2011 ◽  
Vol 105 (6) ◽  
pp. 2753-2763 ◽  
Author(s):  
Gaëlle Doucet ◽  
Mikaël Naveau ◽  
Laurent Petit ◽  
Nicolas Delcroix ◽  
Laure Zago ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Functional Organization ◽  
Brain Activity ◽  
Correlation Coefficients ◽  
Temporal Correlation ◽  
Hierarchical Level ◽  
Spontaneous Brain Activity ◽  
Dorsal Attentional Network

Spontaneous brain activity was mapped with functional MRI (fMRI) in a sample of 180 subjects while in a conscious resting-state condition. With the use of independent component analysis (ICA) of each individual fMRI signal and classification of the ICA-defined components across subjects, a set of 23 resting-state networks (RNs) was identified. Functional connectivity between each pair of RNs was assessed using temporal correlation analyses in the 0.01- to 0.1-Hz frequency band, and the corresponding set of correlation coefficients was used to obtain a hierarchical clustering of the 23 RNs. At the highest hierarchical level, we found two anticorrelated systems in charge of intrinsic and extrinsic processing, respectively. At a lower level, the intrinsic system appears to be partitioned in three modules that subserve generation of spontaneous thoughts (M1a; default mode), inner maintenance and manipulation of information (M1b), and cognitive control and switching activity (M1c), respectively. The extrinsic system was found to be made of two distinct modules: one including primary somatosensory and auditory areas and the dorsal attentional network (M2a) and the other encompassing the visual areas (M2b). Functional connectivity analyses revealed that M1b played a central role in the functioning of the intrinsic system, whereas M1c seems to mediate exchange of information between the intrinsic and extrinsic systems.

scholarly journals Abnormal Spontaneous Brain Activity and Functional Connectivity of the Default Mode Network in Patients with Bipolar Disorder

2021 ◽  
Author(s):  
Lei Zhao ◽  
Qijing Bo ◽  
Zhifang Zhang ◽  
Feng Li ◽  
Yuan Zhou ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Functional Connectivity ◽  
Default Mode Network ◽  
Resting State ◽  
Brain Activity ◽  
Seed Region ◽  
Potential Candidate ◽  
Neural Basis ◽  
Default Mode ◽  
Spontaneous Brain Activity

Abstract Background: No consistent evidence on the specific brain regions is available in the default mode network (DMN), which show abnormal spontaneous activity in bipolar disorder (BD). We aim to identify this region that is particularly impaired in patients with BD by using several different indices measuring spontaneous brain activity and then investigate its functional connectivity (FC).Methods: A total of 56 patients with BD and 71 healthy controls (HC) underwent resting-state functional magnetic resonance imaging. Three commonly used functional indices were used to identify the brain region showing abnormal spontaneous brain activity in BD. Then, this region served as the seed region for resting-state FC analysis to identify its functional networks altered in BD.Results: The BD group exhibited decreased fALFF, ReHo, and DC values in the left precuneus. The BD group had decreased rsFC within the DMN, indicated by decreased resting-state FC within the left precuneus and between the left precuneus and the medial prefrontal cortex. The BD group had decreased negative connectivity between the left precuneus and the left putamen, extending to the left insula.Conclusions: The findings provide convergent evidence for the abnormalities in the DMN of BD, particularly located in the left precuneus. Decreased FC within the DMN and the disruptive anticorrelation between the DMN and the salience network are found in BD. These findings suggest that the DMN is a key aspect for understanding the neural basis of BD, and the altered functional patterns of DMN may be a potential candidate biomarker of BD.

scholarly journals Evaluation of confound regression strategies for the mitigation of micromovement artifact in studies of dynamic resting-state functional connectivity and multilayer network modularity

2019 ◽  
Vol 3 (2) ◽  
pp. 427-454 ◽  
Author(s):  
David M. Lydon-Staley ◽  
Rastko Ciric ◽  
Theodore D. Satterthwaite ◽  
Danielle S. Bassett
Keyword(s):  
Functional Connectivity ◽  
Brain Activity ◽  
Systematic Evaluation ◽  
Resting State Functional Connectivity ◽  
Multilayer Network ◽  
Dynamic Functional Connectivity ◽  
Spontaneous Brain Activity ◽  
Global Signal ◽  
Health And Disease ◽  
Modularity Maximization

Dynamic functional connectivity reflects the spatiotemporal organization of spontaneous brain activity in health and disease. Dynamic functional connectivity may be susceptible to artifacts induced by participant motion. This report provides a systematic evaluation of 12 commonly used participant-level confound regression strategies designed to mitigate the effects of micromovements in a sample of 393 youths (ages 8–22 years). Each strategy was evaluated according to a number of benchmarks, including (a) the residual association between participant motion and edge dispersion, (b) distance-dependent effects of motion on edge dispersion, (c) the degree to which functional subnetworks could be identified by multilayer modularity maximization, and (d) measures of module reconfiguration, including node flexibility and node promiscuity. Results indicate variability in the effectiveness of the evaluated pipelines across benchmarks. Methods that included global signal regression were the most consistently effective de-noising strategies.

scholarly journals Evaluation of confound regression strategies for the mitigation of micromovement artifact in studies of dynamic resting state functional connectivity and multilayer network modularity

2018 ◽  
Author(s):  
David M. Lydon-Staley ◽  
Rastko Ciric ◽  
Theodore D. Satterthwaite ◽  
Danielle S Bassett
Keyword(s):  
Functional Connectivity ◽  
Brain Activity ◽  
Systematic Evaluation ◽  
Resting State Functional Connectivity ◽  
Multilayer Network ◽  
Dynamic Functional Connectivity ◽  
Spontaneous Brain Activity ◽  
Global Signal ◽  
Health And Disease ◽  
Modularity Maximization

Dynamic functional connectivity reflects the spatiotemporal organization of spontaneous brain activity in health and disease. Dynamic functional connectivity may be susceptible to artifacts induced by participant motion. This report provides a systematic evaluation of 12 commonly-used participant-level confound regression strategies designed to mitigate the effects of micromovements in a sample of 393 youths (ages 8-22 years). Each strategy was evaluated according to a number of benchmarks, including (i) the residual association between participant motion and edge dispersion, (ii) distance-dependent effects of motion on edge dispersion, (iii) the degree to which functional sub-networks could be identified by multilayer-modularity maximization, and (iv) measures of module reconfiguration, including node flexibility and node promiscuity. Results indicate variability in the effectiveness of the evaluated pipelines across benchmarks. Methods that included global signal regression were the most consistently effective de-noising strategies.

scholarly journals Spontaneously emerging patterns in human visual cortex and their functional connectivity are linked to the patterns evoked by visual stimuli

2020 ◽  
Vol 124 (5) ◽  
pp. 1343-1363
Author(s):  
DoHyun Kim ◽  
Tomer Livne ◽  
Nicholas V. Metcalf ◽  
Maurizio Corbetta ◽  
Gordon L. Shulman
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Spontaneous Activity ◽  
Spatial Patterns ◽  
Brain Activity ◽  
Spontaneous Brain Activity ◽  
Emerging Patterns ◽  
Early Visual Cortex ◽  
Functional Explanations ◽  
High Level

Spontaneous brain activity was once thought to reflect only noise, but evidence of strong spatiotemporal regularities has motivated a search for functional explanations. Here we show that the spatial pattern of spontaneous activity in human high-level and early visual cortex is related to the spatial patterns evoked by stimuli. Moreover, these patterns partly govern spontaneous spatiotemporal interactions between regions, so-called functional connectivity. These results support the hypothesis that spontaneous activity serves a representational function.

scholarly journals Belief in Communism and Theory of Mind

2021 ◽  
Vol 12 ◽  
Author(s):  
Outong Chen ◽  
Fang Guan ◽  
Yu Du ◽  
Yijun Su ◽  
Hui Yang ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Theory Of Mind ◽  
Resting State ◽  
Brain Activity ◽  
Neural Correlates ◽  
Resting State Functional Connectivity ◽  
Neural Basis ◽  
Spontaneous Brain Activity ◽  
Multiple Regions ◽  
Left Thalamus

A belief in communism refers to the unquestionable trust and belief in the justness of communism. Although former studies have discussed the political aim and social value of communism, the cognitive neural basis of a belief in communism remains largely unknown. In this study, we determined the behavioral and neural correlates between a belief in communism and a theory of mind (ToM). For study 1, questionnaire scores were measured and for study 2, regional homogeneity (ReHo) and resting-state functional connectivity (rsFC) were used as an index for resting-state functional MRI (rs-fMRI), as measured by the Belief in Communism Scale (BCS). The results showed that a belief in communism is associated with higher ReHo in the left thalamus and lower ReHo in the left medial frontal gyrus (MFG). Furthermore, the results of the rsFC analysis revealed that strength of functional connectivity between the left thalamus and the bilateral precuneus is negatively associated with a belief in communism. Hence, this study provides evidence that spontaneous brain activity in multiple regions, which is associated with ToM capacity, contributes to a belief in communism.

scholarly journals Localization of focal epileptic discharges using functional connectivity magnetic resonance imaging

2011 ◽  
Vol 114 (6) ◽  
pp. 1693-1697 ◽  
Author(s):  
Steven M. Stufflebeam ◽  
Hesheng Liu ◽  
Jorge Sepulcre ◽  
Naoaki Tanaka ◽  
Randy L. Buckner ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Ad Hoc ◽  
Refractory Epilepsy ◽  
Brain Activity ◽  
Spontaneous Brain Activity ◽  
Accurate Localization ◽  
Seizure Onset Zone ◽  
Epileptic Discharges ◽  
Presurgical Mapping ◽  
Degree Of Coupling

Object In patients with medically refractory epilepsy the accurate localization of the seizure onset zone is critical for successful surgical treatment. The object of this study was to investigate whether the degree of coupling of spontaneous brain activity as measured with functional connectivity MR imaging (fcMR imaging) can accurately identify and localize epileptic discharges. Methods The authors studied 6 patients who underwent fcMR imaging presurgical mapping and subsequently underwent invasive electroencephalography. Results Focal regions of statistically significant increases in connectivity were identified in 5 patients when compared with an ad hoc normative sample of 300 controls. The foci identified by fcMR imaging overlapped the epileptogenic areas identified by invasive encephalography in all 5 patients. Conclusions These results suggest that fcMR imaging may provide an effective high–spatial resolution and noninvasive method of localizing epileptic discharges in patients with refractory epilepsy.

scholarly journals Normalisation of brain connectivity through compensatory behaviour, despite congenital hand absence

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Avital Hahamy ◽  
Stamatios N Sotiropoulos ◽  
David Henderson Slater ◽  
Rafael Malach ◽  
Heidi Johansen-Berg ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Brain Connectivity ◽  
Brain Activity ◽  
Adaptive Behaviour ◽  
Resting State Functional Connectivity ◽  
Spontaneous Brain Activity ◽  
White Matter Microstructure ◽  
Hand Region ◽  
Ecological Behaviour

Previously we showed, using task-evoked fMRI, that compensatory intact hand usage after amputation facilitates remapping of limb representations in the cortical territory of the missing hand (<xref ref-type="bibr" rid="bib15">Makin et al., 2013a</xref>). Here we show that compensatory arm usage in individuals born without a hand (one-handers) reflects functional connectivity of spontaneous brain activity in the cortical hand region. Compared with two-handed controls, one-handers showed reduced symmetry of hand region inter-hemispheric resting-state functional connectivity and corticospinal white matter microstructure. Nevertheless, those one-handers who more frequently use their residual (handless) arm for typically bimanual daily tasks also showed more symmetrical functional connectivity of the hand region, demonstrating that adaptive behaviour drives long-range brain organisation. We therefore suggest that compensatory arm usage maintains symmetrical sensorimotor functional connectivity in one-handers. Since variability in spontaneous functional connectivity in our study reflects ecological behaviour, we propose that inter-hemispheric symmetry, typically observed in resting sensorimotor networks, depends on coordinated motor behaviour in daily life.

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