The Experts below are selected from a list of 317973 Experts worldwide ranked by ideXlab platform
Winston Chiong - One of the best experts on this subject based on the ideXlab platform.
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the salience Network causally influences default mode Network Activity during moral reasoning
Brain, 2013Co-Authors: Andrew S Kayser, Scott Grossman, Pardis Poorzand, Stephen M Wilson, Winston Chiong, Mark Desposito, William W Seeley, Bruce L MillerAbstract:Large-scale brain Networks are integral to the coordination of human behaviour, and their anatomy provides insights into the clinical presentation and progression of neurodegenerative illnesses such as Alzheimer’s disease, which targets the default mode Network, and behavioural variant frontotemporal dementia, which targets a more anterior salience Network. Although the default mode Network is recruited when healthy subjects deliberate about ‘personal’ moral dilemmas, patients with Alzheimer’s disease give normal responses to these dilemmas whereas patients with behavioural variant frontotemporal dementia give abnormal responses to these dilemmas. We hypothesized that this apparent discrepancy between activation- and patient-based studies of moral reasoning might reflect a modulatory role for the salience Network in regulating default mode Network activation. Using functional magnetic resonance imaging to characterize Network Activity of patients with behavioural variant frontotemporal dementia and healthy control subjects, we present four converging lines of evidence supporting a causal influence from the salience Network to the default mode Network during moral reasoning. First, as previously reported, the default mode Network is recruited when healthy subjects deliberate about ‘personal’ moral dilemmas, but patients with behavioural variant frontotemporal dementia producing atrophy in the salience Network give abnormally utilitarian responses to these dilemmas. Second, patients with behavioural variant frontotemporal dementia have reduced recruitment of the default mode Network compared with healthy control subjects when deliberating about these dilemmas. Third, a Granger causality analysis of functional neuroimaging data from healthy control subjects demonstrates directed functional connectivity from nodes of the salience Network to nodes of the default mode Network during moral reasoning. Fourth, this Granger causal influence is diminished in patients with behavioural variant frontotemporal dementia. These findings are consistent with a broader model in which the salience Network modulates the Activity of other large-scale Networks, and suggest a revision to a previously proposed ‘dual-process’ account of moral reasoning. These findings also characterize Network interactions underlying abnormal moral reasoning in frontotemporal dementia, which may serve as a model for the aberrant judgement and interpersonal behaviour observed in this disease and in other disorders of social function. More broadly, these findings link recent work on the dynamic interrelationships between large-scale brain Networks to observable impairments in dementia syndromes, which may shed light on how diseases that target one Network also alter the function of interrelated Networks. * Abbreviation : FTD : frontotemporal dementia
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The salience Network causally influences default mode Network Activity during moral reasoning.
Brain : a journal of neurology, 2013Co-Authors: Winston Chiong, Andrew S Kayser, Pardis Poorzand, Scott N Grossman, Stephen M Wilson, William W Seeley, Bruce L Miller, Mark D'esposito, Katherine P RankinAbstract:Large-scale brain Networks are integral to the coordination of human behaviour, and their anatomy provides insights into the clinical presentation and progression of neurodegenerative illnesses such as Alzheimer's disease, which targets the default mode Network, and behavioural variant frontotemporal dementia, which targets a more anterior salience Network. Although the default mode Network is recruited when healthy subjects deliberate about 'personal' moral dilemmas, patients with Alzheimer's disease give normal responses to these dilemmas whereas patients with behavioural variant frontotemporal dementia give abnormal responses to these dilemmas. We hypothesized that this apparent discrepancy between activation- and patient-based studies of moral reasoning might reflect a modulatory role for the salience Network in regulating default mode Network activation. Using functional magnetic resonance imaging to characterize Network Activity of patients with behavioural variant frontotemporal dementia and healthy control subjects, we present four converging lines of evidence supporting a causal influence from the salience Network to the default mode Network during moral reasoning. First, as previously reported, the default mode Network is recruited when healthy subjects deliberate about 'personal' moral dilemmas, but patients with behavioural variant frontotemporal dementia producing atrophy in the salience Network give abnormally utilitarian responses to these dilemmas. Second, patients with behavioural variant frontotemporal dementia have reduced recruitment of the default mode Network compared with healthy control subjects when deliberating about these dilemmas. Third, a Granger causality analysis of functional neuroimaging data from healthy control subjects demonstrates directed functional connectivity from nodes of the salience Network to nodes of the default mode Network during moral reasoning. Fourth, this Granger causal influence is diminished in patients with behavioural variant frontotemporal dementia. These findings are consistent with a broader model in which the salience Network modulates the Activity of other large-scale Networks, and suggest a revision to a previously proposed 'dual-process' account of moral reasoning. These findings also characterize Network interactions underlying abnormal moral reasoning in frontotemporal dementia, which may serve as a model for the aberrant judgement and interpersonal behaviour observed in this disease and in other disorders of social function. More broadly, these findings link recent work on the dynamic interrelationships between large-scale brain Networks to observable impairments in dementia syndromes, which may shed light on how diseases that target one Network also alter the function of interrelated Networks.
Bruce L Miller - One of the best experts on this subject based on the ideXlab platform.
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the salience Network causally influences default mode Network Activity during moral reasoning
Brain, 2013Co-Authors: Andrew S Kayser, Scott Grossman, Pardis Poorzand, Stephen M Wilson, Winston Chiong, Mark Desposito, William W Seeley, Bruce L MillerAbstract:Large-scale brain Networks are integral to the coordination of human behaviour, and their anatomy provides insights into the clinical presentation and progression of neurodegenerative illnesses such as Alzheimer’s disease, which targets the default mode Network, and behavioural variant frontotemporal dementia, which targets a more anterior salience Network. Although the default mode Network is recruited when healthy subjects deliberate about ‘personal’ moral dilemmas, patients with Alzheimer’s disease give normal responses to these dilemmas whereas patients with behavioural variant frontotemporal dementia give abnormal responses to these dilemmas. We hypothesized that this apparent discrepancy between activation- and patient-based studies of moral reasoning might reflect a modulatory role for the salience Network in regulating default mode Network activation. Using functional magnetic resonance imaging to characterize Network Activity of patients with behavioural variant frontotemporal dementia and healthy control subjects, we present four converging lines of evidence supporting a causal influence from the salience Network to the default mode Network during moral reasoning. First, as previously reported, the default mode Network is recruited when healthy subjects deliberate about ‘personal’ moral dilemmas, but patients with behavioural variant frontotemporal dementia producing atrophy in the salience Network give abnormally utilitarian responses to these dilemmas. Second, patients with behavioural variant frontotemporal dementia have reduced recruitment of the default mode Network compared with healthy control subjects when deliberating about these dilemmas. Third, a Granger causality analysis of functional neuroimaging data from healthy control subjects demonstrates directed functional connectivity from nodes of the salience Network to nodes of the default mode Network during moral reasoning. Fourth, this Granger causal influence is diminished in patients with behavioural variant frontotemporal dementia. These findings are consistent with a broader model in which the salience Network modulates the Activity of other large-scale Networks, and suggest a revision to a previously proposed ‘dual-process’ account of moral reasoning. These findings also characterize Network interactions underlying abnormal moral reasoning in frontotemporal dementia, which may serve as a model for the aberrant judgement and interpersonal behaviour observed in this disease and in other disorders of social function. More broadly, these findings link recent work on the dynamic interrelationships between large-scale brain Networks to observable impairments in dementia syndromes, which may shed light on how diseases that target one Network also alter the function of interrelated Networks. * Abbreviation : FTD : frontotemporal dementia
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The salience Network causally influences default mode Network Activity during moral reasoning.
Brain : a journal of neurology, 2013Co-Authors: Winston Chiong, Andrew S Kayser, Pardis Poorzand, Scott N Grossman, Stephen M Wilson, William W Seeley, Bruce L Miller, Mark D'esposito, Katherine P RankinAbstract:Large-scale brain Networks are integral to the coordination of human behaviour, and their anatomy provides insights into the clinical presentation and progression of neurodegenerative illnesses such as Alzheimer's disease, which targets the default mode Network, and behavioural variant frontotemporal dementia, which targets a more anterior salience Network. Although the default mode Network is recruited when healthy subjects deliberate about 'personal' moral dilemmas, patients with Alzheimer's disease give normal responses to these dilemmas whereas patients with behavioural variant frontotemporal dementia give abnormal responses to these dilemmas. We hypothesized that this apparent discrepancy between activation- and patient-based studies of moral reasoning might reflect a modulatory role for the salience Network in regulating default mode Network activation. Using functional magnetic resonance imaging to characterize Network Activity of patients with behavioural variant frontotemporal dementia and healthy control subjects, we present four converging lines of evidence supporting a causal influence from the salience Network to the default mode Network during moral reasoning. First, as previously reported, the default mode Network is recruited when healthy subjects deliberate about 'personal' moral dilemmas, but patients with behavioural variant frontotemporal dementia producing atrophy in the salience Network give abnormally utilitarian responses to these dilemmas. Second, patients with behavioural variant frontotemporal dementia have reduced recruitment of the default mode Network compared with healthy control subjects when deliberating about these dilemmas. Third, a Granger causality analysis of functional neuroimaging data from healthy control subjects demonstrates directed functional connectivity from nodes of the salience Network to nodes of the default mode Network during moral reasoning. Fourth, this Granger causal influence is diminished in patients with behavioural variant frontotemporal dementia. These findings are consistent with a broader model in which the salience Network modulates the Activity of other large-scale Networks, and suggest a revision to a previously proposed 'dual-process' account of moral reasoning. These findings also characterize Network interactions underlying abnormal moral reasoning in frontotemporal dementia, which may serve as a model for the aberrant judgement and interpersonal behaviour observed in this disease and in other disorders of social function. More broadly, these findings link recent work on the dynamic interrelationships between large-scale brain Networks to observable impairments in dementia syndromes, which may shed light on how diseases that target one Network also alter the function of interrelated Networks.
Andrew S Kayser - One of the best experts on this subject based on the ideXlab platform.
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the salience Network causally influences default mode Network Activity during moral reasoning
Brain, 2013Co-Authors: Andrew S Kayser, Scott Grossman, Pardis Poorzand, Stephen M Wilson, Winston Chiong, Mark Desposito, William W Seeley, Bruce L MillerAbstract:Large-scale brain Networks are integral to the coordination of human behaviour, and their anatomy provides insights into the clinical presentation and progression of neurodegenerative illnesses such as Alzheimer’s disease, which targets the default mode Network, and behavioural variant frontotemporal dementia, which targets a more anterior salience Network. Although the default mode Network is recruited when healthy subjects deliberate about ‘personal’ moral dilemmas, patients with Alzheimer’s disease give normal responses to these dilemmas whereas patients with behavioural variant frontotemporal dementia give abnormal responses to these dilemmas. We hypothesized that this apparent discrepancy between activation- and patient-based studies of moral reasoning might reflect a modulatory role for the salience Network in regulating default mode Network activation. Using functional magnetic resonance imaging to characterize Network Activity of patients with behavioural variant frontotemporal dementia and healthy control subjects, we present four converging lines of evidence supporting a causal influence from the salience Network to the default mode Network during moral reasoning. First, as previously reported, the default mode Network is recruited when healthy subjects deliberate about ‘personal’ moral dilemmas, but patients with behavioural variant frontotemporal dementia producing atrophy in the salience Network give abnormally utilitarian responses to these dilemmas. Second, patients with behavioural variant frontotemporal dementia have reduced recruitment of the default mode Network compared with healthy control subjects when deliberating about these dilemmas. Third, a Granger causality analysis of functional neuroimaging data from healthy control subjects demonstrates directed functional connectivity from nodes of the salience Network to nodes of the default mode Network during moral reasoning. Fourth, this Granger causal influence is diminished in patients with behavioural variant frontotemporal dementia. These findings are consistent with a broader model in which the salience Network modulates the Activity of other large-scale Networks, and suggest a revision to a previously proposed ‘dual-process’ account of moral reasoning. These findings also characterize Network interactions underlying abnormal moral reasoning in frontotemporal dementia, which may serve as a model for the aberrant judgement and interpersonal behaviour observed in this disease and in other disorders of social function. More broadly, these findings link recent work on the dynamic interrelationships between large-scale brain Networks to observable impairments in dementia syndromes, which may shed light on how diseases that target one Network also alter the function of interrelated Networks. * Abbreviation : FTD : frontotemporal dementia
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The salience Network causally influences default mode Network Activity during moral reasoning.
Brain : a journal of neurology, 2013Co-Authors: Winston Chiong, Andrew S Kayser, Pardis Poorzand, Scott N Grossman, Stephen M Wilson, William W Seeley, Bruce L Miller, Mark D'esposito, Katherine P RankinAbstract:Large-scale brain Networks are integral to the coordination of human behaviour, and their anatomy provides insights into the clinical presentation and progression of neurodegenerative illnesses such as Alzheimer's disease, which targets the default mode Network, and behavioural variant frontotemporal dementia, which targets a more anterior salience Network. Although the default mode Network is recruited when healthy subjects deliberate about 'personal' moral dilemmas, patients with Alzheimer's disease give normal responses to these dilemmas whereas patients with behavioural variant frontotemporal dementia give abnormal responses to these dilemmas. We hypothesized that this apparent discrepancy between activation- and patient-based studies of moral reasoning might reflect a modulatory role for the salience Network in regulating default mode Network activation. Using functional magnetic resonance imaging to characterize Network Activity of patients with behavioural variant frontotemporal dementia and healthy control subjects, we present four converging lines of evidence supporting a causal influence from the salience Network to the default mode Network during moral reasoning. First, as previously reported, the default mode Network is recruited when healthy subjects deliberate about 'personal' moral dilemmas, but patients with behavioural variant frontotemporal dementia producing atrophy in the salience Network give abnormally utilitarian responses to these dilemmas. Second, patients with behavioural variant frontotemporal dementia have reduced recruitment of the default mode Network compared with healthy control subjects when deliberating about these dilemmas. Third, a Granger causality analysis of functional neuroimaging data from healthy control subjects demonstrates directed functional connectivity from nodes of the salience Network to nodes of the default mode Network during moral reasoning. Fourth, this Granger causal influence is diminished in patients with behavioural variant frontotemporal dementia. These findings are consistent with a broader model in which the salience Network modulates the Activity of other large-scale Networks, and suggest a revision to a previously proposed 'dual-process' account of moral reasoning. These findings also characterize Network interactions underlying abnormal moral reasoning in frontotemporal dementia, which may serve as a model for the aberrant judgement and interpersonal behaviour observed in this disease and in other disorders of social function. More broadly, these findings link recent work on the dynamic interrelationships between large-scale brain Networks to observable impairments in dementia syndromes, which may shed light on how diseases that target one Network also alter the function of interrelated Networks.
Rejko Krüger - One of the best experts on this subject based on the ideXlab platform.
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subthalamic stimulation modulates cortical motor Network Activity and synchronization in parkinson s disease
Brain, 2015Co-Authors: Daniel Weiss, Rosa Klotz, Rathinaswamy B Govindan, Marlieke Scholten, Georgios Naros, Friedemann Bunjes, Christoph Meisner, Christian Plewnia, Ander Ramosmurguialday, Rejko KrügerAbstract:Dynamic modulations of large-scale Network Activity and synchronization are inherent to a broad spectrum of cognitive processes and are disturbed in neuropsychiatric conditions including Parkinson’s disease. Here, we set out to address the motor Network Activity and synchronization in Parkinson’s disease and its modulation with subthalamic stimulation. To this end, 20 patients with idiopathic Parkinson’s disease with subthalamic nucleus stimulation were analysed on externally cued right hand finger movements with 1.5-s interstimulus interval. Simultaneous recordings were obtained from electromyography on antagonistic muscles (right flexor digitorum and extensor digitorum) together with 64-channel electroencephalography. Time-frequency event-related spectral perturbations were assessed to determine cortical and muscular Activity. Next, cross-spectra in the time-frequency domain were analysed to explore the cortico-cortical synchronization. The time-frequency modulations enabled us to select a time-frequency range relevant for motor processing. On these time-frequency windows, we developed an extension of the phase synchronization index to quantify the global cortico-cortical synchronization and to obtain topographic differentiations of distinct electrode sites with respect to their contributions to the global phase synchronization index. The spectral measures were used to predict clinical and reaction time outcome using regression analysis. We found that movement-related desynchronization of cortical Activity in the upper alpha and beta range was significantly facilitated with ‘stimulation on’ compared to ‘stimulation off’ on electrodes over the bilateral parietal, sensorimotor, premotor, supplementary-motor, and prefrontal areas, including the bilateral inferior prefrontal areas. These spectral modulations enabled us to predict both clinical and reaction time improvement from subthalamic stimulation. With ‘stimulation on’, interhemispheric cortico-cortical coherence in the beta band was significantly attenuated over the bilateral sensorimotor areas. Similarly, the global cortico-cortical phase synchronization was attenuated, and the topographic differentiation revealed stronger desynchronization over the (ipsilateral) right-hemispheric prefrontal, premotor and sensorimotor areas compared to ‘stimulation off’. We further demonstrated that the cortico-cortical phase synchronization was largely dominated by genuine neuronal coupling. The clinical improvement with ‘stimulation on’ compared to ‘stimulation off’ could be predicted from this cortical decoupling with multiple regressions, and the reduction of synchronization over the right prefrontal area showed a linear univariate correlation with clinical improvement. Our study demonstrates wide-spread Activity and synchronization modulations of the cortical motor Network, and highlights subthalamic stimulation as a Network-modulating therapy. Accordingly, subthalamic stimulation may release bilateral cortical computational resources by facilitating movement-related desynchronization. Moreover, the subthalamic nucleus is critical to balance inhibitory and facilitatory cortical players within the motor program. * Abbreviations : MRD : movement-related desynchronization STN-DBS : subthalamic nucleus–deep brain stimulation UPDRS : Unified Parkinson’s Disease Rating Scale
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Subthalamic stimulation modulates cortical motor Network Activity and synchronization in Parkinson's disease.
Brain : a journal of neurology, 2015Co-Authors: Daniel Weiss, Rosa Klotz, Rathinaswamy B Govindan, Marlieke Scholten, Georgios Naros, Ander Ramos-murguialday, Friedemann Bunjes, Christoph Meisner, Christian Plewnia, Rejko KrügerAbstract:Dynamic modulations of large-scale Network Activity and synchronization are inherent to a broad spectrum of cognitive processes and are disturbed in neuropsychiatric conditions including Parkinson's disease. Here, we set out to address the motor Network Activity and synchronization in Parkinson's disease and its modulation with subthalamic stimulation. To this end, 20 patients with idiopathic Parkinson's disease with subthalamic nucleus stimulation were analysed on externally cued right hand finger movements with 1.5-s interstimulus interval. Simultaneous recordings were obtained from electromyography on antagonistic muscles (right flexor digitorum and extensor digitorum) together with 64-channel electroencephalography. Time-frequency event-related spectral perturbations were assessed to determine cortical and muscular Activity. Next, cross-spectra in the time-frequency domain were analysed to explore the cortico-cortical synchronization. The time-frequency modulations enabled us to select a time-frequency range relevant for motor processing. On these time-frequency windows, we developed an extension of the phase synchronization index to quantify the global cortico-cortical synchronization and to obtain topographic differentiations of distinct electrode sites with respect to their contributions to the global phase synchronization index. The spectral measures were used to predict clinical and reaction time outcome using regression analysis. We found that movement-related desynchronization of cortical Activity in the upper alpha and beta range was significantly facilitated with 'stimulation on' compared to 'stimulation off' on electrodes over the bilateral parietal, sensorimotor, premotor, supplementary-motor, and prefrontal areas, including the bilateral inferior prefrontal areas. These spectral modulations enabled us to predict both clinical and reaction time improvement from subthalamic stimulation. With 'stimulation on', interhemispheric cortico-cortical coherence in the beta band was significantly attenuated over the bilateral sensorimotor areas. Similarly, the global cortico-cortical phase synchronization was attenuated, and the topographic differentiation revealed stronger desynchronization over the (ipsilateral) right-hemispheric prefrontal, premotor and sensorimotor areas compared to 'stimulation off'. We further demonstrated that the cortico-cortical phase synchronization was largely dominated by genuine neuronal coupling. The clinical improvement with 'stimulation on' compared to 'stimulation off' could be predicted from this cortical decoupling with multiple regressions, and the reduction of synchronization over the right prefrontal area showed a linear univariate correlation with clinical improvement. Our study demonstrates wide-spread Activity and synchronization modulations of the cortical motor Network, and highlights subthalamic stimulation as a Network-modulating therapy. Accordingly, subthalamic stimulation may release bilateral cortical computational resources by facilitating movement-related desynchronization. Moreover, the subthalamic nucleus is critical to balance inhibitory and facilitatory cortical players within the motor program.
Vinod Menon - One of the best experts on this subject based on the ideXlab platform.
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default mode Network Activity distinguishes alzheimer s disease from healthy aging evidence from functional mri
Proceedings of the National Academy of Sciences of the United States of America, 2004Co-Authors: Michael D Greicius, Gaurav Srivastava, Allan L. Reiss, Vinod MenonAbstract:Recent functional imaging studies have revealed coactivation in a distributed Network of cortical regions that characterizes the resting state, or default mode, of the human brain. Among the brain regions implicated in this Network, several, including the posterior cingulate cortex and inferior parietal lobes, have also shown decreased metabolism early in the course of Alzhei- mer's disease (AD). We reasoned that default-mode Network Activity might therefore be abnormal in AD. To test this hypoth- esis, we used independent component analysis to isolate the Network in a group of 13 subjects with mild AD and in a group of 13 age-matched elderly controls as they performed a simple sensory-motor processing task. Three important findings are reported. Prominent coactivation of the hippocampus, detected in all groups, suggests that the default-mode Network is closely involved with episodic memory processing. The AD group showed decreased resting-state Activity in the posterior cingu- late and hippocampus, suggesting that disrupted connectivity between these two regions accounts for the posterior cingulate hypometabolism commonly detected in positron emission to- mography studies of early AD. Finally, a goodness-of-fit analysis applied at the individual subject level suggests that Activity in the default-mode Network may ultimately prove a sensitive and specific biomarker for incipient AD.
