The Experts below are selected from a list of 20139 Experts worldwide ranked by ideXlab platform
Arno Villringer - One of the best experts on this subject based on the ideXlab platform.
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Effects of Finger Tapping Frequency on Regional Homogeneity of Sensorimotor Cortex
2016Co-Authors: Daniel S Margulies, Arno Villringer, Yu-feng ZangAbstract:Resting-state functional magnetic resonance imaging (RS-fMRI) has been widely used to investigate temporally correlated fluctuations between distributed brain areas, as well as to characterize local synchronization of low frequency (,0.1 Hz) spontaneous fMRI signal. Regional homogeneity (ReHo) was proposed as a voxel-wise measure of the synchronization of the timecourses of neighboring voxels and has been used in many studies of brain disorders. However, the interpretation of ReHo remains challenging because the effect of high frequency task on ReHo is still not clear. In order to investigate the effect of a high-frequency task on the modulation of local synchronization of resting-state activity, we employed three right-finger movement scanning sessions: slow-event related (‘Slow’), fast-event related (‘Fast’), and continuous finger pressure (‘Tonic’), from 21 healthy participants and compared the ReHo of the three task states with that of resting-state (‘Rest’). In the contralateral Sensorimotor Cortex, ‘Slow ’ task state showed greater ReHo than ‘Rest ’ in low frequency band (0–0.08Hz) fMRI signal, but lower ReHo in high frequency band (0.08–1.67 Hz); ‘Fast ’ task state showed lower ReHo than ‘Rest ’ in both the low and high frequency band; ‘Tonic ’ state did not show any significant difference compared to ‘Rest’. The results in the contralateral Sensorimotor Cortex suggest that local synchronization of BOLD signal varies with different finger tapping speed. In the ipsilateral Sensorimotor Cortex, all the three task states had lower ReHo than the ‘Rest ’ state both in the low and high frequency, suggesting a similar effect of fast and slow finger tapping frequencies on local synchronization of BOL
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functional connectivity based parcellation of the human Sensorimotor Cortex
European Journal of Neuroscience, 2014Co-Authors: Xiangyu Long, Dominique Goltz, Daniel S Margulies, Till Nierhaus, Arno VillringerAbstract:Task-based functional magnetic resonance imaging (fMRI) has been successfully employed to obtain somatotopic maps of the human Sensorimotor Cortex. Here, we showed through direct comparison that a similar functional map can be obtained, independently of a task, by performing a connectivity-based parcellation of the Sensorimotor Cortex based on resting-state fMRI. Cortex corresponding to two adjacent Brodmann areas (BA 3 and BA 4) was selected as the Sensorimotor area. Parcellation was obtained along a medial–lateral axis, which was confirmed to be somatotopic (corresponding roughly to an upper, middle and lower limb, respectively) by comparing it with maps obtained using motoric task-based fMRI in the same participants. Interestingly, the resting-state parcellation map demonstrated higher correspondence to the task-based divisions after individuals performed the motor task. Using the resting-state fMRI data, we also observed higher functional correlations between the centrally located hand region and the other two regions, than between the foot and tongue. The functional relevance of these somatosensory parcellation results indicates the feasibility of a wide range of potential applications to brain mapping.
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effects of finger tapping frequency on regional homogeneity of Sensorimotor Cortex
PLOS ONE, 2013Co-Authors: Daniel S Margulies, Arno Villringer, Yu-feng ZangAbstract:Resting-state functional magnetic resonance imaging (RS-fMRI) has been widely used to investigate temporally correlated fluctuations between distributed brain areas, as well as to characterize local synchronization of low frequency (<0.1 Hz) spontaneous fMRI signal. Regional homogeneity (ReHo) was proposed as a voxel-wise measure of the synchronization of the timecourses of neighboring voxels and has been used in many studies of brain disorders. However, the interpretation of ReHo remains challenging because the effect of high frequency task on ReHo is still not clear. In order to investigate the effect of a high-frequency task on the modulation of local synchronization of resting-state activity, we employed three right-finger movement scanning sessions: slow-event related (‘Slow’), fast-event related (‘Fast’), and continuous finger pressure (‘Tonic’), from 21 healthy participants and compared the ReHo of the three task states with that of resting-state (‘Rest’). In the contralateral Sensorimotor Cortex, ‘Slow’ task state showed greater ReHo than ‘Rest’ in low frequency band (0–0.08Hz) fMRI signal, but lower ReHo in high frequency band (0.08–1.67 Hz); ‘Fast’ task state showed lower ReHo than ‘Rest’ in both the low and high frequency band; ‘Tonic’ state did not show any significant difference compared to ‘Rest’. The results in the contralateral Sensorimotor Cortex suggest that local synchronization of BOLD signal varies with different finger tapping speed. In the ipsilateral Sensorimotor Cortex, all the three task states had lower ReHo than the ‘Rest’ state both in the low and high frequency, suggesting a similar effect of fast and slow finger tapping frequencies on local synchronization of BOLD signal in the ipsilateral motor Cortex.
Edward F. Chang - One of the best experts on this subject based on the ideXlab platform.
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encoding of articulatory kinematic trajectories in human speech Sensorimotor Cortex
Neuron, 2018Co-Authors: Josh Chartier, Keith A Johnson, Gopala Krishna Anumanchipalli, Edward F. ChangAbstract:Summary When speaking, we dynamically coordinate movements of our jaw, tongue, lips, and larynx. To investigate the neural mechanisms underlying articulation, we used direct cortical recordings from human Sensorimotor Cortex while participants spoke natural sentences that included sounds spanning the entire English phonetic inventory. We used deep neural networks to infer speakers' articulator movements from produced speech acoustics. Individual electrodes encoded a diversity of articulatory kinematic trajectories (AKTs), each revealing coordinated articulator movements toward specific vocal tract shapes. AKTs captured a wide range of movement types, yet they could be differentiated by the place of vocal tract constriction. Additionally, AKTs manifested out-and-back trajectories with harmonic oscillator dynamics. While AKTs were functionally stereotyped across different sentences, context-dependent encoding of preceding and following movements during production of the same phoneme demonstrated the cortical representation of coarticulation. Articulatory movements encoded in Sensorimotor Cortex give rise to the complex kinematics underlying continuous speech production. Video Abstract
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functional organization of human Sensorimotor Cortex for speech articulation
Nature, 2013Co-Authors: Kristofer E Bouchard, Keith A Johnson, Nima Mesgarani, Edward F. ChangAbstract:Speaking is one of the most complex actions we perform, yet nearly all of us learn to do it effortlessly. Production of fluent speech requires the precise, coordinated movement of multiple articulators (e.g., lips, jaw, tongue, larynx) over rapid time scales. Here, we used high-resolution, multi-electrode cortical recordings during the production of consonant-vowel syllables to determine the organization of speech Sensorimotor Cortex in humans. We found speech articulator representations that were somatotopically arranged on ventral pre- and post-central gyri and partially overlapping at individual electrodes. These representations were temporally coordinated as sequences during syllable production. Spatial patterns of cortical activity revealed an emergent, population-level representation, which was organized by phonetic features. Over tens of milliseconds, the spatial patterns transitioned between distinct representations for different consonants and vowels. These results reveal the dynamic organization of speech Sensorimotor Cortex during the generation of multi-articulator movements underlying our ability to speak.
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functional organization of human Sensorimotor Cortex for speech articulation
Nature, 2013Co-Authors: Kristofer E Bouchard, Keith A Johnson, Nima Mesgarani, Edward F. ChangAbstract:Speaking is one of the most complex actions that we perform, but nearly all of us learn to do it effortlessly. Production of fluent speech requires the precise, coordinated movement of multiple articulators (for example, the lips, jaw, tongue and larynx) over rapid time scales. Here we used high-resolution, multi-electrode cortical recordings during the production of consonant-vowel syllables to determine the organization of speech Sensorimotor Cortex in humans. We found speech-articulator representations that are arranged somatotopically on ventral pre- and post-central gyri, and that partially overlap at individual electrodes. These representations were coordinated temporally as sequences during syllable production. Spatial patterns of cortical activity showed an emergent, population-level representation, which was organized by phonetic features. Over tens of milliseconds, the spatial patterns transitioned between distinct representations for different consonants and vowels. These results reveal the dynamic organization of speech Sensorimotor Cortex during the generation of multi-articulator movements that underlies our ability to speak.
Antti Revonsuo - One of the best experts on this subject based on the ideXlab platform.
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modulating dream experience noninvasive brain stimulation over the Sensorimotor Cortex reduces dream movement
Scientific Reports, 2020Co-Authors: Valdas Noreika, Jennifer Michelle Windt, Markus Kern, Katja Valli, Tiina Salonen, Riitta Parkkola, Antti RevonsuoAbstract:: Recently, cortical correlates of specific dream contents have been reported, such as the activation of the Sensorimotor Cortex during dreamed hand clenching. Yet, despite a close resemblance of such activation patterns to those seen during the corresponding wakeful behaviour, the causal mechanisms underlying specific dream contents remain largely elusive. Here, we aimed to investigate the causal role of the Sensorimotor Cortex in generating movement and bodily sensations during REM sleep dreaming. Following bihemispheric transcranial direct current stimulation (tDCS) or sham stimulation, guided by functional mapping of the primary motor Cortex, naive participants were awakened from REM sleep and responded to a questionnaire on bodily sensations in dreams. Electromyographic (EMG) and electroencephalographic (EEG) recordings were used to quantify physiological changes during the preceding REM period. We found that tDCS, compared to sham stimulation, significantly decreased reports of dream movement, especially of repetitive actions. Other types of bodily experiences, such as tactile or vestibular sensations, were not affected by tDCS, confirming the specificity of stimulation effects to movement sensations. In addition, tDCS reduced EEG interhemispheric coherence in parietal areas and affected the phasic EMG correlation between both arms. These findings show that a complex temporal reorganization of the motor network co-occurred with the reduction of dream movement, revealing a link between central and peripheral motor processes and movement sensations of the dream self. tDCS over the Sensorimotor Cortex interferes with dream movement during REM sleep, which is consistent with a causal contribution to dream experience and has broader implications for understanding the neural basis of self-experience in dreams.
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modulating dream experience noninvasive brain stimulation over the Sensorimotor Cortex reduces dream movement
bioRxiv, 2019Co-Authors: Valdas Noreika, Jennifer Michelle Windt, Markus Kern, Katja Valli, Tiina Salonen, Riitta Parkkola, Antti RevonsuoAbstract:Abstract Recently, cortical correlates of specific dream contents have been reported, such as the activation of the Sensorimotor Cortex during dreamed hand clenching. Yet, the causal mechanisms underlying specific dream content remain largely elusive. Here, we investigated how alterations in the excitability of Sensorimotor areas through transcranial direct current stimulation (tDCS) might alter dream content. Following bihemispheric tDCS or sham stimulation, participants who were awakened from REM sleep filled out a questionnaire on bodily sensations in dreams. tDCS, compared to sham stimulation, significantly decreased reports of dream movement, especially repetitive actions. Contrary to this, other types of bodily experiences, such as tactile or vestibular sensations, were not affected by tDCS, confirming the specificity of stimulation effects. In addition, tDCS reduced interhemispheric coherence in parietal areas and altered the phasic electromyography correlation between the two arms. These findings reveal that a complex reorganization of the motor network co-occurred with the reduction of dream movement, confirming spatial specificity of the stimulation site. We conclude that tDCS over the Sensorimotor Cortex causally interferes with dream movement during REM sleep.
Daniel S Margulies - One of the best experts on this subject based on the ideXlab platform.
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Effects of Finger Tapping Frequency on Regional Homogeneity of Sensorimotor Cortex
2016Co-Authors: Daniel S Margulies, Arno Villringer, Yu-feng ZangAbstract:Resting-state functional magnetic resonance imaging (RS-fMRI) has been widely used to investigate temporally correlated fluctuations between distributed brain areas, as well as to characterize local synchronization of low frequency (,0.1 Hz) spontaneous fMRI signal. Regional homogeneity (ReHo) was proposed as a voxel-wise measure of the synchronization of the timecourses of neighboring voxels and has been used in many studies of brain disorders. However, the interpretation of ReHo remains challenging because the effect of high frequency task on ReHo is still not clear. In order to investigate the effect of a high-frequency task on the modulation of local synchronization of resting-state activity, we employed three right-finger movement scanning sessions: slow-event related (‘Slow’), fast-event related (‘Fast’), and continuous finger pressure (‘Tonic’), from 21 healthy participants and compared the ReHo of the three task states with that of resting-state (‘Rest’). In the contralateral Sensorimotor Cortex, ‘Slow ’ task state showed greater ReHo than ‘Rest ’ in low frequency band (0–0.08Hz) fMRI signal, but lower ReHo in high frequency band (0.08–1.67 Hz); ‘Fast ’ task state showed lower ReHo than ‘Rest ’ in both the low and high frequency band; ‘Tonic ’ state did not show any significant difference compared to ‘Rest’. The results in the contralateral Sensorimotor Cortex suggest that local synchronization of BOLD signal varies with different finger tapping speed. In the ipsilateral Sensorimotor Cortex, all the three task states had lower ReHo than the ‘Rest ’ state both in the low and high frequency, suggesting a similar effect of fast and slow finger tapping frequencies on local synchronization of BOL
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functional connectivity based parcellation of the human Sensorimotor Cortex
European Journal of Neuroscience, 2014Co-Authors: Xiangyu Long, Dominique Goltz, Daniel S Margulies, Till Nierhaus, Arno VillringerAbstract:Task-based functional magnetic resonance imaging (fMRI) has been successfully employed to obtain somatotopic maps of the human Sensorimotor Cortex. Here, we showed through direct comparison that a similar functional map can be obtained, independently of a task, by performing a connectivity-based parcellation of the Sensorimotor Cortex based on resting-state fMRI. Cortex corresponding to two adjacent Brodmann areas (BA 3 and BA 4) was selected as the Sensorimotor area. Parcellation was obtained along a medial–lateral axis, which was confirmed to be somatotopic (corresponding roughly to an upper, middle and lower limb, respectively) by comparing it with maps obtained using motoric task-based fMRI in the same participants. Interestingly, the resting-state parcellation map demonstrated higher correspondence to the task-based divisions after individuals performed the motor task. Using the resting-state fMRI data, we also observed higher functional correlations between the centrally located hand region and the other two regions, than between the foot and tongue. The functional relevance of these somatosensory parcellation results indicates the feasibility of a wide range of potential applications to brain mapping.
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effects of finger tapping frequency on regional homogeneity of Sensorimotor Cortex
PLOS ONE, 2013Co-Authors: Daniel S Margulies, Arno Villringer, Yu-feng ZangAbstract:Resting-state functional magnetic resonance imaging (RS-fMRI) has been widely used to investigate temporally correlated fluctuations between distributed brain areas, as well as to characterize local synchronization of low frequency (<0.1 Hz) spontaneous fMRI signal. Regional homogeneity (ReHo) was proposed as a voxel-wise measure of the synchronization of the timecourses of neighboring voxels and has been used in many studies of brain disorders. However, the interpretation of ReHo remains challenging because the effect of high frequency task on ReHo is still not clear. In order to investigate the effect of a high-frequency task on the modulation of local synchronization of resting-state activity, we employed three right-finger movement scanning sessions: slow-event related (‘Slow’), fast-event related (‘Fast’), and continuous finger pressure (‘Tonic’), from 21 healthy participants and compared the ReHo of the three task states with that of resting-state (‘Rest’). In the contralateral Sensorimotor Cortex, ‘Slow’ task state showed greater ReHo than ‘Rest’ in low frequency band (0–0.08Hz) fMRI signal, but lower ReHo in high frequency band (0.08–1.67 Hz); ‘Fast’ task state showed lower ReHo than ‘Rest’ in both the low and high frequency band; ‘Tonic’ state did not show any significant difference compared to ‘Rest’. The results in the contralateral Sensorimotor Cortex suggest that local synchronization of BOLD signal varies with different finger tapping speed. In the ipsilateral Sensorimotor Cortex, all the three task states had lower ReHo than the ‘Rest’ state both in the low and high frequency, suggesting a similar effect of fast and slow finger tapping frequencies on local synchronization of BOLD signal in the ipsilateral motor Cortex.
Yu-feng Zang - One of the best experts on this subject based on the ideXlab platform.
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Effects of Finger Tapping Frequency on Regional Homogeneity of Sensorimotor Cortex
2016Co-Authors: Daniel S Margulies, Arno Villringer, Yu-feng ZangAbstract:Resting-state functional magnetic resonance imaging (RS-fMRI) has been widely used to investigate temporally correlated fluctuations between distributed brain areas, as well as to characterize local synchronization of low frequency (,0.1 Hz) spontaneous fMRI signal. Regional homogeneity (ReHo) was proposed as a voxel-wise measure of the synchronization of the timecourses of neighboring voxels and has been used in many studies of brain disorders. However, the interpretation of ReHo remains challenging because the effect of high frequency task on ReHo is still not clear. In order to investigate the effect of a high-frequency task on the modulation of local synchronization of resting-state activity, we employed three right-finger movement scanning sessions: slow-event related (‘Slow’), fast-event related (‘Fast’), and continuous finger pressure (‘Tonic’), from 21 healthy participants and compared the ReHo of the three task states with that of resting-state (‘Rest’). In the contralateral Sensorimotor Cortex, ‘Slow ’ task state showed greater ReHo than ‘Rest ’ in low frequency band (0–0.08Hz) fMRI signal, but lower ReHo in high frequency band (0.08–1.67 Hz); ‘Fast ’ task state showed lower ReHo than ‘Rest ’ in both the low and high frequency band; ‘Tonic ’ state did not show any significant difference compared to ‘Rest’. The results in the contralateral Sensorimotor Cortex suggest that local synchronization of BOLD signal varies with different finger tapping speed. In the ipsilateral Sensorimotor Cortex, all the three task states had lower ReHo than the ‘Rest ’ state both in the low and high frequency, suggesting a similar effect of fast and slow finger tapping frequencies on local synchronization of BOL
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effects of finger tapping frequency on regional homogeneity of Sensorimotor Cortex
PLOS ONE, 2013Co-Authors: Daniel S Margulies, Arno Villringer, Yu-feng ZangAbstract:Resting-state functional magnetic resonance imaging (RS-fMRI) has been widely used to investigate temporally correlated fluctuations between distributed brain areas, as well as to characterize local synchronization of low frequency (<0.1 Hz) spontaneous fMRI signal. Regional homogeneity (ReHo) was proposed as a voxel-wise measure of the synchronization of the timecourses of neighboring voxels and has been used in many studies of brain disorders. However, the interpretation of ReHo remains challenging because the effect of high frequency task on ReHo is still not clear. In order to investigate the effect of a high-frequency task on the modulation of local synchronization of resting-state activity, we employed three right-finger movement scanning sessions: slow-event related (‘Slow’), fast-event related (‘Fast’), and continuous finger pressure (‘Tonic’), from 21 healthy participants and compared the ReHo of the three task states with that of resting-state (‘Rest’). In the contralateral Sensorimotor Cortex, ‘Slow’ task state showed greater ReHo than ‘Rest’ in low frequency band (0–0.08Hz) fMRI signal, but lower ReHo in high frequency band (0.08–1.67 Hz); ‘Fast’ task state showed lower ReHo than ‘Rest’ in both the low and high frequency band; ‘Tonic’ state did not show any significant difference compared to ‘Rest’. The results in the contralateral Sensorimotor Cortex suggest that local synchronization of BOLD signal varies with different finger tapping speed. In the ipsilateral Sensorimotor Cortex, all the three task states had lower ReHo than the ‘Rest’ state both in the low and high frequency, suggesting a similar effect of fast and slow finger tapping frequencies on local synchronization of BOLD signal in the ipsilateral motor Cortex.
