The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Hideaki Onishi - One of the best experts on this subject based on the ideXlab platform.
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Effects on motor learning of transcranial alternating current stimulation applied over the primary motor cortex and Cerebellar Hemisphere.
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia, 2020Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Yasuto Inukai, Yuya Matsumoto, Mai Miyashita, Ryo Takahashi, Hideaki OnishiAbstract:Abstract Transcranial alternating current stimulation (tACS) is a non-invasive method of brain stimulation that modulates oscillatory neural activity in the cortical area under the electrodes. Gamma (γ)-tACS applied over the primary motor cortex (M1) and Cerebellar Hemisphere is known to improve motor performance; however, it is not yet known whether it affects motor learning. Thus, here we investigated whether γ-tACS applied over the M1 and Cerebellar Hemisphere affects motor learning. This study involved 30 healthy subjects (14 females, 16 males) performing a visuomotor control task (eight trials) during an administration of either γ-tACS or a sham stimulation (15 subjects per condition) over their right M1 and left Cerebellar Hemisphere. Each subject performed five trials after 24 h. The motor learning efficiency, motor learning retention and re-motor learning efficiency in each condition were compared. The motor learning retention in the γ-tACS condition was significantly higher than that in the sham condition (p = 0.031). Thus, subjects who were administered γ-tACS maintained their motor performance the next day better than sham-stimulated subjects. There was no significant difference between the conditions in the motor learning efficiency and those in the re-motor learning efficiency. Our results demonstrate that γ-tACS administered over the M1 and Cerebellar Hemisphere during a motor learning task can enhance motor learning retention.
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The effect of gamma tACS over the M1 region and Cerebellar Hemisphere does not depend on current intensity.
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia, 2019Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Hirotake Yokota, Kei Saito, Yasuto Inukai, Hideaki OnishiAbstract:Abstract Transcranial alternating current stimulation (tACS) has been shown to modulate neural connectivity in the cortical area under experimental electrodes. Although gamma tACS over the M1 region and the Cerebellar Hemisphere has been shown to improve motor performance, the optimal stimulation method has not been clarified. In this study, we aimed to clarify whether the effect of gamma tACS over M1 and the Cerebellar Hemisphere depends on current intensity. Twenty healthy adults performed a visuomotor control task using their right index finger for 30 s during tACS (70 Hz) over the left M1 and the right Cerebellar Hemisphere. Each subject participated in 10 trials, separated by intervals of 3 min. Three stimulation conditions were applied: (1) pseudo-stimulation (sham condition), (2) tACS with a current intensity of 1.0 mA and (3) tACS with a current intensity of 2.0 mA. Our results indicated that regardless of the current intensity, participants with the lower motor performance had better motor performance under both tACS conditions. Such a correlation was not observed under the sham condition. Collectively, our findings demonstrated that the effect of gamma tACS over M1 and the Cerebellar Hemisphere does not depend on current intensity, and that motor performance slightly improved in both tACS conditions for participants with lower motor performance.
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Gamma tACS over M1 and Cerebellar Hemisphere improves motor performance in a phase-specific manner.
Neuroscience letters, 2018Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Hirotake Yokota, Kei Saito, Yasuto Inukai, Hideaki OnishiAbstract:Transcranial alternating current stimulation (tACS) modulates neural connectivity in the cortical area under the electrodes. Although gamma tACS over the M1 and the Cerebellar Hemisphere has been shown to improve motor performance, the details of this effect remain unclear. This study aimed to clarify whether the effect of gamma tACS over the M1 and the Cerebellar Hemisphere is a phase-specific. We applied tACS at 70 Hz over the left M1 and the right Cerebellar Hemisphere to 20 healthy adults while they performed a visuomotor control task using their right index finger for 30 s. Three stimulation conditions were applied: (1) pseudo-stimulation (sham condition), (2) 180° phase difference in the two cortical target areas (anti-phase condition) and (3) 0° phase difference (in-phase condition). The anti-phase condition decreased task error compared to the sham condition (P = 0.021), but did not differ from the in-phase condition. Our study demonstrated that the effect of gamma tACS over the M1 and the Cerebellar Hemisphere has phase specificity. This result suggests that intercortical functional synchronization is involved in the improvement of motor performance during gamma tACS over the M1 and the Cerebellar Hemisphere.
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Transcranial Alternating Current Stimulation With Gamma Oscillations Over the Primary Motor Cortex and Cerebellar Hemisphere Improved Visuomotor Performance.
Frontiers in behavioral neuroscience, 2018Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Kei Saito, Yasuto Inukai, Mitsuhiro Masaki, Hideaki OnishiAbstract:Transcranial alternating current stimulation (tACS) can be used to modulate oscillatory brain activity. In this study, we investigated whether tACS applied over the primary motor cortex (M1) and Cerebellar cortex region improved motor performance. We applied tACS (1.0 mA) to 20 healthy adults while they performed an isometric force task with some visuomotor control using their right index finger. Gamma (70 Hz) oscillations in the Experiment 1 or beta (20 Hz) oscillations in the Experiment 2 were applied for 30 s over the left M1, right Cerebellar Hemisphere or both regions ("M1-Cerebellum"), and errors performing the task were compared. Beta-oscillation tACS did not affect motor performance. With the gamma-oscillation tACS, a negative correlation was found between the difference of error in the M1-Cerebellum condition and the number of errors in the sham condition (P = 0.005, Pearson's r = -0.597), indicating that motor performance improved with M1-Cerebellum tACS for subjects with low motor performance in the sham condition. Those who performed poorly in the sham condition made significantly fewer errors with M1-Cerebellum tACS (P = 0.004). Thus, for subjects with poorer motor performance, tACS with gamma oscillations applied over the M1 and contralateral Cerebellar Hemisphere improved their performance.
Shota Miyaguchi - One of the best experts on this subject based on the ideXlab platform.
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Effects on motor learning of transcranial alternating current stimulation applied over the primary motor cortex and Cerebellar Hemisphere.
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia, 2020Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Yasuto Inukai, Yuya Matsumoto, Mai Miyashita, Ryo Takahashi, Hideaki OnishiAbstract:Abstract Transcranial alternating current stimulation (tACS) is a non-invasive method of brain stimulation that modulates oscillatory neural activity in the cortical area under the electrodes. Gamma (γ)-tACS applied over the primary motor cortex (M1) and Cerebellar Hemisphere is known to improve motor performance; however, it is not yet known whether it affects motor learning. Thus, here we investigated whether γ-tACS applied over the M1 and Cerebellar Hemisphere affects motor learning. This study involved 30 healthy subjects (14 females, 16 males) performing a visuomotor control task (eight trials) during an administration of either γ-tACS or a sham stimulation (15 subjects per condition) over their right M1 and left Cerebellar Hemisphere. Each subject performed five trials after 24 h. The motor learning efficiency, motor learning retention and re-motor learning efficiency in each condition were compared. The motor learning retention in the γ-tACS condition was significantly higher than that in the sham condition (p = 0.031). Thus, subjects who were administered γ-tACS maintained their motor performance the next day better than sham-stimulated subjects. There was no significant difference between the conditions in the motor learning efficiency and those in the re-motor learning efficiency. Our results demonstrate that γ-tACS administered over the M1 and Cerebellar Hemisphere during a motor learning task can enhance motor learning retention.
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The effect of gamma tACS over the M1 region and Cerebellar Hemisphere does not depend on current intensity.
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia, 2019Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Hirotake Yokota, Kei Saito, Yasuto Inukai, Hideaki OnishiAbstract:Abstract Transcranial alternating current stimulation (tACS) has been shown to modulate neural connectivity in the cortical area under experimental electrodes. Although gamma tACS over the M1 region and the Cerebellar Hemisphere has been shown to improve motor performance, the optimal stimulation method has not been clarified. In this study, we aimed to clarify whether the effect of gamma tACS over M1 and the Cerebellar Hemisphere depends on current intensity. Twenty healthy adults performed a visuomotor control task using their right index finger for 30 s during tACS (70 Hz) over the left M1 and the right Cerebellar Hemisphere. Each subject participated in 10 trials, separated by intervals of 3 min. Three stimulation conditions were applied: (1) pseudo-stimulation (sham condition), (2) tACS with a current intensity of 1.0 mA and (3) tACS with a current intensity of 2.0 mA. Our results indicated that regardless of the current intensity, participants with the lower motor performance had better motor performance under both tACS conditions. Such a correlation was not observed under the sham condition. Collectively, our findings demonstrated that the effect of gamma tACS over M1 and the Cerebellar Hemisphere does not depend on current intensity, and that motor performance slightly improved in both tACS conditions for participants with lower motor performance.
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Gamma tACS over M1 and Cerebellar Hemisphere improves motor performance in a phase-specific manner.
Neuroscience letters, 2018Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Hirotake Yokota, Kei Saito, Yasuto Inukai, Hideaki OnishiAbstract:Transcranial alternating current stimulation (tACS) modulates neural connectivity in the cortical area under the electrodes. Although gamma tACS over the M1 and the Cerebellar Hemisphere has been shown to improve motor performance, the details of this effect remain unclear. This study aimed to clarify whether the effect of gamma tACS over the M1 and the Cerebellar Hemisphere is a phase-specific. We applied tACS at 70 Hz over the left M1 and the right Cerebellar Hemisphere to 20 healthy adults while they performed a visuomotor control task using their right index finger for 30 s. Three stimulation conditions were applied: (1) pseudo-stimulation (sham condition), (2) 180° phase difference in the two cortical target areas (anti-phase condition) and (3) 0° phase difference (in-phase condition). The anti-phase condition decreased task error compared to the sham condition (P = 0.021), but did not differ from the in-phase condition. Our study demonstrated that the effect of gamma tACS over the M1 and the Cerebellar Hemisphere has phase specificity. This result suggests that intercortical functional synchronization is involved in the improvement of motor performance during gamma tACS over the M1 and the Cerebellar Hemisphere.
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Transcranial Alternating Current Stimulation With Gamma Oscillations Over the Primary Motor Cortex and Cerebellar Hemisphere Improved Visuomotor Performance.
Frontiers in behavioral neuroscience, 2018Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Kei Saito, Yasuto Inukai, Mitsuhiro Masaki, Hideaki OnishiAbstract:Transcranial alternating current stimulation (tACS) can be used to modulate oscillatory brain activity. In this study, we investigated whether tACS applied over the primary motor cortex (M1) and Cerebellar cortex region improved motor performance. We applied tACS (1.0 mA) to 20 healthy adults while they performed an isometric force task with some visuomotor control using their right index finger. Gamma (70 Hz) oscillations in the Experiment 1 or beta (20 Hz) oscillations in the Experiment 2 were applied for 30 s over the left M1, right Cerebellar Hemisphere or both regions ("M1-Cerebellum"), and errors performing the task were compared. Beta-oscillation tACS did not affect motor performance. With the gamma-oscillation tACS, a negative correlation was found between the difference of error in the M1-Cerebellum condition and the number of errors in the sham condition (P = 0.005, Pearson's r = -0.597), indicating that motor performance improved with M1-Cerebellum tACS for subjects with low motor performance in the sham condition. Those who performed poorly in the sham condition made significantly fewer errors with M1-Cerebellum tACS (P = 0.004). Thus, for subjects with poorer motor performance, tACS with gamma oscillations applied over the M1 and contralateral Cerebellar Hemisphere improved their performance.
Yasuto Inukai - One of the best experts on this subject based on the ideXlab platform.
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Effects on motor learning of transcranial alternating current stimulation applied over the primary motor cortex and Cerebellar Hemisphere.
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia, 2020Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Yasuto Inukai, Yuya Matsumoto, Mai Miyashita, Ryo Takahashi, Hideaki OnishiAbstract:Abstract Transcranial alternating current stimulation (tACS) is a non-invasive method of brain stimulation that modulates oscillatory neural activity in the cortical area under the electrodes. Gamma (γ)-tACS applied over the primary motor cortex (M1) and Cerebellar Hemisphere is known to improve motor performance; however, it is not yet known whether it affects motor learning. Thus, here we investigated whether γ-tACS applied over the M1 and Cerebellar Hemisphere affects motor learning. This study involved 30 healthy subjects (14 females, 16 males) performing a visuomotor control task (eight trials) during an administration of either γ-tACS or a sham stimulation (15 subjects per condition) over their right M1 and left Cerebellar Hemisphere. Each subject performed five trials after 24 h. The motor learning efficiency, motor learning retention and re-motor learning efficiency in each condition were compared. The motor learning retention in the γ-tACS condition was significantly higher than that in the sham condition (p = 0.031). Thus, subjects who were administered γ-tACS maintained their motor performance the next day better than sham-stimulated subjects. There was no significant difference between the conditions in the motor learning efficiency and those in the re-motor learning efficiency. Our results demonstrate that γ-tACS administered over the M1 and Cerebellar Hemisphere during a motor learning task can enhance motor learning retention.
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The effect of gamma tACS over the M1 region and Cerebellar Hemisphere does not depend on current intensity.
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia, 2019Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Hirotake Yokota, Kei Saito, Yasuto Inukai, Hideaki OnishiAbstract:Abstract Transcranial alternating current stimulation (tACS) has been shown to modulate neural connectivity in the cortical area under experimental electrodes. Although gamma tACS over the M1 region and the Cerebellar Hemisphere has been shown to improve motor performance, the optimal stimulation method has not been clarified. In this study, we aimed to clarify whether the effect of gamma tACS over M1 and the Cerebellar Hemisphere depends on current intensity. Twenty healthy adults performed a visuomotor control task using their right index finger for 30 s during tACS (70 Hz) over the left M1 and the right Cerebellar Hemisphere. Each subject participated in 10 trials, separated by intervals of 3 min. Three stimulation conditions were applied: (1) pseudo-stimulation (sham condition), (2) tACS with a current intensity of 1.0 mA and (3) tACS with a current intensity of 2.0 mA. Our results indicated that regardless of the current intensity, participants with the lower motor performance had better motor performance under both tACS conditions. Such a correlation was not observed under the sham condition. Collectively, our findings demonstrated that the effect of gamma tACS over M1 and the Cerebellar Hemisphere does not depend on current intensity, and that motor performance slightly improved in both tACS conditions for participants with lower motor performance.
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Gamma tACS over M1 and Cerebellar Hemisphere improves motor performance in a phase-specific manner.
Neuroscience letters, 2018Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Hirotake Yokota, Kei Saito, Yasuto Inukai, Hideaki OnishiAbstract:Transcranial alternating current stimulation (tACS) modulates neural connectivity in the cortical area under the electrodes. Although gamma tACS over the M1 and the Cerebellar Hemisphere has been shown to improve motor performance, the details of this effect remain unclear. This study aimed to clarify whether the effect of gamma tACS over the M1 and the Cerebellar Hemisphere is a phase-specific. We applied tACS at 70 Hz over the left M1 and the right Cerebellar Hemisphere to 20 healthy adults while they performed a visuomotor control task using their right index finger for 30 s. Three stimulation conditions were applied: (1) pseudo-stimulation (sham condition), (2) 180° phase difference in the two cortical target areas (anti-phase condition) and (3) 0° phase difference (in-phase condition). The anti-phase condition decreased task error compared to the sham condition (P = 0.021), but did not differ from the in-phase condition. Our study demonstrated that the effect of gamma tACS over the M1 and the Cerebellar Hemisphere has phase specificity. This result suggests that intercortical functional synchronization is involved in the improvement of motor performance during gamma tACS over the M1 and the Cerebellar Hemisphere.
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Transcranial Alternating Current Stimulation With Gamma Oscillations Over the Primary Motor Cortex and Cerebellar Hemisphere Improved Visuomotor Performance.
Frontiers in behavioral neuroscience, 2018Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Kei Saito, Yasuto Inukai, Mitsuhiro Masaki, Hideaki OnishiAbstract:Transcranial alternating current stimulation (tACS) can be used to modulate oscillatory brain activity. In this study, we investigated whether tACS applied over the primary motor cortex (M1) and Cerebellar cortex region improved motor performance. We applied tACS (1.0 mA) to 20 healthy adults while they performed an isometric force task with some visuomotor control using their right index finger. Gamma (70 Hz) oscillations in the Experiment 1 or beta (20 Hz) oscillations in the Experiment 2 were applied for 30 s over the left M1, right Cerebellar Hemisphere or both regions ("M1-Cerebellum"), and errors performing the task were compared. Beta-oscillation tACS did not affect motor performance. With the gamma-oscillation tACS, a negative correlation was found between the difference of error in the M1-Cerebellum condition and the number of errors in the sham condition (P = 0.005, Pearson's r = -0.597), indicating that motor performance improved with M1-Cerebellum tACS for subjects with low motor performance in the sham condition. Those who performed poorly in the sham condition made significantly fewer errors with M1-Cerebellum tACS (P = 0.004). Thus, for subjects with poorer motor performance, tACS with gamma oscillations applied over the M1 and contralateral Cerebellar Hemisphere improved their performance.
Naofumi Otsuru - One of the best experts on this subject based on the ideXlab platform.
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Effects on motor learning of transcranial alternating current stimulation applied over the primary motor cortex and Cerebellar Hemisphere.
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia, 2020Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Yasuto Inukai, Yuya Matsumoto, Mai Miyashita, Ryo Takahashi, Hideaki OnishiAbstract:Abstract Transcranial alternating current stimulation (tACS) is a non-invasive method of brain stimulation that modulates oscillatory neural activity in the cortical area under the electrodes. Gamma (γ)-tACS applied over the primary motor cortex (M1) and Cerebellar Hemisphere is known to improve motor performance; however, it is not yet known whether it affects motor learning. Thus, here we investigated whether γ-tACS applied over the M1 and Cerebellar Hemisphere affects motor learning. This study involved 30 healthy subjects (14 females, 16 males) performing a visuomotor control task (eight trials) during an administration of either γ-tACS or a sham stimulation (15 subjects per condition) over their right M1 and left Cerebellar Hemisphere. Each subject performed five trials after 24 h. The motor learning efficiency, motor learning retention and re-motor learning efficiency in each condition were compared. The motor learning retention in the γ-tACS condition was significantly higher than that in the sham condition (p = 0.031). Thus, subjects who were administered γ-tACS maintained their motor performance the next day better than sham-stimulated subjects. There was no significant difference between the conditions in the motor learning efficiency and those in the re-motor learning efficiency. Our results demonstrate that γ-tACS administered over the M1 and Cerebellar Hemisphere during a motor learning task can enhance motor learning retention.
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The effect of gamma tACS over the M1 region and Cerebellar Hemisphere does not depend on current intensity.
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia, 2019Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Hirotake Yokota, Kei Saito, Yasuto Inukai, Hideaki OnishiAbstract:Abstract Transcranial alternating current stimulation (tACS) has been shown to modulate neural connectivity in the cortical area under experimental electrodes. Although gamma tACS over the M1 region and the Cerebellar Hemisphere has been shown to improve motor performance, the optimal stimulation method has not been clarified. In this study, we aimed to clarify whether the effect of gamma tACS over M1 and the Cerebellar Hemisphere depends on current intensity. Twenty healthy adults performed a visuomotor control task using their right index finger for 30 s during tACS (70 Hz) over the left M1 and the right Cerebellar Hemisphere. Each subject participated in 10 trials, separated by intervals of 3 min. Three stimulation conditions were applied: (1) pseudo-stimulation (sham condition), (2) tACS with a current intensity of 1.0 mA and (3) tACS with a current intensity of 2.0 mA. Our results indicated that regardless of the current intensity, participants with the lower motor performance had better motor performance under both tACS conditions. Such a correlation was not observed under the sham condition. Collectively, our findings demonstrated that the effect of gamma tACS over M1 and the Cerebellar Hemisphere does not depend on current intensity, and that motor performance slightly improved in both tACS conditions for participants with lower motor performance.
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Gamma tACS over M1 and Cerebellar Hemisphere improves motor performance in a phase-specific manner.
Neuroscience letters, 2018Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Hirotake Yokota, Kei Saito, Yasuto Inukai, Hideaki OnishiAbstract:Transcranial alternating current stimulation (tACS) modulates neural connectivity in the cortical area under the electrodes. Although gamma tACS over the M1 and the Cerebellar Hemisphere has been shown to improve motor performance, the details of this effect remain unclear. This study aimed to clarify whether the effect of gamma tACS over the M1 and the Cerebellar Hemisphere is a phase-specific. We applied tACS at 70 Hz over the left M1 and the right Cerebellar Hemisphere to 20 healthy adults while they performed a visuomotor control task using their right index finger for 30 s. Three stimulation conditions were applied: (1) pseudo-stimulation (sham condition), (2) 180° phase difference in the two cortical target areas (anti-phase condition) and (3) 0° phase difference (in-phase condition). The anti-phase condition decreased task error compared to the sham condition (P = 0.021), but did not differ from the in-phase condition. Our study demonstrated that the effect of gamma tACS over the M1 and the Cerebellar Hemisphere has phase specificity. This result suggests that intercortical functional synchronization is involved in the improvement of motor performance during gamma tACS over the M1 and the Cerebellar Hemisphere.
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Transcranial Alternating Current Stimulation With Gamma Oscillations Over the Primary Motor Cortex and Cerebellar Hemisphere Improved Visuomotor Performance.
Frontiers in behavioral neuroscience, 2018Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Kei Saito, Yasuto Inukai, Mitsuhiro Masaki, Hideaki OnishiAbstract:Transcranial alternating current stimulation (tACS) can be used to modulate oscillatory brain activity. In this study, we investigated whether tACS applied over the primary motor cortex (M1) and Cerebellar cortex region improved motor performance. We applied tACS (1.0 mA) to 20 healthy adults while they performed an isometric force task with some visuomotor control using their right index finger. Gamma (70 Hz) oscillations in the Experiment 1 or beta (20 Hz) oscillations in the Experiment 2 were applied for 30 s over the left M1, right Cerebellar Hemisphere or both regions ("M1-Cerebellum"), and errors performing the task were compared. Beta-oscillation tACS did not affect motor performance. With the gamma-oscillation tACS, a negative correlation was found between the difference of error in the M1-Cerebellum condition and the number of errors in the sham condition (P = 0.005, Pearson's r = -0.597), indicating that motor performance improved with M1-Cerebellum tACS for subjects with low motor performance in the sham condition. Those who performed poorly in the sham condition made significantly fewer errors with M1-Cerebellum tACS (P = 0.004). Thus, for subjects with poorer motor performance, tACS with gamma oscillations applied over the M1 and contralateral Cerebellar Hemisphere improved their performance.
Kei Saito - One of the best experts on this subject based on the ideXlab platform.
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The effect of gamma tACS over the M1 region and Cerebellar Hemisphere does not depend on current intensity.
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia, 2019Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Hirotake Yokota, Kei Saito, Yasuto Inukai, Hideaki OnishiAbstract:Abstract Transcranial alternating current stimulation (tACS) has been shown to modulate neural connectivity in the cortical area under experimental electrodes. Although gamma tACS over the M1 region and the Cerebellar Hemisphere has been shown to improve motor performance, the optimal stimulation method has not been clarified. In this study, we aimed to clarify whether the effect of gamma tACS over M1 and the Cerebellar Hemisphere depends on current intensity. Twenty healthy adults performed a visuomotor control task using their right index finger for 30 s during tACS (70 Hz) over the left M1 and the right Cerebellar Hemisphere. Each subject participated in 10 trials, separated by intervals of 3 min. Three stimulation conditions were applied: (1) pseudo-stimulation (sham condition), (2) tACS with a current intensity of 1.0 mA and (3) tACS with a current intensity of 2.0 mA. Our results indicated that regardless of the current intensity, participants with the lower motor performance had better motor performance under both tACS conditions. Such a correlation was not observed under the sham condition. Collectively, our findings demonstrated that the effect of gamma tACS over M1 and the Cerebellar Hemisphere does not depend on current intensity, and that motor performance slightly improved in both tACS conditions for participants with lower motor performance.
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Gamma tACS over M1 and Cerebellar Hemisphere improves motor performance in a phase-specific manner.
Neuroscience letters, 2018Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Hirotake Yokota, Kei Saito, Yasuto Inukai, Hideaki OnishiAbstract:Transcranial alternating current stimulation (tACS) modulates neural connectivity in the cortical area under the electrodes. Although gamma tACS over the M1 and the Cerebellar Hemisphere has been shown to improve motor performance, the details of this effect remain unclear. This study aimed to clarify whether the effect of gamma tACS over the M1 and the Cerebellar Hemisphere is a phase-specific. We applied tACS at 70 Hz over the left M1 and the right Cerebellar Hemisphere to 20 healthy adults while they performed a visuomotor control task using their right index finger for 30 s. Three stimulation conditions were applied: (1) pseudo-stimulation (sham condition), (2) 180° phase difference in the two cortical target areas (anti-phase condition) and (3) 0° phase difference (in-phase condition). The anti-phase condition decreased task error compared to the sham condition (P = 0.021), but did not differ from the in-phase condition. Our study demonstrated that the effect of gamma tACS over the M1 and the Cerebellar Hemisphere has phase specificity. This result suggests that intercortical functional synchronization is involved in the improvement of motor performance during gamma tACS over the M1 and the Cerebellar Hemisphere.
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Transcranial Alternating Current Stimulation With Gamma Oscillations Over the Primary Motor Cortex and Cerebellar Hemisphere Improved Visuomotor Performance.
Frontiers in behavioral neuroscience, 2018Co-Authors: Shota Miyaguchi, Naofumi Otsuru, Sho Kojima, Kei Saito, Yasuto Inukai, Mitsuhiro Masaki, Hideaki OnishiAbstract:Transcranial alternating current stimulation (tACS) can be used to modulate oscillatory brain activity. In this study, we investigated whether tACS applied over the primary motor cortex (M1) and Cerebellar cortex region improved motor performance. We applied tACS (1.0 mA) to 20 healthy adults while they performed an isometric force task with some visuomotor control using their right index finger. Gamma (70 Hz) oscillations in the Experiment 1 or beta (20 Hz) oscillations in the Experiment 2 were applied for 30 s over the left M1, right Cerebellar Hemisphere or both regions ("M1-Cerebellum"), and errors performing the task were compared. Beta-oscillation tACS did not affect motor performance. With the gamma-oscillation tACS, a negative correlation was found between the difference of error in the M1-Cerebellum condition and the number of errors in the sham condition (P = 0.005, Pearson's r = -0.597), indicating that motor performance improved with M1-Cerebellum tACS for subjects with low motor performance in the sham condition. Those who performed poorly in the sham condition made significantly fewer errors with M1-Cerebellum tACS (P = 0.004). Thus, for subjects with poorer motor performance, tACS with gamma oscillations applied over the M1 and contralateral Cerebellar Hemisphere improved their performance.