Papers - SUGAWARA Kazuhiro

Effects of Go/NoGo stimulus ratio on reaction time, pre-stimulus preparatory activity, and post-stimulus cognitive processing

Matsuda Y., Akaiwa M., Saito H., Kudoh S., Sugawara Y., Kurokawa R., Kosuge R., Shibata E., Sasaki T., Sugawara K.

Experimental Brain Research   243 ( 6 )  2025.05  [Refereed]

Authorship：   Last author  , Corresponding author

DOI

Enhancement of beta rebound elicited by proprioceptive stimulation in the sensorimotor cortex by transcranial alternating current stimulation matched to the dominant beta frequency

Akaiwa M., Kurokawa R., Matsuda Y., Sugawara Y., Kosuge R., Saito H., Shibata E., Sasaki T., Sugawara K.

Neuroscience Research   28  2025.03  [Refereed]

Authorship：   Last author

DOI

Effects of complex movement on the excitability of the ipsilateral primary motor cortex and spinal motoneurons contralateral to the movement: A comparison of ball rotation and grasping tasks with equivalent muscle activity

Kosuge R., Sukegawa T., Akaiwa M., Shibata E., Kurokawa R., Sugawara Y., Kudoh S., Matsuda Y., Saito H., Sasaki T., Sugawara K.

Brain Sciences   15 ( 2 )  2025.02  [Refereed]

Authorship：   Last author  , Corresponding author

DOI

Differing effectiveness of transcranial random noise stimulation and transcranial direct current stimulation for enhancing working memory in healthy individuals: a randomized controlled trial

Tokikuni Y, Watanabe A, Nakazono H, Miura H, Saito R, Miaowen D, Fuyama K, Takahashi K, Okada K, Sugawara K, Tohyama H, Yoshida S, Fong K, Sawamura D

Journal of NeuroEngineering and Rehabilitation ( Springer Science and Business Media LLC )  21 ( 1 )  2024.10

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Abstract Background Transcranial direct current stimulation (tDCS) applied to the left dorsolateral prefrontal cortex (DLPFC) is a promising technique for enhancing working memory (WM) performance in healthy and psychiatric populations. However, limited information is available about the effectiveness of transcranial random noise stimulation (tRNS) applied to the left DLPFC on WM. This study investigated the effectiveness of tRNS on WM compared with that of tDCS, which has established functional evidence. Methods This randomized, double-blind, sham-controlled trial enrolled 120 healthy right-handed adults who were randomly allocated to four stimulation groups: tRNS + direct current (DC) offset, tRNS, tDCS, or sham. Each stimulus was placed over the left DLPFC and had a current intensity of 2 mA applied for 20 min during the dual n-back task. The dual n-back task was repeated thrice: pre-stimulation, during stimulation, and post-stimulation. The d-prime scores, and response times were calculated as the main outcome measures. A linear mixed model was created to identify the main effects and interactions between the groups and times, with the group and time as fixed effects, and baseline performance and the subject as a covariate and random effect, respectively. The relationships between the benefit of each stimulus and baseline WM performance were also examined. Results For the d-prime score during stimulation, the tRNS group significantly performed better than the sham group at online assessment (β = 0.310, p = 0.001). In the relationships between the benefit of each stimulus and baseline WM performance, the tRNS group had significantly larger negative line slopes than the sham group for the d-prime score (β = −0.233, p = 0.038). Conclusions tRNS applied to the left DLPFC significantly improved WM performance and generated greater benefits for healthy individuals with lower WM performance. These findings highlight the potential utility of tRNS for enhancing WM performance in individuals with lower WM performance and contribute evidence for clinical application to patients with cognitive decline. Trial Registration This study was registered in the University Hospital Medical Information Network Clinical Trial Registry in Japan (UMIN000047365) on April 1, 2022; https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000054021.

DOI

Gait Exercise Assist Robot（GEAR）Using Visual and Auditory Feedback Improves Gait in a Hemiplegic Patient with Severe Sensory Impairment：A Case Report

Oikawa Y, Tanaka D, Sakajiri K, Furuta R, Sugawara K

The Japanese Journal of Rehabilitation Medicine ( Japanese Association of Rehabilitation Medicine )  61   655 - 661  2024.07  [Refereed]

Authorship：   Last author  , Corresponding author

DOI

Effects of reduced physical activity due to post stroke apathy on time taken to achieve independent walking in a hospital ward -Comparison of two cases with apathy and non apathy

小菅 凜, 工藤哲史, 赤岩眞悠, 佐々木健史, 古田亮一, 菅原和広

総合リハビリテーション   52 ( 3 )  2024.03  [Refereed]

Authorship：   Last author  , Corresponding author

Does 20-Hz Transcranial Alternating Current Stimulation Over Human Primary Motor Cortex Modulate Beta Rebound Following Voluntary Movement?

Akaiwa M, Matsuda Y, Kurokawa R, Sugawara Y, Kosuge R, Saito H, Shibata E, Sasaki T, Sugawara K, Kozuka N

Brain Sciences   14 ( 1 ) 74  2024.01  [Refereed]

Event-related brain potentials N140 and P300 during somatosensory Go/NoGo tasks are modulated by movement preparation

Matsuda Y, Sugawara Y, Akaiwa M, Saito H, Shibata E, Sasaki T, Sugawara K

Brain Sciences   14 ( 1 ) 38  2024.01  [Refereed]

Authorship：   Last author  , Corresponding author

Movement of the Stimulated Finger in a Go/NoGo Task Enhances Attention Directed to that Finger as Evidenced by P300 Amplitude Modulation

Sugawara K, Akaiwa M, Matsuda Y, Shibata E, Saito H, Sasaki T

Frontiers in Human Neuroscience   ( 17 )  2023.12  [Refereed]

Authorship：   Lead author  , Corresponding author

Case Report: Self-restraint in a Patient with Alien Hand Syndrome Following Cerebral Infarction Involving the Anterior Cerebral Artery Territory

Sugawara K, Takeuchi T, Harada K, Taki M, Fujimura I, Kogami Y, Furuta R

Frontiers in Neurology   Jul 14:14:1203450  2023.07  [Refereed]

Authorship：   Lead author  , Corresponding author

DOI

Effects of repetitive practice of motor tasks on somatosensory gating.

Mayu Akaiwa, Yuya Matsuda, Hidekazu Saito, Eriko Shibata, Takeshi Sasaki, Kazuhiro Sugawara

Frontiers in human neuroscience   17 ( 17 ) 1131986 - 1131986  2023.03  [Refereed]  [International journal]

Authorship：   Last author  , Corresponding author

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INTRODUCTION: During voluntary muscle contraction, the amplitude of the somatosensory evoked potential (SEP) is reduced by inhibiting sensory information from a peripheral nerve supplying the contracted muscle. This phenomenon is called "gating." We reported that participants with good motor skills indicated strong suppression of somatosensory information. The present study investigated the effects of motor performance improvement following repetitive practice on the SEP amplitude. METHODS: The ball rotation task (BR task) was practiced by 15 healthy participants repetitively. SEPs were recorded before (pre) and after (post) repetitive practice. RESULTS: The BR task performance was significantly improved and the required muscle activation to perform the task was significantly reduced after the repetitive practice. The degree of gating was not significant between pre and post- for the SEP amplitude. A significant correlation was found between changes in SEP amplitude from pre to post and performance improvement. DISCUSSION: After repetitive practice, the degree of gating did not change, but the performance of the BR task improved, and the muscle activity required for the BR task decreased. These results suggest that repetitive practice does not change the degree of gating but changes the mechanism of gating. Furthermore, they indicate that suppression of the somatosensory area may play a role in improving task performance.

DOI PubMed

Transcranial direct current stimulation to the left dorsolateral prefrontal cortex enhances early dexterity skills with the left non-dominant hand; A randomized controlled trial

Watanabe A, Sawamura D, Nakazono H, Tokikuni Y, Miura H, Sugawara K, Furuya K, Tohyama H, Yoshida S, Sakai S

Journal of Translational Medicine ( Springer Science and Business Media LLC )  21 ( 143 )  2023.02  [Refereed]

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Abstract Background The left dorsolateral prefrontal cortex (DLPFC) is involved in early-phase manual dexterity skill acquisition when cognitive control processes, such as integration and complexity demands, are required. However, the effectiveness of left DLPFC transcranial direct current stimulation (tDCS) on early-phase motor learning and whether its effectiveness depends on the cognitive demand of the target task are unclear. This study aimed to investigate whether tDCS over the left DLPFC improves non-dominant hand dexterity performance and determine if its efficacy depends on the cognitive demand of the target task. Methods In this randomized, double-blind, sham-controlled trial, 70 healthy, right-handed, young adult participants were recruited. They were randomly allocated to the active tDCS (2 mA for 20 min) or sham groups and repeatedly performed the Purdue Pegboard Test (PPT) left-handed peg task and left-handed assembly task three times: pre-tDCS, during tDCS, and post tDCS. Results The final sample comprised 66 healthy young adults (mean age, 22.73 ± 1.57 years). There were significant interactions between group and time in both PPT tasks, indicating significantly higher performance of those in the active tDCS group than those in the sham group post tDCS (p < 0.001). Moreover, a greater benefit was observed in the left-handed assembly task performance than in the peg task performance (p < 0.001). No significant correlation between baseline performance and benefits from tDCS was observed in either task. Conclusions These results demonstrated that prefrontal tDCS significantly improved early-phase manual dexterity skill acquisition, and its benefits were greater for the task with high cognitive demands. These findings contribute to a deeper understanding of the underlying neurophysiological mechanisms of the left DLPFC in the modulation of early-phase dexterity skill acquisition. Trial registration: This study was registered in the University Hospital Medical Information Network Clinical Trial Registry in Japan (UMIN000046868), Registered February 8, 2022 https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000053467

DOI

The relationships between motor behavior and sensory gating in the ball rotation task

Akaiwa M, Matsuda Y, Soma Y, Shibata E, Saito H, Sasaki T, Sugawara K

Experimental Brain Research   240 ( 10 ) 2659 - 2666  2022.10  [Refereed]  [International journal]

Authorship：   Last author  , Corresponding author

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During voluntary muscle contraction, sensory information induced by electrostimulation of the nerves supplying the contracting muscle is inhibited and the amplitude of the corresponding somatosensory evoked potential (SEP) decreases. This phenomenon is called "gating." The reduction of the SEP amplitude is reportedly significantly larger when task performance is high. However, the relationship between dexterous movement skills and gating remains unclear. In this study, we investigated through a ball rotation (BR) task how dexterous movement skills affect the SEP amplitudes. Thirty healthy subjects performed the BR task comprising the rotation of two wooden balls as quickly as possible. We estimated the median number of ball rotations for each participant and classified the participants into two (fast and slow) groups based on the results. Moreover, we recorded SEPs, while the subjects performed BR tasks or rested. SEP amplitude reduction (P45) was significantly larger in the fast than in the slow group. We also observed that the P45 amplitude during the BR task was attenuated even more so in the case of the participants with better dexterous movement skills. Our results suggest that the participants with better dexterous movement skills might display stronger somatosensory information suppression because of increasing the motor cortex activity and the afferent input during the BR task.

DOI PubMed

The Impact of Visual Cross-modal Conflict with Semantic and Non-semantic Distractors on Working Memory Task: A Functional Near-infrared Spectroscopy Study

Sawamura D, Tanabe Y, Sakuraba S, Cui J, Miura H, Saito R, Sugi M, Watanabe A, Tokikuni Y, Sugawara K, Miyazaki M, Miyamoto R, Sakai S

Medicine   101 ( 36 ) e30330  2022.09  [Refereed]

The Effect of Pedaling at Different Cadence on Attentional Resources

Akaiwa M, Iwata K, Saito H, Shibata E, Sasaki T, Sugawara K.

Frontiers in Human Neuroscience ( Frontiers Media SA )  16   819232 - 819232  2022.02  [Refereed]  [International journal]

Authorship：   Last author  , Corresponding author

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We investigated the relationship between attentional resources and pedaling cadence using electroencephalography (EEG) to measure P300 amplitudes and latencies. Twenty-five healthy volunteers performed the oddball task while pedaling on a stationary bike or relaxing (i.e., no pedaling). We set them four conditions, namely, (1) performing only the oddball task (i.e., control), (2) performing the oddball task while pedaling at optimal cadence (i.e., optimal), (3) performing the oddball task while pedaling faster than optimal cadence (i.e., fast), and (4) performing the oddball task while pedaling slower than optimal cadence (i.e., slow). P300 amplitudes at Cz and Pz electrodes under optimal, fast, and slow conditions were significantly lower than those under control conditions. P300 amplitudes at Pz under fast and slow conditions were significantly lower than those under the optimal condition. No significant changes in P300 latency at any electrode were observed under any condition. Our findings revealed that pedaling at non-optimal cadence results in less attention being paid to external stimuli compared with pedaling at optimal cadence.

DOI PubMed

生体磁気計測関係のアーチファクト MEG計測において歯科矯正器具によるArtifactを認めた一例

齊藤 秀和, 菅原 和広, 臼井 桂子, 篠崎 淳, 石黒 雅敬, 白石 秀明, 松橋 眞生, 長峯 隆

日本生体磁気学会誌 ( 日本生体磁気学会 )  35 ( 1 ) 48 - 49  2022

電流源推定に使用するMEGセンサーの選択範囲による影響に関する検討

齊藤 秀和, 菅原 和広, 臼井 桂子, 篠崎 淳, 石黒 雅敬, 白石 秀明, 松橋 眞生, 長峯 隆

日本生体磁気学会誌 ( 日本生体磁気学会 )  35 ( 1 ) 94 - 95  2022

ボールローテーション課題による新たな手指巧緻運動の機能評価に関する検討

齊藤 秀和, 菅原 和広, 太田 久晶

作業療法の実践と科学 ( (公社)北海道作業療法士会 )  3 ( 1 ) 1 - 8  2021.02  [Refereed]

Altered somatosensory evoked potentials associated with improved reaction time in a simple sensorimotor response task following repetitive practice

Akaiwa M, Iwata K, Saito H, Sasaki T, Sugawara K

Brain and Behavior    2020.06  [Refereed]

Authorship：   Last author  , Corresponding author

Corticospinal excitability related to reciprocal muscles during the motor preparation period: effect of movement repetition

Suzuki M, Suzuki T, Tanaka S, Sugawara K, Hamaguchi T

Neuroreport   12 ( 30 ) 856 - 862  2019.08  [Refereed]