シンコペーション カダイ ニオケル ハツワ ト シュシ ノ ウンドウ ノ ソウゴ サヨウ

The present study examined interactions of speech production and hand performance, using the syncopated motor task of speech and hand movement in ten right-handers. Participants performed two single tasks and one syncopated task. The single tasks were unimanual tapping movements and speech production (target interresponse interval: 500 ms). On the syncopated task, the participants were required to produce one movement exactly midway between two another movements (target interresponse interval: 250 ms). They were further divided into two groups: the tap-preceding group and speech-preceding group. The author observed that the mean differences between onsets of speech and tapping movement were shorter than 250 ms over all condition (the shortest mean difference 50 ms), suggesting an entrainment of two movements. In the syncopated task of the speech-preceding group, on the other hand, the tapping movement of the right hand showed more variable peak force and intertap interval than that of the left hand, indicating an asymmetrical interference of two movements

ジツギ キョウイク ワ チカク ウンドウケイ ニ ヒョウショウ オ モタラス

Prinz\u27s common coding theory proposes that perception and action share a common cognitive architecture. Action experience changes not only domain-specific behavioral performance, but the neural basis of action observation. Because the representation of the action is also activated by observing action effects, the observation of action facilitates its performance. At the neural level, the mirror neuron system may provide the central nervous system for ideomotor mechanisms, and it is thus a candidate neural system underlying mimicry and imitation. When we observe others performing actions with which we are familiar, we experience increased motor resonance even when we have no intent to act. In addition, the extent to which an individual recruits sensorimotor processes during observation seems to be tightly linked to the individual\u27s ability to perform the action he or she is observing. The more familiar the observer is with a given action sequence, the greater the neural response magnitude in premotor and parietal areas seems to be. On the other hand, is the sensorimotor experience beneficial for understanding high-level concepts? For example, students who had acted out the events in sentences showed significantly greater understanding and retention than those who had read the sentences repeatedly. From such embodied cognition perspective, it seems that motor experience can impact high-level cognitive activities (e.g. language or physics comprehension)．This idea carries strong educational implications

リョウテ ノ コウゴ ドウサ ト ドウジ ドウサ ニオケル チカラ ト タイミング ノ セイギョ

本研究は両手交互タッピングと両手同時タッピングにおける筋力とタイミングの制御の類似点と相違点を検討した。運動課題は左右の片手タッピング, 両手交互タッピング, 両手同時タッピングである。目標出力は2Nであり, 目標の手内タップ間間隔は500msである。被験者は右利きの男子大学生11名である。練習試行では出力の視覚的フィードバックが与えられた。テスト試行ではフィードバックなしに運動課題が遂行された。その結果, 3課題共に右手の出力が左手の出力を凌駕していた。さらに, 3課題共に, 右手の出力は左手の出力よりも小さい変動を呈した。それに反して, 3課題のタップ間間隔には左右差が認められなかった。一方, 両手交互課題は他の課題よりも最高出力までの時間と圧持続時間が長かった。このように, 両手課題ではタイミングは力制御よりも運動系において強く結合されていた。An experiment was conducted to examine differences and similarities between alternating and simultaneous bimanual finger tapping in the control of force and timing. Participants were trained to produce both unimanual (left or right hand) tapping tasks and alternating and simultaneous bimanual tapping tasks with a peak force of 2 N and a within-hand intertap interval of 500 ms. During practice, visual force feedback was provided pertaining to the hand performing the tapping sequences. After practice, the participants produced the learned unimanual and bimanual tapping sequences in the absence of feedback. In those trials, the force produced by the dominant (right) hand was larger than that produced by the nondominant (left) hand. Furthermore, the force output of the dominant hand was less variable than that of the nondominant hand, in the absence of a difference between the intertap intervals produced by each hand. The alternating task used longer press duration and time-to-peak force than the two other tasks. These results were discussed in the light of both neurophysiological and anatomical findings, and were interpreted to imply that in bimanual tasks, the control of timing may be more tightly coupled in the motor system than the control of force.国立情報学研究所『研究紀要公開支援事業』により電子化

ハツワ ト シュシ ノ ウンドウ ノ ソウゴ サヨウ

The present study examined the relationships among cerebral asymmetry, speech, handedness, and attention during performance of dual motor tasks in right-handers. Participants performed three single tasks and two dual tasks. The single tasks were unimanual tapping and speech production. On the dual task, they produced concurrent speech and finger-tapping movements. The participants were divided into three groups by focus of attention on both/either speech and/or tapping. The author observed that while the dual task produced more variable intertap intervals than the simple task, the right hand in the dual task of the speech-focused group showed the most variable interval among all tasks of the three groups, indicating an asymmetric interaction of verbal and manual tasks. On the other hand, the dual task produced a higher performance of both speech and tapping in the tap-focused group, indicating a bidirectional entrainment of speech and hand movement

シュウダン スポーツ ノ レンシュウ ト コジン スポーツ ノ レンシュウ トノ リョウホウコウセイ テンイ ニツイテ

The present study examined bidirectional learning transfer between joint and individual actions involving discrete isometric force production with the right index finger. To examine the effects of practice of joint action on performance of the individual action, participants performed a pre−test(individual condition), practice blocks(joint condition), and a post−test(individual condition)(IJI task). To examine the effects of practice of the individual action on performance during the joint action, the participants performed a pre−test(joint condition), practice blocks(individual condition), and a post−test(joint condition)(JIJtask). Whereas one participant made pressing movements with a target peak force of 10％ maximum voluntary contraction(MVC)in the individual condition, two participants produced the target force of the sum of 10％ MVC produced by each of them in the joint condition. In both the IJI and JIJ tasks, absolute errors and standard deviations of peak force were smaller post−test than pre−test, indicating bidirectional transfer between individual and joint conditions for force accuracy and variability. Although the negative correlation between forces produced by two participants(complementary force production)became stronger with practice blocks in the IJI task, there was no difference between the pre− and post−tests for the negative correlation in the JIJ task. In the JIJ task, the decrease in force error and variability during the individual action did not facilitate complementary force production during the joint action. This indicates that practice performed by two people is essential for complementary force production in joint action

ジョイント アクションチュウ ノ ボウガイ ワ パフォーマンス オ テイカ サセル ガ ソウホテキ チカラ ハッキ オ ソクシン スル

In soccer or basketball, a player often passes a ball to a teammate. This is an example of coordination between individuals with a common goal in a motor task. Such coordination may occur intentionally and has recently been termed “joint action”. In practical events such as ball games, players have to pass a ball to a teammate even if opposing players interrupt the passing of the ball. In our previous studies on joint action we found that the force produced by two people is complementary. The optimal feedback control theory predicts that as the error produced by the participants increases, error compensation also increases. The present study thus tested the hypothesis that an interruption facilitates complementary force production but negatively influences performance during joint action. Twenty−one students performed both control and interruption experiments. In the control experiment, two participants produced a target force such that the sum of the discrete peak forces produced by their right index fingers was 10% of maximum voluntary contraction. In the interruption experiment, two cooperative participants（participants a and b）produced the same target force as the control experiment, and another participant（participant c）interrupted the peak forces produced by participant b. The force produced by the index finger or thumb of participant c decreased or increased the force produced by participant b. Both experiments consisted of eight blocks, with 50 trials in each block. The interruption was constant across blocks. The correlation between the forces produced by two cooperative participants was more negative in the interruption experiment than in the control experiment. The magnitude of the absolute error and standard deviation of force was greater in the interruption experiment than in the control experiment. These new findings indicate that interruption caused performance to deteriorate during joint action, but facilitated complementary force production

カフアツ ニヨル ジョウシ キョケツジ ノ シンタイ イメージ ノ キュウゲキナ ヘンカ

The authors examined effects of the joint position before the ischaemia on alternation of the joint angle of a phantom limb. We further investigated which nerve fiber contributes to the alternation. While we first blocked participants’upper arm with cuff?inflation, we assessed changes in the perceived joint angles as well as in sensory test. In the second block of their upper arm, we further assessed changes in the perceived joint angles when the position of the hand was changed immediately before the inflation. These experiments showed that whereas the proximal and distal interphalangeal, metacarpophalangeal and wrist joints of the phantom limb steeply changed from extended position to flexed position at the start of extended position from 10 to 25 min after the start of the inflation, the four joints changed to the opposite direction at the start of flexed position. These findings revealed that perceived joint angles of a phantom hand were changed by the position of the hand immediately before the inflation. On the other hand, while threshold of von Frey test in the thumb was changed until mean 16 min after the start of the inflation, the touch sensation in the thumb was abolished until mean 19 min. From the results of two experiments, acute perceptual distortions of joint angle thus corresponded with paralysis of the large myelinated diameter nerv

リョウウデ ノ イチ カンカク ニ アタエル ミギヒジ クッキングン ノ ヒロウ ノ エイキョウ

The present study examined human bilateral forearm position sense after fatigue of right elbow flexor muscles. Ten male undergraduate students were asked to match their right, left or both elbow joints with three target positions（30, 60, and 90 deg）after they acquired the target positions during three practice trials. After a period of concentric exercise of right elbow flexor muscles, the participants randomly recalled the target positions with their right, left or both elbow joints immediately after the exercise, then at 2 and 24 hr post−exercise. Negative constant errors of the right elbow increased immediately after the exercise as the target angles increased, indicating that the exercised arm was perceived as more extended after the exercise. Because the participants were using as a position cue the perceived effort required to match the target angles, the fall in force from fatigue after exercise meant more effort was required to match the targets. That led to matching errors between the exercised arm and targets. As a new finding, when the participants simultaneously recalled the targets with both arms, positive correlations between angles of bilateral elbow joints after the exercise were higher than those before the exercise. Fatigue of elbow flexor muscles of an arm appeared to produce a high coincidence between bilateral elbow positions through interhemispheric communication across the corpus callosum

カソウ カンキョウ ノ ウデ ノ イチ カンカク ニ アタエル シカク ト コユウ カンカク ノ カソセイ

Visual and proprioceptive signals conflict when looking through a prism or at a mirror. The present study examined the weighting of the vision and proprioception of arm position by ten participants fitted with dual 3D head−mounted displays. A camera was fixed above their right acromion to photograph the extended right arm. The participants fixed their right shoulder joint at 0°, 30°, or 60°in the adducent direction while their right arm was presented on a display as extended horizontally from the trunk for 30 min. To examine the effects of vision on proprioception, participants demonstrated the perceived position of their right shoulder using their left arm. To examine the effects of proprioception on vision, they demonstrated the position of their right arm on a display using their left arm. The perceived arm position more closely approached the fake arm position as the difference between actual and fake arm positions increased. While the arm position is coded by vision more dominantly than by proprioception, the proprioceptive estimates were adapted to match the visual estimates. If the difference between actual and fake arm positions was 90°, the perceived arm position stabilized at a value between the actual and fake positions. Surprisingly, the arm position on the display was very gradually perceived as approaching the actual arm position as time passed. These results indicate visual and proprioceptive adaptation to visual−porprioceptive mismatches of the arm position. The magnitude of the perceptual distortion is larger for proprioception（ 20％）than for vision（under 10％）

フタリ ワ ヒトリ ヨリ チカラ ハッキ モ タイミング モ アンテイ スル

In the present study, ten pairs of two participants simultaneously adopted both complementary and synchronous strategies and the two strategies facilitated the joint action. The pairs produced periodic isometric forces such that the sum of forces produced by them was the target force cycling between lower levels of maximum voluntary contraction with an interval of 1000 ms（joint task）, while individuals alone produced the same target forces with the right hand（individual task）. When the total force was visible, while the correlation between forces produced by two participants was highly negative, the coherence between the forces was highest at the target interval, indicating that the pairs simultaneously adopted both strategies. Surprisingly, the joint task exhibited a less variable force and interval than the individual task, indicating that the joint action exhibited larger performance gains than the individual action