感覚運動制御 Sensorimotor control
P1-2-102 AIP/PFG野における手操作運動ニューロンの自己-他者身体像に対する視覚応答 Visual response to self-other body movement of hand manipulation neurons in area AIP/PFG ○前田和孝1, 稲瀬正彦1,2, 中島克巳2, 村田哲1,2 ○Kazutaka Maeda1, Masahiko Inase1,2, Katsumi Nakajima2, Akira Murata1,2 近畿大院・医・システム脳科学1, 近畿大・医・生理2 Dept. of Systems Brain Science, Grad. Sch. of Med., Kinki Univ., Osaka-Sayama, Japan1, Dept. of Physiol., Facult. of Med., Kinki Univ., Osaka-Sayama, Japan2 A previous study reported that neurons in the inferior parietal cortex of the macaque discharged during hand manipulation movement. Some of these neurons showed visual response with object presentation (object type). This type of neurons should be concerned with the 3D object's properties. On the other hand, another type of these neurons was not active during object presentation (non-object type), suggesting that these neurons represented one's own hand configuration. Then, mirror neurons are activated during observation of hand action by other individual and also during execution of the same action. Functions of parietal mirror neurons are considered to contribute recognition of observed motor acts and understanding intention of agent's action. However, these hand manipulation and mirror neurons may also respond to visual feedback during one's own active movement. To investigate this hypothesis, we recorded the activity of 119 single neurons related to hand manipulation task from the inferior parietal cortex (AIP: 41, PFG: 78) in two monkeys. The monkeys performed a hand manipulation task seeing on-line image of hand movement on a monitor screen, and a fixation task in which they were required to fixate a movie of one's own hand movement that was exactly same as visual feedback during the hand manipulation task, then also to fixate a movie of experimenter's hand action. We found that some of hand manipulation neurons responded to the movie of one's own and/or experimenter's movement (AIP: 20/41, 48.8%, PFG: 29/78, 37.2%). Of these neurons, a number of mirror neurons responded to the movie of one's own grasping with object image (AIP: 8/12, 66.7%, PFG: 11/19 57.9%), then some of them were active just for hand view without image of the object. These results suggest that some of mirror neurons in the parietal cortex have a role of monitoring ongoing movement by comparing predicted visual feedback with actual feedback, rather than representing goal of the action.	P1-2-103 手指運動イメージ中の事象関連脱同期強度と皮質領野間相互作用との関連性 Association between cortico-cortical interaction and the magnitude of event-related desynchronization during hand motor imagery ○武見充晃1, 正門由久2, 里宇明元3, 牛場潤一3,4 ○Mitsuaki Takemi1, Yoshihisa Masakado2, Meigen Liu3, Junichi Ushiba3,4 慶應大院・理工・基礎理工1, 東海大・医・リハビリ2, 慶應大・医・リハビリ3, 慶應大・理工・生命情報4 Grad Sch Fund Sci and Tech, Keio Univ, Kanagawa, Japan1, Dept Rehab Med, Tokai Univ Sch Med, Kanagawa, Japan2, Dept Rehab Med, Keio Univ Sch Med, Tokyo, Japan3, Dept Biosci and Info, Fac Sci and Tech, Keio Univ, Kanagawa, Japan4 Event-related desynchronization (ERD) of electroencephalogram (EEG), which is interpreted as a marker of increased cortical activation, can be observed over the contralateral sensorimotor area (SM1) during actual movements, as well as during motor imagery. However, it remains unclear whether the changes in the interaction between bilateral SM1, known as concomitant phenomena during voluntary movement, are associated with ERD. The present study investigated the association between ERD magnitude during hand motor imagery and cortico-cortical interaction from the outcomes of interhemispheric inhibiton (IHI) and task-related EEG-EEG coherence (TRCoh). Ten healthy subjects were recruited. Each subject performed 60 trials comprising 7 seconds of rest followed by 5 seconds of motor imagery of right index finger abduction, and received real-time visual feedback of the ERD magnitude of the contralateral SM1 while they performed a motor imagery task. IHI assessment using transcranial magnetic stimulation was performed when ERD exceeded 5% or 15% thresholds during motor imagery. The conditioning stimulus was applied to the right motor cortex, and the test stimulus was applied to the left motor cortex. The motor evoked potential (MEP) was recorded from the first dorsal interosseus (FDI) of both hands. The results showed that MEP amplitudes of right FDI were significantly larger at ERD 15% compared to rest (p < .001). IHI was significantly reduced at ERD 15% (p < .001) and ERD 5% (p < .001) compared to rest. There was no main effect of ERD for MEP amplitudes of left FDI (p = .57). TRCoh occurring over bilateral SM1 at ERD 15% was greater than those observed at ERD 5% (p < .05) and at rest (p < .01) and TRCoh at ERD 5% was greater than at rest (p < .05). Our findings indicate that an active intercommunication between bilateral SM1 becomes more intense with increased ERD magnitude during hand motor imagery, similarly to voluntary movement.
P1-2-104 軽量物体把持時の精密把握力制御 Control of prehension force during holding of a light object ○平松佑一1, 陣内裕成1, 木村大輔1, 伊藤太郎2, 門田浩二1, 木下博1 ○Yuichi Hiramatsu1, Hiroshige Jinnouchi1, Daisuke Kimura1, Taro Ito2, Koji Kadota1, Hiroshi Kinoshita1 大阪大院・医・運動制御1, 武庫川女子大・健スポ2 Dept Med, Univ of Osaka, Osaka1, Dept Heal & Spor, Univ of Mukogawa Women's, Osaka2 Light objects are commonly handled between the tips of the fingers and thumb. Its sensory motor functions have been investigated using a force sensor-mounted apparatus weighing several hundred grams or more though the vast majority of small objects weigh less than 100 g. None of the researchers has examined a lighter weight range. The aim of this study was to investigate the grip and load (lifting) force coordination during holding a light object by the precision grip. Twenty young volunteers lifted a force sensor-equipped 6-g object. Its weight was increased to 200-g by hanging additional 13 different weights. The grip surface was also changeable between the rayon and sandpaper materials. The grip and load forces during holding the object, and at slipping moment were measured for each of 224 trials for each subject. In addition, safety margin force, safety margin force relative to static force, and coefficient of static friction were also computed. For the sandpaper surface, the mean static grip force for 6 g was 0.15 N, which increased to 1.4 N with 200-g. For the rayon surface, the corresponding values were 0.18, and 2.95 N, respectively. Slip force, and safety margin force also increased with weight, and they were also greater for rayon than sandpaper. The relative safety margin was about 80% for the 6 g apparatus with both surfaces, which decreased to about a half value for the 200-g weight. It was concluded that a very light object ( < 30-g) demanded different prehension force coordination from that for heavier objects. To understand the cause of this large safety margin with light weight, finger-surface contact area, finger-surface adhesive force, and fingerpad stiffness were additionally examined. The findings suggest that low cutaneous nerve input due to a small finger-surface contact area, adhesive force due to sweaty skin, and a spring element of the fingerpad all can affect difficulty of precise finger tip force in relation to load force.	P1-2-105 課題実行に伴う左右手選択意図を判別する Decoding of effector selection before actual movement ○雨宮薫1, 井澤淳1, 横山寛1,2, 大須理英子1 ○Kaoru Amemiya1, Jun Izawa1, Hiroshi Yokoyama1,2, Rieko Osu1 株式会社 国際電気通信基礎技術研究所 運動制御・機能回復研究室1, 長岡技術科学大学　電気電子情報工学2 Department of Motor control and rehabilitation, ATR, Kyoto, Japan1, Department of Electrical, Electronics and Information Engineering, Nagaoka University of Technology, Nagaokashi, Japan2 Action selection, a process of choosing one from all the possible conflicting motor plans, is central to generate motor movements in our daily life. For instance, even when people encounter a relatively simple task such as pushing the door, he/she should quickly decide which hand ( right versus left) to use to achieve the task What is the neural mechanism underling these action selection process between two limbs? Until now, while accumulating evidence shows that same neural mechanisms are involved in both motor planning and decision process (Cisek and Kalaska, 2010), few studies have specifically elucidated the selection process between limbs (Oliveira et al., 2010). Furthermore, it is still unknown whether the neural mechanisms of selection limbs are lateralized or not is still unknown. To address this question, we measured the whole head 64ch EEG (Active-Two, Biosemi system) during subjects performing the reaching planning and explored the most significant channels that contain information of action planning. To this end, we decoded the arm choice from Event-related potentials (ERP) and analyzed the contribution of each channel to the decoding, using delayed reaching paradigm in which subjects were asked to reach with one hand to a visual target. In this task, participant was free to choose the right or left arm and we aimed to classify the selection process before actual movement . When we used the data during the delayed period and classify with the linear discriminant analysis (LDA), the classification accuracies of predicting limb (reaching with left arm vs. reaching with right arm) were about 70%, and the channels around the posterior parietal cortex (P9 & P10) best contributed the classification. The results suggest that posterior parietal cortex, which are related to the reaching and the processing of visuo-motor transformation, is also responsible for arm choice.
P1-2-106 持続運動中の疲労知覚における進み視覚フィードバックの影響 Impact of preceding visual feedback on fatigue perception during repetitive movements ○伊藤翔1, 木村聡貴1, 五味裕章1 ○Sho Ito1, Toshitaka Kimura1, Hiroaki Gomi1 NTT CS基礎研1 NTT Comm Sci Labs, Atsugi1 Fatigue caused by repetitive movements and exercises is a common phenomenon in daily life. While previous studies have revealed various physiological factors of muscle fatigue, it remains elusive how perception of fatigue is generated in the brain. In previous study, we found that fatigue perception was enhanced when the visual feedback of repetitive finger movement was delayed. This perceptual enhancement was interpreted as an effect of visual error to actual motor output. However, it is unclear how this error is evaluated in our brain and affects fatigue perception. One possibility is that a discrepancy between actual movement and sensory feedback is attributed to an increase in movement variability caused by muscle fatigue, and leads to enhancement of fatigue perception. Another possibility is that the direction of the error is also evaluated as well as its magnitude. That is, temporal lags behind actual movement may cause enhancement of fatigue perception. Thus, if visual feedback precedes, rather than lags behind, actual movement, fatigue perception can be attenuated. To test these possibilities, we provided a preceding visual feedback of finger movement generated by the online prediction technique for human motion [Matsubara et al., 2011, IEICE Tans. J94-D(1)]. Results showed that perceived fatigue during continuous finger movements tended to be increased when preceding visual feedback was provided, which is similar to the increase in fatigue perception when delayed feedback was given. We additionally examined whether or not the magnitude of visual error of the motor performance, regardless of temporal directions, leads to the enhancement of perceived fatigue in a single manner.	P1-2-107 目標移動に対する腕運動修正時の視覚的注意移動 Visual attention in rapid on-line visuomotor adjustment ○安部川直稔1, 五味裕章1 ○Naotoshi Abekawa1, Hiroaki Gomi1 NTT CS基礎研1 NTT Comm Sci Labs, Atsugi1 To interact with visual objects, we perform eye-, arm-, and coordinated eye-arm movements. It is known that attention is directed to the goal of motor actions during voluntary motor planning. Recent visuomotor studies have found that we can make rapid and automatic reach corrections following a target shift during movements. Although this correction movement was thought to be governed by reflexive mechanism, it is less clear whether attention mechanism is related to such on-line control process. To address this issue, we measured attentional allocation by a 2-AFC orientation discrimination task under four motor conditions. In the two conditions including arm-reaching, subjects made a rapid reach correction to the target jump during movements. Reach correction was required with eye saccade (EH) or with eye fixation (H). In the remaining two conditions, subject made a saccade to the target jump without arm-reaching (E) or just kept the fixation without any eye or arm movement (NULL). The orientation stimulus appeared 0, 40, 80, and 120 ms after the target jump. The results showed that orientation discrimination (OD) was generally better when the probe stimulus appeared at the location of the target jump (valid) than when it appeared elsewhere. This effect was true even for the NULL, suggesting that target jump itself can elicit an exogenous attentional shift. However, OD in valid trials was not better for the EH than for the E and NULL, suggesting that generating process of on-line reach correction does not induce additional attentional shift to the motor goal. Furthermore, we found that OD was worse for the H among all the conditions, and the amplitude of reach correction was smaller for the H than for the EH. We assume that coordinated eye-arm movements are implicitly planned during on-line visuomotor corrections. Inhibition mechanism to stop saccades would be required in the H, and it would affect attention and the manual control system in a similar manner.
P1-2-108 ヒゲに対応する一次体性感覚野と一次運動野における皮質－皮質間連絡の形態学的解析 Architecture of cortico-cortical connection between the motor cortex and the somatosensory cortex in rat vibrissal system ○柴田憲一1, 古田貴寛1, 金子武嗣1 ○Ken-ichi Shibata1, Takahiro Furuta1, Takeshi Kaneko1 京都大学大学院　医学研究科　高次脳形態学1 Dept Morphol Brain Sci, Grad Sch of Med, Kyoto Univ, Kyoto, Japan1 Rats move their whiskers to locate and identify objects in their environment. This activity integrates both motor and sensory information. Morphological connections between vibrissal areas of the primary motor cortex (vM1) and of the primary somatosensory cortex (vS1) in rats have not been understood completely. At first, we identified vM1 by electromicrostimulation. Second, we injected Phaseolus vulgaris leucoagglutinin (PHA-L) as an anterograde tracer into each layers in vM1, and Cholera toxin B subunit (CTB) as a retrograde tracer into barrel column and septal column in vS1. We analyzed the difference of axonal arborization in each layers of vM1 and neurons which project to vS1. We injected Sindbis viral vectors (Furuta et al. 2001) which was designed to express palmitoylation site-attached GFP (palGFP) on the membrane into pyramidal cells in vM1, and reconstructed and quantitatively analyzed axons and dendrites of single vM1 neurons. With these experiments, we are going to reveal the integration of motor and sensory information.	P1-2-109 タスクの難易度に依存する関節間協調の変化 Change of joint coordination depending on task difficulty ○東郷俊太1,2, 香川高弘1, 宇野洋二1 ○Shunta Togo1,2, Takahiro Kagawa1, Yoji Uno1 名古屋大学大学院　工学研究科　機械理工学専攻1, 日本学術振興会2 Graduate School of Engineering, Nagoya University1, Japan Society for the Promotion of Science2 Carrying a cup without spilling water is one of dexterous tasks. In our earlier study, we measured that the human walked on a treadmill while holding a cup with water or stones. As a result, we found that reducing hand jerk and keeping cup angle constant are important to achieve the task, and the human coordinates their multi-joints to achieve the task. To quantify the joint coordination, we used UCM analysis. UCM analysis divides the variance of human multi-joints into two components; (1) UCM component which does not affect the task achievement, and (2) ORT component which directly affects the task. Index of synergy is defined as a ratio of UCM and ORT components. Larger index of synergy shows that multi-joints are well coordinated. According to UCM analysis, the index of hand jerk synergy in carrying a cup with water was a little smaller than that in carrying a cup with stones. In this study, we investigate why the index of hand jerk synergy in carrying a cup with water were smaller. Therefore, we would like to compare the indices of hand jerk synergy in various task conditions. However, it is not easy to control a task difficulty when the human walks on the treadmill, because we can not give arbitrary vibration to subjects and some body-constraints which affect both dampening hand vibration and walking. Moreover, a relationship between walking speed and amplitude of vibration is unclear. Thus, in this study, we developed a device to generate arbitrary vibration while holding a cup. Subject stood the device holding a cup with water and kept not spilling water. Their kinematic data were measured and analyzed. We considered five conditions of vibration velocity, and four conditions of body-constraints. In each condition, hand jerk and joint coordination were evaluated, and the relationship between the task difficulty and joint coordination is discussed.
P1-2-110 脊髄損傷マーモセットの自然回復過程における運動機能解析 Behavioral tests in spontaneous motor recovery after C4/C5 spinal lesioned marmosets ○吉野紀美香1,4, 近藤崇弘1, 武見光晃3, 関口智史3, 岡野ジェイムス洋向5, 牛場潤一4, 岡野栄之1 ○Kimika Yoshino1,4, Takahiro Kondo1, Mitsuaki Takemi3, Tomofumi Sekiguchi3, Hirotaka James Okano5, Junichi Ushiba4, Hideyuki Okano1 慶應大・医・生理1, 日本学術振興会2, 慶應大・理工・基礎理工3, 慶應大・理工・生命情報4, 慈恵医大・再生医学5 Dept Physiol, Keio Univ Sch Med,Tokyo1, JSPS2, Grad Sch Fund Sci and Tech, Keio Univ3, Dept Biosci and Info, Fac Sci and Tech, Keio Univ4, Div Regen Med, Jikei Univ Sch Med5 Spinal cord injury (SCI) leads a disruption of ascending and descending fiber tracts followed by loss of sensation and voluntary movements. In order to development of treatments from functional full-recovery after SCI, performing a detail evaluation of the motor dysfunction in primates is indispensable element. We used the common marmoset, which is easy handling small non-human primate, and assessed spontaneous motor recovery for 8 wks after spinal cord hemi-section at C4/C5 level by 4 appraisal methods, which are original open field scoring (MIKY scoring), single-pellet reaching test, kinematics of hand and digit movement, and vertical ladder walking test. MIKY scoring is widely used to assess the sensorimotor dysfunction, but is difficult to distinguish the minute changes. The score increased gradually and reached the plateau from 5 to 7 wks. The success rate of single-pellet reaching test also gradually increased after SCI. Kinematics of hand and digit movement was quantitatively evaluated by high-speed camera system. Reaching speed and changes in the finger joint angle of the impaired hand were reduced and the time integral of jerk was increased. This system could be detected the broad range of dexterous recovery. The horizontal ladder walking test was generally used to assess the skilled walking in rodents, and we inclined the ladder at a vertical angle in order to adapt the tolls for arboreal monkey. Although marmosets could climb up the ladder from 2 to 3 wks after injury, they hardly used affected forelimbs (FLs). The frequency of using FLs gradually became high and marmosets could climb the ladder correctly from 5 to 7 wks. These behavioral tests were suited to judge the neurobehavioral changes during recovery periods quantitatively. Near future, we're planning to adopt various rehabilitation and drug therapy to the marmoset SCI model, and our sensitive tests serve as powerful tools to evaluate the optimal timing of treatment.	P1-2-111 線虫C. elegansの摂食行動におけるRas-MAPK経路の働き The Ras-MAPK pathway is important for foraging behavior in C. elegans ○濱川昌之1, 飯野雄一2, 広津崇亮1 ○Masayuki Hamakawa1, Yuichi Iino2, Takaaki Hirotsu1 九大院・システム生命1, 東京大学大学院理学系研究科生物化学専攻2 Grad Sch. of Sys Life Sci., Kyushu Univ1, Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo2 The Ras-MAPK pathway is well known to be essential for regulating cellular differentiation and growth. In neurons, this pathway plays an important role in axon guidance, synaptic formation, neural plasticity, and so on. Also in C. elegans, this signal transduction pathway is involved in the proliferation of germ cells, vulval induction, olfaction, and olfactory plasticity. Recently, we found that defects in this signaling pathway cause abnormal locomotion behavior in C. elegans. The mutant animals continue to move in a loopy pattern. We named the abnormal behavior, circular locomotion. When wild-type animals crawl on plates, they shake their head rhythmically and symmetrically, which is known to be the foraging behavior. However, the mutants of the Ras-MAPK pathway show aberrant and asymmetrical head movements, indicating that circular locomotion is caused by abnormal foraging behavior. The foraging behavior is controlled by three types of neurons: IL1 and OLQ sensory neurons and RMD motor neurons. To examine the relation between these neurons and circular locomotion, therefore, we genetically inhibited the activity of these neurons respectively and we observed that the treated animals frequently showed circular locomotion. In addition, we found that the defect of locomotion behavior in the Ras mutants was rescued by the expression of Ras in these neurons. Furthermore, these neurons-specific RNAi of Ras caused circular locomotion. These results suggest that Ras functions in the neurons involved in the foraging behavior. Moreover, we found that the embryonic expression of Ras rescued the defect of the Ras mutants, while the expression of Ras in adults did not. These results suggest that Ras regulates the development of the neurons which are involved in the foraging behavior.
P1-2-112 神経構造パラメータが筋力分配に及ぼす影響 Structural MRI captures neural basis of motor costs in muscle force distribution problem ○北佳保里1, 井澤淳1, 細田千尋1, 本田学2, 花川隆2, 大須理英子1 ○Kahori Kita1, Jun Izawa1, Chihiro Hosoda1, Manabu Honda2, Takashi Hanakawa2, Rieko Osu1 ATR 脳情報通信総合研1, 国立精神・神経医療研究センター2 CNS, ATR, Kyoto1, National Center of Neurology and Psychiatry, Tokyo2 One of the central problems in motor control is redundancy. When one makes a reach to a target, there are an infinite number of possible trajectories. In generating a certain trajectory, there are also many possible muscle activities. Implicit in the motor control study is that the brain employs optimization to select a single solution maximizing a task achievement and minimizing a cost. This cost is assumed to be generalized across all subjects, so that it generates a stereotypical motor commands. However, in reality, there are non-negligible variabilities across subjects in behaviors. How does the optimization generate the inter-subject variability? We hypothesized that individuality in the neural architecture generates the inter-subject variabilities. In this view, the optimization process is constrained by the neural structures, so that the optimal motor behaviors varied across subjects. To test this idea, we considered a simple force production task for multiple targets. We first simulated the muscle activation for each target by minimizing the motor cost with different multiplier parameters of the cost function. We found that the area inside the tuning function was significantly influenced by the parameter, suggesting that different cost function alter the muscle tuning function. To examine this, we measured EMG from six muscles around the shoulder- and the elbow- joints during the isometric force production. Structural MRI was also obtained from the same subjects and we performed voxel-based morphometory to explore a correlation between the structural parameters and the area of muscle tuning functions that reflect the difference in multiplier parameters of cost function. We found that the gray matter volume of right premotor cortex was significantly correlated with the area of tuning function. It suggests individuality in the tuning function is the signature of the cost function employed by the brain when the neural architecture optimizes the motor commands.	P1-2-113 発声と全身運動協調における相転移 A PHASE TRANSITION IN VOCALIZATION-WHOLE BODY MOVEMENT COORDINATION ○宮田紘平1, 工藤和俊1 ○Kohei Miyata1, Kazutoshi Kudo1 東京大学大学院　総合文化　身体運動1 Grad Sch of Arts and Sci, Univ of Tokyo, Tokyo1 Studies of rhythmic sensory-motor coordination have reported that phase transition or qualitative changes in coordination are observed as movement frequency increases; Syncronization becomes more stable than syncopation at higher frequencies of rhythmic beat.In studies of rhythmic coordination, sensory information was often generated by external auditory stimuli such as metronome. These auditory stimuli are possible to be made by participants themselves such as vocalization. Here we investigated whether internal auditory information, self-vocalization, would cause phase transition in the same way as external auditory information. Then we studied the stability and variability in the coordination of self-vocalization with whole body movements under different movement frequencies. Whole body movements are two kinds of knee bending movement: down-movement condition (knee flexion with self-vocal) and up-movement condition (knee extension with self-vocal). Analyses of phase relation between movement and self-vocal revealed several distinct differences between the down- and up-movement conditions. Under the up-movement condition, deviation from intended phase relation at higher beat rates and enhanced fluctuations were observed. These results indicate that auditory-motor entrainment occurs regardless of the sources of auditory information, suggesting that different neural circuits behave in accordance with common principles of dynamical systems.
P1-2-114 上肢位置推定おける遠心性情報の関与 Efference signals contribute to positional estimation ○木村聡貴1, 五味裕章1 ○Toshitaka Kimura1, Hiroaki Gomi1 NTT CS基礎研1 NTT Comm Sci Labs, Atsugi1 It is critical to correctly estimate limb position when achieving a goal-directed action. Previous studies have demonstrated that positional estimation mainly relies on vision and proprioception, and those were optimally integrated based on those reliabilities such as prism adaptation. This raises a question of how limb position is estimated when such sensory information is unreliable. We hypothesized that motor command information can be used to compensate sensory unreliability. Participants performed active or passive (manipulandum-driven) right wrist flexion to several target angles, and then reproduced the perceived right hand movement using the left hand. Both hands were occluded from their view by a projector screen. Instead, a hand cursor showing current right hand position was projected on the screen. A visual target as well as the hand cursor were displayed before the trial start, were extinguished during the trial and were re-displayed at the end of trial to avoid online visual feedback for reference hand and target locations. There was no visual feedback of left (test) hand position. We imposed transient vibration to the wrist extensor tendon in the reference hand to induce proprioceptive bias (systematic error) in the wrist flexion direction. Simultaneous application of visual feedback and vibration made participants aware of proprioceptive unreliability. We found vibration-induced proprioceptive error in the test hand reproduction in the passive task when such proprioceptive unreliability existed. However, interestingly, this error decreased in the active task. Further result showed that even when participants reproduced the test hand motion by different arm configuration (wrist abduction and elbow flexion), the decrease of test hand error was observed, indicating involvement of higher estimation process rather than copy of motor commands. We suggest that efference signals are referred to estimate limb position when sensory feedback is unreliable.	P1-2-115 手首運動時の感覚運動野の座標表現―fMRIデコーエィングによる研究 Decoding coordinate representation during wrist movements from fMRI activity patterns ○藤原祐介1, 戸松彩花2, 大須理英子1, 筧慎治3, 井澤淳1 ○Yusuke Fujiwara1, Saeka Tomatsu2, Rieko Osu1, Shinji Kakei3, Jun Izawa1 株式会社国際電気通信基礎技術研究所1, 国立精神・神経医療研究センター2, 東京都医学総合研究所3 CNS, ATR, Kyoto1, National Center of Neurology and Psychiatry, Tokyo2, Tokyo Metropolitan Institute of Medical Science, Tokyo3 When making a movement to a target, the brain calculates coordinate transformation from extrinsic coordinate system (visual space) to intrinsic coordinate system (joint or muscle space). Evidences in electrophysiological monkey studies show that the neurons encode both extrinsic and intrinsic coordinates in the primary motor area (M1) while majority of the ventral premotor neurons (PM) show extrinsic coordinate. However it is still unclear how this coordinate transformation was embedded in other motor-related areas such as primary sensory area (S1) and posterior parietal cortex (PPC). To examine coordinate representations of multiple areas distributed in a human cerebral cortex during a single wrist movement, we conducted the fMRI decoding analysis, which can predict movement directions from fMRI activity patterns. fMRI data of the human cerebral cortex were measured during repetitive wrist movements towards 8 directions in two postures: pronated position and mid-position (i.e., 90 deg supinated from pronated position). In each posture, movement directions were significantly predicted from each fMRI activity pattern of M1, PM, S1 and PPC. To assay the coordinate representations of these areas, fMRI decoder was trained in data from one posture and tested in data from the other posture. Prediction from M1 and S1 activity patterns were 45 deg rotated while that of PM and PPC remained same directions in spite of 90 deg wrist rotation. These results suggest that human M1 and S1 include both extrinsic and intrinsic like activities and PM and PPC activities are extrinsic like. Our fMRI decoding analysis provides a clue as to resolve the coordinate transformation of sensorimotor information in human motor control.
P1-2-116 先行聴覚フィードバック下の単音節発音における調音運動変化と聴覚タイミング変化の相互作用 Interaction between changes in articulatory movement and auditory timing during monosyllable articulation under preceding auditory feedback ○持田岳美1, 五味裕章1 ○Takemi Mochida1, Hiroaki Gomi1 NTT CS基礎研1 NTT Comm Sci Labs, Atsugi1 Auditory feedback is critical for the development and maintenance of speech. On the other hand, it remains unclear whether auditory feedback-based control is essential to ongoing speech articulation, considering that a population of patients with postlingual hearing loss can speak properly. Delayed auditory feedback (DAF) is known to induce various articulatory errors in normal speakers. However, its underlying mechanism has not been elucidated. The relevant aspects of DAF effect stem from (i) phonemic discrepancy in between the feedback signal and the actual production, and (ii) disruptive rhythm. To experimentally disentangle these factors, we developed a novel auditory feedback alteration system which tracks the articulatory movements of a speaker's lips in real-time and presents a pre-recorded speech to the speaker's ears at any given moment relative to a specific articulatory timing. By detecting the preparatory lip movement prior to the production of a lip-related monosyllable, this system enables the speaker to receive the feedback even earlier than the actual timing. In the experiment, participants silently produced /pa/ without a cue, with hearing their own pre-recorded /pa/ earlier or later than the actual timing. They also judged whether the feedback was earlier or later than their own articulatory timing. We evaluated the changes in the lip movements and the perceptual accuracy of the auditory-articulatory timing discrepancy under different feedback timings (-200, -100, 0, 100, and 200 ms). The results showed that the movements were accelerated by the earlier feedback (-200 and -100 ms) but were not affected by the later feedback (100 and 200 ms), and that the perceptual accuracy was higher for the earlier feedback but lower for the later feedback. These results suggest that the higher sensitivity to the time discrepancy during the articulatory preparation phase resulted in the larger change in the articulatory movements.	P1-2-117 高反発クッショングリップを握ると脳梗塞後の手指の拘縮と言語障害が短期間に改善される Hand contracture and speech disturbance after cerebral infarction were improved immediately by grasping high repulsion polyethylene grip ○西野仁雄1,7, 山内智之1,2, 白木基之1,3, 向田カヨ子4, 高田満子4, 榊原和資5, 浦川将6, 西条寿男6 ○Hitoo Nishino1,7, Tomoyuki Yamauchi1,2, Motoyuki Shiraki1,3, Kayoko Mukaida4, Mitsuko Takada4, Kazumasa Sakakibara5, Susumu Urakawa6, Hisao Nisijo6 NPO法人「健康な脳づくり」1, CCRC ジャパン2, ホワイトサンズ3, 津名白寿園4, サンバーデン5, 富山大・医・統合生理6, 名古屋市立大・医・脳神経生理7 NPO Corporation Healthy Brain, Nagoya1, CCRC Japan, Nagoya2, WhiteSunz, Nagoya3, Tsuna Hakujuen, Hyogo4, Sun Barden, Aichi5, Department of Integrative Physiology, Toyama University, Toyama6, Department of Neurosciene and Brain Physiology, Nagoya City University, Nogoya7 Nowadays many persons are attacked by cerebral stroke/infarction and suffered by its aftereffects: contracture of hand/leg, speech disturbance and so on. Rehabilitation is a useful treatment but in reality it doesn't work so well. During the hand/leg contracture, improper (flexion dominant) afferent stimuli are sent to the spinal cord and brain, and these inputs would disturb the recovery of function. We hypothesized that natural proper sensory afferents activate the somatosensory/sensrimotor neuronal networks and offer an appropriate environment for motor output, and we designed a high repulsion cushion grip to offer proper stimuli to the hand. We found that by continuous use of the grip, all 20 patients except two (who stopped grasping the grip by erosion of the palm) improved the symptom in some extent within a week or month: opening of hand and fingers, decrease in muscle tonus, enlargement of joint movement and disappearance of bad smell of the palm. Moreover in some patients who had lost verbal communication recovered mild outlooks, movement of lip/mouth and finally spoke a few words. By grasping the grip, EMG recorded from the forearm flexion/extension muscles exhibited strong activities, and the cerebral blood flow measured by NIRS in the somatosensory area, motor/premotor area and dorsolateral prefrontal cortex was increased. Data indicate that a proper afferent input from the fingers and hands offers a natural (proper) environment for somatosensory-motor coordination in the spinal cord and brain and this may lead to the base of improvement of disturbed function. The result suggests a beautiful and strong restorative power of the brain and body and the importance of patient rehabilitation.
P1-2-118 緊急時における微細運動制御の神経機構 Neuronal correlates of fine motor control under panic-like state ○鈴木裕輔1,2, 池田和司2, 駒井章治1 ○Yusuke Suzuki1,2, Kazushi Ikeda2, Shoji Komai1 奈良先端大・バイオ1, 奈良先端大・情報2 Nara Inst. Sci. Tech., Grad. Sch. Biol. Sci., Nara1, Nara Inst. Sci. Tech., Gnad. Sch., Info. Sci., Nara2 Complex behavior can be constituted from a sequence of finer motions. If animals displayed an anomaly at the behavioral process, segmentation of the behavior into motions would be effective way to find the origins of the anomaly. In contrast to recent success in segmentation of neural circuits, that of behavior has not been enough. Conventional analysis of animal behavior need a lot of assumption to extract and categorize subject's behaviors. This makes it difficult to detect covert motions, and thereby to find novel relationship between behaviors and neural activities. To solve this, we initially demonstrated "behavioral imaging" as a novel behavioral analyzing system that enables automated segmentation and categorization of a behavior, simply based on image-processing and data-mining technique, without assumptions for both animal behavior and experimental environment. We applied this for rat's escape behavior recorded in a threatening situation, and found that some of segmented motions were more accelerated than in usual. Then, we sought how neuronal activity in the survival circuits is causally related to those fine motions. The periaqueductal gray matter, the region of motor output part on the survival circuit, was stimulated by the wireless neuronal stimulator at varied current intensity to directly induce the escape behavior. Combining with the behavior analyzing system, we tested whether each motion segment during the escape behavior could be detected depending on the stimulus intensity. The number of neurons responsible for each segmented motion was also estimated. Our study concluded that precise segmentation of both neural circuit and behavior into fine scale would complementary work as effective tools to find novel neural correlates.	P1-2-119 高齢者における到達運動中のターゲット移動に対する修正動作の空間的正確性 Spatial accuracy of manual response induced by a target jump during reaching in elderly ○木村大輔1, 門田浩二1, 平松佑一1, 陣内裕成1, 木下博1 ○Daisuke Kimura1, Koji Kadota1, Yuichi Hiramatsu1, Hiroshige Jinnouchi1, Hiroshi Kinoshita1 大阪大院・医・運動制御1 Grad Sch Med, Osaka Univ, Osaka, Japan1 A sudden jump of a target during reaching commonly elicits a quick unconscious motor tracking response by the reaching arm (target jump response: TJR). This has been considered as fast on-line arm control mechanism installed in the central nervous system to make an automatic compensation of a motor error caused by the movement of a target (Desmurget et al., 1999). The latency of TJR ranges between 120 and 170 ms, which is clearly faster than that of voluntary reactive arm motion. A recent study has shown that although aging greatly influences the voluntary response latency, it did not affect the TJR latency (Kadota and Gomi, 2010). The neural substrate for TJR processing, therefore, seems to be partly independent from a volitional control system. Here, we investigated a spatial accuracy of TJR in aged people to further clarify age-related changes in TJR processing in their neural system. Participants were 14 elderly individuals with no clear neurological and orthopedic problems (7 male, age 69±5 yrs, MMSE ≥ 28), and 16 younger adults (8 male, age 25±5 yrs). All participants were right-handed. The participants asked to reach towards a visual target (8 mm in diameter) presented in the center of the screen placed 0.5 m in front of them using their right hand. Just after reaching initiation, the target was either jumped to a new location (approximately 5 degrees right, left, above, or below from the screen center) or remained at the central position (the no-jump trial). The hand trajectory measured by 3D motion capturing system (500Hz), and PCs. In the result, ANOVA revealed the movement endpoint variances were greater in the elderly group than these of the young group. In contrast, there was no group difference in the bias for the direction of mean velocity vector at the early phase of TJR (120-180 ms after target-jump onset). It was concluded that age-related modulation in the central neural processing for early visuomotor transformation was quite small if any.

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