BMI Brain Machine Interface
O2-6-3-1 脳-筋肉間の人工神経接続による脳梗塞モデルサルの手の運動機能再建 Volitional control of paretic hand via an artificial cortico-muscular connection in monkey model of stroke ○加藤健治1,2,3, 澤田真寛1,4, 西村幸男1,2,5 ○Kenji Kato1,2,3, Masahiro Sawada1,4, Yukio Nishimura1,2,5 生理研・認知行動発達1, 総合研究大学院大学　生命科学研究科2, 日本学術振興会3, 京都大学大学院　脳神経外科4, 科学技術振興機構・さきがけ5 Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Japan1, Life Science, The Graduate University for Advanced Studies, Hayama, Japan2, Japan Society for the promotion of Science, Tokyo, Japan3, Neurosurgery, Kyoto University Medical School of Medicine4, PRESTO, Japan Science and Technology Agency5 Functional loss of limb control in individuals with spinal cord injury or stroke can be caused by interruption of corticospinal pathways, although the neural circuits located above and below the lesion remain functional. An artificial neural connection that bridges the lost pathway and connects cortical sites to muscles has potential to ameliorate the functional loss. We investigated the effects of introducing novel artificial neural connections in a paretic monkey that had a unilateral stroke at the corona radiata level. The artificial neural connection produces by a brain-computer interface that can detect the particular waveform of cortical activity and converted in real-time to activity-contingent electrical stimuli delivered to muscle. This allowed the monkey to drive the functional electrical stimulation (FES) to muscle through volitionally controlled high-gamma activity of ECoG signal in either the premotor (PM) or motor cortex (M1), and thereby acquire a force matching target. During brain-controlled FES, the monkey was able to modulate stimulation volitionally, thereby repeatedly acquiring the targets. To document the efficacy of the brain-controlled FES, the stimulation was briefly turned off during "catch trials". The monkey continued to make efforts to acquire the target in the catch trial, as evidenced by increasing of high gamma activity, but failed to acquire the targets. We applied the brain-controlled FES in 19 different sessions, using 11 different pairs of cortical site and muscle, the average task performance in brain-controlled FES trials was substantially higher than those in catch trials. Task performance was gradually improved overtime and comparable with ECoG signal recorded from the M1 and PM. These results suggest that artificial neural connection can compensate interrupted descending pathways and promote volitional control of hand movement after damage of descending pathways.	O2-6-3-2 Optimal Balance of the Striatal Medium Spiny Neuron Network ○Adam Ponzi1, Jeffery R Wickens1 OIST1 Slowly varying activity in the striatum, the main Basal Ganglia input structure, is important for the learning and execution of movement sequences. Striatal medium spiny neurons (MSNs) form cell assemblies whose population firing rates vary coherently on slow behaviourally relevant timescales. It has been shown (Ponzi and Wickens, J. Neurosci 30(17):5894 (2010), Front. Sys. Neuro. 6: 1-14 (2012)) that such activity emerges in an MSN network model but only at realistic connectivities of 10-20% and only when MSN generated inhibitory post-synaptic potentials (IPSPs) are realistically sized. Here we suggest a reason for this. We investigate how MSNnetwork generated population activity interacts with temporally varying cortical driving activity, as would occur in a behavioural task. We find that at unrealistically high connectivity a stable winners-take-all regime is found where network activity separates into fixed stimulus dependent regularly firing and quiescent components. Around 15% connectivity a transition to a more dynamically active regime occurs where all cells constantly switch between activity and quiescence. Only in the transition regime where Lyapunov exponents are close to zero do weak changes in cortical driving interact with many population components so that sequential cell assemblies are reproducibly activated for many hundreds of milliseconds after stimulus onset and peristimulus time histograms display strong stimulus and temporal specificity. We show that, remarkably, this activity is maximized at striatally realistic connectivities and IPSP sizes. Thus we suggest the MSN network has optimal characteristics - it is neither too stable to respond in a dynamically complex temporally extended way to cortical variations, nor is it too unstable to respond in a consistent repeatable way. Rather, it is optimized to generate stimulus dependent activity patterns for long periods after variations in cortical excitation.
O2-6-3-3 Spatial Tactile and Auditory Brain Computer Interface based on Head Position Stimulation ○Tomasz Rutkowski1,2, Hiromu Mori1, Yoshihiro Matsumoto1, Zbigniew R. Struzik2,3, Shoji Makino1, Danilo Mandic2,4, Koichi Mori5 Life Science Center of TARA, University of Tsukuba, Japan1, RIKEN Brain Science Institute, Wako-shi, Japan2, Imperial College London, London, UK3, Research Institute of National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan4 The state of the art brain computer interface (BCI) solutions rely mostly on visual and motor imagery paradigms, which require non-disabled vision or long training of the subjects. Recently alternative solutions have been proposed to utilize spatial auditory or tactile (somatosensory) modalities to enhance brain-computer interfacing comfort or to boost the information-transfer-rate achieved by users. We present a study in which the vibrotactile stimuli delivered to the distributed head locations of a subject serve as a platform for a brain computer interface (BCI) paradigm. Six spatially distributed head positions have been used to evoke combined somatosensory and auditory (via bone-conduction effect) brain responses, in order to define a multimodal tactile and auditory brain computer interface (taBCI). The concept described in this abstract of utilizing brain somatosensory (tactile) modality opens up the attractive possibility of targeting the tactile sensory domain, which is not as demanding as vision during operation of robotic interfaces (wheelchair, prosthesis arm, etc.) or visual computer applications. Here we propose to combine the two above-mentioned modalities in the taBCI paradigm, which relies on P300 response evoked by the spatial audio and tactile stimuli delivered simultaneously via the vibrotactile exciters attached to the head positions, thus benefiting from the spatially modulated bone-conduction effect for audio. This offers a viable alternative for individuals lacking somatosensory responses from the fingers. The results of online taBCI interfacing sessions conducted with 11 BCI-naive subjects resulted with the mean accuracies above the theoretical chance level of 16.6%. In our experiments only a single BCI-naive subject obtained 100% and also one obtained 0% for the six digit sequence spelling accuracy with five-trials averaging procedure. The presented study is a step forward in the search for new BCI paradigms.	O2-6-3-4 脳表脳波を用いたワイヤレス体内埋込型ブレインマシンインターフェース装置：W-HERBS A Fully-implantable Wireless System for Human Brain-Machine Interfaces using Brain Surface Electrodes: W-HERBS ○平田雅之1, 松下光次郎1, 鈴木隆文2, 吉田毅3, 佐藤文博4, 梅田達也5, 西村幸男5, 長谷川功6, 安藤博士2, シェインモリス1, 柳澤琢史1, 貴島晴彦1, 川人光男7, 吉峰俊樹1 ○Masayuki Hirata1, Kojiro Matsushita1, Takafumi Suzuki2, Takeshi Yoshida3, Fumihiro Sato4, Tatsuya Umeda5, Yukio Nishimura5, Isao Hasegawa6, Hiroshi Ando2, Shayne Morris1, Takufumi Yanagisawa1, Haruhiko Kishima11, Mitsuo Kawato7, Toshiki Yoshimine1 大阪大学大学院医学系研究科脳神経外科学1, 情報通信研究機構　脳情報通信融合研究センター2, 広島大学大学院先端物質科学研究科3, 東北大学大学院医工学研究科4, 生理学研究所認知行動発達機構研究部門5, 新潟大学大学院統合生理学6, ATR脳情報通信総合研究所7 Dept Neurosurg. Osaka Univ Med Sch, Osaka1, CiNET, NICT, Osaka, Japan2, Dept Semicon Electro Integra Sci, Hiroshima Univ, Hiroshima, Japan3, Grad Schl Biomed Eng, Tohoku Univ, Miyagi, Japan4, Div Behav Develop, Dept Develop Physiol, NIPS, Aichi, Japan5, Dept Neurophysiol, Niigata Univ, Niigata, Japan6, Dept Neuroinfo, ATR Brain Info Commun Res Lab Gr, Nara, Japan7 We are developing a fully-implantable wireless system, which is indispensable for the clinical application of electrocorticogram (ECoG)-based brain-machine interfaces (BMIs) in order to reduce the risk of infection: W-HERBS (Wireless Human ECoG-based real-time BMI system). This system uses many new technologies including a 128-channel integrated analog amplifier chip, a low-power wireless LAN data transfer circuit, a wirelessly rechargeable battery, a high-density 3-dimensional tissue-conformable and double-sided ECoG grid electrode, a titanium artificial skull bone which contains electronic devices, and a fluorine polymer subcutaneous cable. In the present study, we minimized the device to implant in macaque monkeys that are as small as human babies. We temporarily or chronically implanted the device in macaque monkeys and evaluated the safety and performance of the essential part of the device. The ECoG electrodes were placed over the sensori-motor cortices. We were able to implant the device safely and to record ECoGs in real time as well as clear somatosensory evoked responses. Our device is not only expected as a future clinical implantable device for BMIs but also enables us chronic invasive neural recordings under unconstrained conditions, which contributes to various neurophysiological fields.

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