水野 由子

This study examined the differences in functional brain network over time between different anxiety states and evaluated their usefulness in neural networks (NN). Seventeen young adults with high-anxiety and 13 young adults with low-anxiety were examined. The subjects were given three stimulations: resting, pleasant, and unpleasant stimuli, and Electroencephalogram (EEG) was measured immediately after the stimuli. EEG was analyzed for the alpha band using coherence analysis and graph theory. We evaluated the classification accuracy of anxiety states by NN and recurrent neural networks (RNN). The results showed the information processing process and structure of the brain functional network to emotional stimuli differed over time depending on the anxiety state. The time series data of coherence and graph theoretical indicator by EEG would be considered to be useful for discriminating anxiety states using RNN.

本研究では，脳波と心電図を組み合わせた機械学習により，情動判別の精度が向上するかどうかを検証することを目的とした．実験参加者は健常成人16名とし，情動ストレス負荷として安静・不快の視聴覚刺激を呈示した後の180秒間の脳波と心電図を周波数解析した．脳波のβ帯域と心電図のLF，HF，LF/HFを算出した．その後，脳波と心電図それぞれ単体のデータセットと脳波と心電図を組み合わせたデータセットを用いたニューラルネットワークの精度を比較した．その結果，脳波と心電図を組み合わせたデータセットを用いたニューラルネットワークの正解率が79.51%を示し，他データセットの場合よりも高値を示した．このことから，安静と不快に対する情動反応は，脳および自律神経活動において異なると考えられ，両方の指標を組み合わせることで，より精度の高い判別を行うことができる可能性が示唆された．

健常成人の冷え症改善に対し皮膚表面温度と指尖容積脈波を用いてストレッチの有用性を検討した．健常成人31 名（平均年齢22.05±2.6 歳）を上肢筋肉量の上位群（16 名）と上肢筋肉量の下位群（15 名）の2群に分けた．実験1は，手浴後の効果を見るために，1回の手浴を実施した．実験2は，ストレッチと手浴後の効果を見るために，1回の手浴と，ストレッチをして手浴を実施した．実験1と実験2において，手浴後にそれぞれ10 分間脈波振幅値と皮膚表面温度を測定し，各群で比較した．上位群では，脈波振幅値と皮膚表面温度は，両方の実験で，安静時と比較して変化はなかった．下位群では，実験2の安静時，手浴後，ストレッチをして手浴後の脈波振幅値が上位群と比較して，有意に高値を示した．また，実験2の皮膚表面温度は，0分後，2分後，4分後，6分後で上位群と比較して有意に高値を示した．ストレッチは，下位群において，冷え症改善の効果があることが示唆された．<br><br>【キーメッセージ】<br>1．今回の研究は看護・介護のどのような問題をテーマにしているのか？<br> 研究を行うきっかけとなったことはどのようなことか？<br>→ 冷え症は，体調不良の誘因となることに着眼し，セルフケアにより予防できると考えた．<br><br>2．この研究成果が看護・介護にどのように貢献できるのか？あるいは，将来的に貢献できることは何か？<br>→ 冷え症の軽減により，若年者の健康保持増進や，高齢者のフレイル予防に貢献できる．<br><br>3．今後どのような技術が必要になるのか？<br>→ 簡便な保温方法や，取り組みやすいストレッチ方法の改善が必要である．

In this study, a brain network was created using graph theoretical analysis based on electroencephalography (EEG) data. The purpose of the study was to investigate the functional connectivity of the brain in different states of anxiety. Seventeen adults with anxiety (A-G), and 13 adults without anxiety (AF-G) were examined. They were given three different stimulations: resting, pleasant, and unpleasant. EEG was measured immediately after the stimulation. The EEG was analyzed by Fast Fourier Transform (FFT), coherence analysis, and graph theory. The results of FFT and coherence analysis showed that the anxiety group (A-G) had higher power spectra and coherence values than those for the anxiety-free group (AF-G) in all sessions. The results of graph theory analysis showed that the clustering coefficient and small-worldness in A-G were lower than those in AF-G, although the characteristic path length in A-G was higher than that in AF-G. This study shows that the brain of A-G has smaller clusters and longer paths to compare with those of AF-G. These events suggest that the brain of A-G would have an inefficient network structure to transmit emotional information.

本研究では，看護学生を対象にマインドフルネス呼吸法を適用した群と適用していない群に分類し，マインドフルネスの影響を生理学的観点から調べた．被験者（20 名）を無作為に2群に分類し，5日間におけるマインドフルネスを適用した群と，適用しなかった群の課題遂行時の脳波を測定した．解析箇所は両群のタスク間のθ 波，α 波，β 波とし，各周波数帯域のパワースペクトル値含有量を比較した．その結果，マインドフルネスによって，課題遂行中にリラクゼーション効果があること，課題遂行後も注意力を維持することが示唆された．マインドフルネス群の被験者全員が実験期間の5日間継続してマインドフルネスを実践することで，リラクゼーション効果が持続し，緊張が緩和された状況でマインドフルネスを行わない場合でも，リラクゼーション効果が持続した．これらのことから，マインドフルネスは課題遂行やリラクゼーションに有用であることが示唆された．<br><br>【キーメッセージ】<br>1．今回の研究は看護・介護のどのような問題をテーマにしているのか？<br> 研究を行うきっかけとなったことはどのようなことか？<br>→ テーマは看護学生のメンタルヘルス改善であり，看護基礎教育の教育課程の過密がきっかけである．<br><br>2．この研究成果が看護・介護にどのように貢献できるのか？あるいは，将来的に貢献できることは何か？<br>→ 学習面・精神面のつまずきに対する予防や看護学に対するストレスの軽減に貢献できる．<br><br>3．今後どのような技術が必要になるのか？<br>→ マインドフルネスを誰でも活用できるようにするためのプログラム開発と普及啓発が必要となる．

2022年度日本知能情報ファジィ学会論文賞受賞

脳機能とパフォーマンスとの関係性の解明は,脳機能の視点から運動課題介入期間を検討する基礎的資料の提示につながる.そこで健常者18名を対象とし,運動学習進行過程の前頭前野と運動感覚関連領域を近赤外線分光法にて測定し,脳血流動態および脳内ネットワークとパフォーマンスの関係性を検討した.その結果,運動学習の進行とともに前頭前野の脳賦活時間が漸減し,また,脳内ネットワーク効率が上昇した.さらに,パフォーマンス上達後,一部前頭前野の再賦活および脳内ネットワーク効率が低下した.本結果から,更なるパフォーマンス上達に向け,脳機能は変化し続ける可能性があり,同一運動課題の継続実施もまた,一手段と考えられた.(著者抄録)

統合失調症患者の脳波に対してネットワーク解析を用いて，脳の機能的な結合や脳内部位間ネットワークの特徴を抽出することを目的とした．被験者は健常成人10名，統合失調症患者10名とし，閉眼時の脳波を測定した．電極配置は，国際電極配置法（10/20法）に基づき19チャンネルに配置した．脳波はウェーブレット相互相関解析を行い，ウェーブレット相互相関係数(wavelet-crosscorrelation：WCC)を算出し，部位間の関連性を求めた．算出されたWCC値を用いて部位間ネットワークを構築し，ネットワーク解析を用いてクラスタリング係数，特徴的経路長，スモールワールド指標を算出した．ウェーブレット相互相関解析の結果，統合失調症患者の安静時におけるシータ波帯域及びアルファ波帯域の平均WCC値は，健常成人と比較し高値を示した．ネットワーク解析の結果，統合失調症患者は健常成人と比較して，クラスタリング係数は低値を示し，特徴的経路長は高値を示し，スモールワールド指標は低値を示した．本研究の結果より，統合失調症患者は健常成人よりも，規模の大きい脳内ネットワークが形成されているが，脳内局所的な部位間の繋がりが低く，それぞれの部位間における情報伝達経路が長いことがわかった．

<jats:p>Cortical stimulation has been used for brain mapping for over a century, and a standard assumption is that stimulation interferes with task execution due to local effects at the stimulation site. Stimulation can however produce afterdischarges which interfere with functional localization and can lead to unwanted seizures. We previously showed that (a) cognitive effort can terminate these afterdischarges, (b) when termination thus occurs, there are electrocorticography changes throughout the cortex, not just at sites with afterdischarges or sites thought functionally important for the cognitive task used, and (c) thresholds for afterdischarges and functional responses can change among stimulation trials. We here show that afterdischarge termination can occur prior to overt performance of the cognitive tasks used to terminate them. These findings, taken together, demonstrate that task-related brain changes are not limited to one or a group of functional regions or a specific network, and not limited to the time directly surrounding overt task execution. Discrete locations, networks and times importantly underpin clinical behaviors. However, brain activity that is diffuse in location and extended in time also affect task execution and can affect brain mapping. This may in part reflect fluctuating levels of attention, engagement, or motivation during testing.</jats:p>

Graph theoretical analysis has recently been used to study brain function. This study aims to compare the functional brain networks derived from electroencephalography (EEG) of 10 patients suffering from epilepsy with 10 healthy subjects based on graph theory. Five epochs per healthy subject, and ten epochs (during epileptiform discharge and non-discharge) per patient were selected and analyzed using wavelet-crosscorrelation analysis. The clustering coefficient, characteristic path length, small-worldness, and nodal betweenness centrality were calculated using graph analysis. The results showed that in the patients, Wavelet-crosscorrelation Coefficients (WCC) were significantly higher, and clustering and path length were significantly lower during discharge compared with the healthy subjects, along with alterations in the hub regions. These results suggest a loss of small-world topology in the functional brain network of epilepsy patients. A loss of small-world topology was found even during non-discharge, therefore network indices might aid to distinguish epilepsy patients from healthy individuals.

The aim of this study was to assess Virtual Reality (VR) based visual auditory stimulation can relieve pain. To achieve this, the impact that body surface electrical stimulation has on the body surface potentials and activity in the central nervous system in VR environments were extracted. Twenty-two adults participated in this study. The body surface potentials and Electroencephalogram frequencies were measured under various conditions: non-viewing, viewing neutral clips, viewing unpleasant clips, and viewing pleasant clips. The pain index was calculated from the body surface potentials. Participants were asked to complete subjective pain measurement scales. Results showed that the pain index and the relative subjective pain score decreased when presented with unpleasant and pleasant video clips. The incidence of alpha waves declined when presented with unpleasant clips, while the incidence of beta waves increased when presented with unpleasant and pleasant video clips. Inattentiveness to pain due to VR immersion and descending pain inhibition due to awareness of emotional stress after viewing VR clips were considered to have contributed to the decline in the pain index and in relative subjective pain score. This study suggests that it is possible to relieve pain by VR viewing related to unpleasant or pleasant.

<p>The aim of this study was to assess Virtual Reality (VR) based visual auditory stimulation can relieve pain. To achieve this, the impact that body surface electrical stimulation has on the body surface potentials and activity in the central nervous system in VR environments were extracted. Twenty-two adults participated in this study. The body surface potentials and Electroencephalogram frequencies were measured under various conditions: non-viewing, viewing neutral clips, viewing unpleasant clips, and viewing pleasant clips. The pain index was calculated from the body surface potentials. Participants were asked to complete subjective pain measurement scales. Results showed that the pain index and the relative subjective pain score decreased when presented with unpleasant and pleasant video clips. The incidence of alpha waves declined when presented with unpleasant clips, while the incidence of beta waves increased when presented with unpleasant and pleasant video clips. Inattentiveness to pain due to VR immersion and descending pain inhibition due to awareness of emotional stress after viewing VR clips were considered to have contributed to the decline in the pain index and in relative subjective pain score. This study suggests that it is possible to relieve pain by VR viewing related to unpleasant or pleasant.</p>

© 2012 IEEE. Neurons behave like transistors, but have fluctuating characteristics. In this paper, we show that several asynchronous multiplex communication channels can be established in a 2-D mesh neural network with randomly generated weights between eight neighbors. Neurons were simulated by integrate-and-fire neuron models without leakage and with fluctuating refractory period and output delay. If one of the transmitting neuron groups is stimulated, the signal is propagated in the form of spike waves. The corresponding receiving neuron group is able to identify the signal after having learned to form an asynchronous multiplex communication channel. The channel is composed of many intermediate/interstitial neurons working as relays. Each neuron can work as an I/O and as a relay element, i.e., as a multiuse unit. Grouping and synchronic firing is often seen in natural neuronal networks and seems to be effective for stable/robust communication in conjunction with spatial multiplex communication. This communication pattern corresponds to our wet lab experiments on cultured neuronal networks and is similar to sound identification by the ear and mobile adaptive communication systems.

クエン酸第二鉄(FCH)服用中の血液透析患者を対象として、貧血関連指標の特徴を後方視的に検討した。FCH服用によりヘモグロビン(Hb)overshootを起こした61例、ならびにHb overshootを起こしていない血液透析患者で赤血球数(RBC)>350万/μLの34例とRBC≦350万/μLの46例について血液検査評価項目、血液透析処方項目を比較した結果、RBC>350万/μLがHb overshootの必要条件であると考えられた。また、血清フェリチンの変動はFCHの服用量に依存するのではなく、赤血球造血刺激因子(ESA)製剤投与量の変動により鉄が多く分布しているRBCの増減に依存していると考えられた。RBCと平均赤血球ヘモグロビン量を指標にESA製剤投与量を設定することで、FCH服用に伴うHb overshootをコントロールできると考えられた。

© 2019 the Author(s). It is well known that various types of information can be learned and memorized via repetitive training. In brain information science, it is very important to determine how neuronal networks comprising neurons with fluctuating characteristics reliably learn and memorize information. The aim of this study is to investigate the learning process in cultured neuronal networks and to address the question described above. Previously, we reported that the spikes resulting from stimulation at a specific neuron propagate as a cluster of excitation waves called spike wave propagation in cultured neuronal networks. We also reported that these waves have an individual spatiotemporal pattern that varies according to the type of neuron that is stimulated. Therefore, different spike wave propagations can be identified via pattern analysis of spike trains at particular neurons. Here, we assessed repetitive stimulation using intervals of 0.5 and 1.5 ms. Subsequently, we analyzed the relationship between the repetition of the stimulation and the identification of the different spike wave propagations. We showed that the various spike wave propagations were identified more precisely after stimulation was repeated several times using an interval of 1.5 ms. These results suggest the existence of a learning process in neuronal networks that occurs via repetitive training using a suitable interval.

In some individuals, alpha waves appear in many regions of the brain, and this is considered abnormal electroencephalography (EEG). This phenomenon is known as diffuse alpha pattern. This study aims to extract and compare the features of the connectivity between the parts of the brain. The EEGs of healthy individuals and mental disorder patients with the diffuse alpha pattern were analyzed using wavelet-crosscorrelation analysis. Five epochs of 2 seconds were analyzed for each subject. Wavelet-crosscorrelation coefficients were calculated for frequencies in the alpha band for all epochs in each subject. The results showed that the WCC values were higher in the patients with diffuse alpha. The highest wavelet power spectra in the alpha band of the patients occurred at a lower frequency. Our results suggest that the connectivity strength along the sagittal and occipital orientations in the brain of the patients could be stronger than healthy individuals.

<p>The authors carried out a physiological evaluation involving plethysmographic analysis and subjective evaluation to identify differences in the usability of personal computer peripherals. As workload items, the speed of the mouse pointer was changed in three stages, and the plethysmography was measured while the users performed a Trail Making Test. Sympathetic nerve activity in the peripheral region and the central trunk region increases when the movement speed of the mouse pointer is slow. However, there was no significant difference in subjective evaluation and activity of autonomic nervous function. Competitive factors of mental workloads suggested that subjects experienced differences in load recognition of psychological stress and that this may affect the activity of autonomic nerve function.</p>

We investigated the correlation and time-lag (LAG) between the sites of the brain for different durations of epileptiform discharges, using wavelet-crosscorrelation (WCC) analysis. Electroencephalography (EEG) was classified into two epochs according to the epileptiform discharge durations, as follows: short run, 2-3 seconds and long run, 3 seconds or more. Both runs were categorized into before, during, and after the epileptiform discharges. WCC coefficients and LAG in the 6 and 8 Hz bands for each segment were calculated in all the patients. The results of the comparison among all the electrodes in both runs showed that the correlation during the epileptiform discharges was higher than before and after the epileptiform discharges. In the 6 Hz band, in the short run, the results of the comparison among the temporal region electrodes showed that the correlation and LAG between the sites could be stronger in the 2 seconds immediately prior to the beginning of the epileptiform discharges in the EEG. In the long run, the results of the comparison among the temporal region electrodes showed that high correlation and LAG between the sites could be stronger in the 2-4 seconds immediately prior to the beginning of the epileptiform discharges and 2-4 seconds after to the epileptiform discharges in the ipsilateral hemisphere and contralateral hemisphere. It can be suggested that the difference in the duration of the epileptiform discharges may be caused by the balance between the suppressive and excitatory processes in the brain, before and after epileptiform discharges.

In recent years, research has been conducted to quantitatively evaluate the psychological state of a person when he/she is using the target system through the evaluation of biofunctional activity based on physiological indicators. Therefore, in the present study, we extracted autonomic nervous function activity caused by differences in operability of computer operation equipment using fingertip plethysmographic analysis, and evaluated differences in autonomic nervous function activity caused by mood states. The Profile of Mood States (POMS) was used for psychological examination. The fingertip volume pulse wave was measured while the subject performed the Trail Making Test (TMT) at three different mouse point movement speeds as a workload item. The results showed that sympathetic nervous activity in the central (trunk) region as well as the peripheral (distal) vascular region increased when mouse point movement speed was low. On the other hand, it was suggested that there may have been no differences in sympathetic nervous activity of the peripheral (distal) vascular area when the subject's mood tended to be negative as motivation to engage in the task decreased, creating variations in perception of the degree of psychological stress among the subjects. The subject's mood state prior to the experiment should also be evaluated when quantitatively evaluating psychological state during use of the target system.

© 2018 the Author(s). Neuronal networks have fluctuating characteristics, unlike the stable characteristics seen in computers. The underlying mechanisms that drive reliable communication among neuronal networks and their ability to perform intelligible tasks remain unknown. Recently, in an attempt to resolve this issue, we showed that stimulated neurons communicate via spikes that propagate temporally, in the form of spike trains. We named this phenomenon "spike wave propagation". In these previous studies, using neural networks cultured from rat hippocampal neurons, we found that multiple neurons, e.g., 3 neurons, correlate to identify various spike wave propagations in a cultured neuronal network. Specifically, the number of classifiable neurons in the neuronal network increased through correlation of spike trains between current and adjacent neurons. Although we previously obtained similar findings through stimulation, here we report these observations on a physiological level. Considering that individual spike wave propagation corresponds to individual communication, a correlation between some adjacent neurons to improve the quality of communication classification in a neuronal network, similar to a diversity antenna, which is used to improve the quality of communication in artificial data communication systems, is suggested.