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KOHAMA Takeshi

    Department of Computational Systems Biology　Associate Professor
Last Updated :2024/04/19

Researcher Information

J-Global ID

Research Interests

  • 固視微動   眼球運動   視覚的注意   マイクロサッカード   第一次視覚野   眼筋   脳幹   シミュレーション   周波数解析   数理モデル   定量的測定   視覚認知パフォーマンス   発生頻度   モデル   ドリフト眼球運動   トップダウン注意   知覚閾下   上丘   定量的評価   制御モデル   主系列   計算機シミュレーション   動特性   コヒーレント運動   ボトムアップ注意   視覚系   脳波   多次元生体信号   覚醒維持状態   多次元自己回帰モデル   

Research Areas

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Measurement engineering
  • Informatics / Intelligent informatics
  • Life sciences / Biomaterials
  • Life sciences / Biomedical engineering
  • Informatics / Intelligent robotics
  • Informatics / Perceptual information processing
  • Humanities & social sciences / Educational technology
  • Life sciences / Biophysics
  • Life sciences / Neuroscience - general
  • Informatics / Biological, health, and medical informatics
  • Humanities & social sciences / Cognitive sciences

Academic & Professional Experience

  • 2013 - 2014  Kindai UniversityFaculty of Biology-Oriented Science and Technology准教授

Published Papers

  • Soichi Okada; Nobuo Takeshima; Eiji Fujita; Takeshi Kohama; Masanobu Kusunoki; William F. Brechue
    Journal of Physical Therapy Science Society of Physical Therapy Science 36 (1) 9 - 20 0915-5287 2024
  • Takafumi Otsuka; Takashi Izumi; Masaya Yamamoto; Yusuke Seshita; Takeshi Kohama; Masahiro Nishihori; Tetsuya Tsukada; Ryuta Saito
    Nagoya journal of medical science 85 (1) 50 - 58 2023/02 
    In the neuroendovascular field, the training of operators has become an important issue. Recently, eye-tracking technology has been introduced into various fields of medical education. This study aimed to apply eye-tracking technology to the training of neuroendovascular therapy. Six neurosurgeons, including three neuroendovascular specialists and three trainees, at our institution and related facilities participated in the study. Eye movement was recorded by the eye-tracking device during the microcatheter navigation and coil placement into the silastic aneurysm model under biplane X-ray fluoroscopy. Eye-tracking analysis during neuroendovascular therapy was feasible in all six subjects. In microcatheter navigation, specialists tended to more frequently switch their attention between frontal and lateral images than trainees. In coil embolization, the overall gaze frequency tended to increase, and the average fixation duration tended to decrease as the number of experienced cases increased. Inexperienced operators tend to fix their gaze when they are operators than when they are assistants. More experienced operators tended to look at the microcatheter longer in the coil insertion task. The eye-tracking analysis may be useful for operator training in neuroendovascular therapy. Experts may have moved their eyes more frequently than trainees to gaze at the right place. In the future, it will be necessary to collect gaze data for more operators in various tasks.
  • Yosuke Osuka; Nobuo Takeshima; Narumi Kojima; Takeshi Kohama; Eiji Fujita; Masanobu Kusunoki; Aiko Imai; Yukiko Kitabayashi; William F Brechue; Hiroyuki Sasai
    Archives of gerontology and geriatrics 108 104915 - 104915 2022/12
  • Koufuku Keigo; Eiji Fujita; Kubo Seigo; Kohama Takeshi; Kusunoki Masanobu; Takeshima Nobuo; Nakagaichi Masaki
    Research Journal of Sports Performance Japan Society of Sports Performance Research 14 109 - 117 2022 [Invited]
     
    The purpose of this study was to determine the effects of a MotoTiles exercise on balance ability in communitydwelling older adults. The participants were 11 women who lived in T city and had performed a community-group exercise. The exercise was carried out twice a week for a period of 12 weeks using the local community center. For the balance index, a 20-sec stepping test was performed with the eyes open, and the total head movment distance (TMD), maximum movment distance (MMD), and the distance of the knee joint point (KMD) were used using KINECTTM infrared sensor. The pace of both legs (PACE left and right) and its coefficient of variation (CV) were used using Optogait infrared sensor system. Functional reach (FR), up-and-go (TUG), and 30sec-chair stand (30-CS) were also examined. As a result of 12 weeks of exercise, there was significant improved on TMD, MMD, PACE left CV, FR, TUG, and 30-CS (effect size were moderate to large). No significant changes were observed in other infrared sensor-related indexes, but overall, the head and knee sway during the stepping test and the variation when raising the legs tended to be smaller. The MotoTiles Exercise appears to be useful for assessing one of balance ability in older adults.
  • Nobuo Takeshima; Takeshi Kohama; Masanobu Kusunoki; Sochi Okada; Eiji Fujita; Yukiya Oba; William F. Brechuef
    EXPERIMENTAL AGING RESEARCH TAYLOR & FRANCIS INC 46 (3) 244 - 256 0361-073X 2020/05 [Refereed]
     
    Background: Tests such as the Functional Independence Measure (FIM) are widely used measures of infirmity and burden of care. However, these scales are largely qualitative and especially problematic when assessing movement-based tasks. Effective, reliable analysis of human movement is technically complicated and expensive, but an infrared depth sensor is potentially a low-cost, portable devise which may provide a quantitative aspect to clinical testing. Our purpose was to assess the utility of a 20-sec stepping test (ST) and Kinect (TM) infrared-depth sensor in providing objective evaluation of balance toward identifying disability in older adults. Methods: Men and women between 64 and 90 years of age, consisting of independent (IG; n = 37) and dependent (DG; n = 38) living at community, geriatric day-care center in Japan. Total movement distance (TMD) and greatest displacement (MMD) were calculated from Kinect (TM) recording of the ST. Results: DG had lower FIM scores than IG. TMD and MMD were significantly greater in DG than IG, while step number and rate were lower in DG. Receiver-operator characteristic analysis showed TMD, TMD/step, MMDstep, and MMD corrected for time and height strongly discriminated between assignment to DG or IG with moderate sensitivity and specificity. Conclusions: Greater TMD and MMD observed during a 20-sec ST appear to indicate disability with moderate sensitivity and specificity in older adults. Measures of movement distance (e.g. TMD, MMD) appear indicative of changes in dynamic balance due to a circuitous movement pattern generated by aberrant step replacement with repeated stepping-in-place.
  • Eiji Watanabe; Takashi Ozeki; Takeshi Kohama
    Advances in Intelligent Systems and Computing 1134 AISC 27 - 38 2194-5357 2020 
    © Springer Nature Switzerland AG 2020. This paper discusses the modeling for interactions between the behaviors of participants in a meeting for decision making. First, we adopt the behaviors (i.e., eye, facial, and hand movements) detected by OpenPose [9] as a skeleton detection algorithm using a single camera. Second, we propose a modeling method for the participant behaviors based on neural networks. Furthermore, we discuss the relationships between the participant behaviors and the model parameters in multi-layered neural networks based on the experimental results. Notably, we show that the participant characteristics are represented by the indices based on the parameters of the abovementioned models.
  • Nobuo Takeshima; Takeshi Kohama; Masanobu Kusunoki; Soichi Okada; Eiji Fujita; William F. Brechue
    MEDICINE AND SCIENCE IN SPORTS AND EXERCISE LIPPINCOTT WILLIAMS & WILKINS 51 (6) 355 - 355 0195-9131 2019/06 [Invited]
  • Masanobu Kusunoki; Takeshi Kohama; Yoshifumi Yamada; Eiji Fujita; Soichi Okada; Akira Maeda; Nobuo Takeshima
    Disability and rehabilitation. Assistive technology 14 (4) 368 - 378 1748-3115 2019/05 [Refereed]
     
    PURPOSE: With a growing proportion of elderly people in the population, the maintenance of activities of daily living (ADLs) in elderly people is crucial to keep medical costs down. We investigated the ADL measurement accuracy of KINECTTM and Kinect Studio. To eliminate the subjectivity of conventional methods, we numerically assessed motions with computer analysis. METHODS: Eighteen actions that repeated "move" and "stationary" phases, including movement of arms, legs, head and torso were measured using KINECTTM. Errors and standard deviations of joint coordinates at the stationary points outputted from KINECT Studio were evaluated. Simultaneous measurements were performed with KINECTTM using conventional high-performance motion capture, and the output was treated as a true value for comparison. RESULTS: In most motions, errors of the joint coordinates were within 100 mm; however, there were two cases where errors due to the skeleton-model estimation by KINECT Studio increased. Firstly, when a part of the body unexpectedly moved out of the infrared measurable area, and secondly, when parts of the body overlapped each other on the KINECTTM image. CONCLUSIONS: KINECTTM and Kinect Studio are effective for ADL assessment when positions that cause large errors are excluded. Since KINECTTM has sufficient precision, it should also be possible to develop a more appropriate ADL evaluation system with a new algorithm of skeleton-model estimation that does not depend on KINECT Studio. Implications for Rehabilitation The KINECTTM and Kinect Studio are effective for ADL assessment when positions that cause large errors are excluded With an increasing proportion of elderly people in the population, the maintenance of activities of daily living (ADLs) in elderly people is crucial to keep medical costs down Systems such as the KINECTTM can support these goals.
  • Eiji Watanabe; Takashi Ozeki; Takeshi Kohama
    Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 11677 LNCS 191 - 201 0302-9743 2019 
    © Springer Nature Switzerland AG 2019. In this paper, we discuss the modeling for the interactions between non-verbal behaviors of “teaching/learning” students in the cooperative learning. First, we adopt the positions eyes, face and hands detected by OpenPose [7] as a skeleton detection algorithm by a single camera. Next, we propose a modeling method for non-verbal behaviors based on neural networks. Furthermore, we discuss the modeling results for the interactions between non-verbal behaviors of students based on the internal presentations in the above models.
  • Eiji Watanabe; Takashi Ozeki; Takeshi Kohama
    Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) SPRINGER INTERNATIONAL PUBLISHING AG 11626 LNAI 309 - 313 0302-9743 2019 
    © Springer Nature Switzerland AG 2019. This paper proposes modeling methods (i) for the interaction between behaviors of the lecturer and students, (ii) for the interaction between the lecturer and holistic behaviors of students. Moreover, we discuss modeling results based on experimental results.
  • Development of simple, objective chair-standing assessment of physical function in older individuals using a KinectTM sensor.
    Takeshima N; Kohama T; Kusunoki M; Fujita E; Okada S; Kato Y; Kofuku K; Islam MM; Brechue WF
    J Frailty Aging dx.doi.org/10.14283/jfa.2019.2 2019 [Refereed]
  • Eiji Watanabe; Takashi Ozeki; Takeshi Kohama
    ACM International Conference Proceeding Series ACM 370 - 374 2018/03 [Refereed]
     
    © 2018 Association for Computing Machinery. In this paper, we discuss the interactions between lecturers and students. First, we detect their behaviors by extracting the face regions of lecturers and students from moving images. Thereafter, we model the interaction between the lecturers’ writing and explanation behaviors and the students’ note taking and listening behaviors by using multilayered neural networks. We discuss the above interactions based on the internal representations of multilayered neural networks.
  • Kohama Takeshi; Nakai Yuma; Ohtani Shohei; Yamamoto Masaya; Ueda Shinichi; Yoshida Hisashi
    The Transactions of Human Interface Society Human Interface Society 19 (2) 189 - 198 1344-7262 2017 [Refereed]
     
    Voice recognition technologies are widely applied to the general-purpose devices, such as car navigation systems or mobile phones. However, cognitive-loads of voice operations have not been discussed sufficiently. Since it is necessary to translate a command to a verbal phrase, cognitive-loads of voice operations for simple tasks may become higher than those of manual operations. In this study, we analyzed microsaccade rates to compare the cognitive-loads between voice and manual operations objectively. Subjects performed a parafoveal transition detection task of a geometry pattern in which they responded by their voice or mouse clicks. We also evaluated the task performances of simultaneously imposed an RSVP (Rapid Serial Visual Presentation) task to estimate effects on cognitive distractions. The results show that microsaccade rates increase synchronously with the timing of voice responses, and task performances of the RSVP task decline immediately after voice responses compared with the results of manual responses. These findings suggest that voice operations have an effect to disengage subjects' attention from visual targets, and this attentional disengagement might cause the cognitive distraction of gazing objects.
  • Shohei Otani; Takeshi Kohama; Sho Kikkawa; Hisashi Yoshida
    International Journal of Bioelectromagnetism 18 (1) 19 - 25 2016/12 [Refereed]
  • Nobuo Takeshima; Takeshi Kohama; Masanobu Kusunoki; Takashi Ogayu; Soichi Okada; Eiji Fujita; Mohammod M. Islam; William F. Brechue
    JOURNAL OF AGING AND PHYSICAL ACTIVITY HUMAN KINETICS PUBL INC 24 S41 - S41 1063-8652 2016/06 [Refereed]
  • 小濱 剛
    光学 = Japanese journal of optics : publication of the Optical Society of Japan 日本光学会 45 (1) 9 - 15 0389-6625 2016/01
  • Eiji Watanabe; Takashi Ozeki; Takeshi Kohama
    Communications in Computer and Information Science SPRINGER-VERLAG SINGAPORE PTE LTD 647 203 - 211 1865-0929 2016 [Refereed]
     
    © Springer Science+Business Media Singapore 2016. In this paper, we discuss the relationship between non-verbal behaviors and understandings by students in the cooperative learning. First, we detect non-verbal behaviors by students by using image processing methods. Next, we propose a modeling method for non-verbal behaviors. Furthermore, we discuss the relationship between non-verbal behaviors and understandings by students based on the above models.
  • Mitsuhiro Kodama; Takeshi Kohama; Hisashi Yoshida
    Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS IEEE 2015-November 6658 - 6661 1557-170X 2015/11 [Refereed]
     
    © 2015 IEEE. The purpose of this study is to construct a mathematical model which predicts saliency regions in high-speed egocentric-motion movies, filmed by an embedded camera in a driving vehicle, by reproducing the characteristics of the area MT and MST neurons' receptive fields with consideration of visual adaptation properties. The area MT neurons integrate from the area V1 activation and respond well to regions where higher motion contrasts exist. While the area MST neurons detect global motions such as expansion, contraction, rotation, and so on. We modeled the area MT neurons' receptive fields as a center-surround spatial summation of counter sided motion vectors of visual scenery. The area MST neurons in our model integrate the responses of the MT neurons by convolving with spacial weight functions of which central portions are biased to preferred direction. Visual adaptations were taken as the primary delay filters for each visual feature channel to deplete the saliency of stationary objects and regions during particular frames. The simulation results for the movies which were taken in a running vehicle indicate that the proposed model detects more salient objects around the vanishing point than the conventional saliency based model. To evaluate the performance of proposed model, we defined the moving-NSS (normalized scan-path salience) scores as the averaged NSS scores in each moving time window. The moving-NSS scores for motion images of our model were higher than those of the conventional model.
  • KIKKAWA Sho; KOHAMA Takeshi; YOSHIDA Hisashi
    Mem Fac Biol Oriented Sci Technol Kinki Univ 近畿大学生物理工学部 36 (36) 9 - 17 1342-7202 2015/09 [Refereed]
     
    [Abstract] It is believed that median filtering outperforms traditional linear filtering in preserving signal edges while reducing noise. However, this does not always mean that the median filter is superior to the linear filter as a smoother. By comparing the bias-variance characteristics of median filtering and linear filtering, we demonstrate that a linear filter (moving average filter) is a better smoother than the median filter for inputs that have Gaussian or uniform distributions and relatively small signal-to-noise ratios, whereas the median filter outperforms the linear filter for inputs with Laplace distributions. [要旨]メディアンフィルタは, それが提案されて以来, 決定論的信号に対するエッジ保存能力が注目され, エッジ保存が重視される状況下での平滑化フィルタとして, 線形フィルタに勝るものとして頻繁に用いられるようになってきている. しかし, ガウス雑音の仮定のもとでは, メディアンフィルタのエッジ保存能力が線形フィルタを凌駕するのは高SN比入力に対してのみであり, SN比が低下するに従いほとんど両者のエッジ保存能に差はなくなるとの報告がある. また, 同じくガウス雑音に対して, 高SN比でない限り, 出力の平均二乗誤差で見る性能評価では, むしろ線形フィルタの方が優れているとの報告もある. これらは両フィルタを比較するための重要な情報ではあるが, データ処理の現場で実際にどちらを使うべきかの判断材料とするには十分でない. そこで本報告では, 各種雑音に埋もれたエッジ信号入力に対する, メディアンフィルタと線形フィルタ (移動平均フィルタ) の出力のバイアスー分散特性を比較し, 長い尾を持たない雑音 (ガウス分布雑音と一様分布雑音) でかつ高SN比でない場合はむしろ線形フィルタ性能の方が良く, 長い尾を持つラプラス分布雑音の場合はSN比に関わらずメディアンフィルタが良いことを示す. これは一般に流布しているメディアンフィルタの線形フィルタに対する優位性「神話」への警告であり, また, 実際にどちらのフィルタを使うべきかの判断材料の提供でもある.
  • Eiji WATANABE; Takashi OZEKI; Takeshi KOHAMA
    International Journal of Information and Education Technology 5 (10) 723 - 727 2015 [Refereed]
  • WATANABE EIJI; OZEKI TAKASHI; KOHAMA TAKESHI
    電子情報通信学会論文誌 D(Web) J97-D (12) 1725-1728 (WEB ONLY)  1881-0225 2014/12
  • Shogo Honda; Takeshi Kohama; Tatsuro Tanaka; Hisashi Yoshida
    2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2014 IEEE 2014 2229 - 2232 1557-170X 2014/11 [Refereed]
     
    © 2014 IEEE. It is well known that a decline of arousal level causes of poor performance of movements or judgments. Our previous study indicates that microsaccade (MS) rates and pupil fluctuations change before slow eye movements (SEMs) (Honda et al. 2013). However, SEM detection of this study was obscure and insufficient. In this study, we propose a new SEM detection method and analyze MS rates and pupil fluctuations while subjects maintain their gaze on a target. We modified Shin et al.'s method, which is optimized for EOG (electrooculography) signals, to extract the period of sustaining SEMs using a general eye tracker. After SEM detection, we analyzed MS rates and pupil fluctuations prior to the initiation of SEMs. As a result, we were able to detect SEMs more precisely than in our previous study. Moreover, the results of eye movements and pupil fluctuations analyses show that gradual rise of MS rate and longitudinal miosis are observed prior to the initiation of SEMs, which is consistent with our previous study. These findings suggest that monitoring eye movements and pupil fluctuations may evaluate the arousal level more precisely. Further, we found that these tendencies become more significant when they are restricted to the initial SEMs.
  • NISHINO MAKOTO; KOHAMA TAKESHI; YOSHIDA HISASHI
    Mem Fac Biol Oriented Sci Technol Kinki Univ 近畿大学生物理工学部 34 (34) 35 - 46 1342-7202 2014/09 
    type:Departmental Bulletin Paper [要旨] 本研究では, 周辺視野の特性を考慮した網膜数理モデルを対象に, 計算資源の制限の中で計算処理を最大限に効率化することを目的として, 種々の並列計算アルゴリズムを適用し, 富士通製並列計算機PRIMEHPC FX10と汎用のパーソナルコンピュータとの間で計算時間の比較を行った. その結果, 各種の神経細胞層を個別のモジュールとして扱うことで，メッセージ通信によるサイクリック分割とパイプライン通信が実装可能であり，微分方程式の回帰参照の問題が回避できることが示された. また, メッセージ通信が困難な部分にマルチスレッド並列を適用することにより, 効率的な並列処理が実現できた. これらのことから, FX10の性能を最大限に引き出すためには, MPI（Message Passing Interface）を用いたメッセージ通信と, マルチスレッド処理とのハイブリッド並列化が有効であり, これにより高効率で高速な並列計算が可能となることが示された. [Abstract] The purpose of this study is to develop effective methods to compute a mathematical model of the retina which considers peripheral properties of retinal cells in the restriction of computation resources. We compared the machine time with regard to several parallel processing algorithms between the Fujitsu PRIMEHPC FX10 supercomputer system and general personal computers. The results indicate that the implementation of cyclically divided blocks and a pipeline processing with a message passing interface, by dealing with each cell layer as a module, is able to avoid problems of the regression reference of calculation of differential equations. For program codes which are difficult to implement message passing interfaces, we obtained a practical solution by applying multithread processing instead. Furthermore, these results suggest that the performance of the FX10 system is maximized by using a hybrid parallel processing method with message passing interfaces and multithread processing.
  • Hiroki Namikawa; Takeshi Kohama; Hisashi Yoshida
    Transactions of Japanese Society for Medical and Biological Engineering 52 O - 383 1881-4379 2014/08 
    © 2014, Japan Soc. of Med. Electronics and Biol. Engineering. All rights reserved. Recent brain science studies have focused on functional connectivity in functional networks. However, experimental conditions are not sufficiently controlled to reduce individual differences in order to make experimental data stable because the definition of resting states is ambiguous. The purpose of this study is to investigate a more stable method of measuring restiong state brain activity. Subjects performed a 2-back task to facilitate activity of the prefrontal cortex temporally. As half-closed eyes help induce a meditative state, we presented low-passed dynamic random-dot patterns (DRD) in the background to make subjects' vision similar to what they would see if their eyes were half-closed. We measured subjects' brain activity with a NIRS device while subjects observed DRDs for 180 seconds. As a result, prefrontal activity decreased earlier as DRDs increased in blurriness. Moreover, brain activity reactivated immediately after reaching the baseline. This suggests that our method may induce stable resting states effectively.
  • Eiji Watanabe; Takashi Ozeki; Takeshi Kohama
    Proceedings of 2014 International Conference on Interactive Collaborative Learning, ICL 2014 Institute of Electrical and Electronics Engineers Inc. 138 - 143 2014/01 
    © 2014 IEEE. In interviews, the evaluation by the interviewer is affected by not only the reply but also behaviors (eye and face movements) by applicants. Moreover, the evaluation by the interviewer is communicated with applicant as the behavior by the interviewer. Therefore, the interaction between the behaviors by the interviewer and the applicant occurs. In this paper, we show that the evaluation by the interviewer is strongly influenced by behaviors by applicants and the relationship between the evaluation by the interviewer and the behaviors by applicants.
  • Eiji Watanabe; Takashi Ozeki; Takeshi Kohama
    Proceedings of the 7th International Conference on Educational Data Mining, EDM 2014, London, UK, July 4-7, 2014 International Educational Data Mining Society (IEDMS) 329 - 330 2014 [Refereed]
  • Eiji Watanabe; Takashi Ozeki; Takeshi Kohama
    CSEDU 2014 - Proceedings of the 6th International Conference on Computer Supported Education SciTePress 1 191 - 196 2014 [Refereed]
     
    In this paper, the dominant behaviors defined by the face direction of the speaker and audience in lectures are analyzed by using the time-series models. First, we detect the face region of the speaker and audience by the image processing and we adopt the number of skin-colored pixels in face region as features for behaviors by them. Next, we construct piecewise time series models for behaviors by the speaker and audience. Finally, we analyze the synchronization phenomena in speaker and audience by comparing time series models. Concretely, we show that the parameters in the time series models denote the dominant section in lectures. Moreover, we discuss the relationships among notes, test and behaviors by audience.
  • 小濱 剛; 吉田 久; 山脇 伸行; 濱野 友紀; 清水 達央
    Memoirs of the Faculty of Biology-Oriented Science and Technology of Kinki University = 近畿大学生物理工学部紀要 近畿大学生物理工学部 32 (32) 7 - 16 1342-7202 2013/09 [Refereed]
     
    [要旨] 従事すべき作業とは関係の無い考え事に注意が奪われている状態では, 覚醒水準とは無関係に判断や応答といった認知パフォーマンスが低下するため, 判断ミスなどのヒューマンエラーによる事故をもたらす危険性が高くなるが, 作業者がそうした状態に陥っていることを客観的に評価することは極めて困難である. 本研究では, 課題とは無関係な考え事をしている状態を課題非依存性思考状態と定義し, このような課題非依存性思考状態が, 認知パフォーマンスに与える影響の客観的な評価を目的として, あらかじめ提示された8桁の数字の記憶を維持しつつ, 同時に課せられた視覚探索課題を遂行する際の, 目標探索時間や前頭前野外側部の近赤外線スペクトロスコピー(Near-Infrared Spectroscopy: NIRS)信号を解析した. 実験の結果, 複数の視覚属性の組み合わせにより定義された視対象の中から唯一の特徴を持った目標を探索する場合においてのみ, 課題非依存性思考の有無により目標探索時間が影響されることが示された.また, この条件においてはNIRS信号から推定された前頭前野外側部の賦活度が高まることも示唆された.これらのことから, 課題非依存性思考によって前頭前野の情報処理リソースが消費されることが示唆され, こうした状況下では, 認知タスクのパフォーマンスが影響を受ける可能性が示された. [Abstract] Working with stimulus-independent thoughts(SITs) often causes the decline of cognitive performances, such as judgments of signals or response times to certain tasks. It might lead to fatal accidents called "human errors" independently of arousal level. The detection and prediction of these errors is extremely difficult, and the measurement technology of inattentiveness has not yet been established. In this study, we investigate the effect of SITs on the performance of visual search tasks. SITs are the streams of thoughts that are unrelated to immediate situations. The subjects memorized the numeral of eight digits as an SIT while carrying out visual search tasks. The reaction time and the near-infrared spectroscopy signals from the lateral prefrontal cortex(PFC) were analyzed to evaluate the effect of SITs objectively. As a result, the average reaction time for searching targets from distracters only in terms of their feature conjunctions increased when having SITs during the tasks. Also, the SITs in these tasks enhance the activity of the lateral PFC. These results suggest that the SITs occupy the resource of attention and it might affect the performances of certain cognitive tasks under these conditions.【注記】本研究は, 近畿大学生物理工学部戦略的研究NO.11-Ⅰ-3 2012, および, JSPS科研費24560534の助成を受けた.
  • Shogo Honda; Takeshi Kohama; Tatsuro Tanaka; Hisashi Yoshida
    Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS IEEE 2013 2108 - 2111 1557-170X 2013 [Refereed]
     
    In this study, we proposed an objective estimation of decline of arousal level by analyzing microsaccade rate and pupil fluctuation while subjects were continuously gazing a fixation target. Previous studies show that the slow eye movements (SEMs) could be a candidate for an indicator of decline of arousal. However, it is not sufficient to evaluate transition of arousal states since SEMs appear just prior to sleep onset. To establish more objective assessment of arousal, we examined the effects of the transition of arousal on microsaccade rate and pupil fluctuation. The subjects were instructed to indicate by mouse clicks when they were aware of having slept. We have analyzed the eye movement and pupil fluctuation data in advance of the occurrence of SEMs which were detected just before the mouse clicks. In the results, longitudinal pupil diameter shrinking and gradual rise of microsaccade rate were observed prior to SEMs. These results suggest that the arousal level could be evaluated by monitoring eye movements and pupil fluctuations. © 2013 IEEE.
  • Eiji Watanabe; Takashi Ozeki; Takeshi Kohama
    Proceedings of 2013 IEEE International Conference on Teaching, Assessment and Learning for Engineering, TALE 2013 18 - 23 2013 
    In this paper, we consider a learning environment, which students solve the problem while reading digital contents. Here, we extract the relationship between the frequency for reading each page and the understanding for given problems. The above relationship can be modeled by using neural networks. Furthermore, we use a learning method with forgetting for neural networks for the purpose of clarification of internal representations. Finally, we have analyzed the relationship between the frequency for each page and the understanding for given contents based on the internal representations of multi-layered neural networks. © 2013 IEEE.
  • 小濱 剛; 吉田 久; 北林勇弥; 兵藤宏紀
    Memoirs of the Faculty of Biology-Oriented Science and Technology of Kinki University 近畿大学生物理工学部 30 1 - 16 1342-7202 2012/09 [Refereed]
     
    type:Departmental Bulletin Paper [要旨]手振れのような振動や回転を含んだ映像は, 吐気や目眩などの乗り物酔いと同様の症状を引き起こす. この症状を映像酔いと呼ぶ. 本研究では, 映像酔を誘発する映像要素を特定することを目的として, 特定の運動成分からなる映像を観察中の主観的な酔いの程度と固視微動および心拍変動の解析を行った. 映像が水平方向に移動するパン, 回転方向に変移するロール, 拡大と縮小により生じるズームの3種の映像要素により構成される運動するランダムドットパターン(ダイナミックランダムドット)を観察中に計測された固視微動データに対して周波数解析を行った結果, 実験の進行に伴って徐々に視線の揺らぎが増し, 注視の維持が困難になることが示された. また, パンまたはロール成分のみからなる動画を観察する際の心拍変動を解析した結果, パン成分のみの映像の方が, 心拍変動のHRV(HF/LF)が低い値となることが明らかとなり, パン成分が交感神経の亢進をもたらすことが示唆された. これらの結果から, 水平方向の運動成分を持った映像を長時間視聴することによって生じる視覚系と前庭系および体性感覚系との矛盾の蓄積が, 映像酔いをもたらしているものと推察され, 固視微動や心拍変動から酔いの進行の定量化が可能であることが示された. [Abstract] Videos with camera shake containing strong vibrational or rotational motion may cause some symptoms similar to motion sickness such as nausea, dizziness and headache. It is called cybersickness, or visually induced motion sickness. In this paper, we have evaluated cybersickness by analyzing fixation eye movements and heart rate variability of subjects viewing videos of which content was restricted to certain visual factors in order to identify the effective motion component for cybersickness. Firstly, fixation eye movements while subjects were watching random dots which consist of each of three visual factors, such as Pan, Roll and Zoom were measured and evaluated by spectral analysis. The results show that variability of the eye movements is increased as the experiment session progresses and it suggests that it is difficult to maintain the attention of fixation as cybersickness progresses. Secondly, we have evaluated the heart rate variability while subjects were watching the motion pictures which are not random dots but well-controlled motion pictures of an indoor scene and an out outdoor scene. Spectral analysis of the heart rate variability demonstrates that HF/LF measure in the Pan condition has lower values than in the Roll condition and it suggests that Pan motion in the video increases sympathetic nerve activity. These results indicate that cybersickness is caused by cumulative inconsistencies among visual, vestibular, and somatosensory systems for a long time while watching videos. Also, we have shown that progression of sickness can be quantified by analyzing fixation eye movements and heart rate variability. 本研究は近畿大学生物理工学部戦略的研究No.07-I-02, 2007の助成を受けた.
  • Inhibition of microsaccade rate caused by focus of visual attention
    遠藤 翔; 小濱 剛
    Memoirs of the Faculty of Biology-Oriented Science and Technology of Kinki University 近畿大学生物理工学部 29 7 - 15 2012/03
  • Hiroyuki Sakai; Duk Shin; Takeshi Kohama; Yuji Uchiyama
    Ergonomics TAYLOR & FRANCIS LTD 55 (7) 743 - 751 0014-0139 2012 [Refereed]
     
    Alerting drivers for self-regulation of attention might decrease crash risks attributable to absent-minded driving. However, no reliable method exists for monitoring driver attention. Therefore, we examined attentional effects on gaze preference for salient loci (GPS) in traffic scenes. In an active viewing (AV) condition requiring endogenous attention for traffic scene comprehension, participants identified appropriate speeds for driving in presented traffic scene images. In a passive viewing (PV) condition requiring no endogenous attention, participants passively viewed traffic scene images. GPS was quantified by the mean saliency value averaged across fixation locations. Results show that GPS was less during AV than during PV. Additionally, gaze dwell time on signboards was shorter for AV than for PV. These results suggest that, in the absence of endogenous attention for traffic scene comprehension, gaze tends to concentrate on irrelevant salient loci in a traffic environment. Therefore, increased GPS can indicate absentminded driving. Practitioner Summary: The present study demonstrated that, without endogenous attention for traffic scene comprehension, gaze tends to concentrate on irrelevant salient loci in a traffic environment. This result suggests that increased gaze preference for salient loci indicates absent-minded driving, which is otherwise difficult to detect. © 2012 Taylor & Francis.
  • Visual search model considering spatial modification of visual attributes and cortical magnification of retinal images.
    矢野勝也; 小濱 剛
    Memoirs of the Faculty of Biology-Oriented Science and Technology of Kinki University 近畿大学生物理工学部 28 41 - 52 2011/10 [Refereed]
     
    初期視覚神経系の情報処理の特徴を定式化した顕著性マップモデルは，顕著さの勾配に従って走査することで視線の移動を再現することができるが，特定の候補点の中から視線の移動先が選出されるために，ある程度長時間のシミュレーションでは循環が生じてしまう．本研究では，同じ視対象を繰り返し注視することを防ぐ復帰抑制と，周辺視野において生じる目標対象と同じ属性への応答を強化させる復帰増強と呼ばれる現象に着目し，従来の顕著性マップモデルに対して，これらの緒特性についての拡張を行った．さらに，網膜上の錐体細胞の密度分布に起因する第1次視覚野における皮質拡大を考慮し，視線移動のたびに生じる大脳皮質における網膜像の表象の変化を実装した．提案モデルによる視覚探索のシミュレーションを行った結果，従来モデルよりもターゲットの発見率が向上され，また，視線移動の軌跡が一定の戦略を持った探索時の視線移動に似たパターンとなること
  • KOHAMA Takashi; HIRATA Yoshihiro
    The Journal of the Institute of Image Electronics Engineers of Japan The Institute of Image Electronics Engineers of Japan 40 (5) 801 - 807 0285-9831 2011/09 
    This study proposes a binocular vision model that reconstructs 3D structures from autostereograms. Our model is a modified version of the model by Hayashi et al., which cannot resolve the autostereograms, and serves to introduce fusion processes by vergence eye movements in order to obtain depth information from autostereograms. Since autostereograms have a periodic plane as the background, our model starts with the vergence motion of two windows corresponding to the left and right eyes to search maximal output of the binocular energy unit that produces autocorrelation-like patterns of the background. Once the optimum vergence angle has been determined, the model calculates paired or unpaired points using the same procedure employed in the model by Hayashi et al. The results indicate that the model can reconstruct 3D structures even from autostereograms, suggesting that the disparity detection system coordinates with the eye movement system to accurately derive depth perception.
  • Eiji Watanabe; Takashi Ozeki; Takeshi Kohama
    Proceedings - 2011 IEEE 7th International Conference on Intelligent Computer Communication and Processing, ICCP 2011 IEEE 385 - 390 2011 [Refereed]
     
    In this paper, we discuss the analysis of behaviors by lecturer and students in lectures. In lectures, the relationships between lecturer and students depend on not only contents but also the loudness of speech and gestures by lecturer. The behaviors consisting of head and eye movements by students can often represent how they have the interest with the lecture. First, we extract the loudness of speech and the face direction as behaviors by lecturer and the face direction as behaviors by students. Next, we construct piecewise auto-regressive (AR) models for their behaviors. Here, the piecewise AR models can be constructed based on the residual error. Finally, we show the analysis results for a real lecture based on the piecewise AR modeling. © 2011 IEEE.
  • Eiji Watanabe; Takashi Ozeki; Takeshi Kohama
    Journal of the Institute of Image Electronics Engineers of Japan 40 (1) 42 - 51 0285-9831 2011/01 
    This paper proposes a restoration method for JPEG and blurred images based on ensemble learning algorithm. Such as a median filter, various restoration filters for these images have been already proposed and applied in real images. However, when images have edge and non-edge regions, it is difficult for single filter having fixed coefficients to reduce both blocky and mosquito noises adequately. Here, new restoration methods for JPEG and blurred images are proposed by introducing multiple muliti-layered neural networks. Each neural network can be adapted for edge, flat, and texture regions in images by ensemble learning. From experimental results, the proposed method can obtain good restoration accuracy compared with conventional filters. Moreover, we have confirmed that the proposed method could automatically assign restoration tasks to each neural network according to the characteristics of each region in given distorted images. © 2011, The Institute of Image Electronics Engineers of Japan. All rights reserved.
  • Eiji Watanabe; Takashi Ozeki; Takeshi Kohama
    IMAGAPP and IVAPP 2011 - Proceedings of the International Conference on Imaging Theory and Applications and International Conference on Information Visualization Theory and Applications INSTICC-INST SYST TECHNOLOGIES INFORMATION CONTROL & COMMUNICATION 75 - 80 2011 [Refereed]
     
    In this paper, we discuss the extraction of relationships between lecturer and students in lectures by using multi-layered neural networks. First, a few features concerning for behaviors by lecturer and students can be extracted based on image processing. Here, we adopt the following features as behaviors by lecturer and students; the loudness of speech by lecturer, face and hand movements by lecturer, face movements by students. Next, the relations among the above features concerning on their behaviors by lecturer and students can be represented by multi-layered neural networks. Next, we use a learning method with forgetting for neural networks for the purpose of extraction of rules. Finally, we have extracted relationships between behaviors by lecturer and students based on the internal representations in multi-layered neural networks for a real lecture.
  • Eiji Watanabe; Takashi Ozeki; Takeshi Kohama
    2011 IEEE International Conference on Automatic Face and Gesture Recognition and Workshops, FG 2011 IEEE Computer Society 945 - 950 2011 [Refereed]
     
    In this paper, we discuss the extraction of relations between lecturer and students in lectures by using multi-layered neural networks. Here, the relations among a few features concerning on the behaviors of the lecturer and students can be represented by multi-layered neural networks with the time-delay. Furthermore, we introduce a structural learning algorithm with forgetting for neural networks for the extraction of rules in the interaction. The above time-series models are analyzed focusing on weights in multi-layered neural networks. Concretely, we analyze which lecturer's behaviors (face and hand movements and loudness of speech) give great influences on behaviors by students (face movements). On the contrary, we analyze which student's behavior (face movement) give great influences on behaviors by lecturer. © 2011 IEEE.
  • KOHAMA Takeshi; TAKENAKA Haruka; YOSHIDA Hisashi; TODA Naohiro
    The Journal of The Institute of Image Information and Television Engineers The Institute of Image Information and Television Engineers 64 (12) 1892 - 1898 1342-6907 2010/12 
    Recent studies have demonstrated a close relationship between the frequency of microsaccades and covert attention shift. However, there are no arguments of attentional effect on drift movements during attentive or inattentive fixation. We examined whether visual attention has any influence on drift eye movements using statistical analysis of a time series of fixation eye movements. The results indicated that the power in the 3-4 Hz frequency range was enhanced when visual attention was dispersed over the parafoveal visual field. Furthermore, the amplitudes of the drift eye movements were reinforced immediately after the microsaccades, especially after square-wave jerks. These results suggest that microsaccades and drift eye movements are both controlled by higher order brain functions to acquire detailed visual information from the peripheral vision.
  • Predicting human gaze shifts considering the inhibition of return using a modified saliency map model
    郷地大紀; 小濱 剛
    Memoirs of The Faculty of B.O.S.T. of Kinki University 近畿大学生物理工学部 24 45 - 55 2009/11
  • 小濱 剛; 米澤 瑛二
    Memoirs of the School of Biology-Oriented Science and Technology of Kinki University = 近畿大学 生物理工学部 紀要 近畿大学生物理工学部 (22) 61 - 69 1342-7202 2008/09 
    Departmental Bulletin Paper
  • Shinya Magome; Tomohiro Yamashita; Takeshi Kohama; Atsushi Kaneda; Yuichi Hayami; Satoru Takahashi; Hidetaka Takeoka
    JOURNAL OF OCEANOGRAPHY TERRA SCIENTIFIC PUBL CO 63 (5) 761 - 773 0916-8370 2007/10 
    Jellyfish patch formation is investigated by conducting a drifter experiment combined with aerial photography of a sustained patch of the moon jellyfish in Hokezu Bay, Japan. Jellyfish patches are aggregations of individuals that are caused by a combination of swimming (active influence) and advection by currents (passive innuence). The drifter experiment involved the injection of 49 drifters around a distinct surface patch of jellyfish within an area of approximately 300 m x 300 m. The drifters' motion, caused only by the passive influence, was recorded in a series of 38 aerial photographs taken over approximately I h. The ambient uniform current field larger than the patch scale was estimated from the movement of the centroid position of drifters, while the distribution of horizontal divergence and relative vorticity around the patch was estimated from the time-derivative in areas of triangles formed by the drifters. The centroid positions of both drifters and patches moved stably toward the bay head at different speeds. The difference vector between the patch and drifter centroids was directed to the sun, and was opposite to the ambient current. The distributions of vorticity and divergence around patches exhibited inhomogeneity within the patch scale, and the drifters in this nonuniform current field aggregated near the convergence area within 1 h. The results suggest that horizontal patch formation is predominantly influenced by passive factors at the surface of Hokezu Bay. Furthermore, the upward swimming against downwelling may make sustained patch in surface layer.
  • Attentional effects on the microsaccadic eye movements
    Takeshi Kohama; Shiro Usui
    Current Psychology of Cognition 21 (4-5) 377 - 395 2002/05 [Refereed]
  • KOHAMA Takeshi; SHINKAI Ken; USUI Shiro
    The Journal of The Institute of Image Information and Television Engineers The Institute of Image Information and Television Engineers 52 (4) 571 - 576 1342-6907 1998/04 
    To evaluate the effects of visual attention (VA) on human involuntary miniature eye movements (MEM), we analyzed the microsaccades (MSC), which are components of MEM, under the following three experimental conditions : 1) VA was focused on the foveal object, 2) VA was dispersed in the parafoveal visual field, and 3) VA was focused on one of the parafoveal objects. The results showed that the VA was not focused on the foveal object, the frequency and amplitude of the MSC increased, and the scatter of fixation widened. The results from 2) and 3) showed that the frequency of the MSC was grater in 2) and the mean amplitude of the MSC was similar for both conditions. When VA is not focused, the MSC occur more frequently, and when VA is focused on the foveal object, the amplitude of the MSC reduces. These results suggest that MEM are influenced by VA, and MSC may be used as an indicator of the attentional state. It will be possible to establish whether VA is focused or not on the basis of the analysis of MEM characteristics.
  • KOHAMA Takeshi; SHINKAI Ken; SAITOH Tsuyoshi; YAMADA Mitsuho; USUI Shiro; YOSHIDA Tatsuo
    The Journal of The Institute of Image Information and Television Engineers The Institute of Image Information and Television Engineers 51 (8) 1308 - 1318 1342-6907 1997/08 
    In order to consider the effects of spatial attention on human saccadic eye movements, we analyzed peak velocity, duration, latency and amplitude of saccades during Kanji-recognition tasks. The results suggest that the choice of region allocated for spatial attention has no effect on the characteristics of saccades. The distributions of saccadic latency showed 1 to 3 peaks, and their peak values were consistent with the results of earlier studies. Because of these facts, we consider that there are basic phases for making saccades regardless of the complexity of the tasks. The relation between saccadic latency and amplitude shows that a longer latency leads to a smaller amplitude. This suggests that the state of spatial attention before execution of a saccade affects its amplitude. Based on these results, a schematic model of the brain system for generating of saccades is proposed, and the process of generating saccades is hypothesized using this conceptual model.
  • KOHAMA Takeshi; SAITOH Tsuyoshi; SHINKAI Ken; YAMADA Mitsuho; USUI Shiro; YOSHIDA Tatsuo
    The Journal of the Institute of Television Engineers of Japan The Institute of Image Information and Television Engineers 50 (11) 1781 - 1789 0386-6831 1996/11 
    This study examines a contribution of the visual system to the acquisition of visual information during saccadic eye movements (saccade). In the experiment, when the observer made a saccade, the location of a Kanji character displayed on a CRT screen was transferred a random distance and direction, or was kept at the original position. When the character was transferred to a new position, the recognition rate of the character decreased proportionally to the increase in distance between the fixation point after the saccade and the center of the character, in comparison with the case when the character was kept at the original position. We attempted to control the spatial attention during the same tasks. The result suggests that the spatial attention before a saccade might also be involved in the process of visual information acquisition during saccades and the visual system may integrate the positional information into the visual feature information.
  • KOHAMA Takeshi; HATANO Tomoyuki; YOSHIDA Tatsuo
    The Transactions of the Institute of Electronics,Information and Communication Engineers. The Institute of Electronics, Information and Communication Engineers 79 (1) 101 - 110 0915-1923 1996/01 
    本研究では, 視覚系の情報獲得のプロセスにおける眼球運動の機能を解明することを目的として, ランダムに配置された複数の片仮名を同時に短時間呈示した際の, 被験者の注視点の位置と正しく認識された文字の空間的な分布との関係を解析する実験を行った. その結果, saccadeによって注視点の移動が生じる前後の時間帯において, 正しく認識された文字は, (1)視線が静止しておりsaccadeが計画されていない状態では, その時点の注視点を中心に, (2)視線は静止しているが次の注視点に向かってのsaccadeが計画されると, 視線の移動が生じる前の段階で新たに予定された注視点を中心に, (3)実際にsaccadeが生じた後は, 新たな注視点を中心に分布することが示された.

Books etc

  • 持ちつ持たれつ生き物とコンピュータ 第1章 目はみるもの見られるもの
    小濱 剛; 吉川 昭; 中迫 昇; 山脇 伸行; 吉田 久; 長江 貞彦; 奥井 順; 辻合 秀一 (Joint work)電気書院 2006/08

Conference Activities & Talks

  • An evaluation index of fixation scan paths based on the similarity of feature vectors  [Not invited]
    吉野宏紀; 小濱 剛
    映像情報メディア学会2013年冬季大会（12月18日発表）  2013/12  東京都江東区 芝浦工業大学  映像情報メディア学会2013年冬季大会（12月18日発表）
  • The effects of fixation eye movements on retinal responses for two dimensional spatial frequency patterns  [Not invited]
    西野 誠; 小濱 剛
    映像情報メディア学会2013年冬季大会（12月18日発表）  2013/12  東京都江東区 芝浦工業大学  映像情報メディア学会2013年冬季大会（12月18日発表）
  • An automatic counting algorithm of repetitive exercises captured by general motion sensor and a data management system on the cloud services  [Not invited]
    小濱 剛; 楠 正暢; 前田侑大; 並河弘樹; 鬼塚将稔; 橋下尚弥; 森本 譲; 西野 誠; 楠本嘉幹; 新 ゆり
    第33回医療情報学連合大会  2013/11  神戸ファッションマート（神戸市）  第33回医療情報学連合大会
  • Evaluation of visual factors of visually induced motion sickness by analyzing fixation eye movements and heart rate variability  [Not invited]
    吉田 久; 小濱 剛
    35th European Conference on Visual Perception  2013/08  Bremen, Germany  35th European Conference on Visual Perception
  • Persistent inhibition of microsaccades caused by attentional concentration  [Not invited]
    小濱 剛; 吉田 久; 遠藤 翔
    35th European Conference on Visual Perception  2013/08  Bremen, Germany  35th European Conference on Visual Perception
  • 注意集中度の客観的評価 -固視微動解析に基づく注意の統制状態の定量化-  [Not invited]
    小濱 剛
    第3回和歌山医工学研究会  2013/06  和歌山市和歌山県立医科大学（6月28日）  第3回和歌山医工学研究会
  • A mathematical model for reproducing mean square displacement profile of fixation eye movements  [Not invited]
    徳留 健; 小濱 剛; 吉川 昭; 吉田 久
    Neuro 2013  2013/06  京都府 京都国際会館（6月22日発表）  Neuro 2013
  • An arousal level assessment by analyzing microsaccade rate and pupil fluctuation in preceding period of slow eye movements  [Not invited]
    本田彰吾; 小濱 剛; 吉田 久; 田中達郎
    Neuro 2013  2013/06  京都府 京都国際会館（6月22日発表）  Neuro 2013
  • A saliency map computation for dynamic images based on the receptive field properties of visual area MT  [Not invited]
    津田広大; 小濱 剛
    映像情報メディア学会2012年冬季大会  2012/12  東京都 東京理科大学森戸記念館  映像情報メディア学会2012年冬季大会
  • A slow eye movement (SEM) detection method for objective evaluations of arousal fluctuations  [Not invited]
    本田彰吾; 小濱 剛; 吉田 久
    映像情報メディア学会2012年冬季大会  2012/12  東京都 東京理科大学森戸記念館  映像情報メディア学会2012年冬季大会
  • A visual search simulation based on a mathematical model of visual attention system  [Not invited]
    小濱 剛
    第55回自動制御連合講演会  2012/11  京都府 京都大学吉田キャンパス  第55回自動制御連合講演会
  • A saliency-based prediction of gaze shifts while driving vehicles  [Not invited]
    森本 譲; 小濱 剛
    Neuroscience2012 The 35th Annual Meeting of the Japan Neuroscience Society  2012/09  名古屋国際会議場, 名古屋市  Neuroscience2012 The 35th Annual Meeting of the Japan Neuroscience Society
  • A simulation study of retinal enhancement effects caused by fixation eye movements  [Not invited]
    小濱 剛; 福岡卓也
    35th European Conference on Visual Perception  2012/09  Alghero, Italy  35th European Conference on Visual Perception
  • Analysis of reading and writing behaviors for digital contents  [Not invited]
    渡邊栄治; 小濱 剛; 尾関孝史
    IEEE International Conference onTeaching, Assessment and Learning for Engineering 2012  2012/08  Kowloon, Hong Kong  IEEE International Conference onTeaching, Assessment and Learning for Engineering 2012
  • A simulation analysis of visual enhancement caused by fixation eye movements on retinal responses  [Not invited]
    小濱 剛; 福岡卓也
    第56回システム制御情報学会研究発表講演会（5月21日発表）  2012/05  京都市京都テルサ  第56回システム制御情報学会研究発表講演会（5月21日発表）
  • Microsaccade detection based on a discrete pulse transform analysis  [Not invited]
    野口大輔; 吉川 昭; 小濱 剛; 吉田 久
    第51回日本生体医工学会大会（5月10日発表）  2012/05  福岡市  第51回日本生体医工学会大会（5月10日発表）
     
    This study proposes a method for detecting microsaccades based on a discrete ulse transform analysis (DPT). The general methods for microsaccade detection need to decide the threshold for a differentiation signal of eye movements after enoising by the median filter. The median filter well maintain sharp edges configured by microsaccades, however, theoretical prediction of the behavior is difficult.Because of this unpredictability, the trial and error process is necessitated to decide the threshold value or the order of the filters. The proposed method is to detect microsaccades based on the features of the pulse series produced by DPT. The eye movement signal is divided into smoothed and detail components by multiple orders of LULU filters, then the pulse series which represents the dynamics of movements is calculated. The results show the detected microsaccades is more precise than general method. Furthermore,the start- and end-point of each microsaccades is clearly discriminated.
  • Analysis of reading and writing behaviors for digital contents  [Not invited]
    渡邊 栄治; 小濱 剛; 尾関孝史
    IEEE International Conference onTeaching, Assessment and Learning for Engineering 2012  2012  Kowloon, Hong Kong  IEEE International Conference onTeaching, Assessment and Learning for Engineering 2012
  • Embedding time tag in handwritten memorandum by using sunglasses type camera  [Not invited]
    渡邊 栄治; 小濱 剛; 尾関孝史; 棟安実治
    The 2012 International Workshop on Advanced Image Technology (IWAIT 2012)  2012/01  Ho Chi Minh City, Vietnam  The 2012 International Workshop on Advanced Image Technology (IWAIT 2012)
  • Analysis of reading behaviors by learners for contents on papers and digital devices  [Not invited]
    渡邊栄治; 小濱 剛; 尾関孝史
    2011 TERA International Conference on Education  2011/12  Kaohsiung, TAIWAN  2011 TERA International Conference on Education
  • A simulation analysis of the effects of miniature eye movements on retinal responses.  [Not invited]
    福岡卓也; 小濱 剛
    映像情報メディア学会2011年冬季大会  2011/12  東京 芝浦工業大学  映像情報メディア学会2011年冬季大会
  • Microsaccade detection with a order-statistic low-pass differentiation filter.  [Not invited]
    野口大輔; 小濱 剛; 吉川 昭; 吉田 久
    映像情報メディア学会2011年冬季大会  2011/12  東京 芝浦工業大学  映像情報メディア学会2011年冬季大会
  • Inhibition of microsaccade rate caused by increase in visual attention  [Not invited]
    遠藤 翔; 小濱 剛
    Neuroscience2011 The 34th Annual Meeting of the Japan Neuroscience Society  2011/09  パシフィコ横浜（横浜市）  Neuroscience2011 The 34th Annual Meeting of the Japan Neuroscience Society
  • Visual search model considering spatial modication of visual attributes  [Not invited]
    矢野勝也; 小濱 剛
    Neuroscience2011 The 34th Annual Meeting of the Japan Neuroscience Society  2011/09  パシフィコ横浜（横浜市）  Neuroscience2011 The 34th Annual Meeting of the Japan Neuroscience Society
  • Mathematical model of the visual attention system in the posterior parietal and prefrontal lobes  [Not invited]
    小濱 剛; 杉本圭佑
    34th European Conference on Visual Perception  2011/09  Toulouse, France  34th European Conference on Visual Perception
  • Analysis of behaviors by lecturer and students in lectures based on piecewise auto-regressive modeling  [Not invited]
    渡邊 栄治; 小濱 剛; 尾関孝史
    2011 IEEE International Conference on Intelligent Computer Communication and Processing (ICCP2011)  2011/08  Cluj-Napoca, Romania.  2011 IEEE International Conference on Intelligent Computer Communication and Processing (ICCP2011)
  • サングラス型カメラによる手書きメモに関する検討  [Not invited]
    渡邊栄治; 小濱 剛; 尾関孝史
    2011年映像情報メディア学会年次大会  2011/08  成蹊大学、東京  2011年映像情報メディア学会年次大会
  • 注意の集中に伴うマイクロサッカード発生頻度の抑止  [Not invited]
    小濱 剛; 近畿大学大学院生物理工学研究科; 電子システム情報工学専攻
    日本視覚学会2011年夏期大会  2011/08  福岡  日本視覚学会2011年夏期大会
  • 視覚属性に対する注意の修飾を考慮した視覚探索モデル  [Not invited]
    小濱 剛; 近畿大学大学院生物理工学研究科; 電子システム情報工学専攻
    日本視覚学会2011年夏期大会  2011/08  福岡  日本視覚学会2011年夏期大会
  • A mathematical model of the saccadic eye movement system  [Not invited]
    小濱 剛; 近畿大学大学院生物理工学研究科; 愛知県立大学情報科学部
    第55回システム制御情報学会研究発表講演会  2011/05  大阪大学コンベンションセンター  第55回システム制御情報学会研究発表講演会
  • Evaluation of arousal level by microsaccade rate and pupil fluctuation  [Not invited]
    田中達朗; 小濱 剛; 吉田 久
    第50回日本生体医工学会大会  2011/04  東京都 東京電機大学神田キャンパス  第50回日本生体医工学会大会
  • Extraction of relations between lecturer and students by using multi-layered neural networks  [Not invited]
    渡邊 栄治; 小濱 剛; 尾関孝史
    2011/03  International Conference on Imaging Theory and Applications 2011 (Villamoura, Algarve, Portugal)  Institute for Systems and Technologies of Information, Control and Communication
  • Analysis of global gaze regions of learners detected by sunglasses camera in e-Learning  [Not invited]
    渡邊 栄治; 小濱 剛; 尾関孝史
    2011/01  International Workshop on Advanced Image Technology 2011 (Jakarta, Indnesia)
  • A visual search simulation by using a top-down feature feedback model  [Not invited]
    杉本圭佑; 小濱 剛
    Neuro2010  2010/09  Kobe, Japan  Neuro2010
  • Measurement of stress and gaze points in tasks of detection of differences between closely similar images and sentences  [Not invited]
    渡邊栄治; 小濱 剛; 尾関孝史
    33rd European Conference on Visual Perception  2010/08  Lausanne, Switzerland  33rd European Conference on Visual Perception
  • A binocular vision model considering vergence eye movements for solving autostereograms  [Not invited]
    小濱 剛; 平田喜寛
    33rd European Conference on Visual Perception  2010/08  Lausanne, Switzerland  33rd European Conference on Visual Perception
  • Effects of motion sickness on fixation eye movements  [Not invited]
    中川 啓; 小濱 剛; 吉田 久
    第49回日本生体医工学会大会  2010/06  大阪市  第49回日本生体医工学会大会
     
    動画像中の激しい振動や急速な回転は，吐気やめまいなどの乗り物酔いと同様の病的な症状を引き起こす．これを映像酔いと呼ぶ．家庭用テレビの大型化や高精細化と相俟って，日常生活における映像酔いのリスクが高まっているものの，映像酔いが生体に及ぼす影響については，未だ全容の解明には至っていない．映像酔いは，視覚情報と前庭系の不調和に依存して発生するものと考えられ，眼球運動制御系への強い関与が予想されるものの，固視微動への影響に関する詳細な解析例はほどんど存在しない．そこで本研究では，映像酔いを生じさせる要素を含んだ映像を一定時間だけ観察する試行を繰り返し実施し，インターバル中の眼球運動を計測して固視微動の解析を行った．固視微動のうち，微小な視線のジャンプとして観測されるマイクロサッカード（MS）は，視覚的注意の集中度合いによって，その発生頻度が変化することが知られている．映像酔いは集中力の低下をもたらす
  • Microsaccade rate varies with arousal level  [Not invited]
    田中達朗; 小濱 剛; 吉田 久
    第49回日本生体医工学会大会  2010/06  大阪市  第49回日本生体医工学会大会
     
    自動車運転等の視覚依存性の高い作業下における覚醒水準の減衰は，視覚機能や運動能力の低下をもたらし，ヒューマンエラーによる事故のリスクを増加させるため，その変動を客観的に捕らえるための判断基準の確立が望まれている．覚醒水準と眼球運動の動的特性との関係を調査した報告によると，高速で断続的な視線のジャンプであるサッカードの最高速度と継続時間の比 PV/D が，覚醒水準と強い相関を示すことが明らかにされているが，ヒューマンエラーに結び付くような危機的状況の直前の変動については検討されていない（植野ら，2000）．そこで本研究では，覚醒水準が低下して睡眠に至る直前に発生するとされる SEM（slow-rolling eye movement）を覚醒維持の限界点として定め，一定間隔 でステップ的に呈示位置を変える視標をサッカードにより追尾させる実験を実施し，SEM 発生に至るまでの PV/D と，サッカード間の固視微動の解析を行った．その結果，PV/D の値が減少す
  • A saliency map model with the inhibition of return feedbacks  [Not invited]
    小濱 剛; 郷地大紀
    第54回システム制御情報学会研究発表講演会  2010/05  京都府京都市 京都リサーチパーク  第54回システム制御情報学会研究発表講演会
  • A Statistical Model Analysis of Attentional Effects on Fixational Drift Eye Movements  [Not invited]
    小濱 剛; 吉田 久; 戸田尚宏
    International Workshop on Image Media Quality and Its Applications (IMQA2010)  2010/05  Tokyo, Japan  International Workshop on Image Media Quality and Its Applications (IMQA2010)
  • A restoration method for JPEG images based on ensemble learning algorithm  [Not invited]
    渡邊 栄治; 小濱 剛; 尾関孝史
    Image Electronics and Visual Computing Workshop  2010/03  Nice, France  Image Electronics and Visual Computing Workshop
  • 視覚的注意の神経機構を考慮した視覚探索モデル  [Not invited]
    杉本圭佑; 小濱 剛
    日本視覚学会2010年冬季大会（工学院大学）  2010/01  東京  日本視覚学会2010年冬季大会（工学院大学）
  • Analysis of eye movements of learners in e-learning  [Not invited]
    渡邊 栄治; 小濱 剛; 渡邊尚規; 尾関孝史
    International Workshop on Advanced Image Technology 2010  2010/01  Kuala Lumpur, Malaysia  International Workshop on Advanced Image Technology 2010
  • Analysis of movements of students in e-Learning -Relations between eyes movements and understanding-  [Not invited]
    渡邊栄治; 小濱 剛; 渡邊尚規
    電子情報通信学会 教育工学研究会  2009/12  琉球大学  電子情報通信学会 教育工学研究会
  • Analysis of Movements of Students in e-Learning -Relations among face movements, page changes, and understanding-  [Not invited]
    渡邊 栄治; 小濱 剛; 渡邊尚規; 尾関孝史; 棟安実治
    電子情報通信学会 教育工学研究会  2009/12  琉球大学  電子情報通信学会 教育工学研究会
  • Stimulus-independent thoughts affect visual search task performances  [Not invited]
    西田 彩; 小濱 剛
    2009/09  Elsevier
  • A neural model of discharge profiles in the midbrain to reproduce express saccades  [Not invited]
    山下輝彦; 小濱 剛; 神山斉己
    Neuroscience 2009, The 32nd Annual Meeting of the Japan Neuroscience Society  2009/09  Nagoya, Japan  Neuroscience 2009, The 32nd Annual Meeting of the Japan Neuroscience Society
  • An ambiguous distracter disrupts the recognition of nonverbal graphic symbols  [Not invited]
    入江久仁子; 小濱 剛
    Neuroscience 2009, The 32nd Annual Meeting of the Japan Neuroscience Society  2009/09  Nagoya, Japan  Neuroscience 2009, The 32nd Annual Meeting of the Japan Neuroscience Society
  • A gaze prediction model considering the inhibition of return based on the saliency map theory  [Not invited]
    郷地大紀; 小濱 剛
    Neuroscience 2009, The 32nd Annual Meeting of the Japan Neuroscience Society  2009/09  Nagoya, Japan  Neuroscience 2009, The 32nd Annual Meeting of the Japan Neuroscience Society
  • Attentional effects on drift eye movements before and after microsaccades  [Not invited]
    小濱 剛; 吉田 久; 戸田尚宏
    32nd European Conference on Visual Perception  2009/08  Regensburg, Germany  32nd European Conference on Visual Perception
  • A neural model of discharge profiles in the mid brain to reproduce express saccades  [Not invited]
    山下輝彦; 小濱 剛; 神山斉己
    日本視覚学会2009年夏季大会  2009/07  京都工芸繊維大学  日本視覚学会2009年夏季大会
  • A gaze prediction model considering of inhibition of return based on the saliency map theory  [Not invited]
    郷地大紀; 小濱 剛
    日本視覚学会2009年夏季大会  2009/07  京都工芸繊維大学  日本視覚学会2009年夏季大会
  • An ambiguous distractor disrupts higher order cognitive processes  [Not invited]
    入江久仁子; 小濱 剛
    第48回日本生体医工学会大会  2009/04  東京  第48回日本生体医工学会大会
  • An objective estimation for task independent thought on visual search tasks  [Not invited]
    西田 彩; 小濱 剛
    第48回日本生体医工学学会大会  2009/04  東京  第48回日本生体医工学学会大会
  • Attentional effects on power spectra for drift eye movements  [Not invited]
    小濱 剛; 吉田 久; 戸田尚弘
    The European Conference on Visual Perception 2008  2008/08  オランダ ユトレヒト  The European Conference on Visual Perception 2008
  • Evaluation of concentration level of visual attention based on quantitative analysis on fixational eye movements  [Not invited]
    小濱 剛
    第52回システム制御情報学会研究発表講演会  2008/05  京都  第52回システム制御情報学会研究発表講演会
  • Evaluation of concentration level of visual attention based on statistical analysis on drift eye movements  [Not invited]
    竹中 悠; 小濱 剛; 戸田尚宏
    第47回日本生体医工学会全国大会  2008/05  神戸  第47回日本生体医工学会全国大会
  • Concentration of visual attention inhibits the generation of microsaccades  [Not invited]
    半田哲也; 小濱 剛
    第47回日本生体医工学会全国大会  2008/05  神戸  第47回日本生体医工学会全国大会
  • Attentional effect on small drift eye movements during fixation  [Not invited]
    竹中 悠; 小濱 剛; 戸田尚宏
    2007年映像情報メディア学会冬季大会  2007/12  東京（工学院大学新宿キャンパス）  2007年映像情報メディア学会冬季大会
  • A mathematical model of saccadic eye movement system based on neuronal activity in superior colliculus and basal ganglia  [Not invited]
    藤川淳平; 小濱 剛; 神山斉己
    2007年映像情報メディア学会冬季大会  2007/12  東京（工学院大学新宿キャンパス）  2007年映像情報メディア学会冬季大会
  • A model of small involuntary eye movements to reproduce square-wave jerks  [Not invited]
    小濱 剛; 神山斉己
    Neuro2007  2007/09  Yokohama, Japan  Neuro2007
  • A mathmatical model of square-wave jerks during fixation  [Not invited]
    小濱 剛; 愛知県立大学情報科学部; 愛知県立大学情報科学部
    日本神経回路学会第16回全国大会（JNNS2006）  2006/09  名古屋大学  日本神経回路学会第16回全国大会（JNNS2006）
  • A model of square-wave jerks during eye fixation in human  [Not invited]
    小濱 剛; 篠島良太; 神山斉己
    The fourth asian conference on vision (ACV2006)  2006/07  Matsue, Japan  The fourth asian conference on vision (ACV2006)
  • A simulation study of intrasaccadic perception based on an early visual system model  [Not invited]
    篠島良太; 小濱 剛; 神山斉己
    2004年映像情報メディア学会年次大会  2004/08  工学院大学  2004年映像情報メディア学会年次大会
  • Visual information and eye movements  [Not invited]
    小濱 剛; 臼井支朗
    平成15年度電気関係学会東海支部連合大会  2003/11  名古屋大学  平成15年度電気関係学会東海支部連合大会
  • Attentional effects on the microsaccadic eye movements  [Not invited]
    小濱 剛; 臼井支朗
    3rd Conference on sensorimotor controls in men and machines  2001/10  Marseille  3rd Conference on sensorimotor controls in men and machines
  • Does attention affect the fixational stability?  [Not invited]
    小濱 剛; 臼井支朗
    26th SEIRIKEN International Symposium  2000/10  OKAZAKI  26th SEIRIKEN International Symposium

MISC

Industrial Property Rights

Awards & Honors

  • 平成22年度映像情報メディア学会丹羽高柳賞論文賞

Research Grants & Projects

  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2023/04 -2026/03 
    Author : 吉田 久; 小濱 剛
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2022/04 -2025/03 
    Author : 渡邊 栄治; 尾関 孝史; 小濱 剛
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2021/04 -2024/03 
    Author : 小濱 剛; 吉田 久
     
    本研究では，注意統制課題遂行中のfNIRS信号と固視微動の解析に基づいて，持続的注意に関与する情報処理過程を客観的に捉える手法を開発し，認知機能リハビリテーションへの応用を検討することを目的とする．そのための基礎研究として，2種類のキューを持つ周辺ターゲット検出課題による注意統制実験を実施する．モニタ中央の注視視標が一定時間の後に赤か青の＋か×に切り替わる．その後，予め左右に提示されたボックスの一方が45度傾斜し，最後に左右いずれかのボックス内にターゲットが提示される．このような視覚刺激に対し，「注意維持課題」と「注意割込課題」の2条件を設ける．「注意維持課題」では，被験者に注視視標が赤の＋か青の×であれば右，その逆の組み合わせで左にターゲットが提示されることを予め教示し，注視視標の意味する方向に能動的に注意を向けさせる．「注意割込課題」では，注視視標の意味を解釈せずにターゲットを検出するよう教示し，傾きが変化するボックスに対して注意を誘導する．いずれの条件も，被験者が受け取る視覚情報は完全に一致することから，本課題により，意図的に注意を維持する場合と，突発的に注意が奪われた場合との直接的な比較が可能となる．
    令和3年度は，先述した課題に対して fNIRS 計測を行い，注意機能の定量的評価指標としての妥当性を検討した．健常被験者を対象にして，実験遂行中のfNIRS信号を解析し，全被験者で各課題に寄与した脳領域を集計した．その結果，計測対象とした右脳において，上前頭回，上頭頂小葉といった注意の統制に関与する領域の活動が確認された．このうち，「注意維持課題」では適切な注意の配置や持続的注意に寄与する中前頭回が，「注意割込課題」ではボトムアップ注意に強く寄与する角回が特異的に応答していることが示されたことから，fNIRS に基づく注意機能のモニタリングが可能であることが示唆された．
  • 日本学術振興会：科学研究費助成事業 基盤研究(C)
    Date (from‐to) : 2020/04 -2023/03 
    Author : 竹島 伸生; 楠 正暢; 金 憲経; 藤田 英二; 小濱 剛
     
    これまでに東京都健康長寿医療センター研究所とのプロジェクトチームが実施した板橋区の検診において，ジョイントしKINECTを使って高齢者に１回の起居動作と開眼での20秒間その場足踏み（マーチ）テストを1500人に近い大量データを収集した。検診データは研究所において厳重に管理されており，この起居とマーチ時KINECTデータのみを持ち帰り解析を行ってきた。その解析が一人一人の動画を確認しながら行うという状況で大量データの分析プログラムが必要となったこと、歩行数などの新たな追加変数の解析が必要となり，共同研究者の小濱准教授，楠教授によってプログラムの修正を試みた。解析は可能となったが，KINECTデータと研究所に集積されたデータとの連結がコロナ感染予防のために東京への出張等全て禁止となり，データの操作が全くできない環境に陥っていたが，外出移動の緩和に伴い，少しずつであるが解析を進め，その結果から 1) Falling history associated with 20-sec stepping test movement displacement in independent, community-dwelling older women，2) Age-associated decline in 20-sec stepping test performance in independent, community-dwelling older women, 3) Head-knee movement pattern during a 20-sec stepping test discriminates dependent- from independent-living older womenについて比較検討した。これらの結果は，令和４年（2022年）度アメリカスポーツ医学会及び世界大会（サンディエゴ）において成果を公表する予定である。また，これらの成果は最終年度において論文化を行う計画である。また，フレイル，サルコペニア，軽度認知症などの変数との関連性も検討している。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2019/04 -2022/03 
    Author : Eiji Watanabe
     
    For face-to-face collaborative learning, we constructed methods for extracting the relationship between nonverbal behaviors of learners and cooperation. Specifically, we constructed (i) methods for detecting non-verbal motion using a glasses-type device and/or image processing, and (ii) a time-series model for expressing the interaction between behaviors of learners. Furthermore, we constructed a method to clarify the relationship between the parameters in the time series model and the cooperation between the learners, and confirmed their effectiveness by experiments.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2019/04 -2022/03 
    Author : YAMAMOTO Masaya
     
    The purpose of this study is to apply the gaze behaviors as an objective measure of neuroendovascular of cerebral aneurysms to therapy training. We constructed an experimental environment and analyzed gaze data obtained from three pairs of specialists and trainees neurosurgeons. First, trainees were less likely to switch their gaze in response to information, and second, specialists were more likely to disperse their gaze beyond the aneurysm being therapy. Future work is needed to determine if these results are not just an occurrence in a subset of the study population, but occur in many neurosurgeons, and to apply them to training for neuroendovascular therapy.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2018/04 -2021/03 
    Author : Yoshida Hisashi
     
    Network analysis of multidimensional biological signals is a very useful tool to understand the mechanism of signal generation. Although network analysis has been widely used in brain function analysis, most of them are based on linear correlation analysis using the Pearson product-moment correlation coefficients. In this study, we conducted a research on multidimensional network analysis methods using network analysis of intractable epilepsy as a touchstone. We introduced a partial correlation function to accurately capture the network structure in multivariate connectivity analysis, introduced a directional graph that takes into account time delays. We have also developed a macroscopic network analysis method called "average connectivity strength tracking.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2017/04 -2020/03 
    Author : Takeshima Nobuo
     
    Two objective indices of ADL named the chair-standing and the marching test were assessed by optical sensing technology in physically independent versus physically dependent older adults with the aim of examining the difference in movement performance by these two groups of people. Based on the results of ROC analysis, the Kinect-v2 system that used optical sensing technology was found effective in screening physically dependent older adults with a diagnostic accuracy of 70%. However, detection of functional independence as well as level of care needed in rapidly growing frail older adults in Japan by performance of only one chair stand movement by Kinect-v2 indicates that this technique could be a suitable and user friendly mode of testing for these people. In order to analyze a large amount of data at a time, it may be necessary to modify the program of analysis that could be addressed in our future studies.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2017/04 -2020/03 
    Author : Kohama Takeshi
     
    The purpose of this study is to establish an objective evaluation of the functions in neural network involved in visual attention control. We conducted spatial cueing tasks in which the subjects had to concentrate or move their visual attention while maintaining their gaze. The concentration of attention was quantitatively evaluated based on an analysis of the fixation eye movements measured in the tasks. We also analyzed the event-related fNIRS signals to objectively assess the brain activity associated with attentional control. The results showed that the microsaccade-rate varied with passive attention shifts, indicating that the microsaccade-rate is a potential candidate for an objective criterion of attentional state. In addition, the results of the event-related fNIRS analysis suggest that the responses of the brain neural network associated with attention maintenance or interruption can be evaluated quantitatively.
  • 固視微動および事象関連fNIRS信号解析に基づく認知機能のモニタリング
    文部科学省：科学研究費補助金（基盤研究(C)）
    Date (from‐to) : 2017 -2019 
    Author : 小濱 剛
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2015/04 -2018/03 
    Author : YOSHIDA HIISASHI
     
    In this study, we developed a method for removing or separation of additive and convolutive artifacts artifact from multi-dimensional biosignals with independent vector analysis. We applied the method to extract fetal electrocardiogram from maternal abdomen as a test of our proposed method. As a results, the proposed method showed better performance rather than the conventional independent component analysis method. In addition, we developed a method for estimating a distribution of fetal cardiac potential which was observed on the maternal abdomen. The distributions are of help in order to find electrodes’ coordination which has better performance on the maternal abdomen.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2014/04 -2017/03 
    Author : TAKESHIMA Nobuo; FUJITA Eiji; Brechue William F.; Rogers Michael E.; OKADA Soichi
     
    The purposes of this study were to develop an index of measuring independence objectively in ADL of elderly by using an optical sensor (OS) and to determine the effect of exercise using OS. During the course of the study, the OS named KINECT was upgraded to (KINECTv2) by the manufacturer which increased the device’s accuracy. To address the compatibility issue of KINECTv2, we recollected an ADL (chair stand (CS)) data and analyzed the coronal plane angle (CPA) data while performing CS in apparent healthy elderly (HE), and in frail elderly (FE). The CPA exists between a line that connects one’s shoulder-center and waist versus the person’s vertical axis (sagittal plane). The CPA was found to be significantly smaller in HE than in FE while performing CS indicating that OS is effective in assessing independence to complete the CS. However, no exercise intervention efficacy was noted on CS when assessed by the OS, thus further study is needed to address this issue well.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2014/04 -2017/03 
    Author : KOHAMA Takeshi
     
    The purpose of this study is to elucidate the information processing mechanism in visual attention system of brain. We analyzed involuntary fixation eye movements to quantify the degree of focal attention, and near-infrared spectroscopy (NIRS) signal to establish an objective monitoring method of the attention control system. As results from the experiments conducted in this study, we obtained a signal processing technique for extracting microsaccades with high accuracy and a mathematical model necessary for drift eye movement analysis. Moreover, we constituted experiment conditions suitable for brain function measurement by NIRS and its signal processing methods to avoid various artifacts. These results suggest that measurement techniques to elucidate the neural mechanism of attention were confirmed.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2013/04 -2016/03 
    Author : Eiji WATANABE; OZEKI TAKASHI; KOHAMA TAKESHI
     
    In lectures by using blackboards, lecturers give lectures in combination of explanation by speech and writing on blackbirds. On the other hand, students take notes and/or listen to lectures corresponding to behaviors by lecturers. In this research, we have analyzed the relations between behaviors by students corresponding to them by lecturers. Concretely, we have constructed the image processing methods for the extraction of behaviors by lecturer and students and the modeling methods for the relations between behaviors by them. Moreover, we have clarified the relations between behaviors by lecturer and students and the relations between the understandings and behaviors by students.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2013/04 -2016/03 
    Author : KIKKAWA Sho; YOSHIDA Hisashi; NAKASAKO Noboru; KOHAMA Takeshi
     
    (1) We introduced L and U filters having not been well-known as morphological filters and the digital pulse transform (DPT) constructed of L and U filters. (2) We proposed a new method for detecting randomly generated signals buried in noise, in particular, a new method to detect saccades in human eye movement data. We attained error-free detection of the saccades by this method which has not been achieved by traditional linear filters. This method can be widely applied to detection problems in biomedical environmental data processing. (3) Agaist the commomly accepted theory that median filtering outperforms traditional linear filtering in preserving signal edges while reducing noise, we theoretically proved that moving average filter is a better smoother preserving signal edges than the median filter under a practical wide range condition.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2012/04 -2015/03 
    Author : YOSHIDA Hisashi; KOHAMA Takeshi
     
    The main objective of the research is to develop a method for analyzing functional brain networks using electroencephalography (EEG) and functional Near-Infrared Spectroscopy (fNIRS). We introduced fNIRS signal because fNIRS signal have the advantage that there is no interference from electro-oculogram (EOG) signal. However, it has some drawbacks, i.e., it contains not only functional signals of the brain but also systemic physiological signals evoked by physiological changes and body motion. We evaluated a separation method based on differences in hemodynamic modalities and based on independent component analysis (ICA). We, then, propose a new method which combines the above two methods in order to compensate for the drawbacks of both the methods in a complementary style. The results showed that the proposed method could be removed various artifact which often contaminated fNIRS signals.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2010/04 -2014/03 
    Author : KOHAMA Takeshi; YOSHIDA Hisashi
     
    The purpose of this study is to evaluate the influence of ``undetectable motions'', the motion information under the perception threshold, on cognitive functions by statistical analyses of the property of fixation eye movements. Subjects performed rapid serial visual presentation (RSVP) tasks with undetectable or ambiguous motions in the background while maintaining their fixation. We evaluated the influence of these motions on top-down attention mechanism by analyzing fixation eye movements. The results suggest that microsaccade rates were correlated with subliminal motion information, and fluctuations of drift eye movements were modulated by low-contrast motions in the peripheral vision.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2008 -2011 
    Author : YOSHIDA Hisashi; KOHAMA Takeshi
     
    We have measured multi-channel bio-signals, i. e., electroencephalogram, heart rate variability, blood pressure, eye movement and pupil diameter variability in order to evaluate the influence of visual stimuli to the wakefulness maintenance state against sleepiness. We performed time-frequency analysis, conventional spectral analysis, and feedback modeling to those signals. All results showed that physiological activities in wakefulness maintenance state have different features from those in onset of natural sleep. In addition, we have introduced new artifact removal methods to the EEG analysis.
  • 日本学術振興会：科学研究費助成事業 若手研究(B)
    Date (from‐to) : 2004 -2006 
    Author : 小濱 剛
     
    本研究は,視覚的注意機構と眼球運動神経系とがほぼ共通した神経機序に基づくことを示した心理物理学・神経生理学的知見に基づき,視覚的注意機構の機能を考慮した眼球運動神経系の制御モデルの構築を目的とするものである.昨年度までの成果として,一点を固視している状態で発生するsquare-wave jerkに着目し,従来のサッカード眼球運動モデルを拡張して,大脳皮質からのサッカード計画に関する信号と,中脳上丘の注視制御機によってsquare-wave jerkの発生メカニズムを説明する数理モデルを提案した.Square-wave jerkとは,マイクロサッカードと呼ばれる微小な視線のジャンプが,ごく短期間に連続して生じることにより形成される矩形波状の眼球運動であり,マイクロサッカードにより生じた注視目標からの視線のズレ(ポジション・エラー)に対し,別のマイクロサッカードによって自動的に補正する機構により生成されるものと考えられる.本研究では,ポジション・エラーとして発生するマイクロサッカードが,上丘中間層における注視細胞とサッカード細胞との相互抑制的制御機構のノイズ的活動に起因するものと仮定し,注視細胞の活動の低下によって,近辺のサッカード細胞が十分に抑制しきれなくなったとき,マイクロサッカードが発生してポジション・エラーとなると考え,この動作のモデル化に取り組んだ.昨年度までのモデルには,サッカード期間中にのみ,サッカードの振幅や速度に関する信号を発生する上丘の応答特性に問題があり,常に一定の期間だけ発火するような実装となっていた.今年度の成果として,この上丘の応答に関するモデルの記述を見直し,サッカードの速度・振幅特性をコード化した信号を発生するよう修正を施し,その成果を「Asian Conference on Vision」,および,「日本神経回路学会」にて発表した.
  • 日本学術振興会：科学研究費助成事業 奨励研究(A)
    Date (from‐to) : 1998 -1999 
    Author : 小濱 剛
     
    近年増加の一途にある自動車運転中の電話利用時の交通事故は,運転者が会話に注意を奪われたことが原因とされる場合が多い.これまでにも,視覚課題への反応時間の測定などによって注意の客観的に測定する試みがなされているが,応用価値の高い生体信号解析に基づいた測定手法の確立には至っていない.このような背景のもとで,本研究では,ある視覚対象を凝視する際に生じる不随意の微小眼球運動(固視微動)を解析することにより,注意の集中度合いの定量的測定を試みた. 本研究では,被験者の注意を,1)注視位置に集中させた場合,2)注視位置の周辺に分散させた場合,3)周辺視野の特定の位置に注視を集中させた場合,の3つの状態にコントロールする実験課題を提案し,各実験課題のもとで得られた固視微動から,発生したすべてのマイクロサッカードを抽出し,その発生頻度,振幅,ピーク速度について実験課題間での比較を行なった.また,固視微動からマイクロサッカードを取り除いて連結したslow cumulative eye position curveを求め,FFTによる周波数解析を行うことにより,ドリフト成分の周波数解析を行った. 解析の結果,マイクロサッカードの発生頻度は,実験課題1)と実験課題3)ではほぼ等しく,実験課題2)ではこれらよりも有意に高くなることが示された.また,マイクロサッカードの振幅は,実験課題2)と実験課題3)でほぼ等しく,これらに比較して実験課題1)では有意に小さくなることが示された.すなわち,視野内の特定の位置に注意を集中することによりマイクロサッカードの発生が抑制され,このとき注視位置に注視を集中させることによりマイクロサッカードによる固視のブレも押さえられることが明らかとなった.さらに,一般に主系列と呼ばれているマイクロサッカードの速度・振幅特性を比較した結果,実験課題1)におけるマイクロサッカードのピーク速度は,他の2条件に比較して有意に大きいことが示された.一方,ドリフトと呼ばれる注視点が緩やかに揺れる眼球運動に対しては,FFTによる周波数解析では条件間の差を見いだすことができなかった.したがって,視覚的注意は,サッカードシステムにのみ選択的に影響を与えていることが示唆される. これらの結果は,注視システムがマイクロサッカードのトリガーをコントロールしていることや,マイクロサッカードの大きさや速度といったダイナミクスを修飾していることを示しており,また,ドリフト成分のように緩やかな固視の揺れには直接的に関与していないことを示唆している.これらの結果より,注視時に生じるマイクロサッカードを解析することにより,注意の状態をある程度予測することが可能であると思われる.

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