著者

木村 達洋 早坂 明哲 瀬川 典久 山崎 清之 村山 優子 宮崎 正俊

出版者

一般社団法人情報処理学会

雑誌

情報処理学会論文誌 (ISSN:18827764)

巻号頁・発行日

vol.44, no.11, pp.2587-2597, 2003-11-15

参考文献数

25

被引用文献数

4

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近年,インターネットの急速な普及にともないコンピュータが家庭にまで浸透し,VDT作業時間が急激に増加したことで,子供の視力低下や疲労が問題化している.また,ゲームなど強力な動機づけによる長時間使用で健康を害し,極端な場合には死亡例も報告されている.そこでユーザの健康を守る衛生学的観点から視覚系疲労を測定し,インタフェースを低負荷なものにする必要がある.本研究では,事象関連電位(ERP)を用いた視覚系疲労の客観的評価法を提案し,VDT作業による視覚系疲労評価を試みた.ERPは視覚情報の脳内過程を反映する.このうち一次視覚野の反応であるP100成分と,標的を非標的から弁別する際に現れるP300成分を指標とした.また,眼精疲労の指標として焦点調節能(近点)も計測した.その結果,視覚系疲労条件では,ERPのP100の振幅は増大し,非標的によるP300の振幅は,標的の場合の振幅に近づき,弁別性の低下が見られた.この傾向は主観的な疲労感との相関が認められた.一方,ERPの振幅や潜時と近点との相関は認められず,両者は独立な情報を含んでいると思われた.このことは眼調節系の疲労,認知機能の低下である中枢性疲労の2種類から構成されていることを示している.以上から,本方法を用いれば眼調節系と認知過程の2つの処理段階を考慮した視覚系疲労の評価が可能になると考えられた.In order to obtain a guideline for designing low-workload Human Interface (HI). We investigated assessment of visual fatigue induced by performing an interactive task as a model of HI software on personal computers utilizing measurement of Event Related Potentials (ERP) and accommodation. The ERP were measured in this study before and after a visual target detection task in healthy adult participants to assess visual fatigue of the central nervous system. As an index of accommodation, the ophthalmic near point was also measured using an accomodometer. As the experimental task, participants were instructed to click designated targets from a randomly arranged matrix of characters for one hour. All participants reported symptoms of visual fatigue after the task. From the averaged ERP waveform, P100 and P300 components were detected and their amplitudes and peak latencies were analyzed. Amplitude of the P100 component measured after performing the task was larger than that in the control condition. Near points after the task increased in comparison with those before the task. Results indicated that visual fatigue by the experimental task evoked both eye-strain and altered function of the primary visual cortex. Feasibility of applying the present method to a low-workload software development is discussed.

著者

石井 裕也 大矢 誠司 赤坂 知恵 木村 達洋 長島 圭子 金井 直明 山崎 清之 岡本 克郎

出版者

東海大学

雑誌

東海大学紀要. 開発工学部 (ISSN:09177612)

巻号頁・発行日

vol.11, pp.112-114, 2002-03-30

被引用文献数

1

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To investigate the cognitive aspects of posture control under the apparent force condition generated by auditory stimulation, body sway fluctuation was measured with healthy adult subjects. As an experimental stimulation, an increasing tone for the left ear and a decreasing tone for the right ear were used. Generaliy, while listening to the stimulus, subjects felt that the sound source was moving from right to left under an eyes closed condition. On the contrary , subjects who were shown a moving image of a natural scene which was interlocked to the auditory stimulus before the experiment (cognitive preparation), they felt themselves moving from a left to right direction. In this experiment, body sway was measured with and without the cognitive preparation. Results showed that the center of gravity biased to the opposite direction of subjective movement of the sound source with cognitive preparation. Without cognitive preparation, the center of gravity biased in the same direction of subjective movement of the sound source. It suggests that the higher level posture control reflex was observed in the cognitive condition without any sensory input from the muscle receptors.