著者

水野 松本 由子 田中 康仁 林 拓世 岡本 永佳 西村 治彦 稲田 紘

出版者

一般社団法人 日本生体医工学会

雑誌

生体医工学 : 日本エム・イー学会誌 = Transactions of the Japanese Society for Medical and Biological Engineering : BME (ISSN:1347443X)

巻号頁・発行日

vol.48, no.1, pp.11-24, 2010-02-10

参考文献数

32

被引用文献数

2

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The aim of this research was to assess the physiological signals which were relevant working efficiency under mental workload. Eleven healthy subjects were examined. In the first step, their mood status and stress level were evaluated with questionnaire methods:“Profile of Mood States (POMS)” and “Stress Self Rating Scale (SSRS)”, respectively. In the second step, electroencephalography (EEG) and photoplethysmography under the mental workload tasks in four auditory stimuli (silent circumstance, white noise, classical music, and up-tempo music) were measured. The mental workload tasks consisted of two parts:performing Uchida-Kraepelin test (calculating task:CAL) on PC monitor in two minutes and fixating on a crosshair image (after CAL) in two minutes. A procedure of the mental workload task in each auditory stimulus was repeated three times. EEG data were analyzed using a discrete Fourier transform to obtain power spectral density (PSD) in theta, alpha, and beta bands. Pulse waves from photoplethysmography were analyzed for estimating the pulse wave amplitude (PWA) and length (PWL). PSDs of theta band in silent circumstance and classical music under and after CALs, alpha band in classical music under and after CALs, and beta band in up-tempo music under CAL on most or all areas were significantly larger than those in the other auditory stimuli. The results of photoplethysmography analysis showed that changes of PWA and PWL in silent circumstance and classical music were more stable than those in the other auditory stimuli. It was suggested that the classical music would not only affect brain activity under the mental workload and augment the efficiency of it, but also facilitate recovery of the physiological conditions from the stressful situations. These events from the physiological point of view showed that working environments could be considered to avoid adding stress on the brain function and autonomic nervous system during and even after the tasks.