Physiological Responses Induced by Mental Workload Simulating Daily Work

This study investigated the psychological effects of a mental task which is similar to daily work such as detecting a typo in an attempt to provide pathways to improve workers’ mental health. Twenty healthy male undergraduate students participated in this study. ECG and SCL were recorded during resting periods and mental task performance alike. NASA-TLX, Japanese UWIST mood adjective checklist, and Subjective feelings of fatigue were employed after the task as the subjective assessments. All participants repeated this task twice under three different visual conditions: against a monochromatic wall, a picture of a forest, and a video of a forest. Mean RR intervals, SD1, SD2, CSI, and CVI were calculated from ECG. Participants’ average SCL values were obtained in each block. All indexes were analyzed by repeated measures two-way ANOVA with condition (i.e., control, picture, and video) and block (i.e., REST, TASK1, and TASK2) as factors. In results, the main effects of condition and block in CSI and the main effects of block were found in SD2, CSI, CVI, and SCL. There were significant differences between REST and TASK in all indexes. No condition x block interaction was observed in any indexes. The post hoc test revealed that CSI in the picture condition was significantly longer than it was in other conditions.