An Analysis of the Effect of Integrated Thermal Control on Cognitive Task Performance Using Time-Series Changes in Intellectual Concentration
Authors: Ueda Kimi , Yumura Kohei , Ishii Hirotake , Shimoda Hiroshi , Obayashi Fumiaki 
Published: June 2022

In today’s developed information society, improving the performance of intellectual work is considered important not only for increasing corporate profits but also for improving occupational health, including improving work-life balance. Therefore, various methods have been attempted to improve intellectual work performance. Since the workplace environment during intellectual work is known to affect performance, many efforts have been made to improve intellectual work performance by devising the workplace environment. Based on the knowledge from many studies which have focused only on the environment during working or only on the environment during breaks, the authors have proposed integrated thermal control, which combines and controls both the environments during working and breaks, and have examined the effect of this proposed control on the performance of intellectual work.In our previous studies [1-3], we have shown the performance-enhancing effect of integrated thermal control throughout the day using the concentration time ratio (CTR), which is a performance evaluation index of the ratio of time when workers concentrated on their work during their working time. However, although performance during work changes moment by moment due to accumulation of fatigue and other factors, time-series changes in intellectual performance during work was not examined, and the details of the effects of integrated thermal control on performance remain unclear.Therefore, the purpose of this study was to analyze and evaluate the effects of integrated thermal control on work performance in more detail by focusing on the time-series changes in concentration on intellectual work. For the analysis, the answering time data of the cognitive task for intellectual concentration evaluation [4], which was obtained by 44 participants performing 4 sets of 30 minutes each in the integrated thermal control condition using airflow and control conditions, was used to calculate the time-series changes of intellectual concentration based on the idea of conventional CTR calculation method. The calculated time-series data was separated by Ward’s method of clustering. As a result of clustering, for example, the number of data included in the cluster that tended to decrease in concentration during the 30-minute work period decreased in the integrated thermal control condition compared with the control condition. Results suggested the possibility that the integrated thermal control improved intellectual performance throughout the day by suppressing the decline in concentration during each working period.[1] Kimi Ueda, et al.: An experimental study on integrated thermal control of office room and break room to improve intellectual concentration, Roomvent & Ventilation 2018 Conference, pp.43-48, 2018.[2] Soma Kawamoto, et al.: An Experimental Study on Airflow Control to Improve Intellectual Concentration, Roomvent & Ventilation 2018 Conference, pp.31-36, 2018.[3] Kimi Ueda, et al.: A Study of Analysis Framework to Construct Mechanism Model of Intellectual Productivity Changes Affected by Workplace Environment, The 8th International Conference on Applied Human Factors and Ergonomics, pp.121-131 2017.[4] Kimi Ueda, et al.: Development of a new cognitive task to measure intellectual concentration affected by room environment, The Fifth International Conference on Human-Environment System ICHES2016 Nagoya, 2016.