Effect of the intermittent aroma stimuli on work performance: analysis
using the drop point of time-series intellectual concentration
Authors: Ueda Kimi , Yumura Kohei , Ishii Hirotake , Shimoda Hiroshi , Obayashi Fumiaki 
Published: February 2023

With the rapid development of information society, the importance of
knowledge work is increasing. Such knowledge work performance has been
evaluated in various ways. The authors have developed and used CTR
(Concentration Time Ratio), which is a performance evaluation index based on
the ratio of time spent concentrating on a cognitive task for a total task
conducted time. Although work concentration changes from moment to moment
due to fatigue accumulation, distraction, and other factors, CTR ignored the
time-series changes in performance while conducting the task.In this study,
a new analysis method was applied to evaluate the effect of intermittent
aroma stimuli on work performance, which was evaluated previously by CTR
[1]. Totally 88 answering time data of the comparison task [2] that 22
participants performed 2 sets each in 2 conditions, with-aroma and
without-aroma were included. Comparison task is a cognitive task developed
to evaluate the workers’ intellectual concentration during conducting the
task, which requires numerical and language processing, comparison and
judgement [2]. Time series data of concentration were generated using the
method used in our previous study [3]. In the with-aroma condition, aroma
stimuli were presented for 10 seconds every 5 minutes. Therefore, the time
window was decided to be relatively shorter to capture short-term temporal
variation in concentration on task. We focused on the drop points of
concentration. The drop points represent the timing at which the
participants restarted concentrating and solving the cognitive task after
slowing down due to fatigue accumulation or other factors while conducting
the task. In other words, it is expected that there are more drop points
when they were unable to maintain their concentration during the task
time.When comparing sets conducted at the same time in two aroma conditions,
in the group in which the average concentration value improved in the
with-aroma condition (n=26), the average number of drop points was higher in
the without-aroma condition. On the other hand, in the group in which the
average concentration value decreased in the with-aroma condition (n=18),
the average number of drop points was higher in with-aroma condition. It was
suggested that for the participants whose concentration were improved by the
intermittent aroma-stimuli, the occurrence of drop points was suppressed in
with-aroma condition.[1] Kimi Ueda, et al.: An Objective and Quantitative
Evaluation of Intermittent Aroma Stimuli on Intellectual Concentration. AHFE
2020 International Conference, pp.245-251, 2020.[2] Kimi Ueda, et al.:
Development of a new cognitive task to measure intellectual concentration
affected by room environment, ICHES2016 Nagoya, 2016.[3] Kimi Ueda, et al.:
An Analysis of the Effect of Integrated Thermal Control on Cognitive Task
Performance Using Time-Series Changes in Intellectual Concentration. AHFE
2022 International Conference. vol 56. pp. 205–210.