Experimental study on the effect of micro-refresh during office work in VR space to restore intellectual concentration decline
Authors: Nomura Kento , Higashimaki Takuto , Abe Reika , Ueda Kimi , Ishii Hirotake , Shimoda Hiroshi , Obayashi Fumiaki 
Published: January 2024

The authors expect that short breaks during work to promote refreshment will suppress the decline in intellectual concentration. In addition, we have been studying the effect of micro refresh (MR), which is a refreshment stimulated by very short breaks and stimuli during work. In this study, we focused on visual changes caused by VR as a method to promote MR appropriately. For example, in a VR space, it is possible to change the environment in a way that is not possible in reality, such as instantly moving from a space where work is performed to a space where nature spreads out. We believe that such a brief distraction from the content of work is an effective way to refresh oneself during work. The purpose of this study is to create a system that encourages brief refreshments during work by changing the environment using VR and to confirm the effect of the system on suppressing the decline in concentration. To evaluate the effect of suppressing the decline in concentration, we calculated and used the concentration time ratio (CTR), which is an indicator of the degree of intellectual concentration, from the response time data of the comparison questions. In addition, several questionnaires were administered to evaluate subjective changes in fatigue and other symptoms. Participants in the experiment were asked to wear a VR head-mounted display and answer the comparison questions. In this research system, the background changes to a natural landscape after a certain amount of time elapses during the work, prompting the participants to take a break. In this experiment, the background changed for 40 seconds every 7 minutes and 30 seconds. When the background changes, the cognitive task is still displayed, and the participant can continue to answer the task. 3 types of backgrounds were created for the MR prompt, and the participant can select one of the backgrounds of their choice. Twelve participants took part in this experiment, and four sets of 25-minute comparison questions were conducted for four hours each. One of the sets 3 and 4 were conducted with MR, and the other set was conducted without MR. When asked why they chose the landscapes, they focused on brightness, color, and motion (especially water currents). Regarding brightness, only one respondent chose the brightest landscape. As for color, green grass and trees tended to be preferred over blueish colors such as the sky and the sea. The CTR results were high for five participants with the MR condition and low for seven participants without the MR condition. The results of the subjective questionnaire showed that eight participants did not change between conditions in the questionnaire asking whether they refreshed during the task, and one participant's value was lower in the condition with MR. The reason for this may be that the visual stimuli were weak. The CTR results with the MR condition were not good because the participants continued to perform the task without paying attention to the background, even though they noticed changes in the background.