Walking into a Japanese “Washitsu” room, one of the first things you might notice is the tatami mats laid on the floor. Japanese have been using these grass mats for over a thousand years, and they have become deeply ingrained in Japanese culture and architecture. Recent studies have found that the aroma emitted by traditional tatami mats can reduce people’s feelings of tension and anxiety, as well as enhance focus at work.
According to a press release issued by Kyushu University in Japan on September 8, research conducted by the university’s team revealed that tatami mats made from rush grass, also known as igusa, were associated with enhanced activity in brain regions related to concentration and focus. Participants in the study also reported a reduction in feelings of tension and anxiety after using tatami mats.
The traditional method of making tatami mats involves weaving rush grass to create the surface layer, which wraps around a core made of stacked rice straw. Freshly made tatami mats have a strong verdant hue and a herbal scent, but over time, the rice straw core has gradually been replaced by modern materials such as wood chips or polystyrene foam.
Leading the research, Associate Professor Kuniyoshi Shimizu from the Faculty of Agriculture at the university stated that in Japan, there is a belief that the aroma of rush grass can induce feelings of comfort and relaxation, although there is little scientific evidence to support this claim.
The team has been dedicated to exploring the effects of rush grass on the human body using objective scientific methods. Previous studies confirmed the relaxing effect of rush grass aroma, prompting them to investigate its benefits in other areas such as emotions, stress resistance, and work engagement.
In this study, researchers had 17 volunteers with an average age of 21.5 undergo tests in soundproof rooms under two conditions: sitting on a rush grass mat and sitting on a tasteless polypropylene mat. The participants were tasked with completing simple tasks while researchers recorded their reaction times and brain activity using electroencephalography (EEG). Subsequently, the participants’ stress levels and comfort were evaluated through psychological questionnaires.
Shimizu noted that significant differences were found between the two conditions. “The EEG showed that when participants completed tasks while seated on the rush grass mat, activity in specific regions of their brains known for attention and engagement increased. This indicates heightened focus and cognitive involvement.”
The researchers also observed that participants exhibited noticeable changes in gamma wave activity in multiple brain regions and maintained higher stability in alpha wave activity during resting periods while using the rush grass mat. Overall, participants demonstrated increased resilience to stress through more effective relaxation.
Participants reported that feelings of tension and anxiety were alleviated after using the rush grass mat, although there were no significant changes in other aspects of emotions.
This study provides new empirical evidence of the potential benefits of rush grass mats, particularly in alleviating tension and anxiety and enhancing stress resilience. However, the study had a limited number of participants, prompting researchers to plan for a larger-scale, more diversified study in the future.
With changing lifestyles and modern living environments, the use of rush grass has decreased in Japan. The researchers aim to increase understanding of how traditional materials, like rush grass, impact people and explore their new applications in contemporary society.
The research findings were published in the journal “Scientific Reports” on September 8.
Apart from making tatami mats and rush grass mats, rush grass is also used to weave hats, coasters, brooches, and other items or artistic works, known as Lirong craft in Taiwan. This craft has been passed down for nearly three hundred years in Miaoli Yuanli.
The locally grown triangular column rush grass can grow up to 170 centimeters in height, possessing characteristics of resilience, water absorption, and a rich aroma. During the Japanese colonial period, it briefly became an export industry second only to sugar and rice. After harvesting, rush grass needs to be evenly sun-dried before being used for weaving.
This tough rush grass was once an indispensable weaving material in coastal areas. With the advent of industrialization, scenes of families sun-drying rush grass at their doorsteps and weaving on stools have become part of history. Fortunately, young artisans have established studios to ensure the continuation of this craft.
Sources:
– Dajiyuan News – September 9, 2026 (translated and rewritten from Chinese news article)