"Totonou"时会发生什么？为了更加了解这一现象，我们使用MEG（Magnetoencephalography）这一超高精度脑电图检测技术，分析了30名体验者在桑拿前后大脑机能的变化，并观察到了一个有趣的现象。 除了与人体放松状态有关的α波被正常化外，在放松过程中常常被抑制的β波仅有位于大脑右侧顶叶的一部分会被激活。大脑的右侧顶叶负责包括空间和视觉感知、身体感觉与位置信息在内的所有的感官认知。这与桑拿爱好者的反馈是一致的，例如在"Totonou"时脑海中浮现了新的想法，或开始意识到平时没有察觉到的声音和气味等等。此外，β波会因此而减弱。 由于β波的强弱与大脑的兴奋程度成反比，因此当我们蒸完桑拿后，会发觉自己变得精神焕发，头脑也感觉更加清醒。
In the middle of the Muromachi Period (1336 - 1573), a type of tea ceremony in which tea was served to guests after their baths was called rinkan-chanoyu (rinkan sauna and tea ceremony). Much like with shoin-cha (decorative tea time), paintings, incense burners, vases, and hanging scrolls were displayed in the bathing rooms, and it is said that many spectators came to watch toucha (tea-tasting games) after bathing.
Rinkan-chanoyu was a widely-practiced basara (eccentric hobby) in Japan, particularly at the Kofukuji Temple in Nara.
In those days, a bath was a steam bath, or what we would today call a sauna, in which water is poured over heated sauna stones. People in Japan have long enjoyed the acts of viewing art in a sauna and drinking tea as a cultural pastime.
The term basara refers to the social and cultural trends in the middle ages in Japan, mainly during the early Muromachi Period (the Nanboku-cho Period). It was an aesthetic of meritocracy, one that disregarded the status quo, belittled, ridiculed, and rebelled against the authority of those noble in name alone, and instead favored extravagance, flamboyant behavior, and chic clothing. This culture was also the seed of the later revolutions in the Warring States Period.
It is said that Murata Juko (1422 - 1502), the teacher’s teacher of Sen no Rikyu (1522 - 1591) and the inventor of wabi-cha (tea ceremony), was also enamored with rinkan-chanoyu when he was young. He later studied under the Japanese monk Sosun Ikkyu at Daitokuji Temple, reached a state of chazenichimi (the realization that tea ceremony and Zen are one), and created wabi-cha. Then, the brothers Furuichi Choei and Furuichi Choin, who were main figures of rinkan-chanoyu, became disciples of Murata Juko, and rinkan-chanoyu became wabi-cha.
2008年前后，桑拿爱好者开始在SNS（社交网络）上进行信息的传播和交流，2009年，漫画家タナカカツキ（Tanaka Katsuki）开始了《サ道（桑拿之道）》文章的连载，首次通过漫画的形式，将进行“热水浴”、“冷水浴”、“休憩”的反复为人体带来"Totonou"的特殊状态的过程与方法进行了可视化。（ 2011年《サ道（桑拿之道）》文字版发行时，将"Totonou"称为"Sauna Trance"）。 桑拿爱好者濡れ頭巾ちゃん（Nure zukin-chan）在2011年开通博客时发表的评论"Totonou！"使"Totonou"一词在以SNS（社交网络）为中心的桑拿爱好者中开始逐渐流行起来。 2015年《漫画版 サ道（桑拿之道）》连载开始时，采用了"Totonou"的用法，"Totonou"由此正式传播开来。
*衷心感谢田タナカカツキ（Tanaka Katsuki）及濡れ頭巾ちゃん（Nure zukin-chan）为本文的撰写提出的宝贵建议。
Inference of Connection of Sauna Trance with Japan's Infrastructure and Cultural: Public Baths and Water Baths
When did the sauna trance method of bathing, which has been implicitly inherited by sauna lovers, begin?
The Japanese steam bath was replaced by the modern bathing in hot water baths in the mid-Edo period (early 17th century). The modern sauna was introduced to Japan from Finland around the time of the 1964 Tokyo Olympics. In Finland, there are many lakes, and in saunas near lakes people do jump into the cold lakes, however, saunas in the city do not always have cold water baths.
So when did saunas in Japan start to always include a water bath? In fact, it is believed that water baths existed in public baths long before saunas. If you were born in the countryside in Japan, you may have been told by your grandfather to "pour cold water over yourself" at the end of a bath.
The story of pouring cold water over yourself after a steam bath appears in the collection of medical essays by the court physician of the late Kamakura period (late 13th century), Tomotoshi Koremune, in his book "Idansho" (one of the oldest essays by a physician in Japan). Since the days of the steam bath, cold water has been poured over the body after a steam bath. This may have something to do with misogi, the ancient Japanese Shinto ritual of purifying oneself by bathing in waterfalls and rivers. Even today, this is done at shrines at its chozu-ya pavilion which contains a large water-filled basin. Since the Nara period (8th century), when public baths were built, people have been pouring cold water over themselves after steaming baths. At the very least, the alms baths created in the Nara period were replaced by hot water and remained in the city as public baths called sento, and the pouring of cold water over oneself was somehow replaced with water baths. The practice of alternating hot and cold baths may have been implicit for more than a thousand years. This may have been the infrastructure and cultural foundation that led to the development of totonou (sauna trance) brought about by alternating super hot and cold baths.
Reference (Japanese): Sento kentei koushiki text 1
(Reference) Gyoki and the Origins of Japanese Baths (Saunas) teamLab Ruins and Heritage: Rinkan Spa & Tea Ceremony