I'm posting this BBC podcast (The Compass BBC World Service) by Dava Sobel as she discusses living for about a month in a sensory deprived environment. She discusses it's effects on her including altered circadian rhythm. I haven't listened myself. My husband described it to me so thought I'd post it if anyone is interested. The podcast is free on iTunes but I don't think I can link directly so the podcast I'm referring to is number 5 in the series: https://itunes.apple.com/ca/podcast/the-compass/id1052738045?mt=2&i=1000426850786 Also, it's a US link. I have no idea how that will affect users elsewhere but it's BBC so no doubt can be found elsewhere as well.