“Really, I think of flotation like ‘screen therapy’. It seems to reverse some of the anxiety or stress that we inflict on ourselves by constantly using backlit screens — monitors, television sets, and smartphones. You might think you would fall asleep if placed in the dark and deprived of sensory input, but I tend to feel more intensely aware and awake in the tank, even as it primes me for reverie. Flotation also seems to help with several mysterious hitches in my body. My habitually tight pectoral minor muscles and the soreness in my right hip disappear or are relieved by that dip in the dark.”
Read the whole article on National Review. You can skip about halfway down, past the usual description of the experience.