Sensory Deprivation: Meditation Isolation Chambers aka Flotation Tanks - amazing! At 1st my breathing was fast & my heart was pounding in the darkness. Weightless, the tank eventually seems as big as the universe. You can't tell which direction your body is floating. You can no longer feel your body, it totally "disappears". Nothing is left but your mind, your thoughts... and sometimes "I" would disappear in my thoughts. A separate "I" no longer existed. This was my experience. jc
“Many floaters experience hallucinations as their brains respond to not getting sensory input. This is part of the vivid mental imagery I mentioned earlier—your brain is relaxed enough to visualize strong images you wouldn’t see normally.”—Belle Beth Cooper. http://blog.bufferapp.com/the-power-of-shutting-down-your-senses-how-to-boost-your-creativity-and-have-a-clear-mind
Isolation is a primary method of control by the narcissist. By keeping you away from others, it is less likely that their true self will be revealed. They will only "allow" you to interact with your friends or family that they've been able to keep their "true identity" from being revealed.
On Fringe, a sensory deprivation tank can activate your mental powers and even open a gateway to another universe. But what can floating in a dark warm tank do for you in real life? And why would people even want to do such a thing?