The effects of living on its own for a human or any other members of the animal kingdom either deaf, mute or even blind and the possibility of time-travel.
This is an experiment with time and the mind.
Selected people are forced to live in separate rooms in the dark for a month and they can't see or hear each other. The house is riddled with "night-vision" cameras. Each day the patient will be undergoing an "auditing" and interview process.
The only way anyone can depart from his living condition to a different time and universe is by cleaning the mind and the soul, a process that can only be obtained by living in the dark.