A Horizon BBC documentary; Total isolation.
"or the first time in 40 years Horizon re-creates a controversial sensory deprivation experiment. Six ordinary people are taken to a nuclear bunker and left alone for 48 hours. Three subjects are left alone in dark, sound-proofed rooms, while the other three are given goggles and foam cuffs, while white noise is piped into their ears."
I suppose you have to be really zen to do this.
To see the moving images you have to click here.