The keyword here is Freewill. I think you could isolate for months if it is your own choice. But if you are forced to be isolated for 3 hours it makes a huge difference.
This reminds me of a guy named Tehching Hsieh, who voluntarily isolated himself in a cage in his New York City apartment for a year. The cage and pictures of him are on display at MoMA.
Anyone remember the name of the Japanese game show where the comedian was locked in a room for (n) and had to win his way free via magazine giveaways? I always thought it was fake/marketing, but an interesting.