What are the effects of prolonged boredom, for example as experienced by 17 months of interplanetary travel? This is the question investigated by a new European Space Agency project in which 12 volunteers will be locked in an isolation tank for 500 days. (In the comments, A.R. points out that this is probably bad reporting by the BBC, as the project actually seems to involve an isolated living space rather than a true isolation tank).
An “isolation tank” is a dark, soundproof container of salt water heated to skin temperature which is intended to induce sensory deprivation – an absence of all sensory stimulation. Such tanks were first used by John Lilly to research the dissociative and psychomimetic effects of the drug ketamine (see “Altered States.”)
Even earlier work from the 1930’s into the effects of isolation by Nathaniel Kleitman involved locking human subjects in an underground cave, without exposure to natural light, in which light was provided according to scheduled artificial day-lengths.
The European Space Agency is looking for volunteers – you can find the application form for the Mars500 project here.
(Thanks to J.N. for the tip)