According to one of the paranormal investigator TV shows, this is the type of chair that was used to punish prisoners that would be caught speaking to other inmates. Communication was not allowed at E.S.P. A clamp would be put on their tongue and attached to their tied hands around their back while strapped very tightly to the chair. Circulation would be cut off from being tied tightly to the chair and if they moved at all, the tongue clamp would cut their tongue. The victim would be left their for days like this without food or drink.
I do not know if it is true, but if sure makes for one heck of a story!