Everything we know about deja vu may be wrong; Everything we know about deja vu may be wrong

A blind man suffering déjà vu? It certainly sounds like the punchline to a bad joke. But it provides a clue to the true nature of the "I've seen this before" feeling.

Déjà vu is the feeling of having been here before in a most eerie way. The term is French for French for "already seen." A majority of people claim to have experienced it at least once in their lives.

The traditional explanation has been that images from one eye are delayed and arrive in the brain microseconds after images from the other eye -- causing a sensation that something was being seen for the second time.

Science Daily reports on new research that says this is wrong. It would be impossible for a blind person to experience déjà vu if in fact it was the result of optical pathway delay -- but the blind experience déjà vu just like the sighted.

Researchers at the University of Leeds now believe that déjà vu experiences are the result of disruption in area of the brain that deals with familiarity. In fact, they've been able to create the illusion of déjà vu in subjects through the use of hypnosis. However the subjective nature of deja vu continues to make déjà vu a difficult phenomenon to study. However the subjective nature of déjà vu continues to make déjà vu a difficult phenomenon to study (got you!).

More at Wikipedia and deja vu.