(literally, French for “already seen”) is the feeling that we
have already seen or experienced something that we are seeing or
experiencing for the first time. Occasional déjà vu experiences
are normal, and they may reflect momentary glitches in
memory. One explanation is that the
neurons in the brain may get temporarily out of
phase, and mislabel incoming new information as old. This may
be particularly likely if some elements of the current situation
are familiar, so that some aspects of the current situation
match an old situation. Another explanation for déjà vu is a
momentary lapse in
attention: you see or hear something but aren’t
paying attention and, a moment later, you process the scene more
fully and think it’s familiar – and it really is, because you
processed it a moment ago.
basis of déjà vu is not understood, but it may involve
malfunction of the
temporal lobes, a part of the brain that is important
for new memory formation. Some patients, with damage to the
temporal lobes or with
epilepsy that originates in the temporal lobes,
experience persistent déjà vu.
There, Done That, Seen That"
by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain