THE ROUGH GUIDE TO PSYCHOLOGYexperience it at one time or another, and it usually occurs in mundane
circumstances, such as when sitting down for a meal at home or crossing
a street on the way to work.
An early, popular explanation for déjà vu – which literally means
“already seen” – suggested that it was caused by information from one
eye, or one visual pathway, becoming desynchronized with the other, thus
triggering a mistaken sense of familiarity with a scene when the later
signal arrived milliseconds after the first. However, the psychologists
Akira O’Connor and Chris Moulin at the University of Leeds challenged
this account when they documented the case of M.T., a 25-year-old blind
man who occasionally experiences déjà vu just as sighted people do.
Other clues have come from studying a rare complaint in some elderly
patients in which it seems to them that life is constantly repeating itself.
Moulin and his colleagues have identified several elderly people who no
longer enjoy watching television, especially the news, because they feel
as though they’ve seen it all before. The difference from classic déjà vu is
that these individuals really believe that their experiences are repeated
whereas healthy people know the situation is actually novel, even though
it feels uncannily familiar.
Though it appears as if these older patients are delusional, anti-
psychotic drugs failed to alleviate the symptoms. Moulin suspects some
kind of degeneration in the temporal lobes may be playing havoc with
the patients’ sense of familiarity and recollection, and that a temporary
blip with the same system is at the root of classic déjà vu. The temporal
lobes have been further implicated in déjà vu by reports that some
people with temporal lobe epilepsy experience the sensation just before
or during a seizure.
In research with healthy people, Moulin has shown that distraction
during learning can lead to a later sense of “knowing” without a corre-
sponding feeling of familiarity, and he’s hopeful that his older patients
could find respite from their symptoms by performing secondary tasks
- for example, knitting while watching TV.
Research into déjà vu is hampered by the fact that it’s well nigh
impossible to catch people in the process of having the sensation.
However, in an intriguing paper published in 2009, Alan Brown and
Elizabeth Marsh claimed they may have found a way to simulate the
sensation in the lab. Their method is based on Brown’s idea that déjà
vu could stem from implicit memories. Imagine glancing fleetingly at
an unfamiliar street scene, being distracted by a poster in a window,
and then returning your gaze to the street and experiencing a feeling