I’ve Been Here
Before…

Most people – two out of
three according to surveys - have experienced déjà vu. It is  that  weird  sensation of  having  “been here before” or having  “lived this moment already”.
You may be talking to a stranger, for instance,  and  suddenly feel that your conversation is
a replay, word for word,  of a
previous one. Or you may be visiting some entirely unfamiliar town  and
“realise” that you have been right there, in that precise spot, at
some other time, even though you know it is impossible. The feeling goes way
beyond any vague sense of  having seen or done something similar
before – it feels identical to a past experience. Yet trying to pin down
the memory is like trying to catch a dream – just as you think you are
homing in on it, it
turns to vapour.

The  eeriness of deja vu has led to all sorts of spooky theories. One
popular one is that it
is evidence of reincarnation – a bit of a past life
“breaking through”.
Others believe it is the memory of a dream in which the person has lived
through the current moment in advance. In recent years, however, neuroscientists  have
discovered enough about perception and memory to piece together a more
plausible explanation.

Every conscious  experience we have  is
“constructed” by our brain out of lots of different
components, rather as a car might be made in a factory. We tend to think of an
event as a bundle of sensations: sight, sound etc, but there is actually much
more to it.  If you (literally) bump
into someone in the street, for example, you will be aware of the sight of
them, the touch of them as you bump, the sound each of you make   and so on. But you will also be
aware of  the meaning, tone and
intention of the sound, the pain from the bump,  a sense of irritation or  embarrassment;  a thought, perhaps,  that you, or the other person, is
clumsy, and so on….. There is much more to experience than simple
sensations.

One, very important  “component” that
often gets added is a sense of familiarity. This is generated in the deep part
of the brain that creates emotions.
The sense of : “ah yes! I recognise
this!” usually only gets attached to experiences which
“match” stored memories.    Sometimes though, the part
of the brain which generates the feeling  of familiarity becomes “trigger
happy” and attaches the feeling to an experience that is actually quite
novel.  This is what seems to happen
in déjà vu. The brain then tries to dig out matching memories,
but of course, they aren’t there – hence the maddeningly feeling of
chasing shadows.

For most people déjà
vu is a rare and fleeting phenomenon, intriguing rather than disturbing. And
it   doesn’t seem to be unhealthy .– indeed, déjà vu is most
commonly reported by people who are
young, intelligent,
well-educated and wealthy. Given that it is actually a minor brain
malfunction, this may seem strange. The explanation may be that young brains
are more   “recognition sensitive ”, so they are more easily triggered into
familiarity mode. Similar sensitivity may also be a factor in intelligence
– bright people “see things” quickly ,
meaning they get that “ah-ha!” feeling more readily than others. And  intelligent
people tend to go on to higher education and thus become wealthy. So
déjà vu may be a side-effect of having a brain that is quick to
recognise things.

For an unfortunate few, though,
déjà vu is a constant companion, and a serious blight on their
lives.  Dr Chris Moulin is a
psychologist at Leeds
University who is studying  this
strange disorder.  He first came
across it when he was working in a memory clinic:.
“We had a peculiar referral from a man who said there was no point
visiting the clinic because he’d already been there, although this would
have been impossible. Déjà vu has developed  to such an extent that he had
stopped watching TV - even the news - because it seemed to be a repeat, He even
believed he could hear the same bird singing the same song in the same tree
every time he went out.”

Apart from the Groundhog Day
tedium of chronic deja vu, the condition can also get
people into social difficulties. “Some  patients feel that everyone they
meet is familiar and this makes them dangerously trusting of  strangers. “ says Moulin.
“If they don’t constantly remind themselves that the sensation is
false they are at risk of being exploited.”

So next time you find yourself
“re-living” an experience, don’t struggle to recall the
previous time. Just sit back and relax. And make sure that you don’t sign
on the dotted line until the moment has passed