Deja
vu, which means, "already seen" in French is the feeling of
familiarity of something that is not supposed
to be familiar at all.
Example, a person who was in a certain restaurant for the first time,
waiting for his date, was suddenly consumed of the feeling that he
have been at that restaurant before waiting also for someone at that
very table and at that very time. Or maybe a person walking alone in
a deserted corridor would suddenly have the strange feeling that he
have walked in that corridor like that before. The human brain is
a very complex organ. Even with the advent of new studies and
discoveries, still only a little can be told about the yet so many
unveiled mysteries of the human brain. One of the so many mysterious
parts of the brain is the dentate gyrus, which, according to studies,
has something to do with deja vu. Dentate gyrus is said to
contribute to new memories as it is part of the hippocampal
formation. The
hippocampus is a part of the forebrain, located in the
medial temporal lobe. It plays a part in long-term memory and spatial
navigation. But aiding it in its memory functions is the dentate
gyrus which is also used into making split second decisions. The
dentate gyrus is like one of the many mini-computers in the brain.
Through the five senses of the body, it records the information it
perceived in the environment and stores it for future references.
When the brain comes across a thing, say for example, a familiar
scent of a perfume, the dentate gyrus will confirm the familiarity of
that scent by matching it on its
previously stored information of
perfume scents. Once the matching scent is found, the brain will now
identify the name of the perfume and tell the reason for its
familiarity. However, if damage occurred at the dentate gyrus, it
will not be able to perform its amazing work of matching newly
perceived information with its previously available ones. Mismatching
occurs. It could mistake a new scent for a previously encountered
scent or it could mistake a completely new place for a previously
visited place that leads to the famous deja vu. Deja vu occurs
even in people with no medical conditions at all. However, according
to researches, it is associated with aging. The more that the age
advance the more that cell granules in the dentate gyrus degenerate
thus making deja vu a common occurrence to those who are already in
their old age. However, this does not excuse the young individuals.
When confusion in the dentate gyrus happens, anyone could experience
deja vu.