We’ve all had that vivid feeling of remembrance, even though we haven’t encountered this familiar
situation, right?
Well, this occurrence is called déjà vu, the French phrase for “already seen”.
Déjà vu is usually observed in people aged 15-25, and is very common among younger children.
Currently, scientists have not identified the exact reason deja vu can occur in young,
healthy minds, but there are hundreds of theories justifying this occurrence.
Epilepsy is a neurological sickness that behaves similarly to the déjà vu phenomenon, and
is characterized by uncontrolled neuronal activation.
Once scientists discover the reason deja vu occurs, they can utilize this knowledge to
develop novel treatments for epilepsy, and create technological advancements that will
help scientists to better understand how the brain works.
So, what is known about how does déjà vu occurs?
One conjecture explains the process as a “mental hiccup” in the limbic system.
The limbic system consists of several brain areas, including the hippocampus, amygdala,
cingulate gyrus, thalamus and hypothalamus.
The limbic system is located underneath the cerebral cortex, where motivation, emotion,
learning, and memory are all wired for output.
When the eyes process an object, it is immediately sent to the hippocampus as short-term memory,
waiting to be converted to long-term memory.
Not all short-term memory is converted to long-term, as it must undergo a laborious
journey in the brain.
According to Scientific American, "A short-term memory's conversion to long-term memory requires
the passage of time, which allows it to become resistant to interference from competing stimuli
or disrupting factors such as injury or disease."
Other sources state there is an emotional factor that determines what is turned into LTM.
That is why you remember experiences like your 6th-grade birthday party, rather than
what grade you got on your second-semester math test in high school.
The limbic system interacts with the basal ganglia system, which is important in the
formation and retrieval of procedural memory.
The present theory is; when the STM is on its way to be converted to LTM in the hippocampus,
a "mental hiccup occurs", and the STM immediately is sent to the basal ganglia system, and instead
of the formation of a new memory, the brain comprehends this memory as an old one, and
the basal ganglia system "retrieves" this new memory.
As the body takes this new event in, it is perceived as an old memory, instead of a new one.
That is why you feel you've already experienced this event, when the brain just really had
a small hiccup in its conversion process.
The theory present has described the process of how deja vu occurs, but not the small details like,
what exactly is the "hiccup"?
What biochemical interactions occur in the brain to achieve this phenomenon?
And finally, what neurotransmission occurs between the synapses that carry out the function
of feeling "deja vu"?
Another theory states that deja vu is just your subconscious mind remembering a dream
similar to the event you are experiencing, but this theory has an inadequate amount proof
to support it.
Once scientists find the reason deja vu occurs, it can be implemented to treat epilepsy, a
disease where the victim has excessive or abnormal brain cell activity, and in its most
extreme example, Grand Mal, they get non-stop seizures.
Scientists and researchers have discovered that it is possible to stimulate deja vu in
patients who suffer from epilepsy, but no one knows why.
In normal patients, the only thing deja vu can be measured in is the frequency it occurs,
where it happens, when it happens, and the age of the participant.
Scientists have identified similar instances of deja vu, but they are not exactly the same.
According to sources, "Presque vu is the feeling of being on the very brink of a powerful insight,
or revelation, without actually achieving the revelation.
The feeling is often therefore associated with a frustrating, tantalizing sense of incompleteness
or near-completeness.
Déjà rêvé is the feeling of having already dreamed something that you are now experiencing.
Déjà entendu is the experience of feeling sure about having already heard something,
even though the exact details are uncertain or were perhaps imagined."
Deja vu has rattled the minds of scientists for the past few years and we are still trying
to understand how the brain processes and integrates all of this information.
In further years, younger scientists, such as myself, will take up the challenge to solve
the mysteries of the all too peculiar phenomenon, deja vu.
But for now, adios!