Do you remember ever thinking “Um, I think I’ve seen this happen before!” Or did you ever go like, “Omg!, I’ve done this previously!”? We call this short experience, déjà vu – an expression derived from the french meaning, “already seen”.
With it’s recurring frequency decreasing with age, only about 60% of the population have experienced the déjà vu. Apart from Stress and fatigue being another reason, scientists have found four potential sources for the appearance of this phenomena : dual processing (two cognitive processes momentarily out of sync), neurological (seizure, disruption in neuronal transmission), memory (implicit familiarity of unrecognized stimuli), and attentional (unattended perception followed by attended perception).
so what causes déjà vu?
This is still a mystery! However, there are some theories that give us an insight on what causes déjà vu.
- One side of your brain is associated with a particular skill, for instance, in most right handed people, the left side of the brain is associated with language. What if the two halves of your brain were not connected? One explanation for déjà vu is that there is a split second delay in transferring information from one hemisphere to the other. Due to this short delay, one side of the brain receives information twice. This gives the sensation that an event has already occurred before.
- Some clues from groups suggest that, people get Epilepsy in the temporal lobe. Epilepsy causes brain cells to send out-of-control signals that affect brain cells around them, or in some cases, the whole brain. This is called a seizure and can result in people having epilepsy – loss of control of one’s thoughts. People having temporal epilepsy often report having déjà vu just before a seizure.
Researchers today say that not experiencing a déjà vu could be a sign of health issues. Brain scans have revealed that the phenomenon is simply the brain appraising its memory. Hence, not experiencing this could mean that there is an issue with one’s memory.
Akira O’Connor believes that frontal regions of the brain checks through memories, and sends signals if there’s some kind of memory error.
This is consistent with the idea of déjà vu as the conscious awareness of a discrepancy in memory signals being corrected.
O’Connor states, “This in turn sheds some light on why déjà vu occurrence appears to decline with age despite the fact that memory errors tend to only increase”.
“It’s not an error, but the prevention of an error!”.
Further research is required to cement this theory.
Edited by : Keerthana Suresh