You could imagine that déjà vu is a fault in the matrix. In this respect it is, though in this case the cause of the fault is the electrical activity in your brain.
The feeling known as déjà vu is a strange sense of familiarity, as though you have gone through the exact situation before. While for most people it occurs occasionally and fades away just as quickly as it appears, scientists have discovered that the phenomenon can show us some interesting things about how memory functions.
As cognitive psychologist Dr. Anne Cleary has pointed out, some groups of people who have neurological conditions suffer from déjà vu more frequently than other groups; for instance, individuals with temporal lobe epilepsy may suffer bursts of electrical activity in the brain’s memory areas.
Déjà vu can actually be a warning sign that a seizure is about to occur for many people who have epilepsy, but the experience of déjà vu is also something normal in having a healthy brain.
How can we tell if something we’re remembering is actual or merely a case of déjà vu?
As Adam Zeman, a clinical neurologist from the University of Exeter in the U.K., points out, healthy brains seem to have déjà vu in the same way as people who have epilepsy, and around two thirds of people have the experience at some time in their lives.
Some situations can make it more likely to have this feeling. When you travel a lot or when you are tired and under stress, you are more prone to suffering memory errors since fatigue and stress can affect the temporal lobe, a part of the brain that is involved in forming memories.
You too can give your brain a large number of new experiences through travel, and at times it may happen that your brain comes across something similar to an old memory and thereby feels a strong sense of familiarity.
Individuals who can recall their dreams might also be more susceptible to experiencing déjà vu. If you’re interested in looking into this association, keeping a dream journal could help you to notice if familiar situations occur more often.
There is in fact a medical method of inducing déjà vu. Scientists have achieved the production of this sensation by using electrodes to stimulate parts of the medial temporal lobe, although it is by no means reasonable to deliberately cause déjà vu in this manner.
It is thought that some of the parts of the temporal lobe have a role in producing the feeling of familiarity, although other areas of the brain might also be involved. The cognitive neuropsychologist Chris Moulin has proposed that the prefrontal cortex may assist in enabling us to recognise that a memory feels familiar even if it is in fact false.
That brings up an even stranger question. What if déjà vu is not just a false memory, but somehow lets us see a bit of the future?
A research study carried out by Dr. Anne Cleary at Colorado State University discovered that the participants at times felt that they could predict what would happen next when experiencing déjà vu; yet the feeling of knowing what comes next does not always mean that a person can actually foresee the future.
Some people even think that déjà vu might have a connection with memories of previous lives, but a more probable explanation is that the brain is getting a sense of familiarity from a distorted or similar memory.
If you are sure that you’ve met that person before, all that may be happening is that they look like someone you have come across before. Your brain could identify the sense of familiarity even before you are aware of where it comes from, producing one of the most strange sensations that the human mind is capable of.
