Have you ever felt like you have experienced something before? Sometimes people perceive their situation as having been experienced and this happens from various situations, even from a simple situation as being in an elevator while feeling something similar to one’s past.
Déjà vu is a fleeting sensation of having already experienced a situation at some point in the past. The word Déjà vu is a French word, meaning “already seen”. However, despite the meaning of the word itself, Déjà vu is a false sense of familiarity. It is caused by the fact that the brain creates a sensation as if you have been in a certain situation before, which in fact you have not experienced. Because the sensation does not come from an actual memory, it is not easy to identify the actual situation.
When you are feeling Déjà vu, you might be feeling as if you are in a conversation, feeling the sensation that you have had before. In this situation, you might also be able to predict what the person is going to say next. For example, when you are in an elevator and someone comes in and talks to you, you might recognize the same scene before, even though you don’t remember the exact same scene with the same person, same scent, or same atmosphere.
What causes Déjà vu to happen? A neurologist, Jean Jhoury, MD explains that it is caused by dysfunctional connections between the parts of the brain that play a role in memory recollection. In this case, the line between the memory from the past and a new experience can be blurred due to a miscommunication between two parts of the brain. Specifically, the one part responsible for memories (the temporal lobe) and another part responsible for new information formation (the hippocampus) would be the contributing factors. Another explanation for the occurrence of Déjà vu is that the recurrence of situations makes the feeling again. When the split perception is repeatedly experienced, it leads to the feeling of Déjà vu. You might not feel familiar enough to say that this is your first experience since you are unaware of the circumstances. In this case, it can be understood that the memory has been only partially processed.
Though the actual feeling of Déjà vu is the same for all people with healthy brains and those with neurological conditions, some different things tend to happen among some types. Generally, people who experience Déjà vu more regularly show less grey matter than those who do not. Grey matter is the outermost layer of the brain that is responsible for controlling memory, emotions, and movements. The more gray matter, the more effective it is. Moreover, people with neurological conditions such as epilepsy and schizophrenia tend to experience more Déjà vu than those with a healthy brain.
Sometimes, some negative health conditions could indirectly make people feel Déjà vu. For instance, fatigue, sleep deprivation, stress, or anxiety can lead to Déjà vu. Therefore, it is also important to keep in mind that you should keep yourself in a healthy condition.
By. Jeonghwa Oh
References
https://health.clevelandclinic.org/deja-vu-what-it-is-and-when-it-may-be-cause-for-concern
https://pubmed.ncbi.nlm.nih.gov/29546854/
https://www.verywellmind.com/what-is-deja-vu-why-do-we-experience-it-5272526