Déjà vu happens due to a miscommunication or "misfire" between different parts of the brain involved in memory and familiarity. Specifically, it arises when the brain mistakenly signals that a current experience is familiar, even though it is new. This is often caused by a brief disruption between the temporal lobe (which processes memories) and the hippocampus (which takes in new information), creating a false sense of memory and familiarity mixed with present experience. Several theories explain why this occurs:
- A brief electrical "glitch" or malfunction in brain circuits where present events are falsely processed as past memories.
- A mismatch or delay in how sensory information is processed in the brain, causing one pathway to send the signal slightly earlier than another.
- Implicit memory triggers where the current environment resembles a forgotten past experience, leading to familiarity without conscious recollection.
Fatigue, stress, and younger age seem to increase the likelihood of experiencing déjà vu, possibly due to increased random neural activity or temporary cognitive processing errors. In rare cases, frequent déjà vu can be linked to medical issues like temporal lobe epilepsy. Overall, déjà vu is a normal experience caused by the brain's complex memory and recognition systems briefly getting out of sync, producing the eerie feeling of "already having seen" a new experience.
