What is deja vu?

Déjà vu is a phenomenon where an individual feels that they have experienced something before, even though they can't exactly recall when or where it happened. This can include a sense that they've been in a particular place before or a sense of familiarity with a situation or person.

Neuroscientist Andrew Huberman explains that déjà vu occurs due to a specific pattern of neural firing in the hippocampus, the area of the brain responsible for memory. Essentially, neurons can fire in a sequence similar to the one they used when encoding a past memory, even if the current experience doesn't exactly match that past event. This can lead to the sensation of familiarity or the feeling that the experience has happened before 1.

Additionally, Huberman notes that this is a normal function of the hippocampus's role in encoding new experiences and isn't usually indicative of any pathological condition 1.