Deja vu is likely a symptom of the brain's conflict resolution system attempting to process a phantom signal of familiarity without finding an actual matching memory.

“So, the argument here is that deja vu, as we experience it, it's not this false memory. It's more like your factchecking software, as it were, in your head is kind of running through.”

The leading hypothesis for deja vu is that the brain is attempting to solve a processing mismatch where the feeling of familiarity occurs faster than the actual perceptual awareness.

“The processing of the data happened way faster than the perceptual awareness. So your brain is already responding with feelings and associations to the thing before you actually see it and you're going hold on but this is already here.”