Question: What is deja-vu?

Ed Bracey answered on 8 Nov 2017:

Hi Hattie, good question!
About 2/3rds of people have reported having a Deja Vu episode.
I have, and they’re really quite confusing!
We’re not sure yet what causes them.
We think the part of the brain that stores memories (the temporal lobes) are involved because people who have seizures in this part of the brain often have a feeling of deja vu before a seizure occurs.
One cause might be that when information comes into your brain via the senses, it’s sent to lots of different parts of the brain to get processed first, and then all put back together to reach the part of the brain where your become conscious of that information.
Normally the information all arrives at the same time.
If it gets out of synch though, you might think you’ve seen or done something already.
It could also be that your brain tends to use information it has already to second guess new information coming in.
It could be that when new information coming in is so similar to what you predicted, you think you’ve seen it before, even though it’s never happened before!
One cause might be that when information comes into your brain via the senses, it’s sent to lots of different parts of the brain to get processed first, and then all put back together to reach the part of the brain where your become conscious of that information.
Normally the information all arrives at the same time.
If it gets out of synch though, you might think you’ve seen or done something already.
It could also be that your brain tends to use information it has already to second guess new information coming in.
It could be that when new information coming in is so similar to what you predicted, you think you’ve seen it before, even though it’s never happened before!
(Sorry, couldn’t help myself)!