1, the hippocampus effect is also commonly known as the sense of vestigial vision, which refers to people facing an unfamiliar person or in an unfamiliar environment, the phenomenon of producing a sense of "déjà vu".

2. For example, when we do something, we suddenly have a strong feeling that we have done exactly the same thing, and this is the hippocampus effect. At present, the reason why the hippocampus effect has not been fully confirmed, there are only many hypotheses about it.

3. Some people think that the hippocampus effect is a processing error in the brain, others think it is a short-lived precognition of the brain for the future, and still others think that it arises because of people's perceptions of what's happening in other multiverses at the same time.