The principle of hippocampus effect is mainly explained by the information difference in cerebral hemisphere, memory management error and brain prediction. Some scientists believe that when we process information, the processing speed of the two hemispheres is different, so it is likely to appear briefly.

Hippocampus effect, also known as visual perception and apparent phenomenon, is the feeling that human beings suddenly feel that they have "experienced something in a certain picture or place" in the real environment (relative to dreams). According to most people's memories, it seems that I have seen a scene in my dream, but I have forgotten it. Later, when they met that scene in reality, they would feel "deja vu".

Hypothesis and theory:

When we encounter a situation similar to the past experience, the neurons in the brain that process the past experience may produce impulses at the same time, thus producing a sense of sight.

Because the human brain predicts things that don't happen in the short term. It belongs to people's cognition of what happened in other multiverses on the same time axis.

Because of the brain processing errors, the information in front of us is mistaken for "the picture in memory". From a medical point of view, it is due to the sudden disharmony of information processing between the left and right brains.