Why and how does deja vu happen

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First, we cannot ask everyone in the world so we have to use the results of surveys of small groups of people. This is a problem because surveys can give us quite different results depending on who we ask. Asking the question in different ways can get very different results. For many younger kids, this may be a tricky thing to do. This is puzzling for researchers because we are used to thinking of memory problems increasing with age, not decreasing with age! It lets you know that while you may feel really strongly that something is familiar, this feeling is wrong and you should try to ignore it.

Perhaps what is happening in people over the age of 25 is that they get worse at spotting incorrect familiarity signals and they actually start believing them. Can you think of any others? Any such research is reliant on self-reporting from the people involved. Epileptic seizures are evoked by alterations in electrical activity in neurons within focal regions of the brain. This dysfunctional neuronal activity can spread across the whole brain like the shock waves generated from an earthquake.

The brain regions in which this electrical activation can occur include the medial temporal lobes. These neuronal discharges can occur in a non-pathological manner in people without epilepsy. An example of this is a hyponogogic jerk , the involuntary twitch that can occur just as you are falling asleep.

That is, information bypasses short-term memory and instead reaches long-term memory. This explains why a new experience can feel familiar, but not as tangible as a fully recalled memory.