What it is
Déjà vu is the sensation that a current experience has happened before, despite being new.
How it works
It is believed to result from temporary mismatches in brain processing, such as:
- Memory systems incorrectly signalling familiarity
- Timing delays between perception pathways
- Partial pattern recognition from similar past experiences
- Brief overlap between short-term and long-term memory systems
This creates a false sense of recognition.
Why it matters
Déjà vu shows how memory is:
- Constructive, not perfect
- Dependent on prediction systems
- Prone to short, harmless errors
It reveals how the brain builds reality from patterns.
Analogy
It’s like opening a book and feeling you’ve read the page before even though it’s the first time you’ve seen it.
