Memory & retrieval · Memory Bias · Entry 168
Boundary Extension – when your memory ‘zooms out’ beyond what you actually saw
Do you look at a photo and later recall seeing more details than were actually there? That’s Boundary Extension – the tendency to remember the background of an image as more expansive than it really was.
Where it can show up
- Perceiving photographs – you recall a full landscape in a photo, even though only a small section was framed.
- Eyewitness testimony – people insist they saw the whole scene, even if their field of view was limited.
- Past memories – your brain ‘fills in the gaps,’ making you believe you saw more than you actually did.
A practical countermeasure
- Trust facts, not feelings – your memory isn’t always accurate.
- Double-check images – compare what you remember with the actual photo.
- Remember that your brain auto-fills details – the more familiar a scene, the stronger the effect.