When talking about vision and what you see and don't I like bringing up the Your Brain: Perception Deception Nova PBS episode.
https://www.youtube.com/watch?v=HU6LfXNeQM4
Also Your Brain: Who's in control Nova PBS
> In other words, [the visual system] makes “assumptions” about what we’re seeing based on what it already knows.
Presumably there are also “can’t unsee” neurons similar to that.