Well, it’s the nature of attention itself. Emotion is what brings something from awareness to attention. Amygdala does the sorting based on how it feels. Feeling of certainty is one i use a lot.
Emotion is an automatic response. You can change emotion rationally after around 400ms but most people can’t prior to that.
So, that’s where you get “microexpressions”. A slight upturn of the lip and nose indicating disgust. Or a brief flash of a smile out of the corner of the mouth before returning to neutral face. etc
I think the phenomenon you’re talking about (in the other post) is called selective attention. With that, you have a rational choice and can decide on an ongoing basis to “pay attention” or “ignore”.
But the instantaneous “pay attention” (sound of an explosion, something moving out of the corner of your eye) sudden light changes, strange touch, or “the creeps” coming up randomly, it’s an instant emotional reaction.