Always love when this pops up. I always think of it when I use a credit card and the POS device says "do not remove card" and then "remove card". I think it would be much clearer to simply say "insert card" or "leave card inserted" and "remove card" and not rely on the small, hard to read and understand modifier of "not".
I'm not sure of the name for what you're talking about, but the most prominent example I've heard is from people who work with kids (teachers, life guards, etc). Instead of saying, "don't run!" you say, "walk" for the reasons you mentioned.
I frigg'n hate those credit card machines that beep and blink "do not remove card" using the same font and sound as the other messages.
I've noticed this in product design a lot; designers/programmers assume way more attention from the user than is typical.
Most of the time, I don't read instructions, I just do what's "intuitive". Designing with the assumption of minimal attention / laziness is so important.
The worst part is when the "wait" step blinks through 2-3 different messages. A card reader shouldn't attract the user's attention until they actually need to do something.
I'm always waiting for something to happen so I can take my card out finally. Then the message changes, so I take my card out. But it was only changing to yet another phrasing of "Do not remove your card". Like when you're a kid about to start a race, and the starter says "Ready, set, STOP! Ha ha ha"
Similarly, I remember when those card readers would beep loudly at you when it was time to remove the card. "EEP EEP EEP!" they'd go, like something went horribly wrong, but when you'd look at the screen it would just tell you the transaction was complete and to remove your card. I think the manufacturers eventually realized what a poor choice of sound effect it was and eventually changed it.
This very much reminds me of how Mac OS applications use "Don't save" to confirm exiting, but some Linux office applications use "Don't close" to cancel exiting in the same type of confirmation dialog.
I've had the problem where I try to close something, reflexively hit "don't close", and complete that loop a couple of times before my brain catches up.
