Now You See It, Now You Don't
While working at the Canadian Film Board in the early 1960s I met Norman McClaren, the experimental film maker, and asked if he thought films could be used in this way. I got a record on self-hypnosis, and he had some experimental films with concentric circles gradually shrinking. We put them together and showed the result. It made many people seasick!!!
I never pursued that line again, but later worked in advertising when Subliminal Advertising was tested. It was so successful that it was banned, or supposedly so, but one doesn't know if it actually was, but 'Placement Advertising' is perfectly legal, so in effect the method is still being used.
I have used it in animation as a Special Effect. If you want to create a disturbing image you can colour it with two very close colours and let them flicker. It is not visibly noticeable but mentally upsetting.
These ideas came to mind recently when reading about Spam mail. It seems one way to fool Spam filters is to have the background colour actually several very close colours.
You can write white text on a very slightly off-white background and mentally take it in without actually seeing it; a hi-tec invisible ink. And text can easily be implanted into an image. This is a common encryption method.
Forgetting Conspiracy Theories of us all being brainwashed, could such methods be used as anaesthetics? Could it be a way to control crowds with flashing lights? Could it be used in education? Whatever, there is no doubt that Animation has come a long way from funny cartoons.