I was reading the Einstein Factor, the author of which is also the creator of genius code, mentions that PR'ing uses some of the same theory as subliminal messages use.
One example the author uses was back in 1954, a movie theater tested the idea of subliminal messages on it's patrons.
It flashed messages like "Hungry? Eat Popcorn" and Drink Coca-cola". The messages were up on the screen for 40 milliseconds, a shorter amount of time than the pages you're photoreading, and the sales of popcorn went up 57.7% and coke sales 18.1%
The moral was that the conscious mind would have been unable to catch the subliminal messages because it went by too fast, just like your conscious mind won't be able to pick up what you're photoreading. Doesn't mean your brain didn't catch the info and is processing it subconsciously processing it, like the fact that food sales increased at the movie theater. Does this help any?