You don't think humans know the difference?
Paul,
You really think people do not know the difference between computer simulations and the real thing? I was watching a movie the other night where a tractor trailer crash scene was so obviously a computer simulation. They did a nice job, but my reaction to the violence was much different than had they used a real truck and real people, even if I know they are actors.
You think soldiers and law enforcement people are any different? If you know the image is not real, at some very basic level of your brain you are processing the input that way, and it has to effect your judgement. If the images are real, then you think differently.
Andy