Yes, your mother was right all along. According to a study conducted at Yale, viewing erotic or gory images causes the brain to stop processing visual input for a period of time, up to 800 milliseconds.
Dr. Most showed volunteers a series of images, one of which, the target, was rotated. Amongst the images shown were those of violent images or mutilated bodies, and if the target image was too close in sequence to the violent image, the viewer failed to perceive it. The same results were obtained when the violence was replaced by erotica.
Dr. Most began working on the problem of rubbernecking, where a traffic accident will cause long backups as everyone stops to get a good peek, but these findings have greater implications for traffic safety, as drivers could well be distracted by billboards long enough to get into accidents of their own
http://arstechnica.com/columns/scien...e-20050820.ars