On the HFI site Susan Weinschenk is doing a top 100 things you should know about humans. Her first item is Inattention Blindness. This stuff is so cool. I love the human brain. You can be asked to focus on one thing and in the process you ignore what seems to be the irrelvant items. Then when you are asked about the irrelevant you cannot recall what happened. Watch the videos it is fabulous.