It's one of the most famous experiments in perception. In 1999, Daniel Simons and Christopher Chabris of Harvard University showed subjects a short video of two basketball teams, one in white shirts, the other wearing black. Subjects were asked to count the number of passes made by the team wearing white.
Halfway through the video, a woman wearing a full-body gorilla suit walks slowly to the middle of the screen, pounds her chest, and then walks out of the frame. If you are just watching the video, it's the most obvious thing in the world. But when asked to count the passes, about half the people miss it.
The phenomenon, inattentional blindness, illustrates the brain's vulnerability with regard to perception, attention, and consequently, memory. It underlies what we see (or don't) in stage magic and what we are led to believe we know (or don't) by politicians.
For decades America's Republicans have been steadily eroding a woman's right to choose. The attacks on women's control of their bodies go far beyond opposition to abortion, but include legal requirements for intra-vaginal ultrasounds, and laws against mammograms for the poor and even contraception.
This year's Republican platform is so anti-abortion it carries no exceptions for rape or incest. Hardly anyone would have noticed but for a 200lb gorilla in the form of Todd Akin, Republican candidate for Senate from Missouri and current member of the House Science Committee.