Background

Inattentional blindness refers to a phenomenon in which people fail to perceive an object or event that is visible but not attended to. This refers to situations in which a well-above-threshold event or object is not seen because the person’s attention is directed elsewhere. In the 1963 movie, “Cleopatra,” during one scene an airplane can be seen passing above. Given that the movie was supposed to take place in 48 B.C., this is clearly an error on the part of the filmmakers. However, most viewers will not notice the passing airplane, as it is irrelevant to the storyline and certainly not expected. Even if you watch it now, alerted to this anachronism, you will likely miss it. Movie directors who miss these goofs definitely benefit from inattentinal blindness! Perhaps the most famous demonstration of inattentional blindness comes from a study conducted by Simons and Chabris (1999) which builds on an earlier example shown first by Neisser (1979).

You can check out Dr. Simon's website here where they are many more examples to be observed and tried. This site is definitely worth the visit.

Original Clip

Monkey Business Illusion