(hat tip: Mind Hacks).
Please try this experiment, conceived by Simons and Chabris for their now classic study, and now packaged in a nicer video production. You will watch a brief video clip showing two teams, and your challenge is to count the TOTAL number of times that the basketballs change hands.
Click Here to view the Basketball Experiment clip.
You can read about the fascinating results here, and read the full study on sustained inattentional blindness (PDF).
Credit for pic: Haines World