For more than a decade, my colleagues and I have been studying a form of invisibility known as inattentional blindness. In our best-known demonstration, we showed people a video and asked them to count how many times three basketball players wearing white shirts passed a ball. After about 30 seconds, a woman in a gorilla suit sauntered into the scene, faced the camera, thumped her chest and walked away. Half the viewers missed her. In fact, some people looked right at the gorilla and did not see it.

That video was an Internet sensation. So, in 2010, I decided to make a sequel. This time viewers were expecting the gorilla to make an appearance. And it did. But the viewers were so focused on watching for the gorilla that they overlooked other unexpected events, such as the curtain in the background changing color.




Invisible Gorilla Basketball Video