The Invisible Gorilla

Many of you have seen the video posted below.    The exercise is simple.    You ask people to count the number of passes made by people in white shirts in this short video.   At the end, you ask people whether they saw the person in the gorilla suit appear in the video.   Many people do not notice the gorilla!  They are too focused on the task that has been given to them; they are busy counting passes.  Scholars describe this problem as "inattentional blindness."  Basically, we see what we expect to see.  We expect to see people passing a ball, and we don't expect to see a person in a gorilla suit. 

Now we have an interesting new study that's a simple twist on this infamous gorilla video.  Harvard Medical School researchers Trafton Drew, Melissa L.-H. Võ, and Jeremy M. Wolfe decided to examine whether experts engaged in a serious task are "less blind" than the usual naive observer conducting a mundane task such as counting passes of a ball.   Here's what the scholars report about their study: 

We asked 24 radiologists to perform a familiar lung-nodule detection task. A gorilla, 48 times the size of the average nodule, was inserted in the last case that was presented. Eighty-three percent of the radiologists did not see the gorilla. Eye tracking revealed that the majority of those who missed the gorilla looked directly at its location. Thus, even expert searchers, operating in their domain of expertise, are vulnerable to inattentional blindness.