...radiologists still sometimes fail to see important things, and Drew wanted to understand more. Because of his line of work, he was naturally familiar with one of the most famous studies in the field of attention research, the Invisible Gorilla study.
In that groundbreaking study, research subjects are shown a video of two teams of kids — one team wears white; the other wears black — passing two basketballs back and forth between players as they dodge and weave around each other. Before it begins, viewers are told their responsibility is to do one thing and one thing only: count how many times the players wearing white pass the ball to each other:
The "cuties" version of the Invisible Gorilla Gag. I didn't see the Gorilla even though I expected it...
"Sounds ridiculous, right?" says Drew. "There's a gorilla on the screen — of course you're going to see it! But 50 percent of people miss the gorilla."
This is because when you ask someone to perform a challenging task, without realizing it, their attention narrows and blocks out other things. So, often, they literally can't see even a huge, hairy gorilla that appears directly in front of them.
That effect is called "inattentional blindness" — which brings us back to the expert lookers, the radiologists.
Drew wondered if somehow being so well-trained in searching would make them immune to missing large, hairy gorillas. "You might expect that because they're experts, they would notice if something unusual was there," he says.
|83 percent of radiologists didn't notice the gorilla in the top right portion of this image.|
He took a picture of a man in a gorilla suit shaking his fist, and he superimposed that image on a series of slides that radiologists typically look at when they're searching for cancer. He then asked a bunch of radiologists to review the slides of lungs for cancerous nodules. He wanted to see if they would notice a gorilla the size of a matchbook glaring angrily at them from inside the slide.I'm often concerned that I might miss big shark's teeth because I'm so focused on seeing the small ones.
But they didn't: 83 percent of the radiologists missed it, Drew says.
This wasn't because the eyes of the radiologists didn't happen to fall on the large, angry gorilla. Instead, the problem was in the way their brains had framed what they were doing. They were looking for cancer nodules, not gorillas, so "they look right at it, but because they're not looking for a gorilla, they don't see that it's a gorilla."