Inattentional Blindness

By Tadgh Connery

Can we Trust our Brains? Cognitive Psychology suggests not (or at least, not all the time).

You may, or may not, be familiar with the famous “basketball attention test” video. If you’re not, I would encourage you to go to Youtube now and watch it before reading on. Go on now, I’ll wait! Search for “basketball attention test” and click on the first option entitled “selective attention test.” Take your time. I’ll wait for you.

The video depicts individuals, wearing either black or white t-shirts, passing basketballs between them. Viewers are asked to count how many times the white-clad players pass a ball. Sounds easy, doesn’t it? And it is. Most people who watch this video keep an accurate count. However, as you may have guessed, there’s a catch.

The goal here was never to assess viewers’ counting ability but rather to examine how many people spot the gorilla who walks across the screen, beating his chest, in amongst the players. Did you spot him? Don’t be frustrated if not – approximately 50% of people don’t. You might wonder how on earth you missed something so obvious and incongruent with the environment you were watching. But cognitive psychology has shown that our brains often do not always show us the full picture. The phenomenon at play here is what cognitive psychology refers to as inattentional blindness. This is a visual awareness glitch where individuals fail to perceive something important in your environment when your attention is focused on something else, such as a task, object or a person. You may have experienced this when you are so engrossed in a film or in working on an assignment that you don’t notice someone else in the room is talking to you.

Research has found inattentional to have serious real-world implications. One study, “Crime blindness: The impact of inattentional blindness on eyewitness awareness, memory, and identification”  by A.N.Wulff and I.E.Hyman Jr., presented participants with a video in which an obvious crime was committed. The researchers asked participants to either: watch the video; count the number of people in the video wearing white clothing or; look out for a crime. They found that participants in the former two categories were significantly more likely to experience inattentional blindness, and not notice any crime being committed, than participants who were instructed to keep an eye out for crime.

 Another study “Perceptual Load Induces Inattentional Blindness in Drivers” by G.Murphy and C.M.Greene had participants drive in a driving simulator and judge whether their car would fit through a gap between two cars in front of them. For some participants, the gap was obviously big enough to fit through. For others, though, it was more difficult to judge, requiring more concentration at the task at hand. These participants were more likely to experience inattentional blindness to a pedestrian at the side of the road than those who did not expend as much cognitive effort to judge the size of the gap.

While inattentional blindness is not necessarily something you can avoid, you may be able to limit its effects by becoming better in tune with your visual surroundings. Limiting distractions while engaged in important tasks, such as turning the radio off and putting your phone away while driving, may aid in reducing your susceptibility to inattentional blindness. Some car manufacturers have recently become aware of the dangers posed by inattentional blindness and have started to incorporate audio and visual signals when they detect a hazard nearby.

To sum up, inattentional blindness is a common experience and does not reflect poorly on your mental state or ability. If, and when, you experience it, please don’t panic or start to doubt the brain's reliability. But keep your eyes peeled for gorillas – they may appear when you least expect it!