Tag Archives: inattentional blindness

Inattentional Blindness

As evidenced by my previous post, I have always been fascinated with the concept of blindness – all types, in fact. Since I discovered my love and interest in psychology, I have found myself to be more aware of examples of anything I learn in class or from the textbooks in everyday life, particularly examples of any kind of blindness. A couple of weeks back my friends and I got together for out weekly Tuesday dinners at Seacobeck. While one of my friends – Timmy – got up from the table to get more food, my prankster friend decided to steal his phone and stash it in my coat pocket. As a side note, my coat is black. When he came back, it took him about twenty minutes to realize his phone was gone. Once he reached that realization, he began quizzing us on where it was. I gave him three clues:

1) It’s in a deep, dark place where hidden objects often go.
2) It’s in a place of pitch blackness.
3) You’re looking right at it.
(He sat across the table from me.)

Regardless of these clues, Timmy simply could not figure out where his phone was, looking under the table, in the flag, in my black purse, and in my shoes. I was surprised that he missed the most obvious of places – my coat. I then began to wonder: “Is it simply because it’s so obvious, that he missed it?” This brought me back to our discussion of inattentional blindness, something I think Timmy perfectly demonstrated that night in Seacobeck.

An article in the Psychological Review refers to many incidents where people fail to notice stimuli appearing in front of their eyes when they are preoccupied with an attention-demanding task; the task Timmy in particular was preoccupied with was finding his missing cell phone. In this article, each study refers to incidents when people were so focused on one task, they missed another stimulus that may seem blatantly obvious to others. For example, there was an American naval submarine that slammed into a Japanese fishing vessel, killing nine crew members and students on board. When questioned, the crew in the sub all insisted that while quickly scanning the waters for enemies and other submarines, they had simply missed the fishing trawler. While this is a catastrophic example, one that certainly does not have a very clear correlation to Timmy’s search, it makes me think of how exactly he was searching for his cell phone. Instead of looking carefully and really thinking about the clues I gave him, he was scanning the area around where we were sitting very quickly, not lingering on any object. When thinking about this case of the submarine and traffic accidents where drivers missed seemingly obvious obstacles in their way, I am able to see how Timmy may have missed the obvious choice of my black coat.

Though Timmy admittingly does not have the best common sense in the world, I still don’t want to think that he simply did not even consider the fact that the phone in my pocket – in fact, the reason my friend hid the phone in my pocket was because she thought it would be the first place he would think of. As this article points out, there is a phenomenon within inattentional blindness, called implicit perception, that suggests that when people don’t consciously notice a stimuli, it still is encoded outside of their awareness, also determining their future behaviors. As Timmy did finally decide that I had it hidden somewhere in my coat (nearly half-an-hour later), this suggests that he had registered the existence of my coat in his consciousness, but didn’t access it until we practically gave away the location.

This experience of inattentional blindness in my everyday life was not only hilarious and slightly annoying, it further instilled in me an understanding of this concept, as well as a deeper understanding of the mind of my friend Timmy. I look forward to more times I can experience the concepts of cognitive psychology in real life!

There Was A Gorilla???



This meme is an accurate representation of how I felt after watching “The Invisible Gorilla” video. I just couldn’t believe that a gorilla had walked through the two teams, and that I wasn’t capable of seeing it! How did that happen? Why was it so hard to count the passes AND find the gorilla?


The original video was done for an experiment by cognitive psychologists Daniel Simons and Christopher Chabris in 1999. It shows how easily people become blind to things that are right in front of their faces. When given the task of counting the passes thrown by either team, people develop something called selective attention. Although there is no one true definition for how selective attention is caused, there are several theories that try to explain the phenomenon.

There are currently three types of theories that are currently accepted: Filter theories, Bottleneck Theories, and Attentional Resource Theory.

Filter theories state that attention filters our extraneous information so that only the relevant stuff gets through to consciousness. So in the gorilla example, if someone chooses to focus on the white team’s passes, he/she filters all the extra things they see, these being the members of the black team and the gorilla crossing the screen.

Bottleneck theories are somewhat similar to Filter theories, but instead of a filter, there is a bottleneck in the flow of information that prioritizes the importance of information coming in, and only allows what is deemed necessary. So in terms of the video, this means that people do see the gorilla, however their brain deems in unnecessary due to the importance of counting the passes.

Attentional Resource theory says that we only have a limited amount of cognitive processing available at any one time. Once the cognitive processing has been used up, performance starts to suffer. In regards to the video, this means that trying to count the amount of passes uses up most of someone’s cognitive processing, making him/her unable to process that the gorilla is present.

After doing research on these different theories, it is much easier to understand why it was easy to miss the gorilla. Had there been no task to count the passes, the gorilla wouldn’t have been hard to miss. However, because the mind is preoccupied with a task, the gorilla essentially becomes obsolete and unnecessary information that becomes tuned out before the mind even processes it.

The theory that I agree with the most is the Attentional Resource Theory. This theory would also make sense as to why some people’s performance lowers while multi-tasking. If our mind only has a limited amount of space to process things at one time, then adding multiple targets of focus makes it more difficult on the mind, and thus making performance poor.

I think this video and experiment is a humbling experience for most people. We take advantage of our mind’s capacity on a daily basis, and because of this, we tend to believe that we are incapable of missing details in our environment that seem so obvious. However, we are not limitless in what we can process.

If you find videos like “The Invisible Gorilla”, here are a few more selective attention tests that you can try.