Have you ever walked into your bedroom and noticed a slight difference but could not pin-point exactly what had changed since the last time you were in the room? What about if you were finding the 12 significant differences between two photos in the second glance section of the Washington Post magazine? Both these examples are of change blindness. The visual processing that occurs in change blindness is when someone is unable to detect the precise changes in settings that they’re looking at directly. The reason behind this phenomen is because our brain fills in the slight differences to make us not process these changes until we actually focus on the image.

For example, if we were looking at two images that pretty much looked exactly the same but instead of someone wearing a green colored shirt in one photograph, they are wearing a blue colored shirt in the other photograph. However, our brain skips over this difference and we don’t even realize we are making this mistake. This concept can commonly happen because our brain processes visual stimuli so quickly that we don’t visually pick up on these changes between these two pictures. In the picture above, we see two scenes that pretty much show the same stimuli but there are a few differences between both the photos. Until further examination, do you begin to notice the little differences between the two pictures. For example, in the first photo the man in the white tank top is wearing a gold watch but in the second photo, there is no gold watch on his wrist.  Some of my research about change blindness tries to understand why this concept even happens on a regular basis. Researchers ask questions like what sorts of changes did they miss? Under what conditions? What are the limits of their ability to remember these scenes? With what attention do we hold onto to these visual details? These are all valid questions when it comes to trying to piece together how change blindness evolves in the visual cortex of the brain.

 Why can’t you notice direct changes that are directly in front of you at first glance? New York Times writer Natalie Anger writes in Blind to Change, Even as It Stares Us in the Face how visual stimuli is processed during change blindness. Anger argues that the two key processes that occur during in change blindness is top-down processing and bottom-up processing. During bottom-up processing a person is more likely to see a stimuli popping up in view like their friend was waving at them from across the room. Although, the top-down processing is harder to detect. Top-down processing requires someone to really focus on the stimuli in front of them. Angier references what Dr. Jeremy Wolfe of Harvard Medical School had to say about this concept. Wolfe says, “The basic problem is that far more information lands on your eyes than you can possibly analyze and still end up with a reasonable sized brain”(Angier). What Wolfe is saying here is that our brain can only handle so much information at once. Which is why sometimes people can skip over stimuli that is right in front of them.

Let’s dig deeper into more change blindness examples. In several magic tricks, the magician performs a task that makes the participant think they are perceiving one action take place but they’re not paying enough attention to process the actual trick the magician is executing. Our brain tricks into this misconception. In addition, sometimes the magician might be distracting the participant by talking to them or make them focus their attention on something else during the magic trick. Once the trick is over, we think the answer is obvious but it is not until that we really focus that we realize we were compliantly “blind” during the whole trick. This is exactly how magicians decieve people into their tactics of change blindness.

I think change blindness can be applied in most every day situations. Overall, the human brain can only retain so much rapid information at a constant period. Which is why you’re more likely to not see every single difference that you encounter. Even if when you think you feel like you have all your attention on certain type of stimuli in front of you, you can still miss a small detail that passes by faster for you even to process and retain it later. The important thing to remember about change blindness is that its okay to miss some stimuli that appears in front of you, as long as it doesn’t become a habit in which it takes you longer for you to process every single type of stimuli.


Young, J. (2016, February 21). Second Glance. Washington Post Magazine. from

Angier, N. (2008, April 1). Blind to Change, Even as It Stares Us in the Face. New York Times. from

Simons, D. J. (2000). Current Approaches to Change Blindness. Visual Cognition, 7(1-3), 1-15. Doi:10.1080/135062800394658