Change Blindness: Definition & Examples Video

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: The Retinex Theory of Color Vision

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:02 What Is Change Blindness?
  • 0:44 Experiments
  • 1:40 Inattentional Blindness
  • 2:57 Causes
  • 4:25 Importance
  • 5:18 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: David White
Change blindness is a fascinating phenomenon that most people experience throughout their lives. Through this lesson, you will learn how to define change blindness and explore some of the ways that it operates in the real world.

What Is Change Blindness?

Have you ever been so engrossed in a conversation at a party that you failed to notice that someone new is standing only six inches away from you, trying to get your attention? It's possible that you were so distracted that you didn't notice someone approaching you. But it's also entirely likely that you were experiencing change blindness.

Change blindness is a phenomenon that occurs when a person is unable to notice visual changes in their environment, despite the fact that they are often rather obvious. In cases of change blindness, the person isn't failing to notice small or insignificant changes, but will probably miss big changes, like someone standing next to them waving their hand.


Early experiments with change blindness focused largely on memory and perception when viewing pictures. For example, a person might be shown a photograph of a street scene in Egypt and told to memorize the image. Following that, they would be shown the same picture with certain elements added or taken away and asked to identify what's different. Very often the individual could recall the larger aspects of the picture but couldn't recognize the smaller changes.

An inability to recognize every change in a crowded or complicated picture is generally attributed to the brain's capacity to remember complex images in a broad scope. For example, they might remember looking at a picture of a crowded street with stores and restaurants, but they probably wouldn't notice that the names of the stores had changed. In general, this is because the brain cannot possibly process every element of an experience and has to prioritize what it believes to be important.

Inattentional Blindness

In the 1990s, researcher Daniel Simons conducted a fascinating study into change blindness that many people find unbelievable. In Simons' study, he asked participants to watch a video of a basketball being passed around between several people, with a particular focus on the basketball itself. When the experiment was over, Simons found that a large number of participants were so focused on watching the basketball being passed around that they failed to notice a man in a gorilla suit jumping around in front of the camera.

It's important to note that the change in Simons' video wasn't subtle. The gorilla is very obviously taking up much of the frame. Simons concluded that participants were experiencing inattentional blindness, which is when a person fails to notice a major change because they are so focused on another task. In this case, because participants were asked to focus on the movement of the basketball, their brains prioritized that task in order to do it properly, thereby missing the other things happening in the video.

In the case of Simons' study, participants engaged what's referred to as attentional selection, which is when a person selects certain things to focus on in order to achieve a task and filters out anything that is unrelated to the objective.


There are a number of theories about what causes a person's inability to recognize obvious changes in their environment, but most agree that the phenomenon is related to sensory processing. Broadly speaking, our brains have a limited capacity to detect and process everything in our environment. Instead, what the brain does is choose certain things to process, evaluate, and store, which allows other things to be missed or filtered out.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account