The Brains Behind 'Where's Waldo?'
Have you ever wondered what makes you notice a certain person or object when you're rushing along in a crowd? Why do some things stand out whereas others melt into the background? In this activity you can explore the psychology of how things get noticed by studying how our brains help us perform a visual search. Specifically, you'll look at how changing the number and type of visual distractions affects a person's ability to find what they're looking for.
This activity is not appropriate for use as a science fair project. Good science fair projects have a stronger focus on controlling variables, taking accurate measurements, and analyzing data. To find a science fair project that is just right for you, browse our library of over 1,200 Science Fair Project Ideas or use the Topic Selection Wizard to get a personalized project recommendation.
Have you ever looked for something you really need to find—quickly? The classic example is when someone loses a set of keys. This frustrating situation is the perfect example of performing what cognitive psychologists call a visual search. During a visual search, an observer (the person who is searching for the keys, for example) looks for a target (the keys) in the midst of distracters (all the other stuff in a home). By making the target easier to see, such as by putting the keys on a big, bright red key chain, the observer could improve on their visual search and improve its chances of success.
What properties are important for performing a successful visual search? Consider the following exercise to help you think about the variables: If you had a printed page full of letter L’s in blue ink and just one letter T in red ink, it would be pretty easy to find the red T, right? However, what if half of the L’s were blue and half were red? In the latter situation, there are more complex distracters, making finding the target (the red letter T) more difficult.
Extra: Repeat this activity but try changing some different variables and see how it affects reaction time and the percent of the answers that are correct. You could try changing the number of targets instead of distracters. Is it easier or harder to spot multiple targets? You could also measure percent correct instead of response time. Do people give fewer correct answers as more distracters are present? Try changing the number of images by changing the number of rows and columns. Is it harder to find the target when there are more images? You could also try changing the images, such as using symbols, letters or numbers instead of types of food, or change the colors of the target and distracter. Is it harder to find the target as its similarity to the distracters increases?
Extra: This cognitive test has real-world applications that you could investigate. Look into how logos and brand names are designed to be noticed, the way Web sites are designed to be easy to navigate, how points of interest on a map are marked or other data are displayed in a way that highlights what's important. How are visual search properties used in these different areas?
Observations and Results
Did the reaction time increase as more distracters were added? Did it take longer for volunteers to answer when the target was absent compared with when it was present?
You should have seen that, in general, the reaction time needed to do the visual search increased as more distracters were added. (There may have been some exceptions, such as a person taking only slightly longer to do a visual search with three distracters present in comparison with four, but it should have clearly taken a good deal more time to find the target when there were four distracters compared with when there was just one.) When more distracters are present, it makes finding the target more difficult. (Think of the example with the red letter T target and letter L distracters that became more distracting when they changed from all blue to half red.) This makes people take more time in their visual search, even if the target is not there. In fact, you should have seen that people actually take more time when the target is absent compared with when it is present, as they may spend more time checking and rechecking to make sure that the target is really not there.
More to Explore
Cognitive Science Software: Visual Search, from Tom Busey at Indiana University Bloomington
Teisha Rowland, PhD, Science Buddies
Science Buddies |
Visual search, perception, distractions, reaction time
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