The Stroop Effect

What is the color of each words below? Say the name of each color aloud as you look at each word:

Green  Red  Blue  Purple  Blue  Purple

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Now do the same thing for the words below. Don't read the words. Just say the name of the color of type used for each word.


Blue  Purple  Red  Green  Purple  Green

For most people, the second task is more difficult. It takes longer to name the colors when the word doesn't match the color, and mistakes happen more often.

This experiment was first conducted by John Ridley Stroop in 1935, and has been used to understand how different pathways of information can interfere with each other in the brain. 

One explanation for why we have such a hard time sorting out the conflicting information is that it takes us longer to identify the color names than it does to read the words, so the brain has to go back and reconfigure each guess.

-----Wikipedia on the Stroop Effect