After we learn to read, recognizing words becomes an automatic behavior that our brains can process much faster than recognizing colors. For example, say these words: Red. Green. Blue.

So what happens when we introduce conflicting word and color information to your brain? For example, name the colors that you see here: Red. Green. Blue.

Is it harder to say the colors than to read the words? That’s the Stroop effect — “a demonstration of interference in the reaction time of a task.” From Science World at TELUS World of Science, an explanation and a demo of the Stroop Test in the video above.

Related watching: How do your eyes perceive color? How many smells can you identify? and How does playing an instrument benefit your brain?