What is the Stroop effect?
The Stroop effect is the delay and extra errors that happen when you name the ink colour of a word whose meaning names a different colour. It shows how strongly reading competes with a simpler colour-naming task, even when reading is not required.
A word fighting its own colour
In 1935, the psychologist John Ridley Stroop published an experiment that is still run today. Show someone a colour word, like “blue”, printed in a colour of ink, and ask them to name the ink colour out loud. When the word and the ink agree, this is easy. When they disagree, people are reliably slower and make more mistakes.
That slowdown is the Stroop effect. It is small on any single trial, usually a few hundred milliseconds, but it is remarkably consistent across people, languages and testing methods.
Why reading gets in the way
For a fluent reader, reading a word is close to automatic. Naming an ink colour takes a little more deliberate effort. When those two processes disagree, the automatic one intrudes on the slower one, and the extra time your brain spends resolving that conflict is what gets measured.
Try it
The word BLUE, printed in red ink. Name the ink colour.
This is Colour Conflict, the Brain Gym version of the Stroop task.
What a Stroop score measures
Colour Conflict shows colour words printed in colours of their own. Your score reports the interference cost, the gap in reaction time between conflicting and matching trials. This is a task-specific score, not an IQ test and not a medical measure.
Try Colour Conflict