Stroop Test
Name the ink, not the word
Start training freeFree to start. Plays in your browser, no download.
What is the Stroop Test?
The Stroop Test is one of the best known tasks in psychology. A colour word such as RED is printed in a different ink, say blue, and you have to name the ink rather than read the word. John Ridley Stroop described the effect in 1935, and people have been tripping over it ever since. Reading is so automatic for adults that the printed word keeps pushing its way into the answer.
Researchers use the Stroop Test to measure inhibitory control: how well someone can hold back a habitual response and give a less automatic one instead. Versions of it appear in laboratory studies and in clinical assessment batteries. The Neuroptimize version is a fast, 45 second Stroop game. You tap the ink colour of each word, and at higher levels a cue sometimes switches the rule so that you tap what the word says instead.
How to play the Stroop Test
- A colour word appears in the middle of the screen, printed in a coloured ink. A cue above it says "Tap the INK colour", and a row of colour buttons sits below.
- Tap the button that matches the ink, not the word. On a keyboard you can press the number shown on each button instead. Every tap moves straight on to the next word, and a wrong tap breaks your combo.
- You have 45 seconds to answer as many words as you can. Your average reaction time on correct answers is shown at the end.
- Early levels use two colours with solid colour buttons, and many words match their ink. As the level rises you get up to six colours, and fewer words match their ink.
- From level 8 the buttons show colour names instead of solid swatches, and from level 12 those names are printed in the wrong ink, so the buttons themselves become a Stroop test.
- From level 15 some trials say "Tap what the WORD says" instead. The cue changes colour and icon when the rule flips. From level 24 the button order is also shuffled on every word.
Strategies and tips
Read the cue first
Once word trials appear at level 15, glance at the cue before the word on every trial. The cue only changes when the rule flips, so a quick check is enough, but skipping it is the most common way to lose a combo.
Blur the letters slightly
On ink trials, try to take in the word as a patch of colour rather than a string of letters. Some players look at the edge of the word or soften their focus so the reading habit has less to grab onto.
Learn the button positions
Until level 24 the buttons stay in the same order, so you can learn where each colour lives. Tapping by position is faster than reading the button labels, which from level 12 are printed in misleading inks anyway.
Use the number keys
On a computer, each button has a number from 1 upwards. Resting your fingers on the keys removes the hand travel of tapping and lets you focus on the word itself.
Trade a little speed for accuracy
The level adapts to your accuracy, not just your score: 90% or better moves you up two levels, while under 55% drops you one. A steady pace with few mistakes climbs faster than rushing and guessing.
The science behind the Stroop Test
The Stroop effect, described by John Ridley Stroop in 1935, is the delay in naming the ink colour of a word when the word itself names a different colour. Because reading is largely automatic, the task requires suppressing a habitual response. It is one of the most widely used measures of inhibitory control.
Frequently asked questions
What does the Stroop Test measure?
The Stroop Test measures inhibitory control, the ability to suppress an automatic response in favour of a less automatic one. The key result is how much slower and less accurate people are when the word and the ink conflict than when they match. That difference is called the Stroop effect.
Why is the Stroop Test so hard?
For fluent readers, reading a word happens almost automatically, while naming an ink colour takes a deliberate step. When the two disagree, the word competes with the colour and you have to override it. That competition is what makes mismatched trials feel slow and error prone.
What is the difference between congruent and incongruent trials?
A congruent trial is one where the word and the ink match, such as RED printed in red. An incongruent trial is one where they differ, such as RED printed in green. In Neuroptimize, low levels include many congruent trials and higher levels are mostly incongruent.
Is the Neuroptimize Stroop game free?
Yes. The Stroop Test game is available on the free plan from the start. Like every Neuroptimize game it has 30 difficulty levels that adjust after each session.