20 trials
Correct: 0
Avg. RT: —
Best: —
Stroop Test
Color words appear in various colors.
Choose the color the word is displayed in — not what the word says.
20 trials. Accuracy and average reaction time are measured.
Choose the color the word is displayed in — not what the word says.
20 trials. Accuracy and average reaction time are measured.
How to Play
- Press Start and color words (RED, BLUE, GREEN, YELLOW) appear in a different color.
- Choose the color the word is displayed in from the four buttons — not what the word says.
- 20 trials, mixing congruent (word matches color) and incongruent (word differs from color) questions at random.
- After each answer, correct/wrong feedback appears and the next question follows automatically.
- At the end, your level is judged from accuracy (%) and average reaction time (ms).
Score Guide
The Stroop test measures cognitive control and interference suppression. The average score is 70-85%.
SS
Phenomenal
Perfect cognitive control.
100% and <800ms
S
Excellent
Strong interference suppression.
95〜100%
A
Great
Above-average cognitive control.
85〜94%
B
Average
A standard result — the Stroop effect gets to you.
70〜84%
C
Below average
Practice will improve this.
50〜69%
D
Keep practicing
Take it slow and steady.
0〜49%
Last 10 Scores
No history yet. Press Start and give it a try.
What Is the Stroop Test?
The Stroop Test is a cognitive test based on the 1935 paper "Studies of Interference in Serial Verbal Reactions" by American psychologist John Ridley Stroop. The slowdown that occurs when a word\u2019s meaning conflicts with its display color is called the Stroop effect — one of the most replicable phenomena in cognitive psychology, still widely used in research and clinical practice more than 90 years after its discovery.
How the Stroop Effect Works
The Stroop effect arises from two competing processes in the brain. Reading is highly automated, demanding almost no conscious effort; recognizing the display color requires deliberate attentional control. When the two conflict (the word BLUE shown in red), the prefrontal cortex — especially the anterior cingulate cortex (ACC) — must suppress the interference and select the correct response (the display color).
This interference-control process sits at the core of executive function, deeply linked to selective attention, response inhibition, and cognitive flexibility. The Stroop test measures these abilities simply and reliably, giving it an important place in neuropsychological assessment.
Everyday Relevance
The cognitive control the Stroop test measures shows up throughout daily life: multitasking, restraining impulsive reactions, and flexibly switching attention all draw on interference suppression. Clinically, it is used in ADHD assessment, cognitive screening for older adults, early dementia detection, and rehabilitation evaluation after brain injury.
How to Score Higher
- Don\u2019t read the word: deliberately ignore its meaning and lock onto the color. View the text softly and extract only the color information.
- Focus on the display color: attend to the color itself, not the letterforms. Sense the color with your peripheral vision and avoid reading with your central vision.
- Keep a steady rhythm: answer at a constant tempo without rushing. Haste drags you back toward the automatic response (reading).
- Practice repeatedly: interference suppression improves with training. Cognitive control is a trainable ability.
Frequently Asked Questions
Q. What is an average score?
A. Typical adults score 70-85% accuracy. On incongruent trials, accuracy drops and reaction times stretch — that is normal. Above 95% indicates outstanding cognitive control.
A. Typical adults score 70-85% accuracy. On incongruent trials, accuracy drops and reaction times stretch — that is normal. Above 95% indicates outstanding cognitive control.
Q. Why are the mismatched trials so hard?
A. Reading is so automated that suppressing it takes real effort. Seeing BLUE, the brain automatically processes blue, conflicting with the display color. Suppressing that interference engages the prefrontal cortex, stretching reaction times and adding errors.
A. Reading is so automated that suppressing it takes real effort. Seeing BLUE, the brain automatically processes blue, conflicting with the display color. Suppressing that interference engages the prefrontal cortex, stretching reaction times and adding errors.
Q. Does practice help?
A. Yes. Repetition improves interference suppression, likely as the prefrontal control circuits grow more efficient. Reducing the Stroop effect to zero is rarely possible — some interference remains in everyone.
A. Yes. Repetition improves interference suppression, likely as the prefrontal control circuits grow more efficient. Reducing the Stroop effect to zero is rarely possible — some interference remains in everyone.
Q. Does age matter?
A. Yes. The effect tends to be larger in children (developing prefrontal cortex) and older adults (declining executive function). Performance peaks in the 20s-30s, then declines gently.
A. Yes. The effect tends to be larger in children (developing prefrontal cortex) and older adults (declining executive function). Performance peaks in the 20s-30s, then declines gently.
Q. How does this differ from reaction time or chimp tests?
A. A reaction test measures reflexive speed; the chimp test measures spatial working memory. The Stroop test measures interference suppression — inhibiting the automatic response (reading) to choose the deliberate one (naming the color). Fundamentally different cognitive resources.
A. A reaction test measures reflexive speed; the chimp test measures spatial working memory. The Stroop test measures interference suppression — inhibiting the automatic response (reading) to choose the deliberate one (naming the color). Fundamentally different cognitive resources.