One attempt per challenge. Finish each stage in order to unlock the next.
Complete 32 scored rounds. Every round counts.
Latest run
Challenge complete
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Each ability contributes equally to the Arena score.
CFX · Attention
Start 32 scored rounds directly. Follow the current color or shape rule. Left means blue circle; right means orange triangle. Use the buttons or arrow keys.
If you press before the figure appears, that trial counts as incorrect and the next trial follows. If you do not answer in time, it counts as a miss. Results stay on this device.
The main score is your overall accuracy, plus the median response time on correct trials measured with performance.now(). Human Arena also reports repeat versus switch accuracy, repeat and switch medians, the switch cost, and rule-maintenance errors. Higher accuracy and lower time are better.
Attention, fatigue, screen refresh rate, input hardware, and browser work can all shift a result. Treat the number as an entertainment and general-information measurement, not a medical, diagnostic, neurological, or IQ assessment.
Cognitive Flexibility Test measures task switching: how quickly you can follow one rule and then switch to another. It trains and reflects mental flexibility, not intelligence or overall ability.
Every figure uses both a color and a shape, and the response buttons are labeled with both. That means the task never relies on color alone, so it stays fair for color-blind players and for screen readers that announce the figure description.
This is a game result, not an IQ score or diagnosis. Read the scoring methods and measurement limits.
It measures cognitive flexibility: how quickly you can follow a rule, then switch to a different rule and keep responding accurately. Each round tells you whether to match by color or by shape.
Switching rules is the challenge. When the rule changes, your brain has to let go of the old rule and apply the new one. That small adjustment is what makes switch trials a little slower.
Switch cost is the difference between your median time on rule-switch trials and rule-repeat trials. It is shown as an explanatory difference, not the only result.
These are wrong answers on a switch trial where you accidentally used the previous rule. They show when the old rule was still active in your mind.
Only approximately. Screen size, input hardware, browser work, and touch latency can all shift measured time.
Choose another skill to practise as a separate test.
Alternate the relevant classification rule and compare repeat trials with switch trials.
Independent color and shape attributes allow the two rules to demand different responses. Our randomized cues differ from the paper's predictable letter/digit switching protocol.
Accuracy, repeat and switch timing, descriptive switch difference and previous-rule errors.
Research informs the task design. It does not validate this implementation, its game-point scales, or the five-ability profile. Read our methodology →