Cancellation Task: Sweep the Field, Miss Nothing
A cancellation task drops you into a dense field of characters and asks you to cross out every instance of one target. It's deceptively simple: the difficulty isn't seeing any single target, it's covering the whole field without losing track of where you've already been. That's why what you miss says more than what you find. Free to play, scored instantly, no sign-up required.
Not a diagnostic tool. Cancellation tasks come from neuropsychology, where standardised versions help screen for conditions such as hemispatial neglect. This is a simplified version for practice and self-tracking — it is not validated or normed, and it cannot screen for or diagnose anything.
A quiet round of Cancellation Task — Letters. When you start, everything else fades — just you and the task.
No sign-up needed. Press Esc to exit anytime.
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How to play
- A target character is named at the top — every copy of it is hidden in the grid below.
- Tap each one you find. Wrong taps count against you.
- Work systematically — row by row beats hunting at random.
- Tap Done when you think you have them all. Missed targets are part of your score.
Frequently asked questions
What does a cancellation task measure?+
Visual scanning efficiency and selective attention — how quickly and how systematically you can sweep a cluttered field for one specific thing. Because you have to cover the entire field rather than stop at the first hit, it also draws on keeping track of where you've already looked.
How is this different from a visual search test?+
A visual search test gives you one target per round and ends the moment you find it, so it measures how fast you can spot a single item. A cancellation task asks you to exhaust the whole field, so it also measures whether your scanning has a strategy. Missing three targets in a corner you never swept is a different failure from being slow.
Should I go fast or be thorough?+
Both count. The score multiplies your accuracy — which penalises misses and wrong taps alike — by your speed, so racing through and leaving half the field unswept scores worse than a steady, complete sweep.
Is this a medical or diagnostic test?+
No. Cancellation tasks come from neuropsychology, where clinicians use standardised versions to screen for conditions such as hemispatial neglect after a stroke. This is a simplified version built for practice and self-tracking. It is not validated, not standardised, and cannot screen or diagnose anything. If you have concerns about your attention or vision, talk to a professional.
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