Objective: Scan the grid and mark every target as quickly and accurately as possible — the classic cancellation task used to measure visual scanning, selective attention, and processing speed.
How it works:
- The target letter or symbol (one or two of them, depending on your setting) is shown above the grid
- Tap every cell containing a target — found targets turn teal
- Tapping a non-target counts as an error and marks the cell red; each wrong cell is only counted once
- The test ends automatically when every target is found, or press Finish if you believe you're done — any targets you missed are then highlighted in gold
About this test:
- Cancellation tasks are a standard tool in neuropsychology — a version of this task is the supplemental processing speed subtest in the WAIS-IV battery, alongside digit symbol coding and symbol search
- Performance reflects a trade-off between speed (targets per minute) and accuracy (errors and misses) — track both over time, not just the clock
Tips:
- Scan systematically — row by row like reading — rather than jumping around; skipped regions are where misses hide
- With two targets, resist checking each cell against both at once; many people are faster making two passes, one target per pass