Vigilance test

Can you keep watching?

Watch a clock for ten minutes and press when the hand jumps twice as far as usual. It's less fun than it sounds, which is the point.

This is a game, not a medical test, and it can't tell you anything about your health or your brain. We don't compare you with anyone. It relies on seeing the moving hand, so it isn't usable with a screen reader.

Where this comes from

During the Second World War, radar operators watched screens for rare blips, and they missed more of them as a watch went on. Norman Mackworth studied why using a clock of his own design: a hand moved in short steps, about once a second, and now and then it jumped twice as far. People pressed a button when they saw it. Sessions typically ran for two hours, and accuracy fell notably after about half an hour.

This version is much shorter and isn't a research tool. Double jumps come rarely and at random, so you can't get into a rhythm.

What to look for in your results

The table splits your session into two-minute blocks. Researchers call a slide in catches over time the vigilance decrement. Ten minutes may be too short to show one, and a few jumps in a block is too few to mean very much. A decline, if you see one, tells you that watching a clock is boring.

Prefer a longer version?

This is a warm-up for Don't Close the Tab, where you get on with your day and the phone rings every 1 to 5 minutes for as long as you last. We've also written about attention span tests and what they do and don't tell you.