Green Light · Go/No-Go Impulse Test
The panel flashes green or red. Green: tap as fast as you can. Red: do absolutely nothing. Simple — until your finger disagrees.
How to play Green Light
For 45 seconds the panel flips between green and red at unpredictable intervals. Tap green quickly for +1 point. Tapping red — a false alarm — costs 2 points. The tension between speed and restraint is the whole game.
What it measures
Green Light is a go/no-go task, one of the most widely used laboratory measures of response inhibition — the brain's braking system. Because most trials are 'go', your motor system builds momentum, and stopping on the rare 'no-go' trial takes genuine top-down control.
Honest note: A couple of false alarms is human — the task is designed to lure your finger. Zero false alarms with a slow average usually means you're waiting too long on green.
What's a good score?
Scores in the mid-20s are typical; 35+ with few false alarms means both your accelerator and your brakes are in good shape. The percentile we show is an estimate based on typical distributions, not a clinical norm.
FAQ
Why do I keep tapping red?
The task stacks the odds against you: green appears far more often, so your motor system pre-loads the tap. Inhibiting that prepared response is exactly the skill being measured.
Is faster always better?
No — the score balances speed on green against restraint on red. A slightly slower, cleaner run usually beats a twitchy one.