Go/No-Go Test

The letters decide; the colour does not

A colour-only panel is a simple reaction test with a costume. This one writes the instruction on the stimulus. GO on a red field is still go. NO on a green field is still withhold. Following the paint instead of the word is the mistake the block is built to catch.

The charted score stays a mean of GO times. Accuracy is printed next to it: hit GO and leave NO. A tap on NO costs accuracy, not milliseconds on the hits you already made. Mixing those into one adjusted number would hide whether you read the word.

That split is the honest one for a chart. A distribution of GO times can sit next to the simple-reaction curve and mean something. A distribution of “score after penalties” would mean whatever the penalty rule said that week.

Why a quarter of the trials say NO

If every word were GO the test would collapse into simple reaction with extra ink. If half were NO, people start waiting to read, and the GO times stop being reaction times. A quarter is enough that withholding is required and not so many that waiting becomes the strategy.

The words are placed at random, not on a rhythm, and the tint is chosen independently. A fixed pattern would be learned by the third block and the test would measure memory of the schedule.

Twenty trials rather than five, because a rare word needs a longer run before the voids stop dominating the story the card tells.

What the chart is allowed to claim

It claims that, among people who took this browser test in the same input mode, this is where your GO-time sat. It does not claim anything about impulsivity, attention, or fitness to drive. Those words belong to clinicians and this page will not borrow them.

A run with no valid GO hits — every go missed or every trial voided — produces no score. That is rarer than it sounds and it is refused rather than recorded as a miracle time.

The margin uses the same refresh-rate probe as the rest of the site. Reading a word does not change the physics of the display.

This is a measurement toy, not a medical or psychological test. No score here says anything about your health, attention or cognition, and it is not a screening tool of any kind.

Questions

Do I go on green, or on the word GO?

On the word. GO on a red field is still a go. NO on a green field is still a withhold. Colour is there to pull the other way.

Does tapping NO make my time worse?

It does not add milliseconds to the GO words you hit. It does count against the accuracy printed next to that time.

Is this an attention or impulsivity screen?

No. It is a browser game with a chart. Nothing here is a clinical instrument.