Go/No-Go Reaction Test
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10 trials — respond to GO, hold still on WAIT
What is a Go/No-Go Test?
A Go/No-Go test measures impulse control by mixing two kinds of signals: "go" signals you should react to, and "no-go" signals you should ignore. Reacting to a no-go signal counts as a mistake, even if it's fast. This makes it fundamentally different from a simple reaction test, where speed is the only thing that matters.
The task was first developed in experimental psychology in the mid-20th century and is now one of the most widely used tools for studying response inhibition -- your brain's ability to stop an action that's already been triggered.
Speed vs. Accuracy
Unlike a simple reaction test, going faster isn't always better. If you react to every signal without thinking, you'll rack up errors on the no-go trials. The goal is a balance: quick reactions when you should respond, and restraint when you shouldn't. Researchers call this the "speed-accuracy tradeoff," and it's a core concept in cognitive psychology.
Healthy young adults typically average about 280-320ms on go trials in a standard Go/No-Go task. That's roughly 50-100ms slower than a simple reaction test, because your brain needs extra time to check whether the signal is a "go" before committing to a response. The Baltimore Longitudinal Study of Aging found that this type of "disjunctive" reaction time slows at about 1.6ms per year -- roughly three times faster than simple reaction time.
What It Tells You
Go/No-Go performance reflects executive function -- the set of mental skills that help you plan, focus, and control impulses. Research published in PLOS ONE has shown that the variability of your reaction times (not just the average) is a useful marker for how well these executive processes are working. More consistent times generally indicate better attentional control.
Clinicians use versions of this test to assess conditions like ADHD, traumatic brain injury, and age-related cognitive decline. In research settings, Go/No-Go error rates and reaction times help separate people who are genuinely fast from people who are just impulsive.