Go / No-Go
A shape flashes on screen. Click for green circles, resist clicking for red squares. Tests impulse control.
This task measures response inhibition — the ability to suppress a prepotent response. It's a core measure of executive function used in ADHD research.
d-prime combines your hit rate and false alarm rate into a single sensitivity score, separating true ability from response bias.
| 😴 | Sleep | Sleep deprivation increases false alarms dramatically. |
| 🍷 | Alcohol | Even small amounts impair inhibition control. |
| 🏃 | Exercise | Acute exercise improves inhibitory control. |
| ⏰ | Time of Day | Inhibition is strongest in the morning hours. |
Go/No-Go Test Online (Inhibitory Control)
The Go/No-Go test is a cognitive reflex assessment designed to measure your motor suppression and response inhibition capabilities. During this test, shapes flash rapidly in the center of the screen. When a green circle (the "Go" signal) appears, you must click as fast as possible. However, when a red square (the "No-Go" signal) appears, you must suppress your click reflex and hold back. This test measures how effectively your brain can cancel an already planned motor action.
How the Go/No-Go Task Works
- Click Start Test. A crosshairs symbol (+) will appear in the center of the box.
- Shapes will flash quickly at random intervals.
- Click or tap the screen as fast as possible only when you see a green circle.
- Do NOT click when you see a red square. Hold back your finger.
- The test consists of 20 trials, with a mix of Go and No-Go stimuli. Once completed, your reaction speed and response accuracy are calculated.
Understanding Your Score: d' and Response Inhibition
Your results are calculated using d' (d-prime), a metric from Signal Detection Theory. This score represents your brain's sensitivity in distinguishing Go signals from No-Go signals. The assessment tracks three key metrics:
- Hits: Correctly clicking on green circles.
- False Alarms: Accidentally clicking on red squares (representing a failure of impulse control).
- Go RT: Your average reaction time (in milliseconds) on correct Go clicks.
An elite score combines a very fast Go Reaction Time with zero False Alarms, demonstrating perfect motor control under pressure.
Go/No-Go Score Table
| Cognitive Tier | d' (Sensitivity Score) | Percentile Bracket |
|---|---|---|
| Exceptional | >= 3.0 d' | Top 10% |
| Good | 2.2 – 3.0 d' | Top 25% |
| Average | 1.2 – 2.2 d' | Middle 50% |
| Developing | Under 1.2 d' | Bottom 25% |
The Neurology of Impulse Control
Response inhibition is an essential component of the brain's executive functions. It is regulated by the right inferior frontal gyrus and the pre-supplementary motor area (pre-SMA). When a Go stimulus appears, the motor cortex immediately prepares a signal to move your finger. When a No-Go stimulus is detected, the pre-SMA sends a rapid inhibitory signal to cancel the motor command. If this signal is too slow, a False Alarm occurs.
Strategies for High Impulse Control Scores
- Keep Your Finger hovering slightly: Position your mouse finger or tap thumb slightly above the button. A relaxed, hover position allows for rapid activation but prevents accidental trigger clicks compared to resting your finger directly on the surface.
- Focus on the Red: Because the green circle represents a highly frequent, automatic action, prime your brain to detect the *red square*. Think of "Stop" as the priority trigger, and let your green reactions handle themselves naturally.
- Avoid Clicks in Anticipation: Never try to predict the flash pattern. The stimulus intervals are randomized to prevent clicking based on rhythm.
- Beware of Stimulants: Excessive caffeine or energy drinks can speed up your average reaction time but can significantly impair your inhibitory control, causing more false alarm errors.
Go/No-Go FAQ
What is the difference between a reaction time test and a Go/No-Go test?
A simple reaction time test only measures processing speed (clicking as soon as you see a color change). A Go/No-Go test requires choice and cognitive control, you must process the shape/color and decide whether to act or withhold action, adding a layer of executive processing.
How is this test used to screen for ADHD?
In clinical settings, Go/No-Go assessments are used to measure response inhibition deficits. Individuals with ADHD typically show normal reaction speeds but significantly higher false alarm rates because their brain's frontal circuits struggle to inhibit motor commands in time.
Does sleep deprivation affect my score?
Yes. The prefrontal cortex is the first brain region to suffer from sleep loss. Being sleep-deprived degrades your ability to inhibit actions, causing a dramatic surge in false alarms and slower overall reaction speeds.