This is not a medical or screening tool
First things first: nothing on ReactionBench can diagnose ADHD, concussion, or any other condition. Worried about attention, memory or focus, for yourself or for a child? Talk to a doctor or a qualified clinician. A validated clinical assessment weighs far more than how quickly you click a button, and this page exists to state that gap honestly rather than soften it.
Reaction tasks in attention science
For more than a century, psychologists have treated reaction time as a rough index of how fast the brain registers a signal and acts on it. Within attention research, though, the interesting number is rarely a single fast click. What matters is whether speed and accuracy hold up across many trials, and whether someone can halt a response already in motion. Two families of task carry most of the load in this field, and this site's go/no-go and 5-choice tests are the nearest available cousins of each.
Continuous performance tasks run a long, repetitive stream of stimuli: you respond to most and withhold on a rare few, while the task tracks whether speed and accuracy drift as minutes pass. Rosvold and colleagues designed the paradigm in 1956 to study lapses of sustained attention following brain injury. It has grown into one of the most widely used tools in attention research as a whole, ADHD studies included but by no means exclusively. Closest here: the go/no-go test. Choice and inhibition tasks take a different route, presenting several possible signals that each demand a different response or none at all, which probes decision speed and the ability to suppress the wrong, faster answer. Donders' 19th-century mental-chronometry work gave rise to the go/no-go paradigm, while Logan and Cowan formalised the closely related stop-signal task in 1984 as a race between a "go" process and a "stop" process. Closest here: the 5-choice test.
These tests exist for curiosity and self-benchmarking, not assessment. Calibrated hardware, controlled rooms, age-matched norms and trained scoring are what validated clinical batteries bring. None of that is reproducible on a web page.
What a reaction test can — and can't — hint at
Handled honestly, a handful of metrics gathered across repeated runs can be interesting to you personally as a baseline to follow. None of them are evidence of anything clinical.
| Signal | What it is | How much it tells you |
|---|---|---|
| Median reaction time | Your typical speed on a given day | Meaningful only against your own past runs on the same device — never an absolute verdict |
| Consistency (spread) | How much your rounds vary | More telling than raw speed, though wide variation may just mean fatigue, boredom or distraction |
| False starts | How often you respond before the signal | Worth noticing as a personal habit; on its own a single session tells you almost nothing |
| Drift over a session | Whether you slow down toward the end of a long run | Everyone drifts a little — a laggy tab or a noisy room yields the same pattern |
The gap between a home game and a clinical diagnosis
Diagnosing an attention condition such as ADHD takes trained clinicians working from a structured history, observations gathered across multiple settings, standardised rating scales, and a picture assembled over months rather than minutes. At most, reaction tasks amount to one supporting data point among many. Even the purpose-built continuous performance tests used in clinical research are recognised as sensitive but not specific: tiredness, low motivation or an unrelated condition can produce poor performance just as readily as an attention disorder can. Hence clinical guidance treats them as a supplement to a full assessment and never a replacement for one.
Four gaps separate a browser game from a real evaluation. One setting, one moment: clinicians examine behaviour across home, school and work over time, whereas a session here captures a single moment on a single device. No calibration: clinical tools run on controlled hardware with age-matched norms, while an ordinary monitor and mouse contribute their own uncontrolled latency. Confounds everywhere: sleep, caffeine, mood, practice and a slow connection shift a score far more than any underlying trait could. No trained scoring: professionals interpret real assessments alongside history and rating scales, rather than an automatic grade badge doing it for them.
- 01Rosvold, H. E., Mirsky, A. F., Sarason, I., Bransome, E. D., & Beck, L. H. (1956). A continuous performance test of brain damage. Journal of Consulting Psychology, 20(5), 343-350. Rosvold, H. E., Mirsky, A. F., Sarason, I., Bransome, E. D., & Beck, L. H. (1956). A continuous performance test of brain damage. Journal of Consulting Psychology, 20(5), 343-350.
- 02Logan, G. D., & Cowan, W. B. (1984). On the ability to inhibit thought and action: A theory of an act of control. Psychological Review, 91(3), 295-327. Logan, G. D., & Cowan, W. B. (1984). On the ability to inhibit thought and action: A theory of an act of control. Psychological Review, 91(3), 295-327.
- 03Riccio, C. A., & Reynolds, C. R. (2001). Continuous performance tests are sensitive to ADHD in adults but lack specificity: A review and critique for differential diagnosis. Annals of the New York Academy of Sciences, 931, 113-139. Riccio, C. A., & Reynolds, C. R. (2001). Continuous performance tests are sensitive to ADHD in adults but lack specificity: A review and critique for differential diagnosis. Annals of the New York Academy of Sciences, 931, 113-139.