Dual N-Back · Guides
Reaction time: a repeatable measurement protocol
Compare reaction-time trials on the same device, read the median alongside errors, and understand what a phone result can show.
In this guide5
Choose the response rule first
In a simple reaction task, one signal calls for one known response. A choice task adds alternatives and a decision. Write down which task you used; times from different rules cannot be treated as the same measurement.
Keep one comparison consistent
Use the same device, app, input method and stimulus type. Keep sound and visual trials separate. Note interruptions and a changed setting. Consistent conditions reduce some differences between sessions; they do not remove hardware delay or every source of variation.
A fictional median example
Suppose five valid responses take 310, 280, 400, 290 and 300 milliseconds. Sort them: 280, 290, 300, 310, 400. The middle value is 300 ms; the arithmetic mean is 316 ms. These invented values illustrate two summaries, not a normal range or a target.
Record errors alongside time
Keep anticipations, wrong choices and missed responses in the record. If an app excludes errors from its time summary, note that rule. A faster median with more wrong answers is not automatically a better run. Do not quietly remove inconvenient trials.
What a phone result means
The result describes this task on this device under the recorded conditions. It does not identify an IQ score, diagnose fatigue, or establish fitness for driving or hazardous work. A change after practice cannot by itself separate learning the interface from other explanations.
Questions
Is 300 ms a normal or target score?
No. The 300 ms median in this guide comes from invented values used to explain a calculation. Different tasks, devices and scoring rules are not interchangeable.
Does a faster result prove a training benefit?
No. Read the errors and conditions as well as the time. Familiarity, timing and the response rule can affect the result; it does not demonstrate a general cognitive improvement.
Does using the same device remove hardware delay?
No. It keeps one part of the comparison more consistent, but the device still contributes delay and software or input settings may change.
Further reading
- Stroop (1935), Studies of interference in serial verbal reactions, Journal of Experimental Psychology
- MacLeod (1991), Half a century of research on the Stroop effect: an integrative review, Psychological Bulletin
- Deary, Der & Ford (2001), Reaction times and intelligence differences: a population-based cohort study, Intelligence
- Jaeggi et al. (2010), The relationship between n-back performance and matrix reasoning, Intelligence
Guides
How to play dual n-back: a clear first session
Understand position matches, sound matches and the meaning of N before your first dual n-back session.
Dual N-Back settings on iPhone: audio, feedback and levels
Understand audio, feedback, N-levels, progression locks and session length with an annotated screenshot of the Dual N-Back iPhone app.
Dual n-back scoring: formulas, examples and calculator
Understand hits, misses and false alarms in dual n-back. Compare scoring formulas with a worked example and an interactive calculator.
Does dual n-back training work? What the evidence actually says
An honest walk through the research on dual n-back: what improves, what does not, why the meta-analyses disagree, and how to train without fooling yourself.