Understand N-back scores
An N-back task asks whether the current item matches an earlier item at a specified distance. The rule must be clear before the score has any meaning.
By Zehano · Original AI-assisted explanation and worked example · Updated 16 October 2026 · Editorial approach
A worked example
For A, B, A, the third letter matches the letter two positions earlier, but differs from the letter one position earlier. In Zehano’s two-back sequence, the first two letters establish the starting history and are not scored comparisons. A 16-letter sequence therefore has 14 scored decisions. This self-paced activity does not include a reaction-time measure.
Try it in three steps
- Choose one-back or two-back.
- Use the exact comparison distance on each turn.
- Inspect the comparison history after the sequence.
What to watch for
The result describes this sequence. Repeating the task or changing its pace changes the conditions; the count is not an IQ score or a clinical assessment.
Apply it to your own material
Choose one topic from your current course or project. Write down the question you want to answer, make an attempt, and keep a note of how you checked it. Use the example above as a pattern; replace its subject matter and assumptions rather than copying an answer into a different task.
Open N-Back Lab ↗