N-back
A continuous stream of stimuli is presented one at a time; on each item the participant signals whether it matches the item presented n positions earlier. Holding and continuously updating the last n items taxes working memory, and detection sensitivity falls as the load n rises. Performance is scored with signal-detection theory: a 'match' to a true n-back item is a hit, a 'match' to a non-matching item is a false alarm, and the bias-corrected sensitivity d' is the primary index. The load-dependent decline in d' — not mere match detection — is the paradigm's signature.
- Defining contrast
d-prime (load-response)- Family
- n-back
- Human review
- sourced — unreviewed
- Executable test
- verify:task — an implementation can be driven and judged against this spec
- Schema
- spec version 4
- Catalog entry
- N-back in the paradigm catalog
Where this spec stands
This record is sourced. The ladder below is the human-review axis
only — a passing executable test never moves a record up it.
sourcedLiterature-linked, drafted with LLM assistance or by a contributor, and unreviewed. The honest default.corroboratedIndependently cross-checked against the cited sources, but not signed by a named expert.expert-annotatedAll three claims attested by named experts. Derived, never self-declared.contestedA named expert disputes at least one claim. A real outcome, kept visible.
Implementations driven through this spec
| Implementation | Platform | Verdict | Note |
|---|---|---|---|
| demos/n_back | Pavlovia / PsychoJS | conforms | mouse-driven; oracle policy recovered, d' ≈ 3.08 — an n-back the survey's static probe could only call undeterminable, shown conformant when driven |
Origin reference
- Kirchner, W. K. (1958). Age differences in short-term retention of rapidly changing information. Journal of Experimental Psychology, 55(4), 352-358. doi:10.1037/h0043688
Review this specification
Three separable claims: does the contrast identify the paradigm, is it a defensible measure of the named construct, and are the psychometric numbers correctly conditioned? Attest one, contest another — a split outcome is a real result.