Lexical Decision Task
A letter string is shown and the participant classifies it as a real WORD or a NONWORD by a speeded keypress. It is the canonical instance of the speeded-classification family — a stimulus, a speeded categorical response, scored by RT and accuracy — and the first catalog-matched family the harness specs (the two subject audits found the NCCR catalog is mostly such language/perception tasks, which none of the cognitive-control families covered). The defining contrast is the lexicality effect: words are classified faster than nonwords, because a real word finds a lexical entry while a nonword requires an exhaustive (failing) search. Word frequency adds a parametric layer (high-frequency words faster than low). The conditions ('word'/'nonword') are TASK-DEFINED categories, not a paradigm-fixed enum — the contract novelty of this family, of which the congruency contract (congruent/incongruent) is a special case.
- Defining contrast
lexicality-effect-rt (condition-difference)- Family
- speeded-classification
- Human review
- sourced — unreviewed
- Executable test
- verify:task — an implementation can be driven and judged against this spec
- Schema
- spec version 10
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 |
|---|---|---|---|
| lexical-decision-task | NCCR / jsPsych | conforms | the clean centre — lexicality effect computable and recovered, nothing for a human to flag about the wiring |
Origin reference
- Rubenstein, H., Garfield, L., & Millikan, J. A. (1970). Homographic entries in the internal lexicon. Journal of Verbal Learning and Verbal Behavior, 9(5), 487-494. doi:10.1016/s0022-5371(70)80091-3
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.