Sequential Congruency (Gratton effect)
Run on a standard congruency task (here an arrow Flanker; equally a Simon or Stroop), with the trial order preserved, the congruency cost on a trial is smaller when the previous trial was incongruent — the congruency sequence effect (Gratton effect / conflict adaptation). The headline measure is therefore an interaction of previous-trial congruency with current-trial congruency on RT: a difference of two difference scores, whose unit of analysis is a trial pair. Whether a trial follows a congruent or an incongruent one is not a property of its stimulus but of its position in the sequence, which the implementation must label from the trial order. The effect is read as a signature of conflict-driven control, but only under designs that control feature-repetition and contingency confounds — an unusually strong validity condition that the spec records explicitly.
- Defining contrast
congruency-sequence-effect (interaction)- Family
- sequential-congruency
- Human review
- sourced — unreviewed
- Executable test
- verify:task — an implementation can be driven and judged against this spec
- Schema
- spec version 6
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.
Origin reference
- Gratton, G., Coles, M. G. H., & Donchin, E. (1992). Optimizing the use of information: Strategic control of activation of responses. Journal of Experimental Psychology: General, 121(4), 480-506. doi:10.1037/0096-3445.121.4.480
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.