Altmann, E. M. & Davidson, D. J. (2001). An integrative approach to Stroop: Combining a language model and a unified cognitive theory. Proceedings of the 23rd annual conference of the Cognitive Science Society (pp. 21-26). Hillsdale, NJ: Erlbaum.

The rich empirical puzzle of the Stroop effect has traditionally been approached with narrowly focused and somewhat atheoretical models. A recent exception is a simulation model based on the WEAVER++ language theory. The present model, WACT, combines components of WEAVER++ with the memory and control processes of the ACT-R cognitive theory. WACT accounts for the time course of inhibition from incongruent word distractors, facilitation from congruent word distractors, the lack of effect of color distractors, and the semantic gradient in inhibition. WACT goes beyond WEAVER++ to account for Stroop performance errors as well as latencies, and its implementation in a unified cognitive theory opens doors to broader coverage of Stroop phenomena than standalone models are likely to attain. Documented and executable code for WACT is available for inspection and comment at

Full text is here.  Documented code for the model is here.  To run it, you will need ACT-R.

Please send comments to or

Last updated 8/23/01. Please send email if links or files aren't cooperating.

Back to Altmann's homepage.