A unified computational account of cumulative semantic, semantic blocking, and semantic distractor effects in picture naming.

Computational models of lexical selection in spoken word production have been applied to semantic interference effects in picture naming response times obtained with continuous naming, blocked-cyclic naming, and picture-word interference paradigms. However, a unified computational account of the effects in the three paradigms is lacking. Here, I show that the inclusion of conceptual bias in the WEAVER++model (Levelt, Roelofs, & Meyer, 1999) explains cumulative semantic and semantic blocking effects while preserving the model's account of semantic distractor effects. The key assumptions of the account are (1) lexical selection by competition, and (2) a conceptual origin and lexical locus of the semantic effects. I provide a proof of concept of the account by reporting computer simulation results, addressing behavioral and neuroimaging evidence. The assumptions are sufficient for a unified account of semantic effects in the three paradigms, contrary to pessimistic views of this area.