Towards a theory of multimorphemic word production: The heterogeneity of processing hypothesis

Theories of spoken production have not yet addressed the post-lexical processing of multimorphemic words, that is, how a multimorphemic word's phonological form is prepared for production. This paper reviews what is known about how multimorphemic words are represented in production at lexical and post-lexical stages as well as the influence that lexical properties have on post-lexical processes. A proposal linking these facts together is presented which predicts that post-lexical processes (1) should be weaker when acting across morpheme bundaries and (2) should be influenced by the lexical properties of each morpheme. Post-lexical processing is thus predicted to vary, or be “heterogeneous”, across a multimorphemic word. Phoneme competition (as indexed by inhibitory effects of phoneme similarity) is compared within and across morphemes in three analyses of oral reading latencies. Competition is found to be weaker across morpheme boundaries, providing support for heterogeneity.