Effects of Semantic Integration and Advance Planning on Grammatical Encoding in Sentence Production

To examine how semantic integration and the scope of advance planning affect utterance planning and subject-verb agreement error rates, participants described picture displays using complex subject noun phrases (e.g., the apple for the pie(s)), with singular head nouns (apple) and local nouns (pie(s)) in prepositional phrase modifiers, and then completed them as full sentences. Semantic integration (the conceptual link between elements within a phrase; Solomon & Pearlmutter, 2004) was manipulated by varying the preposition used to link the head noun and local noun. Speech onset times and agreement error rates were recorded. Speakers were faster to initiate speech when the head and local noun were integrated than when they were unintegrated. Agreement errors were more likely when the local noun was plural than when it was singular. Supporting the scope of planning account of agreement (Gillespie & Pearlmutter, 2011), speakers who were slower to initiate speech produced more agreement errors, suggesting that speakers who do more advance planning are more likely to experience interference during agreement computation.