Flexibility in language production

2012-08-03The study of sentence production investigates how speakers turn preverbal messages into utterances. Researchers generally characterize the language production system into three broad components: the message component (conceptualization), the grammatical component (formulation), and the phonological component (articulation) (Bock 1995; Bock & Levelt 1994; Garrett, 1975; Levelt, 1989). Specifically, my work aims to explore the nature and processes of the message component and grammatical component by investigating three primary questions. First, what would happen if there is freedom of choice for message formulation (termed semantic flexibility in my work)? Second, do accessibility effects of thematic prominence and animacy condition syntactic choice in Mandarin? Third, how does speakers’ strategic control in response to communicative goals influence the processes of message and grammatical encoding? In my dissertation, I report five sentence production tasks in Mandarin Chinese and English designed to address these questions. ❧ Experiments 1 and 2 explored the effects of semantic flexibility in the production of Mandarin BA and BEI constructions. The results suggest that message formulation processes are highly sensitive to the interaction between thematic role and animacy: Whether having choice of multiple propositions hinders or facilitates production is contingent upon verb thematic structure. Additionally, these findings extend effects of thematic prominence and animacy to Mandarin BA and BEI constructions, providing cross-linguistic evidence for the incrementality-based account for grammatical encoding. ❧ Experiment 3 investigated both effects of thematic prominence and semantic flexibility in the production of English actives and passives. The results confirm effects of thematic prominence in English, but do not replicate the asymmetric pattern of semantic flexibility I found in Mandarin Chinese, suggesting that semantic properties of a syntactic construction may also play a role in message formulation. In sum, the findings of Experiments 1-3 indicate that the operation of the message component may be carried out competitively or incrementally, in contrast to the incremental nature of grammatical encoding. In a broad sense, linguistic information such as verb thematic structure and semantic properties of a syntactic construction may guide the process of sentence production at an early stage. ❧ Experiments 4 and 5 studied how extra-linguistic factors, in particular, speakers’ strategic control, influences sentence production in both the message and grammatical component. Existing work suggests that speakers’ strategy or task sensitivity has the potential to affect both referent processing in message planning and the scope of advance linguistic planning. Thus, I hypothesize that in prepared speech vs. fast speech, effects of semantic flexibility and thematic prominence would vary with the communicative goal aiming at accuracy or speed. The results of Experiments 4 and 5 show that consistent with the results of Experiment 3, effects of semantic flexibility are not found. Contrastively, effects of thematic prominence are found in prepared speech but not in fast speech. In conclusion, speakers’ strategic control can affect the processes of grammatical encoding, depending on whether the goal speakers aim to achieve is speed or accuracy. ❧ As a whole, my findings suggest that message formulation is sensitive to the interaction of linguistic information such as verb thematic structure, conceptual accessibility such as noun animacy, and semantic properties pertaining to syntactic constructions. In contrast to grammatical encoding, message formulation may not always proceed incrementally. Moreover, the language production system is susceptible to extra-linguistic factors such as strategic control, in particular the grammatical component. By exploring the nature and processes of the individual components as well as the interactions between them, my research helps shed light on how people produce speech