Syntactic Priming in German Sentence Production

Syntactic Priming in German Sentence Production Christoph Scheepers (chsc@coli.uni-sb.de) Department of Computational Linguistics Saarland University, 66041 Saarbr¨ucken, Germany Martin Corley (Martin.Corley@ed.ac.uk) Department of Psychology and Human Communication Research Centre University of Edinburgh, Edinburgh EH8 9JZ, UK Abstract Current theories of language production tend to differentiate between a (syntactic) functional level and a (surface) posi- tional level in the generation of sentences, where functional selection precedes and constrains positional processing. In this paper, we present evidence from a syntactic priming study in German, where position, function, and type of constituent are orthogonally specified for monotransitive and ditransitive verbs. In contrast to findings for English (in which these fac- tors are confounded) we show that previous generation of a ditransitive structure can inhibit the production of a further ditransitive when the order of potential arguments differs be- tween prime and target. Our results suggest that positional pro- cessing must at the least interact with functional processing in production, and point to the importance of cross-linguistic ev- idence in the formation of models of language processing. Syntactic Priming is the name given to the tendency that peo- ple have to re-use syntactic structure that they have just gen- erated. For example, Bock (1986) demonstrated that, having read aloud a sentence such as The rock star sold some co- caine to an undercover agent, participants are more likely to describe a picture with a phrase such as The girl handed a paintbrush to the man rather than with the alternative The girl handed the man a paintbrush. Current interpretations of these findings tend to emphasise a functional level of sentence production, at which syntactic information (such as subcate- gorisation properties of verbs) is specified and syntactic roles (such as subject or object) are assigned. The eventual posi- tions of constituents in the utterance are determined by subse- quent processes which take as their input the representations built at the functional level (e.g., Bock & Levelt, 1994). Evidence supporting the existence of a functional level in production has been found in a series of studies by Bock and colleagues (Bock, 1986, 1989; Bock & Loebell, 1990). (1a) The secretary baked a cake for her boss. (1b) The wealthy widow drove her Mercedes to the church. (1c) Susan brought a book to study. Taking X primes Y to mean that utterance Y is more likely to be produced by participants who have just produced utter- ance X, it has been demonstrated that The girl handed a paint- brush to the man is primed by (1a) (individual lexical items do not affect priming) and by (1b) (the priming of a preposi- tional phrase is not affected by its thematic role). However, (1c) does not prime The girl handed a paintbrush to the man (prosodic similarity does not affect production). Starting with this evidence, Pickering and Branigan (1998, henceforth P&B) have recently argued for the specification of syntactic verb information within the production lexicon. Us- ing a localised network model of the production lexicon de- rived from Roelofs (1992, 1993) they argue that lemma nodes for verbs are linked to additional nodes representing syntac- tic features such as tense and aspect. These nodes in turn link to ‘lexeme nodes’ on a separate stratum, which represent po- tential lexical forms of verbs. If the verb lemma and both a past tense node and a perfective aspect node are active, a likely articulation through the lexemic level would be gave. The syntactic feature nodes are unique, such that any verb which can be expressed in the past tense is linked to the same past tense node as is . Importantly, P&B also assume that verb lemmas are linked to ‘combinatorial’ nodes which express the constructions in which a verb can be used. would have links to (at least) two combina- torial nodes, representing ‘NP NP’ (give the dog a bone) and ‘NP PP’ (give the bone to a dog) combinations. It is worth noting that (at least) two types of information traditionally described as subcategorisation information are combined by these nodes, since they encode not only the types (syntactic category and case) of arguments used, but also the number of arguments (i.e., the verb’s valence). Using standard assumptions about decaying activation, 1 the priming of The girl handed the paintbrush to a man by The rock star sold some cocaine to an undercover agent is ac- counted for by suggesting that the ‘NP PP’ node retains some activation and thus reaches threshold more easily when mak- ing the second utterance. P&B provide support for this model by adopting a novel methodology (see also Branigan, Picker- ing, Liversedge, Stewart, & Urbach, 1995), in which partici- pants provide written completions for partial sentences. The prime sentences are pragmatically constrained such that the most likely completion is of a given form (e.g., The racing 1 P&B’s model deviates from more traditional activation models in that some links, as well as nodes, retain activation over time. However the detail of the model has no bearing on the functional/positional dichotomy to which we address ourselves in this paper.