LEXICAL STRUCTURE AND PARSING COMPLEXITY

In recent work on sentence processing, lexical frequencies have been p roposed as a primary mechanism for syntactic and lexical disambiguatio n. In this paper, we instead focus on the consequences that the struct ural configuration of lexical knowledge has for the timecourse of pars ing. We concentrate on reduced relative clauses and propose a new lexi cal-structural analysis for those verbs that are difficult in this con struction, manner of motion verbs. The interaction between the propose d lexical structure and the competitive attachment parser (Stevenson, 1994b) explains the persistent difficulty of this construction with a manner of motion verb, even in disambiguating contexts (e.g. a reduced relative in object position) or with non-ambiguous past participle ve rb forms. Weighted influences on the activation competition are possib le with other verbs, and the model can therefore also explain data tha t demonstrate contextual effects on reduced relatives with simple tran sitives. Consequences for the frequency-based models, and all models w hich base the explanation of the difficulty on the ambiguity of the pa st participle form, are discussed.