Word category conversion causes processing costs: evidence from adjectival passives.

Constructing syntactic representations in language comprehension begins with the identification of word categories. Whether the category information is stored in the mental lexicon is a matter of debate in current linguistic theorizing. The standard view assumes that the syntactic category of a word is lexically specified (lexicalist approach). More recently, it has been proposed within the paradigm of distributed morphology that lexical elements (roots) are stored without any syntactic category information: The syntactic category of a lexical element is determined only by the syntactic context in which it appears (syntactic approach). For processing category-ambiguous words, different hypotheses can be derived from these two accounts. The lexicalist approach predicts that there are productive grammatical processes, such as nominalization and adjectivization, that convert a word of Category A into one of Category B. Such a conversion might be assumed to create additional processing costs. Within the syntactic approach, on the other hand, no additional processing step is expected, because there is no need for any category shift. In a self-paced reading study on so-called adjectival passives, we found evidence of costs predicted under the lexicalist approach (i.e., for a grammatical process that changes the category of a word). More specifically, the present study provides evidence for category conversion from a verbal participle into an adjectival one. We also discuss an alternative explanation for this finding in terms of frequency.