Syntactic Priming without Lexical Overlap in Reading Comprehension

Syntactic priming without lexical overlap is well-documented in language production. In contrast, reading-time comprehension studies, which typically use locally ambiguous sentences, generally find syntactic priming only with lexical overlap. This asymmetry has led some researchers to propose that distinct mechanisms underlie the comprehension and production of syntactic structure. Instead, we propose that methodological differences in how priming is assessed are largely responsible for the asymmetry: in comprehension, lexical biases in a locally ambiguous target sentence may overwhelm the influence of syntactic priming effects on a reader's interpretation. We addressed these issues in a self-paced reading study by (1) using target sentences containing global attachment ambiguities, (2) examining a syntactic structure which does not involve an argument of the verb, and (3) factoring out the unavoidable lexical biases associated with the target sentences in a mixed-effects regression model. Under these conditions, syntactic priming affected how ambiguous sentences were parsed, and facilitated reading times when target sentences were parsed using the primed structure. This resolves discrepancies among previous findings, and suggests that the same mechanism underlies syntactic priming in comprehension and production.