Wave-ering: An ERP study of syntactic and semantic context effects on ambiguity resolution for noun/verb homographs
Journal of Memory and Language
Two event-related potential experiments investigated the effects of syntactic and semantic context information on the processing of noun/verb (NV) homographs (e.g., park). Experiment 1 embedded NV-homographs and matched unambiguous words in contexts that provided only syntactic cues or both syntactic and semantic constraints. Replicating prior work, when only syntactic information was available NV-homographs elicited sustained frontal negativity relative to unambiguous words. Semantic
... s eliminated this frontal ambiguity effect. Semantic constraints also reduced N400 amplitudes, but less so for homographs than unambiguous words. Experiment 2 showed that this reduced N400 facilitation was limited to cases in which the semantic context picks out a nondominant meaning, likely reflecting the semantic mismatch between the context and residual, automatic activation of the contextually-inappropriate dominant sense. Overall, the findings suggest that ambiguity resolution in context involves the interplay between multiple neural networks, some involving more automatic semantic processing mechanisms and others involving top-down control mechanisms. One central feature of language is that a single spelling or pronunciation is oftentimes associated with multiple senses. The appropriate interpretation of a word therefore needs to be established via a variety of contextual constraints, including lexical associations among cooccurring words, restrictions set by the syntactic structure, message-level semantic information built as context unfolds, pragmatic factors, world knowledge, and so forth. A primary goal of psycholinguistic research is thus to understand how information gleaned from individual lexical items is brought together with that derived from the larger language and communicative Corresponding author: Chia-lin Lee, University of Illinois, Psychology Department, 603 East Daniel St., Champaign, IL 61820, phone: (217) 244-7334, email@example.com. 2 Van Petten & Kutas (1987) do explicitly comment on the lack of difference between the waveforms elicited by sentence final ambiguous and unambiguous words in their probe study. However, there are a number of procedural differences between their study and the present one, as they used a mixture of NN-and NV-homographs, sentence contexts that consistently biased toward the subordinate meaning of a homograph (whereas bias was unpredictable in the present study), and a slower (900 ms SOA) presentation rate.