Poster C71, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
Neural correlates of referential processing: Event-related potentials for ambiguity versus resolution
Les Sikos1, Harm Brouwer1, Matthew Crocker1; 1Saarland University
Successful language comprehension involves establishing reference. In the Event-Related Potential (ERP) signal, referential ambiguities (e.g., David shot at John as _he_...) elicit a sustained negativity (Nref) relative to controls (David shot at Linda as _he_...; Van Berkum et al., 1999). The processes underlying this effect are, however, poorly understood: it is unclear whether Nref is simply a marker of ambiguity, or if it is sensitive to the _degree_ of ambiguity. We investigated whether Nref amplitude is proportional to the number of potential antecedents for a referential expression using a visual-world paradigm and manipulating the number of competitor candidates. Native-German participants (N=22) answered Yes/No questions (e.g., Is the _ball_ that is striped on the right?) while viewing displays containing four objects arranged around a central fixation cross. Displays contained one (1-ref), two (2-ref), or three (3-ref) objects of the same type (e.g., ball), of which only one matched the pattern in question (e.g., striped). Participants previewed displays but subsequently maintained fixation while questions were presented visually, word-by-word. Results show that both temporarily ambiguous conditions (2-ref, 3-ref) elicited an Nref effect at the critical word (e.g., ball) relative to unambiguous controls (1-ref) but did not differ from each other. This pattern of results suggests that Nref is simply a marker of ambiguity. A secondary question investigating the correlates of reference resolution found equal magnitude P600-effects at disambiguation (e.g., striped) for both ambiguous conditions relative to control. We discuss the implications for the functional interpretation of these ERP components in referential processing.
Topic Area: LANGUAGE: Other