Who are you talking about? Tracking discourse-level referential processing with ERPs

In this event-related brain potentials (E RP) study, we explored the possibility to selectively track referential ambiguity during spoken discourse comprehension. Earlier ERP research has shown that referentially am biguous nouns (e.g., “the girl” in a two-girl context) elicit a frontal, sustained negative sh ift relative to unambiguous control words. In the current study, we examined whether this ERP effect reflec ts ‘deep’ situation model ambiguity or ‘superficial’ textbase am biguity. We contrast ed these different interpretations by investigating whether a discourse-level semantic manipulation that prevents referential ambiguity also averts t he elicitation of a referentially induced ERP effect. We compared ERPs el icited by nouns that were re ferentially non-ambiguous but were associated with two discourse entities (e .g., “the girl” with two girls introduced in the context, but one of which has died or le ft the scene), with referentially ambiguous and non-ambiguous control words. While temporally referentially ambiguous nouns elicited a frontal negative shift compared to control words, the ‘double bo und’ but referentially non-ambiguous nouns did not. These results suggest that it is possible to selectively track referential ambiguity with ERPs at the level that is most relev ant to discourse comprehension, the situation mode