The neurophysiological correlate to grammatical function reanalysis in Swedish

Abstract

Language comprehension is assumed to proceed incrementally, and comprehenders commit to initial interpretations even in the absence of unambiguous information. Initial ambiguous object arguments are therefore preferably interpreted as subjects, an interpretation that needs to be revised towards an object initial interpretation once the disambiguating information is encountered. Most accounts of such grammatical function reanalyses assume that they involve phrase structure revisions, and do not differ from other syntactic reanalyses. A number of studies using measurements of event-related brain potentials (ERPs) provide evidence for this view by showing that both reanalysis types engender similar neurophysiological responses (e.g., P600 effects). Others have claimed that grammatical function reanalyses rather involve revisions of the mapping of thematic roles to argument noun phrases (NPs). In line with this, it has been shown that grammatical function reanalysis during spoken language comprehension engenders a N400 effect, an effect which has been shown to correlate with general problems in the mapping of thematic roles to argument NPs in a number of languages. This study investigated the ERP correlate to grammatical function reanalysis in Swedish. Postverbal NPs that disambiguated the interpretation of object-topicalised sentences towards an object-initial reading engendered a N400 effect with a local, right-parietal distribution. This “reanalysis N400” effect provides further support for the view that grammatical function reanalysis is functionally distinct from syntactic reanalyses and rather involves a revision of the mapping of thematic roles to the sentence arguments. Postverbal subject pronouns in object-topicalised sentences were also found to engender an enhanced P300 wave in comparison to object pronouns, an effect which seems to depend on the overall infrequency of object-topicalised constructions. This finding provides support for the view that the “reanalysis N400” in some cases can be attenuated by a task-related P300 component.