Event-related potentials and oscillatory brain activity reflect a complex interplay of syntactic, semantic and pragmatic information during the processing of German discourse particles

Discourse particles are little words that provide non-at-issue content to sentences, reshaping the illocutionary force of an utterance. Among them, question-sensitive discourse particles (QDiPs), like German denn, are subject to a number of interacting syntactic, semantic and pragmatic licensing constraints, offering a unique window into language processing at the interfaces. We present EEG data on the processing of QDiPs in different types of interrogatives (eliciting either syntactic/semantic or pragmatic QDiP licensing), along with QDiPs in declaratives (i.e., unlicensed QDiPs resulting in ill-formed structures). The analysis of event-related potentials shows an increased negativity for QDiPs relative to a non-QDiP baseline in the P300/N400 time window; this is more pronounced for unlicensed QDiPs (in declaratives) than licensed QDiPs (in interrogatives). In the P600 time window, QDiPs elicit more positive-going curves than non-QDiPs, with this pattern wearing off for licensed, relative to unlicensed, QDiPs at later timepoints. Time-frequency analysis of the same EEG data reveals increased theta-band activity for non-QDiPs relative to QDiPs. We interpret the lower theta-band activity for QDiPs as reflecting the fact that QDiPs contribute non-at-issue meaning, but not at-issue meaning. Taken together, our findings showcase different aspects of QDiP processing; ranging from ERP correlates for straightforward licensing violations (late P600) and for increased processing cost during successful licensing (early P600) to oscillatory reflections of the ‘semantic weakness’ of discourse particles (lower theta-band activity). The two types of EEG analysis complement each other and tap into different aspects of language processing. (*Kharaman and Czypionka share first authorship.)