Augurzky, P. & Franke, M.
University of Tuebingen
ERP studies on scalar implicatures show heterogeneous results with respect to time course of inference generation, potential processing cost, and observed ERP correlates of implicature processing. Hypothesizing that results may differ because of a previous focus on specific sentential positions (i.e. the quantifier or its argument), we investigated the time-course of implicature processing by comparing ERPs at different positions (quantifier, adjective, and clause-final NP). German sentences like 'All/Some dots are red/blue that are in the circle/square' were preceded by pictures showing a square and a circle, containing variable proportions of red/blue circles. Our hypothesis is largely confirmed by standard ERP analyses involving ANOVAS at each position of interest.
Moreover, we suggest a post-hoc modeling approach based on subjects' incrementally updated pragmatic expectations about sentence continuations. We derive pragmatic expectations from a variant of the Rational Speech Act model (Frank & Goodman, 2012) as a quantitative measure of what a speaker seeing the picture would likely utter. This measure is a highly successful predictor in a regression model of the observed ERPs, suggesting that EEG data might be influenced by violations of listener expectations more generally: not only syntactic or semantic (e.g. Levy 2008), but also pragmatic expectations may matter.