title: Pupillometry reveals increased pupil size during indirect request comprehension.
abstract: Fluctuations in pupil size have been shown to reflect variations in processing demands during lexical and syntactic processing in language comprehension. An issue that has not received attention is whether pupil size also varies due to pragmatic manipulations. In two pupillometry experiments, we investigated whether pupil diameter was sensitive to increased processing demands as a result of comprehending an indirect request versus a direct statement. Adult participants were presented with 120 picture-sentence combinations that could be interpreted either as an indirect request (a picture of a window with the sentence "it's very hot here") or as a statement (a picture of a window with the sentence "it's very nice here"). Based on the hypothesis that understanding indirect utterances requires additional inferences to be made on the part of the listener, we predicted a larger pupil diameter for indirect requests than statements. The results of both experiments are consistent with this expectation. We suggest that the increase in pupil size reflects additional processing demands for the comprehension of indirect requests as compared to statements. This research demonstrates the usefulness of pupillometry as a tool for experimental research in pragmatics.
authors.affiliation: a Max Planck Institute for Psycholinguistics , Nijmegen , The Netherlands.|b International Max Planck Research School for Language Sciences , Nijmegen , The Netherlands.
authors.forename: Johanne
authors.initials: J
authors.lastname: Tromp
authors.affiliation: a Max Planck Institute for Psycholinguistics , Nijmegen , The Netherlands.|c Donders Institute for Brain, Cognition and Behaviour, Radboud University , Nijmegen , The Netherlands.
authors.forename: Peter
authors.initials: P
authors.lastname: Hagoort
authors.affiliation: a Max Planck Institute for Psycholinguistics , Nijmegen , The Netherlands.|c Donders Institute for Brain, Cognition and Behaviour, Radboud University , Nijmegen , The Netherlands.
authors.forename: Antje S
authors.initials: AS
authors.lastname: Meyer
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology*; D032882:Comprehension / Q000502:physiology*; D005260:Female; D006801:Humans; D007802:Language; D016014:Linear Models; D008297:Male; D010775:Photic Stimulation; D011680:Pupil / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D055815:Young Adult
keywords: Experimental pragmatics; Indirect requests; Language comprehension; Pupillometry; Speech act