Conventional metaphors elicit greater real-time engagement than literal paraphrases or concrete sentences

•Pupil dilation indexed greater focused attention on task (i.e., greater engagement).•Greater metaphoricity predicts fast, sustained dilation during auditory presentation.•60 sentence triples contain conventional metaphor, paraphrase, concrete description.•Stimuli normed on gradient metaphoricity and 7 other psycholinguistic factors.•Greater metaphoricity predicts likelihood that sentence conveys “richer meaning”