Disfluent, But Fast: Inverted-U Shaped Effect of Fluency on Decision Times

Processing fluency, a metacognitive feeling of ease of cognitive processing, serves as a cue in various types of judgments. Processing fluency is sometimes evaluated by response times, with shorter response times indicating higher fluency. The present study examined existence of the opposite association; that is, it tested whether disfluency may lead to faster decision times when it serves as a strong cue in judgment. Retrieval fluency was manipulated in an experiment using previous presentation and phonological fluency by varying pronounceability of pseudowords. Participants liked easy-to-pronounce and previously presented words more. Importantly, their decisions were faster for hard-to-pronounce and easy-to-pronounce pseudowords than for pseudowords moderate in pronounceability. The results thus showed an inverted-U shaped relationship between fluency and decision times. The findings suggest that disfluency can lead to faster decision times and thus demonstrate the importance of separating different processes comprising judgment when response times are used as a measure of processing fluency.