Modality-specific effects of processing fluency on cognitive judgments

Fluency of processing – the ease with which one extracts information from stimuli – affects a variety of cognitive processes over and above the influence of declarative content. Although this influence has been extensively demonstrated in a variety of different domains (Alter & Oppenheimer, 2009), there are virtually no studies exploring this effect with auditory material. Moreover, although research on modality differences suggests that people process auditory information differently than they process visual or written information (Conway & Gathercole, 1987; Markman, Taylor & Gentner, 2007), there are no studies that directly compare the effects of processing fluency on judgments across different modalities. The current dissertation reports two sets of studies, one investigating the effects of processing fluency on cognitive judgments in the auditory modality, and a second exploring cross-modal differences in processing fluency. The first set of studies showed that although foreign-accented speech is more difficult to process, this disfluency does not affect cognitive judgments. In the second set of studies, two experiments show that disfluency in processing affects judgments of truth (Experiment 1) and the intention to purchase a product (Experiment 2) only with written – non-verbal – material. Experiment 3 investigates one possible explanation for the limited influence of processing fluency in speech: because people tend to focus on conceptual information over low-level acoustic information when processing language (Lahiri & Marslen-Wilson, 1991; Gow & Gordon, 1995; Mattys, White & Melhorn, 2005; Norris, McQueen & Cutler, 1995), distortions to the superficial features of the speech signal is likely to have limited impact on how people process the conceptual content. In Experiment 3 participants are primed to attend to the superficial features of foreign-accented speech. The results showed that when people are primed to attend to features that make foreign-accented speech difficult, non-native speech has an impact on subsequent judgments of truth. Overall, the studies presented here show that listeners can extract content from speech, even when it is distorted. They also show that when attention is directed to low-level acoustic features of speech, processing fluency effects becomes apparent.