Proceedings of the Annual Meeting of the Cognitive Science Society

Some people say they routinely think in an “inner voice,” while others assume this phrase is just a figure of speech. Across two preregistered experiments (N = 190), we investigated whether such subjective differences in internal verbalization predict attested effects of language on perceptual discrimination. Participants completed a canonical discrimination task assessing language-driven categorical perception of facial expressions, plus a self-report measure of internal verbalization and other modes of mental representation. The results replicated the behavioral signatures of categorical perception—faster and more accurate responses for cross-category than within-category discriminations. However, the strength of these effects was unrelated to participants’ propensity for internal verbalization. Our findings suggest that subjective experiences of inner voice use are not a reliable indicator of linguistic involvement in perceptual discrimination. These findings add to an emerging body of research showing that even large differences in mental experiences often lack clear behavioral consequences.