Cognitive processes underlying the repetition-based truth effect: A diffusion model study.

= 81), participants judged the validity of one-word answers to previously shown questions, allowing separate measurement of reading times and tighter control over nondecision time. When modeling only the answer-related response times, repetition did not affect drift rate, but the repetition-enhanced response bias remained. Reading times for repeated questions were reduced, indicating facilitated encoding. An additional analysis using total trial reaction times (reading + response time) revealed a repetition effect on drift rate, suggesting that information accumulation may begin during question reading. Together, these findings indicate that the illusory truth effect results from a combination of perceptual facilitation, response bias, and increased speed of information accumulation supporting the truthfulness of a statement-each contributing at different stages of the decision process. (PsycInfo Database Record (c) 2026 APA, all rights reserved).