Dorsolateral Prefrontal Cortex Causally Supports the Memory Advantage of Reading Aloud

Reading words aloud improves later recognition relative to reading them silently, a phenomenon known as the production effect. This advantage may reflect not only the distinctive sensorimotor information generated by production, but also cognitive control processes that prioritise this information during encoding. Given the central role of the dorsolateral prefrontal cortex (DLPFC) in supporting cognitive control, we tested whether this region causally contributes to the production effect using transcranial magnetic stimulation (TMS). In a preregistered within-participant study, 40 adults completed three sessions in which TMS was delivered bilaterally to the DLPFC. They received continuous theta-burst stimulation (cTBS), expected to reduce DLPFC excitability; intermittent theta-burst stimulation (iTBS), expected to increase it; or sham stimulation. Participants then read words aloud or silently before completing an old/new recognition test with confidence and recollection judgements. There was a clear production effect: words read aloud were recognised more accurately and quickly, with greater confidence and more frequent recollection ratings, than words read silently. Crucially, cTBS reduced the accuracy advantage for aloud words relative to sham and iTBS. Exploratory receiver-operating-characteristic (ROC) and unequal-variance signal-detection (UVSD) modeling approaches provided converging evidence that cTBS reduced the memory advantage for words read aloud. Stimulation did not reliably affect responses to new words. These findings provide the first causal evidence that the DLPFC helps make words read aloud more memorable, consistent with a role for cognitive control in prioritising the distinctive information generated by speaking.