Production Effect in Adults with ADHD with and Without Methylphenidate (MPH): Vocalization Improves Verbal Learning

Objectives: Reading aloud (vocal production) enhances memory relative to reading silently, the Production Effect (PE) in memory. Thus, vocalization has been suggested as a mnemonic device. The current study tested the PE in a sample of adults with ADHD and in a control sample, evaluating verbal learning. Methods: Twenty adults with ADHD and 21 controls learned a list of words, half by reading aloud and half by reading silently. Free recall test followed. The participants with ADHD performed the task twice (in two different sessions in a counterbalanced order), before self-Administration of a single dose of methylphenidate (MPH) and 60-min after dosage. Results: PEs were found for all groups. Memory was better for the controls than for the ADHD group (with or without MPH). In the ADHD group, recall rates and the PE were higher with than without MPH. Conclusions: These results suggest that vocalization yields a larger memory gain with MPH. Possibly, MPH enables the ADHD participants to better shift their attention to the aloud words, enhancing their retrieval rates. Theoretically, these findings stress the role of attention in the PE. (JINS, 2019, 25, 230-235).