The analysis of the independence hypothesis: Working and procedural memory in young adults with Attention Deficit and Hyperactivity Disorder

The aim of this study was to test Oberauer’s independence hypothesis in young adults with Attention Deficit Hyperactivity Disorder (ADHD) and typically developing ones (TD). More precisely, the objective was to verify if the manipulation of two memory systems influences the other in ADHD and TD individuals in a different way. Fifty-nine participants, 35 with ADHD and 24 TD, matched for age, gender and IQ, participated in this study. A complex span task paradigm was used. Participants were asked to remember a series of letters (recalling) while performing a concurrent response selection task after each letter presentation. Results do not confirm the independence hypothesis, suggesting that both working and procedural memory systems share common resources, and the manipulation of each of the two systems influences the other in the same way, both in TD and ADHD participants. ADHD participants showed deficits in both procedural and working memory.