Associative learning processes in ADHD.

ADHD is highly prevalent and very impairing. Theoretically, ADHD is attributed to a rewardprocessing deficit, impaired cognitive functioning (e.g., working memory), or both. Little research has assessed if ADHD symptoms might also be caused or mediated by a deficit in associative learning processes, although both reward processing and working memory are important for learning and ADHD has been linked to dopamine malfunctioning in the brain (dopamine being crucial for the coding of prediction error signals that drive learning). Yet, evidence-based behavioral treatment for ADHD relies heavily on learning principles. We will explore whether ADHD is accompanied by deficits in elementary learning in two different procedures. First, we will assess conditional discrimination learning (learning which choice of behavior is appropriate in which situation) and test whether a deficit in such learning can be remediated by rewarding correct choices with an outcome unique to the situation rather than a generic reward or by game-based working memory training. Second, we will explore partial reinforcement learning and evaluate the effects of gradually introducing partial reinforcement and of increasing the incentive value of the reinforcer. This research should yield a better understanding of the interplay between reward processing, working memory and elementary learning deficits in normally developing children and children with ADHD and help improve behavioral interventions for ADHD.