Dottorato in NEUROSCIENZE DEL COMPORTAMENTO

Titolo della tesi: Reward and decision making in childhood psychiatric disorders: creation of a task with low and high reward.

Reward and decision making are human and animal behavioural characteristics studied by different disciplines. In fact, these concepts apply in different fields and in different contexts. For example, they have been studied in neuroeconomics that is an interdisciplinary field in which economics, psychology, computational science, and neuroscience converge to allow for examinations of the neural basis of reward-related decision making in social and nonsocial contexts (Glimcher & Rustichini, 2004). Regarding social decision making specifically, neuroeconomics combines fMRI with multiplayer exchange games drawn from behavioral economics and computational approaches to examine interpersonal functioning. Recently, this approach has been applied also to psychiatric population using neuroeconomic games to examine reward-related decision making (Sharp, Monterosso & Montague 2012). The relationship between these different disciplines have been expressed very much interest in recent years, leading to the construction of a real discipline in the field of psychiatry: computational psychiatry. Referring to the topic discussed in this work, clinical interest focus on the possibility that impairment in decision making and altered reward might constitute models of dysfunctional action selection in psychiatric disorders, in particular in Attention-Deficit/Hyperactivity Disorder (ADHD). So, in this paper, we will try to study ADHD and emotional (ED) disorders using different disciplines and points of view, to try to understand these disorders on a comprehensive level. In fact, we will start from the psychological and medical context, passing through neuroscience and computational models. In order to achieve this purpose, a new task was created to study reward (in particular a smaller immediate reward and a larger delayed reward) and decision making in children with ADHD compared to children with ED. Several neuropsychological tests have been designed to assess reward-related decision making in general, mainly by either indexing the preference for smaller but immediate rewards over larger but delayed rewards, or higher tolerance of risk in favor of a desired reward (e.g., gambling tasks) (Wu et al 2016). The aim of the present study is to assess and study reward response and decision making in children with psychiatric disorders such ADHD and internalizing disorders, through the developed tools, cross-referencing the data with tests assessing executive functions, attention and cognitive abilities.