Understanding social motivation: a neuro-pharmacological and clinical account.
G. Silani1, S. Korb1, C. Massaccesi1, S. Götzendorfer1, E. Chiappini1, C. Eisenegger1, M. Willeit2
1 University of Vienna, Austria;
2 Medical University of Vienna, Austria
Human behavior is motivated not only by primary rewards (such as food), but also by social rewards (such as approval). In the last decade, a fundamental challenge has been to understand the different aspects involved in reward. While animal research has clearly established "wanting" and "liking" as two components differing on the neurobiological and neurochemical level, corresponding research in humans is less conclusive. The present talk addresses this gap of knowledge by testing: a) whether "wanting" and "liking" can be dissociated in humans on the behavioral and neurochemical level for non-social and social rewards; and b) whether such components are differently impaired in clinical conditions such as autism spectrum disorders (ASD). By employing a novel behavioral paradigm in combination with pharmacological manipulations (i.e. dopamine and opioid antagonists; experiment 1 and 2), we first aimed at differentially targeting these two components. In experiment 3, the same paradigm combined with fMRI was used to investigate reward processing in individuals with ASD compared to neurotypical controls. Participants were tested in a real effort task, to determine their explicit (ratings of wanting and liking and squeezing of hand dynamometer) and implicit (hedonic facial reactions) responses to different types of rewards. Nonsocial rewards were small amounts of milk with different concentrations of cacao. Social rewards were gentle caresses delivered to the forearm at different speeds by a same-sex experimenter. The findings are discussed in light of the current theory of reward processing and social motivation in particular.