Neurocomputational study on the impact of beliefs about social others on risky decision-making among smokers and non-smokers

Abstract

This dissertation explored the impact of social beliefs on risky decision-making and smoking behavior. The first study investigated how individuals processed beliefs about social observers during decision-making, using a gambling task under observation by risk-averse or risk-seeking partners. Behavioral and computational modeling analyses revealed that participants simulated partners’ choices, integrating these into their own decisions. Neural data highlights the role of the temporoparietal junction (TPJ) in representing social simulations and its connectivity with the dorsomedial prefrontal cortex (dmPFC) in modulating responses to social cues. The second study examined how smokers and non-smokers differed in using social information during decision-making. Smokers were shown to be more influenced by risk-seeking observers, especially those they perceived as similar, while non-smokers exhibited the opposite pattern. EEG data revealed distinct neural responses, with P2 and P300 components varying according to observer type and risk preferences. The third study investigated how social influence affected smoking cravings, showing that group opinions significantly modulated cue-induced cravings. Current-smokers were more resistant to lower group norms but exhibited increased cravings when exposed to higher norms, whereas past smokers conformed more to lower norms. These findings demonstrate how social beliefs shape decision-making and addiction-related behaviors, uncovering key neural mechanisms and providing insights into how social contexts influence smoking cravings and risky decisions. Together, this dissertation offers a comprehensive understanding of how social information impacts behavior and highlights the potential for targeting social beliefs in interventions for smoking cessation.