16/04/19
Speaker: Prof. Salvatore Maria Aglioti (in representation of Vanda Viola)
Temporal discounting (TD) refers to the devaluation of offered rewards as a function of the time until their delivery. Although the phenomenon has been widely studied, little is known about how interpersonal factors like trust or group coding influence TD. Religion is a belief system promoting group affiliation and group bias, and thus may have a strong impact on inter-temporal choices. We designed a task in which volunteers had to choose between immediate and delayed rewards proposed by an offerer belonging to the same vs. different religious group. fMRI scanning was performed in Muslim and Catholic individuals who had to perform an inter-temporal choice task between an immediate reward and a greater-but-delayed reward offered by either a Muslim or Christian offerer. Behavioural results show increased TD for Outgroup than Ingroup offerers. Analysis of BOLD signal show a parametric decrease of activity in the medial prefrontal cortex as delays increased. The inter-temporal modulation was stronger for Outgroup than for Ingroup offerers indicating higher devaluation of delayed payoffs offered by religious outgroup than ingroup individuals.