The neural mechanisms of identifiable victim effect in prosocial decision-making.

The phenomenon known as the "identifiable victim effect" describes how individuals tend to offer more assistance to victims they can identify with than to those who are vague or abstract. The neural underpinnings of this effect, however, remain elusive. Our study utilized functional magnetic resonance imaging to delve into how the "identifiable victim effect" influences prosocial decision-making, considering different types of helping costs, across two distinct tasks. Participants were instructed to decide whether to help a victim with personal information shown (i.e., the identifiable victim) and an unidentifiable one by costing their money (task 1) or physical effort (task 2). Behaviorally, we observed a pronounced preference in both tasks for aiding identifiable victims over anonymous ones, highlighting a robust "identifiable victim effect." On a neural level, this effect was associated with heightened activity in brain areas like the bilateral temporoparietal junction (TPJ) when participants confronted anonymous victims, potentially indicating a more intensive mentalizing process for less concrete victims. Additionally, we noted that the TPJ's influence on value judgment processes is mediated through its functional connectivity with the medial prefrontal cortex. These insights contribute significantly to our understanding of the psychological and neural dynamics underlying the identifiable victim effect.