Divergent Neural Mechanisms of Self-Concerned and Prosocial Decision-Making Under High and Low Cognitive Loads

Abstract

This study examined how cognitive load differently affects the neural mechanisms of self-concerned and prosocial decisions. Under low and high cognitive load, participants chose how many tokens (0–5) to spend to reduce unpleasant noise for themselves or others. Results showed that high cognitive load increased token spending for both self and others, with a stronger effect for others. Individuals with higher empathy showed greater prosocial behavior under high load, highlighting empathy's moderating role. Neuroimaging revealed that high load boosted left insula activation during self-concerned decisions, reflecting internal salience and self-protection. In prosocial decisions, cognitive load increased activation in the bilateral temporo-parietal junction (TPJ) and right dorsolateral superior frontal gyrus (dlSFG), areas linked to mentalizing and cognitive control. Functional connectivity within the TPJ-dlSFG-prefrontal network predicted the impact of cognitive load on prosocial choices. These findings reveal distinct neural pathways: cognitive load enhances self-concern via insula salience, while prosocial behavior relies on TPJ-dlSFG integration of empathy and control, deepening the understanding of social decision-making under cognitive constraints.