Fairness during resource allocation influences event-related potential (ERP) responses during memory of receivers'...

The abilities of memorizing others' faces are critical in social interactions. Previous event-related potential (ERP) studies have shown that neural responses during face memory (e.g., face encoding and recognition) are affected by emotional contexts that do not involve social interactions. Only a few studies have investigated the effects of social interaction-related contexts on neural responses during face memory. Here, we aimed to extend this investigation by exploring whether fairness-relevant contexts during resource allocations influence ERP responses during face encoding and recognition. To address the issue, 41 participants were required to view resource allocations between the participants themselves and a partner. The allocations were either fair or unfair to the participants. To understand the influence of allocation motivation, resources were proposed by either the partner or the computer. Participants were then presented with the face of the partner. After all the faces had been encoded, participants were required to recognize relevant faces. ERP results showed that fair compared to unfair allocations resulted in larger N170 responses to faces when resources were allocated by computers, whereas this effect was weakened for partner proposers. For both partner and computer proposers, fair-relevant compared to unfair-relevant faces evoked stronger late positive potential (LPP) responses. In the subsequent recognition phase, partner proposers reduced the differences between fair-relevant and unfair-relevant faces on N170 and LPP responses that were evident for computer proposers. These findings might suggest that social interaction-related contexts involving fairness affect neural responses during face memory, which, to some extent, rely on allocation motivation.