Are you worth the wait? Waiting time modulates the social feedback processing: Evidence from event-related potentials

Processing social feedback is essential for establishing appropriate social connections. However, social feedback is not always immediate, and the impact of waiting time on social feedback processing remains unexplored. Using electroencephalography (EEG) and event-related potentials (ERPs), the present study investigated how waiting time affects the N170, reward positivity (RewP), and P3. Participants (N = 36) completed a social evaluation task, awaiting feedback from liked and disliked peers with short (800-1200 ms) or long (5000-6000 ms) waiting times. Participants were more motivated to receive feedback from liked peers, and they rated acceptance from liked peers as more pleasant than rejection. Notably, participants found longer waits more worthwhile when receiving acceptance from liked peers, but less worthwhile when awaiting feedback from disliked peers. EEG results revealed that the RewP was increased for long waiting times for feedback from liked peers, and, conversely, reduced for long waiting times for feedback from disliked peers. Additionally, N170 and P3 were found to be sensitive to waiting time, with larger amplitudes for long compared to short waits. Overall, this study demonstrates that waiting time differentially affects social feedback processing, as reflected by changes in the N170, RewP, and P3. Our findings suggest that increased waiting time does not necessarily reduce reward value; it can enhance it depending on subjective social preferences. The increased N170 and P3 amplitudes during longer waits may indicate heightened attentional and memory demands. This study advances our understanding of the neurocognitive mechanisms underlying social decision-making.