Social relevance reshapes memory encoding and promotes false memories across sensory modalities

Memory is shaped not only by the information itself but also by its social relevance. The present study investigated whether, in the absence of misleading information, social relevance can increase false memory by altering encoding processes, and whether this effect depends on sensory modality. Using a social DRM paradigm combined with fNIRS, we manipulated item relevance (self-relevant, partner-relevant, irrelevant) and encoding modality (visual, auditory). Behavioral results showed that partner-relevant items elicited more false memories than irrelevant items, indicating that social relevance alone is sufficient to enhance false memory; moreover, this effect was stronger under auditory than visual encoding. Neural findings revealed that socially relevant items recruited the frontal, temporal, and temporoparietal regions during encoding, suggesting that social relevance may trigger a spontaneous monitoring process. Further analyses indicated that frontal and temporal activity predicted subsequent false memory, whereas temporoparietal activity reflected social orienting rather than directly predicting memory distortion. These results suggest that false memory may arise not only from external misinformation but also from encoding biases triggered by social cues. Overall, this study provides new evidence for understanding how social contexts influence false memory and suggests that social relevance may shape subsequent memory performance by modulating attentional allocation and encoding processes.