Reactivating Positive Personality Traits During Sleep Promotes Positive Self-Referential Processing

Positive self-view is evident by a bias in favor of positive self-referential processing, as individuals tend to endorse positive characteristics over negative ones when making self-judgments. While research suggests that a positivity bias can contribute to psychological well-being, it remains unclear how to enhance positive self-referential processing. Here, we reported an integrated training procedure that aimed at enhancing individuals positive self-referential processing. Specifically, participants engaged in a cue-approach training task (CAT) during wakefulness where they gave speeded motor responses to positive personality traits. In a subsequent nap, we unobtrusively re-played half of the trained positive traits during participants slow-wave sleep to reactivate memories associated with these positive traits (targeted memory reactivation, TMR). Upon awakening, we found that CAT+TMR enhanced participants positive self-referential processing, as evidenced by faster endorsement of positive traits. Further analysis revealed that this enhancement was associated with specific brainwave patterns during sleep: delta (1-4 Hz) traveling waves moving from posterior to anterior brain regions. These findings demonstrate the potential benefits of integrated wakeful cue-approach training and sleep-based memory reactivation in strengthening positive self-referential processing.