A nap before retrieval reduces false identifications in target absent lineups

Abstract

Abstract Eyewitness misidentifications are a major cause of wrongful convictions. While most research has focused on the role of sleep in memory encoding and consolidation, recent findings suggest that non-REM sleep may also enhance retrieval processes by restoring executive and monitoring functions. Here, we investigated whether a short nap before retrieval could improve performance in forensic memory tasks. Participants watched an aversive video of a robbery and, after 24 h, either took a 60-minute nap (Sleep group) or stayed awake (Wake group) before completing a series of memory tasks, including face recognition (target-present and target-absent lineups), free recall, context recognition, and temporal order. A nap prior to retrieval selectively reduced false identifications in target-absent lineups, increasing correct rejections without affecting performance in target-present trials. Temporal order memory also improved in the Sleep group, whereas no significant differences were observed in free recall or context recognition. Confidence-accuracy calibration was stronger in the Sleep group, particularly when the perpetrator was absent. These findings suggest that a brief nap prior to memory retrieval may improve the accuracy of eyewitness decisions by enhancing metacognitive monitoring and temporal discrimination, offering a simple, non-invasive intervention to reduce errors in forensic settings.