Sleep spindles consolidate declarative memory with tags: A meta-analysis of adult data

Abstract

Tags are attached to salient information during the wake period, which can preferentially determine what information can be consolidated during sleep. Previous studies demonstrated that spindles during non-rapid eye movement (NREM) sleep give priority to strengthening memory representations with tags, indicating a privileged reactivation of tagged information. The current meta-analysis investigated whether and how spindles can capture different tags to consolidate declarative memory. This study searched the Web of Science, Google Scholar, PubMed, PsycINFO, and OATD databases for studies that spindles consolidate declarative memory with tags. A meta-analysis using a random-effects model was performed. Based on 19 datasets from 18 studies (N = 388), spindles had a medium effect on the consolidation of declarative memory with tags (r = 0.519). In addition, spindles derived from whole-night sleep and nap studies were positively related to the consolidation of memory representations with tags. These findings reveal the shared mechanism that spindles are actively involved in the prefrontal-hippocampus circuits to consolidate memory with tags.