Reactivation and consolidation of memory traces during post‐encoding rest across the adult lifespan

Authors:
Open Access
Publisher website
Google Scholar
Abstract
Episodic memory is a critical cognitive function that enables the encoding, storage, and retrieval of new information. Memory consolidation, a key stage of episodic memory, stabilizes this newly encoded information into long‐lasting brain “storage.” Studies using fMRI to investigate post‐encoding awake rest holds promise to shed light on early, immediate consolidation mechanisms. Here, we review fMRI studies during episodic memory to document common methods to investigate post‐encoding consolidation, such as multivoxel pattern analysis (MVPA) and functional connectivity, and the current state of the science in both healthy younger and older adults. In young adults, post‐encoding reactivation of stimuli‐specific neural patterns in the hippocampus and its connectivity with cortical and subcortical areas (e.g., visual‐temporal cortex, medial prefrontal, and medial parietal cortex) correlate with subsequent memory performance. Conversely, studies in older adults highlight the importance of large‐scale brain networks during post‐encoding rest, particularly the default mode network (DMN). Alterations in connectivity between the DMN and task‐positive networks may help older adults maintain episodic memory. Furthermore, non‐invasive brain stimulation techniques can enhance these post‐encoding consolidation processes and improve memory performance in both younger and older adults. Notably, a lack of studies has investigated post‐encoding memory consolidation in neurodegenerative disorders. This review underscores the importance of understanding how post‐encoding neural reactivation and connectivity evolve with age to partially explain age‐related declines in episodic memory performance and how such declines can be restored.

This publication has 47 references indexed in Scilit: