Evidence for Maintained Post-Encoding Memory Consolidation Across the Adult Lifespan Revealed by Network Complexity

Abstract

Memory consolidation is well known to occur during sleep, but might start immediately after encoding new information while awake. While consolidation processes are important across the lifespan, they may be even more important to maintain memory functioning in old age. We tested whether a novel measure of information processing known as network complexity might be sensitive to post-encoding consolidation mechanisms in a sample of young, middle-aged, and older adults. Network complexity was calculated by assessing the irregularity of brain signals within a network over time using multiscale entropy. To capture post-encoding mechanisms, network complexity was estimated using functional magnetic resonance imaging (fMRI) during rest before and after encoding of picture pairs, and subtracted between the two rest periods. Participants received a five-alternative-choice memory test to assess associative memory performance. Results indicated that aging was associated with an increase in network complexity from pre- to post-encoding in the default mode network (DMN). Increases in network complexity in the DMN also were associated with better subsequent memory across all age groups. These findings suggest that network complexity is sensitive to post-encoding consolidation mechanisms that enhance memory performance. These post-encoding mechanisms may represent a pathway to support memory performance in the face of overall memory declines.

Negative affect homogenizes and positive affect diversifies social memory consolidation across people

“…A great deal of research identifies post-encoding rest as a critical moment for memory. 4,28,29 At the same time, a growing area of research investigates how neural similarity predicts meaningfully similar cognition and behavior. 9,30,31,32 In fact, recent work in this area found that people who are closer to one another in a social network also show similar resting state functional connectivity profiles, particularly in the default network.…”

Major Role of Multiscale Entropy Evolution in Complex Systems and Data Science

“…Multiscale complex system analysis, particularly multiscale entropy evolution, may improve the effectiveness of healthcare and public health [21]. Investigation of memory consolidation across different age groups found that multiscale entropy (MSE) is a sensitive measure to improve memory mechanisms [22]. The MSE measures can distinguish sleep stages in preterm infants [23,24].…”

Multiscale Entropy Approaches and Their Applications

“…McDonough et al were interested by post-encoding memory consolidation mechanisms in a sample of young, middle-aged and older adults [ 14 ]. For this purpose, they tested a novel measure of information processing, network complexity and studied if it was sensitive to these post-encoding mechanisms.…”