Memory specificity is linked to repetition effects in event-related potentials across the lifespan

Verena R Sommer,Luzie Mount,Sarah Weigelt,Markus Werkle-Bergner,Myriam C Sander

doi:10.1016/j.dcn.2021.100926

Abstract

The specificity with which past experiences can be remembered varies across the lifespan, possibly due to differences in how precisely information is encoded. Memory formation can be investigated through repetition effects, the common finding that neural activity is altered when stimuli are repeated. However, whether differences in this indirect measure of memory formation relate to lifespan differences in memory specificity has not yet been established. In the present study, we examined repetition effects in event-related potentials and their relation to recognition. During incidental encoding, children (aged 7–9 years), young adults (18–30 years), and older adults (65–76 years) viewed repeated object images from different categories. During subsequent recognition, we distinguished memory for the specific items versus the general categories. We identified repetition suppression in all age groups, and repetition enhancement for adults. Furthermore, individual item recognition performance comprising lure discrimination was positively associated with the magnitude of the neural repetition effects, which did not differ between groups, indicating common neural mechanisms of memory formation. Our findings demonstrate that neural repetition effects reflect the formation of highly specific memory representations and highlight their significance as a neural indicator of individual differences in episodic memory encoding across the lifespan.

Highlights

Memories of past events vary in their degree of specificity from very unique and detailed to more general and gist-like
Given that previous findings are mixed, the current study addresses the question whether repetition effects can be leveraged as a useful indicator for successful episodic memory formation within and across different populations, for example, age groups
The present study investigated whether processes of memory for mation, as reflected in neural repetition effects, are associated with inter-individual differences in item and category memory

Summary

Introduction

Memories of past events vary in their degree of specificity from very unique and detailed to more general and gist-like. Variability in memory specificity partly reflects how precisely incoming information has been encoded (McClelland and Rumelhart, 1985; Robin and Moscovitch, 2017). Forming precise memory representations is critical in many sit uations as it enables remembering specific details and avoiding confu sion with similar information. This ability changes across lifespan development (cf Ofen and Shing, 2013). Understanding how memory representations are formed is crucial in the study of memory, with regard to differences in memory competences across the lifespan

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