Sleep reduces the semantic coherence of memory recall: An application of latent semantic analysis to investigate memory reconstruction

Autor: Marc N. Coutanche, Xueying Ren
Rok vydání: 2021
Předmět:
Zdroj: Psychonomic Bulletin & Review. 28:1336-1343
ISSN: 1531-5320
1069-9384
DOI: 10.3758/s13423-021-01919-8
Popis: Sleep is thought to help consolidate hippocampus-dependent memories by reactivating previously encoded neural representations, promoting both quantitative and qualitative changes in memory representations. However, the qualitative nature of changes to memory representations induced by sleep remains largely uncharacterized. Another contributor to memory encoding and retrieval, prior knowledge, also facilitates the integration of novel information with existing memory representations. In this study, we investigated how memories of naturalistic visual episodes are reconstructed. We hypothesized that semantic coherence, quantified as conceptual relatedness between statements using latent semantic analysis (LSA), will be affected by both post-encoding sleep and the presence of prior knowledge. Short naturalistic videos of events featuring rare animals were presented to 115 participants that were randomly assigned to either 12- or 24-hour delay groups featuring sleep or wakefulness. Participants’ free recall responses were analyzed using LSA to measure two types of semantic coherence: sequential semantic coherence (SSC), which represents the conceptual similarity between adjacent sentences within a free recall text; and topic semantic coherence (TSC), which represents the conceptual similarity between all sentences within a text. Both SSC and TSC of memory recall were significantly reduced after sleep comparing to wakefulness, with no differences due to prior knowledge. These findings support the notion that sleep-dependent consolidation qualitatively changes the feature of reconstructed memory representations by reducing semantic coherence.
Databáze: OpenAIRE
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