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Computational Intelligence and Neuroscience
Volume 2017 (2017), Article ID 8091780, 16 pages
https://doi.org/10.1155/2017/8091780
Research Article

Dorsoventral and Proximodistal Hippocampal Processing Account for the Influences of Sleep and Context on Memory (Re)consolidation: A Connectionist Model

1Department of Psychology, University of Arizona, Tucson, AZ 85721, USA
2Neuroscience Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ 85721, USA
3Program in Applied Mathematics, University of Arizona, Tucson, AZ 85721, USA

Correspondence should be addressed to Jean-Marc Fellous; ude.anozira.liame@suollef

Received 13 February 2017; Revised 23 May 2017; Accepted 1 June 2017; Published 3 July 2017

Academic Editor: Jens Christian Claussen

Copyright © 2017 Justin Lines et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The context in which learning occurs is sufficient to reconsolidate stored memories and neuronal reactivation may be crucial to memory consolidation during sleep. The mechanisms of context-dependent and sleep-dependent memory (re)consolidation are unknown but involve the hippocampus. We simulated memory (re)consolidation using a connectionist model of the hippocampus that explicitly accounted for its dorsoventral organization and for CA1 proximodistal processing. Replicating human and rodent (re)consolidation studies yielded the following results. (1) Semantic overlap between memory items and extraneous learning was necessary to explain experimental data and depended crucially on the recurrent networks of dorsal but not ventral CA3. (2) Stimulus-free, sleep-induced internal reactivations of memory patterns produced heterogeneous recruitment of memory items and protected memories from subsequent interference. These simulations further suggested that the decrease in memory resilience when subjects were not allowed to sleep following learning was primarily due to extraneous learning. (3) Partial exposure to the learning context during simulated sleep (i.e., targeted memory reactivation) uniformly increased memory item reactivation and enhanced subsequent recall. Altogether, these results show that the dorsoventral and proximodistal organization of the hippocampus may be important components of the neural mechanisms for context-based and sleep-based memory (re)consolidations.