journal.pcbi.1010566.pdf (2.93 MB)
Hippocampal and medial prefrontal cortices encode structural task representations following progressive and interleaved training schedules
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posted on 2023-06-10, 05:08 authored by Samuel BerensSamuel Berens, Chris BirdChris BirdMemory generalisations may be underpinned by either encoding- or retrieval-based generalisation mechanisms and different training schedules may bias some learners to favour one of these mechanisms over the other. We used a transitive inference task to investigate whether generalisation is influenced by progressive vs randomly interleaved training, and overnight consolidation. On consecutive days, participants learnt pairwise discriminations from two transitive hierarchies before being tested during fMRI. Inference performance was consistently better following progressive training, and for pairs further apart in the transitive hierarchy. BOLD pattern similarity correlated with hierarchical distances in the left hippocampus (HIP) and medial prefrontal cortex (MPFC) following both training schedules. These results are consistent with the use of structural representations that directly encode hierarchical relationships between task features. However, such effects were only observed in the MPFC for recently learnt relationships. Furthermore, the MPFC appeared to maintain structural representations in participants who performed at chance on the inference task. We conclude that humans preferentially employ encoding-based mechanisms to store map-like relational codes that can be used for memory generalisation. These codes are expressed in the HIP and MPFC following both progressive and interleaved training but are not sufficient for accurate inference.
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- Published
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- Published version
Journal
PLoS Computational BiologyISSN
1553-734XPublisher
Public Library of Science (PLoS)External DOI
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10Volume
18Page range
1-30Department affiliated with
- Psychology Publications
Full text available
- Yes
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- Yes
Legacy Posted Date
2022-10-18First Open Access (FOA) Date
2022-11-02First Compliant Deposit (FCD) Date
2022-10-17Usage metrics
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