Holistic Recollection via Pattern Completion Involves Hippocampal Subfield CA3

Journal article

Event memories consist of associations between their constituent elements, leading to their holistic retrieval via the process of pattern completion. This holistic retrieval can occur, under specific conditions, when each within-event association is encoded in a separate temporal context: adults are able to integrate the information into a single coherent representation. In this study, we sought to replicate the holistic retrieval of simultaneously encoded event elements in children, and examine whether children can similarly integrate across separated encoding contexts. Children (aged 6-7 years; 9-10 years) and adults encoded two series of three-element "events" consisting of an animal, object, and location. In the simultaneous condition, they encountered all three event elements at once; in the separated condition, they encountered each pairwise association separately (animal-object, animal-location, object-location). After encoding, they were tested on the retrieval of each within-event association using a 4-alternative-forced-choice task. We inferred the presence of holistic retrieval using a measure of retrieval dependency-the statistical dependency between retrieval of within-event associations. Memory for the pairs improved across ages, but there were no developmental differences in retrieval dependency. In the simultaneous encoding condition, all three age groups showed retrieval dependency. However, counter to previous studies, retrieval dependency was not observed in any age group following separated encoding. The results from the simultaneous encoding condition support the idea that pattern completion processes are developed by early childhood. The absence of retrieval dependency in adults following separated encoding prevent conclusions regarding the developmental trajectory of mnemonic integration

Authors: Grande, X; Berron, D; Horner, AJ; Bisby, JA; Düzel, E

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Society for Neuroscience
• Journal: The Journal of Neuroscience
• Volume: 39
• Issue: 41
• Pages: 8100-8111
• Publication date: 2019-08-12
• DOI: 10.1523/JNEUROSCI.0722-19.2019
• EISSN: 1529-2401
• ISSN: 0270-6474
• Language: English
• Keywords: Cognition; Neuroscience; Psychology; Episodic memory; Neuroimaging; Recall; Hippocampus; Hippocampal formation; Mnemonic; Cognitive psychology; Dentate gyrus