Novel characterization of the relationship between verbal list-learning outcomes and hippocampal subfields in healthy adults

• Main Authors: Beguedou, N. (Author), Cremona, S. (Author), Crivello, F. (Author), Joliot, M. (Author), Laurent, A. (Author), Mazoyer, B. (Author), Mellet, E. (Author), Pepe, A. (Author), Petit, L. (Author), Tsuchida, A. (Author), Tzourio, C. (Author), Zago, L. (Author)
• Format: Article
• Language: English
• Published: John Wiley and Sons Inc 2021
• Subjects: adolescent; Adolescent; adult; Adult; aged; anatomy and histology; article; association-based mnemonics; CA1 Region, Hippocampal; controlled study; diagnostic imaging; female; Female; healthy young adults; hippocampal CA1 region; hippocampal subfields; hippocampus; Hippocampus; human; human experiment; Humans; intelligence; learning test; Magnetic Resonance Imaging; major clinical study; male; Male; middle aged; Middle Aged; nuclear magnetic resonance imaging; physiology; recall; reliability; structural MRI; verbal learning; Verbal Learning; verbal list-learning; volumetry; young adult; Young Adult
• Online Access: View Fulltext in Publisher

 The relationship between hippocampal subfield volumetry and verbal list-learning test outcomes have mostly been studied in clinical and elderly populations, and remain controversial. For the first time, we characterized a relationship between verbal list-learning test outcomes and hippocampal subfield volumetry on two large separate datasets of 447 and 1,442 healthy young and middle-aged adults, and explored the processes that could explain this relationship. We observed a replicable positive linear correlation between verbal list-learning test free recall scores and CA1 volume, specific to verbal list learning as demonstrated by the hippocampal subfield volumetry independence from verbal intelligence. Learning meaningless items was also positively correlated with CA1 volume, pointing to the role of the test design rather than word meaning. Accordingly, we found that association-based mnemonics mediated the relationship between verbal list-learning test outcomes and CA1 volume. This mediation suggests that integrating items into associative representations during verbal list-learning tests explains CA1 volume variations: this new explanation is consistent with the associative functions of the human CA1. © 2021 The Authors. Human Brain Mapping published by Wiley Periodicals LLC.