Spatial and semantic memory reorganize a hippocampal long-axis gradient.
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| Title: | Spatial and semantic memory reorganize a hippocampal long-axis gradient. |
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| Authors: | Jordan, Anikka G.1, Voss, Joel L.1, Kragel, James E.1 jkragel@uchicago.edu |
| Source: | Proceedings of the National Academy of Sciences of the United States of America. 4/14/2026, Vol. 123 Issue 15, p1-12. 22p. |
| Subjects: | Spatial memory, Semantic memory, Cognitive maps (Psychology), Hippocampus (Brain), Episodic memory, Functional magnetic resonance imaging |
| Abstract: | The hippocampus supports episodic memory by binding spatial and semantic information, yet how this information is simultaneously organized along its long axis remains debated. Gradient accounts propose a continuous shift in representational scale, from coarse coding in anterior to fine coding in posterior regions, whereas modular accounts posit discrete subregions specialized for distinct functions. Using high-resolution fMRI together with eye tracking as a readout of spatial and semantic memory during sequence learning, we directly tested these competing models. During predictable sequences, hippocampal activity continuously varied along the long axis. In contrast, modular organization emerged when sequences mismatched memory. Subregions in the anterior and posterior hippocampus were sensitive to semantic and spatial mismatches, respectively. Notably, the intermediate hippocampus was specifically sensitive to concurrent mismatches in both dimensions, but not to mismatches in either dimension alone. These content-sensitive subregions were embedded within distinct cortical networks that reorganized according to memory demands. Together, our findings reveal a dynamic hippocampal architecture that flexibly combines gradient and modular principles to simultaneously represent the spatial and semantic content that defines episodic memory. [ABSTRACT FROM AUTHOR] |
| Copyright of Proceedings of the National Academy of Sciences of the United States of America is the property of National Academy of Sciences and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 193036217 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1073/pnas.2525724123 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 22 StartPage: 1 Subjects: – SubjectFull: Spatial memory Type: general – SubjectFull: Semantic memory Type: general – SubjectFull: Cognitive maps (Psychology) Type: general – SubjectFull: Hippocampus (Brain) Type: general – SubjectFull: Episodic memory Type: general – SubjectFull: Functional magnetic resonance imaging Type: general Titles: – TitleFull: Spatial and semantic memory reorganize a hippocampal long-axis gradient. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Jordan, Anikka G. – PersonEntity: Name: NameFull: Voss, Joel L. – PersonEntity: Name: NameFull: Kragel, James E. IsPartOfRelationships: – BibEntity: Dates: – D: 14 M: 04 Text: 4/14/2026 Type: published Y: 2026 Identifiers: – Type: issn-print Value: 00278424 Numbering: – Type: volume Value: 123 – Type: issue Value: 15 Titles: – TitleFull: Proceedings of the National Academy of Sciences of the United States of America Type: main |
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