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Paper Detail

Paper: PS-2A.52
Session: Poster Session 2A
Location: H Lichthof
Session Time: Sunday, September 15, 17:15 - 20:15
Presentation Time:Sunday, September 15, 17:15 - 20:15
Presentation: Poster
Publication: 2019 Conference on Cognitive Computational Neuroscience, 13-16 September 2019, Berlin, Germany
Paper Title: A cognitive map of social network space
Manuscript:  Click here to view manuscript
License: Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 Unported License.
Authors: Seongmin Park, Douglas Miller, University of California, Davis, United States; Hamed Nili, University of Oxford, United Kingdom; Charan Ranganath, Erie Boorman, University of California, Davis, United States
Abstract: The hippocampal-entorhinal (HPC-ERC) system may serve a general mechanism for navigating non-spatial cognitive maps. Here, we investigate whether this system uses the same principles to represent entities along abstract and discrete dimensions, and how the brain integrates separately learned relational structures. Participants learned ranks of individuals in two groups on two separate dimensions independently. Their knowledge about between-group relationships was limited to selected individuals called hubs, who created a unique associative path between groups. In fMRI, participants made inferences about the relative ranks of novel pairs between groups. During inferences, the ERC and ventromedial prefrontal cortex (vmPFC) encode Euclidean distances from the hub on the 2-D social space. Trial-by-trial fMRI suppression analysis revealed that HPC activity was suppressed when the novel face pair was followed by their relevant hub compared to other matched hubs, suggesting a neural reinstatement of the hub. Finally, we found a robust linear relationship between the pairwise Euclidean distance between individuals in the social network and the dissimilarity in activity patterns in the HPC, ERC, and orbitofrontal cortex (OFC). These results shed light on how abstract and discrete structures are represented, navigated, and combined in the human brain, suggesting that general mechanisms in the HPC-ERC system are leveraged to navigate discrete and abstract social networks.