Schedule of Events | Symposia

Abstract relational distance coding in the human brain

Poster Session B - Sunday, March 30, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Michael Starrett Ambrose¹ (mjstarrett@gmail.com), You Cheng¹, Rie Davis², Craig Stark¹, Elizabeth Chrastil¹; ¹University of California, Irvine, ²University of California, Santa Barbara

The ability to perceive distances within environments is essential for navigation. However, “distance” can extend beyond spatial relationships. Research on non-spatial relational processing suggests substantial overlap with spatial processing networks (i.e., domain general), with some important distinctions (domain specific function), but the degree of overlap remains poorly understood. Moreover, no study has explicitly incorporated manipulations of a core feature of spatial representations: the distinction between self-referential (egocentric) and observer-independent (allocentric) reference frames. Here, we developed a task that directly compares distance ratings across three domains (spatial, temporal, and social) and two frames (egocentric and allocentric). Participants were cued to a domain, viewed side-by-side images of either two historical figures (allocentric) or a historical figure and the participant themself (egocentric), and rated the distance for the cued domain. Participants (N=37) completed eight fMRI runs (30 trials/run) and provided confidence ratings outside the scanner. Univariate activity revealed substantial overlap across domains and activity in the anterior hippocampus across all conditions in the relational distance task. Activity in medial prefrontal cortex, posteromedial cortex, posterior parietal cortex, and anterior hippocampus showed sensitivity to whether judgements were allocentric or egocentric. Moreover, univariate activity scaled with domain-general distance primarily along the left middle temporal gyrus and occipital fusiform gyri. These results suggest that similar brain regions support relational processing for a variety of spatial and non-spatial domains. Moreover, egocentric and allocentric reference frames appear to rely on distinct neural codes to represent these domain-general relational distances.

Topic Area: LONG-TERM MEMORY: Other