Charting Spatial Memory Over Time in Developmental Amnesia

Poster Session E - Monday, March 9, 2026, 2:30 – 4:30 pm PDT, Fairview/Kitsilano Ballrooms

Tolu Faromika¹ (tolufaro@yorku.ca), Katherine Herdman⁴, R. Shayna Rosenbaum^1,2,3; ¹York University, ²Rotman Research Institute, Baycrest Academy for Research and Education, ³Centre for Integrative and Applied Neuroscience, York University, ⁴Ottawa Hospital

Spatial memory enables our navigation and orientation in the world. Cognitive Map Theory posits that the hippocampus is critical for allocentric spatial memory; however, evidence from the literature on hippocampal amnesia presents a mixed picture. While adult-onset hippocampal damage is associated with impaired formation of new allocentric representations, individuals with hippocampal damage have been shown to retain coarse, gist-like representations of highly familiar environments and even newly experienced environments. Preliminary evidence links spatial memory deficits in developmental amnesia to atypical development of the hippocampus and extended hippocampal system. This raises the question of whether extended learning can support the development of gist-like spatial representations. We investigated this question through a longitudinal examination of spatial memory in an individual with developmental amnesia, H.C. Building on prior work (Rosenbaum et al., 2015), H.C. was retested on a battery of mental navigation tasks based on familiar environments. Performance was compared to that of control participants with similar environmental exposure. Results indicate that extended learning supports the development of gist-like spatial representations in developmental amnesia. H.C. demonstrated preserved relational knowledge sufficient for coarse navigation and landmark anchoring, but continued to show reduced flexibility, limited detail, and swap errors. These findings suggest that while neocortical systems may support schematic spatial representations, the hippocampus remains critical for binding fine-grained relational detail within a coherent and flexible map. These results encourage refinement of traditional models of hippocampal involvement in spatial memory and highlight the role of experience in shaping spatial knowledge.

Topic Area: LONG-TERM MEMORY: Other