Biopsychology Colloquium: Encoding of Path Network Structure at the Juncture of Hippocampus and Cortex

The hippocampus and posterior parietal cortex are each known to be key contributors to spatial cognition. Anatomically between these structures lie the subiculum and the retrosplenial cortex, brain structures whose roles in a distributed system for cognitive mapping are only now being revealed. Our recent projects examining the dynamics of neurons in these regions during performance of navigational tasks reveal conjunctions of multiple spatial relationships consistent with a transformation of spatial cognition to action. However, we also observe unique forms of tuning to orientation and route locations that signal a larger role in encoding the structural layout of paths within an environment. We therefore speculate that these brain regions together map path network topologies.