Map-Like Representations of an Abstract Conceptual Space in the Human Brain.

Much of higher cognition involves abstracting away from sensory details and thinking conceptually. How do our brains learn and represent such abstract concepts? Recent work has proposed that neural representations in the medial temporal lobe (MTL), which are involved in spatial navigation, might also support learning of higher-level knowledge structures. These ideas are supported by findings that neural representations in MTL, as well as medial prefrontal cortex (mPFC), are involved in “navigation” of simple two-dimensional spaces of visual stimuli, social spaces and odor spaces. A recent study in the Journal of Neuroscience by Viganò & Piazza (2020) takes this research further by suggesting that entorhinal cortex (EHC) and mPFC are capable of mapping not only sensory spaces, but also abstract semantic spaces. In this opinion piece, we first describe the paradigm and results of the study, as well as the importance of the findings for the field. We then raise several methodological concerns and suggest changes to the paradigm to address these issues. Finally, we discuss potential future research directions including experimental and modelling approaches to tackle outstanding questions in the field.