A metric for the cognitive map: found at last?

A network of brain areas collectively represent location, but the underlying nature of this "cognitive map" has remained elusive. A recent study reports that the activity patterns of some entorhinal cortical neurons form a remarkably regular array of evenly spaced peaks across the surface of the environment. These "grid cells" might be the basis of a metric used for calculating position, and their discovery could greatly advance our understanding of how navigational computations are performed.

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