A collaboration of scientists from Drexel, Penn, Princeton, and UCLA recently announced they found grid cells in the brain of humans. The scientists measured human brain activity by opportunistically performing (highly invasive) electrode recordings in the brains of patients who were undergoing brain surgery for severe epilepsy. Grid cells form a regular lattice in a particular region of the brain and this lattice can be directly related to their functional properties of encoding position in euclidean space (and more speculatively, perhaps position even in more abstract types of mental space).
Neuroscience can seem very slow moving and sometimes repetitive (grid cells were, of course, previously identified in other species). But if you step back a bit, it’s surprising and impressive to recognize that we are starting to generate measurements, and mechanistic hypotheses, for the basic organization of some significant parts of human thought.
(“Direct recordings of grid-like neuronal activity in human spatial navigation” Jacobs et. al, Nature Neuroscience).