How the grid cell system of the brain maps mental spaces

How exactly the grid cell system works in the human brain, and in particular with which temporal dynamics, has until now been speculation. A much-discussed possibility is that the signals from these cells create maps of 'cognitive spaces' in which humans mentally organize and store the complexities of their internal and external environments. A team of scientists has now been able to demonstrate, with electrophysiological evidence, the existence of grid-like activity in the human brain.