How do people orient themselves when they are in a new area? How do we use street signs or houses, for instance, to estimate the distance we have traveled? Put simply: how do we update our mental map? Neuroscientists have been studying such questions in animals to learn about the basic principles of spatial cognition. "Until now, we have envied an invention from the world of science fiction: a holodeck like they have in Star Trek," says Prof. Dr. Andrew Straw. The holodeck is a space which can simulate any desired virtual world.