A sense of direction in human entorhinal cortex.

Abstract

Finding our way in spatial environments is an essential part of daily life. How do we come to possess this sense of direction? Extensive research points to the hippocampus and entorhinal cortex (EC) as key neural structures underlying spatial navigation. To better understand this system, we examined recordings of single-neuron activity from neurosurgical patients playing a virtual-navigation video game. In addition to place cells, which encode the current virtual location, we describe a unique cell type, EC path cells, the activity of which indicates whether the patient is taking a clockwise or counterclockwise path around the virtual square road. We find that many EC path cells exhibit this directional activity throughout the environment, in contrast to hippocampal neurons, which primarily encode information about specific locations. More broadly, these findings support the hypothesis that EC encodes general properties of the current context (e.g., location or direction) that are used by hippocampus to build unique representations reflecting combinations of these properties.