How does the human brain encode egocentric spatial maps?

Lukas Kunz, Armin Brandt, Peter C. Reinacher, Bernhard P. Staresina, Eric T. Reifenstein, Christoph T. Weidemann, Nora A. Herweg, Ansh Patel, Melina Tsitsiklis, Richard Kempter, Michael J. Kahana, Andreas Schulze-Bonhage, Joshua Jacobs. A neural code for egocentric spatial maps in the human medial temporal lobe. Neuron, 2021. https://doi.org/10.1016/j.neuron.2021.06.019 

Highlights
• Human single-neuron recordings during navigation identify egocentric bearing cells (EBCs)
• These EBCs provide a counterpart to allocentric, world-referenced spatial cell types
• EBCs encode self-centered bearings and distances toward reference points in space
• EBCs play a role in human spatial and episodic memory
Summary
Spatial navigation and memory rely on neural systems that encode places, distances, and directions in relation to the external world or relative to the navigating organism. Place, grid, and head-direction cells form key units of world-referenced, allocentric cognitive maps, but the neural basis of self-centered, egocentric representations remains poorly understood. Here, we used human single-neuron recordings during virtual spatial navigation tasks to identify neurons providing a neural code for egocentric spatial maps in the human brain. Consistent with previous observations in rodents, these neurons represented egocentric bearings toward reference points positioned throughout the environment. Egocentric bearing cells were abundant in the parahippocampal cortex and supported vectorial representations of egocentric space by also encoding distances toward reference points. Beyond navigation, the observed neurons showed activity increases during spatial and episodic memory recall, suggesting that egocentric bearing cells are not only relevant for navigation but also play a role in human memory.”

Lukas Kunz, Armin Brandt, Peter C. Reinacher, Bernhard P. Staresina, Eric T. Reifenstein, Christoph T. Weidemann, Nora A. Herweg, Ansh Patel, Melina Tsitsiklis, Richard Kempter, Michael J. Kahana, Andreas Schulze-Bonhage, Joshua Jacobs. A neural code for egocentric spatial maps in the human medial temporal lobe. Neuron, 2021. https://doi.org/10.1016/j.neuron.2021.06.019