Title
Vector-based navigation using grid-like representations in artificial agents.
Abstract
Deep neural networks have achieved impressive successes in fields ranging from object recognition to complex games such as Go(1,2). Navigation, however, remains a substantial challenge for artificial agents, with deep neural networks trained by reinforcement learnine(3-5) failing to rival the proficiency of mammalian spatial behaviour, which is underpinned by grid cells in the entorhinal cortex'. Grid cells are thought to provide a multi-scale periodic representation that functions as a metric for coding space(7,8) and is critical for integrating self-motion (path integration)(6,7,9) and planning direct trajectories to goals (vector-based navigation)(7,10,11). Here we set out to leverage the computational functions of grid cells to develop a deep reinforcement learning agent with mammal-like navigational abilities. We first trained a recurrent network to perform path integration, leading to the emergence of representations resembling grid cells, as well as other entorhinal cell types(12). We then showed that this representation provided an effective basis for an agent to locate goals in challenging, unfamiliar, and changeable environments optimizing the primary objective of navigation through deep reinforcement learning. The performance of agents endowed with grid-like representations surpassed that of an expert human and comparison agents, with the metric quantities necessary for vector-based navigation derived from grid-like units within the network. Furthermore, grid-like representations enabled agents to conduct shortcut behaviours reminiscent of those performed by mammals. Our findings show that emergent grid-like representations furnish agents with a Euclidean spatial metric and associated vector operations, providing a foundation for proficient navigation. As such, our results support neuroscientific theories that see grid cells as critical for vector-based navigation(7,10,11), demonstrating that the latter can be combined with path-based strategies to support navigation in challenging environments.
Year
DOI
Venue
2018
10.1038/s41586-018-0102-6
NATURE
DocType
Volume
Issue
Journal
557
7705
ISSN
Citations 
PageRank 
0028-0836
27
1.26
References 
Authors
15
26
Name
Order
Citations
PageRank
Andrea Banino1412.84
Caswell Barry2282.29
Benigno Uria3271.26
Charles Blundell482241.64
Timothy P. Lillicrap54377170.65
Piotr Mirowski6271.26
Alexander Pritzel7301.97
Chadwick Martin8272.61
Thomas Degris9271.26
Joseph Modayil10271.26
Greg Wayne11271.26
Hubert Soyer12271.26
Fabio Viola132028.87
Brian Zhang14271.26
Ross Goroshin15412.16
Neil Rabinowitz16271.26
Razvan Pascanu172596199.21
Charlie Beattie18271.26
Stig Petersen19632.36
Amir Sadik20271.26
Stephen Gaffney21271.26
Helen King22271.26
Koray Kavukcuoglu2310189504.11
Demis Hassabis24271.26
Raia Hadsell25271.26
Dharshan Kumaran26271.26