Navigation in Real-World Environments: New Opportunities Afforded by Advances in Mobile Brain Imaging

Abstract

A central question in neuroscience and psychology is how the mammalian brain represents the outside world and enables interaction with it. Significant progress on this question has been made in the domain of spatial cognition, where a consistent network of brain regions that represent external space has been identified in both humans and rodents. In rodents, much of the work to date has been done in situations where the animal is free to move about naturally. By contrast, the majority of work carried out to date in humans is static, due to limitations imposed by traditional laboratory based imaging techniques. In recent years, significant progress has been made in bridging the gap between animal and human work by employing virtual reality (VR) technology to simulate aspects of real-world navigation. Despite this progress, the VR studies often fail to fully simulate important aspects of real-world navigation, where information derived from self-motion is integrated with representations of environmental features and task goals. In the current review article, we provide a brief overview of animal and human imaging work to date, focusing on commonalties and differences in findings across species. Following on from this we discuss VR studies of spatial cognition, outlining limitations and developments, before introducing mobile brain imaging techniques and describe technical challenges and solutions for real-world recording. Finally, we discuss how these advances in mobile brain imaging technology, provide an unprecedented opportunity to illuminate how the brain represents complex multifaceted information during naturalistic navigation.

Keywords: EEG; fNIRS; mobile brain imaging; spatial navigation; virtual-reality (VR).

Figure 1

Recording procedure in rodents and basic navigation cells. (A) Schematic illustration of the setup for recording single cell data. (B) Examples of place and grid cell firing patterns: the gray lines show the animals’ path while exploring a square enclosure and the small dots highlight locations at which single neurons fired action potentials. Brain diagram highlights the location of place cells in the hippocampus and grid cells in the entorhinal cortex.

Figure 2

Imaging and virtual reality (VR). Example screenshots of VR style navigation tasks typically employed in the scanner (left), and images of depicting fully immersive 3D VR technology (right), highlighting limitations in the degree of psychological presence that can be obtained when combining a VR approach with static imaging techniques (i: adapted from Chadwick et al., ; ii: adapted from King et al., and iii: Courtesy of Matt Wain photography).