VISUAL PROJECTIVE PERSPECTIVE CUES INFLUENCE DISTANCE ESTIMATION BEHAVIOUR AND PLACE CELL CODING IN RODENTS

Cells within the hippocampal formation code components of egocentric self-motion and allocentric environmental features essential for effective navigation. Vision is a highly immersive sense rich with spatial information and is vital for the accurate representation of spatial layout in the brain, however the susceptibility of the visual cortex to perceptual error may put regions of the cognitive map sensitive to visual input at risk of accumulating bottom-up error, particularly during travel through environments with ambiguous or distorted visual cues to perceived motion and environmental scale. This research utilises a novel distance estimation behavioural paradigm to assess the effect of distorting visual perspective features of the local environment on navigational behaviour and CA1 place cell activity in rats. Animals consistently overestimated the distance travelled to a learned reward zone when projective perspective cues were diverged, and underestimated distance when the cues converged. This behavioural change coincided with experience-dependent rate remapping and relocation of firing field locations during place cell recording. These distortive effects were rescued upon the inclusion of local landmarks into the environment and exacerbated by the removal of distal landmarks. Our findings are further supported by comparative performance of humans using wireless virtual reality and collectively suggest that perceived environmental perspective is essential for the accurate estimation of distance during visually guided navigation in rodents and humans. Through behavioural, electrophysiological and psychophysics research, we present novel evidence for the role of the visual perception of local environmental scale on spatial reasoning across species.