Combination and competition between path integration and landmark navigation in the estimation of heading direction

Abstract

Successful navigation requires the ability to compute one’s location and heading from incoming multisensory information. Previous work has shown that this multisensory input comes in two forms: body-based idiothetic cues, from one’s own rotations and translations, and visual allothetic cues, from the environment (usually visual landmarks). However, exactly how these two streams of information are integrated is unclear, with some models suggesting the body-based idiothetic and visual allothetic cues are combined, while others suggest they compete. In this paper we investigated the integration of body-based idiothetic and visual allothetic cues in the computation of heading using virtual reality. In our experiment, participants performed a series of body turns of up to 360 degrees in the dark with only a brief flash (300ms) of visual feedback en route. Because the environment was virtual, we had full control over the visual feedback and were able to vary the offset between this feedback and the true heading angle. By measuring the effect of the feedback offset on the angle participants turned, we were able to determine the extent to which they incorporated visual feedback as a function of the offset error. By further modeling this behavior we were able to quantify the computations people used. While there were considerable individual differences in performance on our task, with some participants mostly ignoring the visual feedback and others relying on it almost entirely, our modeling results suggest that almost all participants used the same strategy in which idiothetic and allothetic cues are combined when the mismatch between them is small, but compete when the mismatch is large. These findings suggest that participants update their estimate of heading using a hybrid strategy that mixes the combination and competition of cues.

Spatial memory distortions for the shapes of walked paths occur in violation of physically experienced geometry

“…For the false intersection-no cross (FI-NC) condition in Experiment 4, participants pointed in a manner consistent with the experienced path (in other words, little to no distortion), contrary to our findings in Experiments 2&3. Given the differences between our desktop and immersive (walking) conditions, and low distortions in the pole-guided (idiothetic) condition, our findings suggest that the distortions we observed likely arise from competition between idiothetic and visual cues [12,33,34]. This is also notable in terms of our findings for the immersive (walking) VR conditions in Experiments 1 and 2.…”

“…In Experiment 4, we employed an identical design to Experiment 2 but using desktop virtual reality in which body-based cues were absent, degrading the fidelity of idiothetic cues and selectively emphasizing visual cues. This was included to determine whether any topological distortions might arise from a simple preference for visual input or whether the distortions in Experiments 1-3 came about instead from competition and integration of idiothetic and visual input [12][13][14]33,34].…”

Gated transformations from egocentric to allocentric reference frames involving retrosplenial cortex, entorhinal cortex, and hippocampus

“…The mechanism of grid cell firing could depend upon different influences, including both transformation of sensory input that could drive egocentric boundary responses or path integration of self‐motion. Behavioral data shows that sensory inputs versus self‐motion integration can be combined when they give similar results or compete when they are inconsistent (Harootonian et al, 2022). The importance of sensory input in driving grid cells is supported by evidence that rotation of grid cell firing fields occurs with rotation of visual cues on the wall of a circular environment (Hafting et al, 2005; Savelli et al, 2017), and that grid cells show compression of the spacing between their firing fields in the dimension in which the walls of the environment are shifted closer to one another (Barry et al, 2007; Munn et al, 2020; Stensola et al, 2012).…”

Virtual Reality as a Tool to Understand Spatial Navigation

“…Yet, participants who walk on a path interrupted by these redirection techniques are able to point to previously learned locations in the virtual environment with relatively good accuracy (Williams, Narasimham, Rump, et al, 2007), indicating that they can mostly suppress the conflicting body-based cues and rely solely on visual cues. Research in which the visual world is offset from the body by varying degrees indicates that small deviations between body-based and visual cues lead to cue combination, whereas large deviations lead to reliance on a single cue type (Harootonian et al, 2022;Sjolund et al, 2018;Zhao & Warren, 2015), reflecting a qualitative change in cue processing when large conflicts are detected. In this way, redirection techniques that involve large conflict may cause greater reliance on visual input.…”