Spatial reorientation with a geometric array of auditory cues

Abstract

A visuocentric bias has dominated the literature on spatial navigation and reorientation. Studies on visually accessed environments indicate that, during reorientation, human and non-human animals encode the geometric shape of the environment, even if this information is unnecessary and insufficient for the task. In an attempt to extend our limited knowledge on the similarities and differences between visual and non-visual navigation, here we examined whether the same phenomenon would be observed during auditory-guided reorientation. Provided with a rectangular array of four distinct auditory landmarks, blindfolded, sighted participants had to learn the location of a target object situated on a panel of an octagonal arena. Subsequent test trials were administered to understand how the task was acquired. Crucially, in a condition in which the auditory cues were indistinguishable (same sound sample), participants could still identify the correct target location, suggesting that the rectangular array of auditory landmarks was encoded as a geometric configuration. This is the first evidence of incidental encoding of geometric information with auditory cues and, consistent with the theory of functional equivalence, it supports the generalisation of mechanisms of spatial learning across encoding modalities.

Interindividual differences influence multisensory processing during spatial navigation.

“…This finding confirmed that it is necessary to consider the natural variability across subjects, especially in terms of the heterogeneity of unimodal precision (Rohde et al, 2016). In addition, this research extended previous findings, which stated that it was possible for people to use auditory sources of information to orient themselves efficiently through space (Jetzschke et al, 2017;Nardi et al, 2020;Viaud-Delmon & Warusfel, 2014). This last evidence is particularly relevant to studying navigation and orientation in more ecological and real-life environments and exploring landmark-based navigation in visually impaired people.…”

“…We chose animal sounds to make the landmarks distinguishable from one another and semantically congruent to the accompanying visual cues. Similar to previous studies (Jetzschke et al, 2017;Nardi et al, 2020;Viaud-Delmon & Warusfel, 2014), we provided steady auditory landmarks to increase auditory information spatial reliability and make it more comparable with visual cues to spatial navigation. It is plausible to assume that the continuous presence of the sounds would indeed increase the saliency of spatial information, while intermittent sounds are more likely to produce disorientation in the moments of silence, considering the overall poor spatial acuity of auditory information.…”

“…Similar to what has been previously found regarding visual cues, an array of auditory landmarks can be encoded as a geometric configuration; in turn, this can provide people with information about the distance and direction among the auditory landmarks (Nardi et al, 2020). In addition, auditory sources in space provide people with enough spatial information to successfully orient themselves in an auditory equivalent of the Morris water maze (Viaud-Delmon & Warusfel, 2014), which is a classical paradigm used to assess spatial learning and memory in animals.…”

“…Regarding the use of spatial auditory information, sound properties of the auditory landmarks may have a role in the ability to spatially orient through space. In our experiments, we provided steady auditory landmarks, as done in previous studies (Jetzschke et al, 2017; Nardi et al, 2020; Viaud-Delmon & Warusfel, 2014), because we intended to provide constantly active sound stimuli that may be more likely to be detected and used to spatially navigate (see “Apparatus and Stimuli” section for details). Still, in a real-world environment, auditory landmarks can be either continuous (e.g., a river flowing) or irregular (e.g., a ball bouncing), likely conveying different levels of spatial information.…”

Effects of neuromodulation-inspired mechanisms on the performance of deep neural networks in a spatial learning task

“…It is worth noting that DNNs in the present study receive angular and linear velocities, rather than employing sensory inputs such as visual 32 , 33 , 34 , 35 and auditory 36 , 37 , 38 , 39 , 40 , 41 signals, or even information such as terrain slant. 42 Essentially, based on a functional equivalence view, different sensory inputs can result in corresponding spatial representations, exploratory behavior, and navigation performance.…”