Biology subjects

Mallot, H. A.

Publications and source records attributed to Mallot, H. A..

4 recordsLinked to original sources

bioRxiv2023

Metric information in cognitive maps: Euclidean embedding of non-Euclidean environments

The structure of the internal representation of surrounding space, the so-called cognitive map, has long been debated. A Euclidean metric map is the most straight-forward hypothesis, but human navigation has been shown to systematically deviate from the Euclidean ground truth. Vector navigation based on non-metric models can better explain the observed behavior, but also discards useful geometric properties such as fast shortcut estimation and cue integration. Here, we propose another alternative, a Euclidean metric map that is systematically distorted to account for the observed behavior. The map is found by embedding the non-metric model, a labeled graph, into 2D Euclidean coordinates. We compared these two models using human data from Warren et al. (2017), where participants had to navigate and learn a non-Euclidean maze (i.e., with Wormholes) and perform direct shortcuts between different locations. Even though the Euclidean embedding cannot correctly represent the non-Euclidean environment, both models predicted the data equally well. We argue that the so embedded graph naturally arises from integrating the local position information into a metric framework, which makes the model more powerful and robust than the non-metric alternative. It may therefore be a better model for the human cognitive map.

neuroscience↗

bioRxiv2022

When your border and my border differ: Spatial regionalisation and route choice depends on perceived landmark categorization

Humans spontaneously structure spatial environments into a hierarchy of regions. Besides connectivity and boundaries, sensory or functional similarities of landmarks have been shown to influence construction of regions. In natural spaces, regions and places are usually named and these names provide additional cues for the cognitive construction of regions. In this study we investigate the role of semantic similarities of place names in the formation of regions in a virtual environment with homogeneous connectivity. Place names were selected and distributed in a way that two alternative semantic categorizations were possible which corresponded to two equally valid regionalisations of the same environment. Region perception was assessed by having subjects choose between two equidistant routes crossing different numbers of region boundaries (classification consistent route choice). In a priming phase, subjects were biased to sort the landmark names in one or the other categorization scheme. In the test phase, subjects preferably selected routes with a lower number of region crossings according to the categorization previously discovered. The results show that perceived semantic similarity of place names does affect route choice and the formation of spatial regions.

neuroscience↗

bioRxiv2022

Presence and perceived body orientation affect the recall of out-of-sight places in an immersive sketching experiment

The orientation of sketch maps of remote but familiar city squares produced from memory has been shown to depend on the distance and airline direction from the production site to the remembered square (position dependent recall, Rohrich, Hardiess, & Mallot, 2014). Here, we present a virtual reality version of the original experiment and additionaly study the role of body orientation. Three main points can be made: First, "immersive sketching" is a novel and useful paradigm in which subjects sketch maps live on paper while being immersed in virtual reality. Second, the original effect of position dependent recall was confirmed, indicating that the sense of presence generated in a virtual environment suffices to bias the imagery of distant places. Finally, the orientation of the produced sketch maps depended also on the body orientation of the subjects. At each production site, body orientation was controlled by varying the position of the life feed in the virtual environment such that subjects had to turn towards the prescribed direction. Position dependent recall is strongest if subjects are aligned with the airline direction to the target and virtually goes away if they turn in the opposite direction.

neuroscience↗

bioRxiv2022

Gateway Identity and Spatial Remapping in a Combined Grid and Place Cell Attractor.

The spatial specificities of hippocampal place cells, i.e., their firing fields, are subject to change if the rat enters a new compartment in the experimental maze. This effect is known as remapping. It cannot be explained from path integration (grid cell activity) and local sensory cues alone but requires additional knowledge of the different compartments in the form of context recognition at the gateways between them. Here we present a model for the hippocampalentorhinal interplay in which the activity of place and grid cells follows a joint attractor dynamic. Place cells depend on the current grid cell activity but can also reset the grid cell activity in the remapping process. Remapping is triggered by the passage through a gateway. When this happens, a previously stored pattern of place cell activity associated with the gateway is reactivated from a "gateway database". The joint attractor will then reinstate the grid cell pattern that was active when the gateway had first been learned and path integration can proceed from there. The model is tested with various mazes used in the experimental literature and reproduces the published results, and we make predictions for remapping in a new maze type. We propose the involvement of memory in the form of "gate cells" that drive the place cells and with them the joint hippocampal-entorhinal loop into the corresponding attractor whenever a compartment is entered.

neuroscience↗