bioRxiv Science⌕ Search

bioRxiv · 10.1101/2021.10.27.465887

On the dynamics of spatial updating

Abstract

Most of our knowledge on the human neural bases of spatial updating comes from fMRI studies in which recumbent participants moved in virtual environments. As a result, little is known about the dynamic of spatial updating during real body motion. Here, we exploited the high temporal resolution of electroencephalography (EEG) to investigate the dynamics of cortical activation in a spatial updating task where participants had to remember their initial orientation while they were passively rotated about their vertical axis in the dark. After the rotations, the participants pointed towards their initial orientation. We contrasted the EEG signals with those recorded in a control condition in which participants had no cognitive task to perform during body rotations. We found that the amplitude of the P1N1 complex of the rotation-evoked potential (RotEPs) (recorded over the vertex) was significantly greater in the Updating task. The analyses of the cortical current in the source space revealed that the main significant task-related cortical activities started during the N1P2 interval (136-303 ms after rotation onset). They were essentially localised in the temporal and frontal (supplementary motor complex, dorsolateral prefrontal cortex, anterior prefrontal cortex) regions. During this time-window, the right superior posterior parietal cortex (PPC) also showed significant task-related activities. The increased activation of the PPC became bilateral over the P2N2 component (303-470 ms after rotation onset). In this late interval, the cuneus and precuneus started to show significant task-related activities. Together, the present results are consistent with the general scheme that the first task-related cortical activities during spatial updating are related to the encoding of spatial goals and to the storing of spatial information in working memory. These activities would precede those involved in higher order processes also relevant for updating body orientation during rotations linked to the egocentric and visual representations of the environment.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Blouin, J., Pialasse, J.-P., Mouchnino, L., Simoneau, M.. 2021-10-28. On the dynamics of spatial updating. https://doi.org/10.1101/2021.10.27.465887

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Constraining Palaeogeography and Palaeotides for the Cambrian using cnidarian medusae

The ocean tides influence key Earth system processes at a range of spatial and temporal scales. It is known that the geometry of ocean basins is the leading controller of tidal energetics, so well-constrained palaeogeographic reconstructions and tidal properties for Earths past are imperative when investigating other Earth system processes. Here, we present a novel way to constrain both deep-time tidal model results and reconstructions, by combining palaeoecology with sedimentology. We compare new palaeo-tidal model simulations for the Cambrian period, significant for the early origin and radiation of major animal fauna, to tidal proxies. One of the most abundant soft-bodied organisms preserved during this time are cnidarian medusae (jellyfish). A total of 17 cnidarian medusae localities were obtained through the literature, which had an adequate global distribution and occurred at regular intervals throughout the period of study. In some locations there were also estimates of palaeo-tidal range. Our results show a good agreement between the simulations and proxy data. In the few locations where there is disagreement, it is proposed that the palaeogeographic reconstructions are missing details, e.g., island chains, and our results allow for the palaeogeographic reconstructions to be improved. The proxy method presented is promising and can be applied to other time-periods with different marine fossils, particularly at evolutionary and extinction periods where the marginal marine environment is of importance.

paleontology↗

The disadvantage of derivation: conserved systematic flaws in primary data have repeatedly biased the phylogenetic inference of Temnospondyli (Tetrapoda, Amphibia)

Phylogenetic analyses and their resultant tree topologies underlie paleobiological studies. Regardless of the type of study, the relationships of focal taxa are foundational, whether implemented in a qualitative or a quantitative framework. This reliance places a premium on the continued refinement of both phylogenetic methods and inference. Temnospondyls are a diverse clade of non-amniote ( amphibian) tetrapods whose phylogenetic relationships have been extensively explored due to their speciose nature, widespread occurrence in Paleozoic and Mesozoic paleoenvironments, and putative relationship to extant amphibians. Despite being studied by a diversity of workers, there is only one dataset that is widely employed to test the broad-scale relationships of Temnospondyli, that of Schoch (2013). This dataset has been reused in several high-profile studies testing the question of lissamphibian origins, and the original resultant topology has been widely adopted by taxonomic specialists and non-specialists alike. However, close examination of this matrix reveals discernible patterns of problematic codes related to non-homology, dependency, and unsubstantiated data (e.g., codes for postcranial characters for taxa with no known postcrania). These patterns, in conjunction with their prevalence, warrant a thorough survey of the entire matrix and subsequent reanalysis of its various forms to test whether previously published findings regarding the relationships of temnospondyls and the origins of lissamphibians are substantiated. A thorough reassessment of this matrix and several of its high-profile derivates revealed that the phylogeny of temnospondyls is more poorly known than depicted by the literature and that certain hypotheses of lissamphibian origins within Temnospondyli lack phylogenetic support.

paleontology↗

Fossil-explorer.com: An efficient interactive approach to exploring fossil data

Fossils today are increasingly being digitized and documented by multi-modal data obtained from visual data (i.e., photos and tomographic images), as well as text, locations, geological ages, and other chemical and physical measurements. Popular online websites such as PBDB and GBDB offer visual explorations of specimens localities, but they have limited multi-modal data visualization abilities and face challenges related to visual obscuration and insufficient interaction/exploration. Here, we present fossil-explorer.com, a continuously developing open-source online tool for assisting paleontologists with interactively exploring fossil collections. The tool is designed to address the issues of visual clutter, limited data types, and insufficient interactions. It is intuitive and endorsed by paleontologists. We have also quantitatively evaluated the tool by measuring the interaction scaling performance. The results show that it provides sublinear interaction performance and thus is able to deal efficiently with millions-level data. The current fossil-explorer.com demonstrates the Ordovician to Silurian graptolite fossil multimedia dataset, which is significant in global stratigraphy and shale gas exploration. The extended version also facilitates the use of Deepbone (http://deepbone.org), worlds most comprehensive database of vertebrate paleontology database. We developed the code for fossil-explorer.com to be open access and will continue to improve it.

paleontology↗