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Introduction: The normal hemispheric balance can be altered by the asymmetric sensorimotor signal elicited by Cervical Dystonia (CD), leading to motor and cognitive deficits. Methods: Directional errors, peak velocities, movement and reaction times of pointing towards out-of-reach targets in the horizontal plane were analysed in 18 CD patients and in 11 aged-matched healthy controls. Results: CD patients displayed a larger scatter of individual trials around the average pointing direction (variable error) than normal subjects, whatever the arm used, and the target pointed. When pointing in the left hemispace, all subjects showed a left deviation (constant error) with respect to the target position, which was significantly larger in CD patients than controls, whatever the direction of the abnormal neck torsion could be. Reaction times were larger and peak velocities lower in CD patients than controls. Discussion: Deficits in the pointing precision of CD patients may arise from a disruption of motor commands related to the sensorimotor imbalance, from a subtle increase in shoulder rigidity or from a reduced agonists activation. Their larger left bias in pointing to left targets could be due to an increased right parietal dominance, independently upon the direction of head roll/jaw rotation which expands the left space representation and/or increases left spatial attention. These deficits may potentially extend to tracking and gazing objects in the left hemispace, leading to reduced skills in spatial-dependent motor and cognitive performance. [ABSTRACT FROM AUTHOR]

IntroductionThe normal hemispheric balance can be altered by the asymmetric sensorimotor signal elicited by Cervical Dystonia (CD), leading to motor and cognitive deficits.MethodsDirectional errors, peak velocities, movement and reaction times of pointing towards out-of-reach targets in the horizontal plane were analysed in 18 CD patients and in 11 aged-matched healthy controls.ResultsCD patients displayed a larger scatter of individual trials around the average pointing direction (variable error) than normal subjects, whatever the arm used, and the target pointed. When pointing in the left hemispace, all subjects showed a left deviation (constant error) with respect to the target position, which was significantly larger in CD patients than controls, whatever the direction of the abnormal neck torsion could be. Reaction times were larger and peak velocities lower in CD patients than controls.DiscussionDeficits in the pointing precision of CD patients may arise from a disruption of motor commands related to the sensorimotor imbalance, from a subtle increase in shoulder rigidity or from a reduced agonists activation. Their larger left bias in pointing to left targets could be due to an increased right parietal dominance, independently upon the direction of head roll/jaw rotation which expands the left space representation and/or increases left spatial attention. These deficits may potentially extend to tracking and gazing objects in the left hemispace, leading to reduced skills in spatial-dependent motor and cognitive performance.

The objective of this study is to systematically describe the diminutive/augmentative mechanism through noun inflection in Kirundi. By applying the cognitive theory of space representation to the size of the static and bounded object (without considering its geometric shape), three results were obtained. First, the diminutive/augmentative is expressed by means of the secondary noun classification with derivational purpose. Then, the marks of secondary classes in the singular (-ki-, -ka-, -ru-) represent a mode of occupation of the continuous space while those of the plural (-bi-, -tu-, -bu-) serve as support for a mode of occupation of discontinuous space. Finally, taking the primary noun class as a mark of the normal reference size, the diminutive/augmentative mechanism distinguishes two degrees from the normal size of the object considered. [ABSTRACT FROM AUTHOR]

At present, ArchDaily.com is the most visited virtual architecture platform in the world. Aware of the importance acquired in the architectural practice, the site declares itself to be the main source from which architects feed on tools, information and inspiration to develop their projects. However, it is clear that its importance is not limited to its status as reference bank for professional practice. The accumulation of visual and textual representations contributes to the idea of “good architecture”, in turn transforming this platform into an institution validating and legitimizing the understanding of the discipline, its scope and limitations, its protagonists and predominant methods applied. The following pages propose an analysis of the platform’s content in its residential architecture section, an analysis that supports a critical reflection on its wider cultural effects.

Grid cells are crucial in path integration and representation of the external world. The spikes of grid cells spatially form clusters called grid fields, which encode important information about allocentric positions. To decode the information, studying the spatial structures of grid fields is a key task for both experimenters and theorists. Experiments reveal that grid fields form hexagonal lattice during planar navigation, and are anisotropic beyond planar navigation. During volumetric navigation, they lose global order but possess local order. How grid cells form different field structures behind these different navigation modes remains an open theoretical question. However, to date, few models connect to the latest discoveries and explain the formation of various grid field structures. To fill in this gap, we propose an interpretive plane-dependent model of three-dimensional (3D) grid cells for representing both two-dimensional (2D) and 3D space. The model first evaluates motion with respect to planes, such as the planes animals stand on and the tangent planes of the motion manifold. Projection of the motion onto the planes leads to anisotropy, and error in the perception of planes degrades grid field regularity. A training-free recurrent neural network (RNN) then maps the processed motion information to grid fields. We verify that our model can generate regular and anisotropic grid fields, as well as grid fields with merely local order; our model is also compatible with mode switching. Furthermore, simulations predict that the degradation of grid field regularity is inversely proportional to the interval between two consecutive perceptions of planes. In conclusion, our model is one of the few pioneers that address grid field structures in a general case. Compared to the other pioneer models, our theory argues that the anisotropy and loss of global order result from the uncertain perception of planes rather than insufficient training.

Grid cells are crucial in path integration and representation of the external world. The spikes of grid cells spatially form clusters called grid fields, which encode important information about allocentric positions. To decode the information, studying the spatial structures of grid fields is a key task for both experimenters and theorists. Experiments reveal that grid fields form hexagonal lattice during planar navigation, and are anisotropic beyond planar navigation. During volumetric navigation, they lose global order but possess local order. How grid cells form different field structures behind these different navigation modes remains an open theoretical question. However, to date, few models connect to the latest discoveries and explain the formation of various grid field structures. To fill in this gap, we propose an interpretive plane-dependent model of three-dimensional (3D) grid cells for representing both two-dimensional (2D) and 3D space. The model first evaluates motion with respect to planes, such as the planes animals stand on and the tangent planes of the motion manifold. Projection of the motion onto the planes leads to anisotropy, and error in the perception of planes degrades grid field regularity. A training-free recurrent neural network (RNN) then maps the processed motion information to grid fields. We verify that our model can generate regular and anisotropic grid fields, as well as grid fields with merely local order; our model is also compatible with mode switching. Furthermore, simulations predict that the degradation of grid field regularity is inversely proportional to the interval between two consecutive perceptions of planes. In conclusion, our model is one of the few pioneers that address grid field structures in a general case. Compared to the other pioneer models, our theory argues that the anisotropy and loss of global order result from the uncertain perception of planes rather than insufficient training. [ABSTRACT FROM AUTHOR]

The introduction of time-based media into the design stage opened up a new understanding of architectural and represented space as a dematerialized, dynamic, and user-dependent concept. Unbuildable architectural projects always relied on specific techniques and media. Their radical nature usually channelled innovative artistic currents and visualization tools, like collage and pop art aesthetics in the works of Archigram. Cinema is yet another ground for such deliberations. With Instant City (Archigram’s Peter Cook and Ron Herron) and The Zero Theorem (Terry Gilliam) the problem of dematerialization is being channelled by architectural/spatial proposals that involve a range of literary tropes, cultural texts, and filmic intertexts, in order to create a rich embroidery of references that forward a new look upon architectural production as a practice of creating protocols for dynamic and all the more elusive imagery. This article’s central objective lies in the task of reframing a discussion on iconicity, media facades, and mutative building skins, so as to include modes of cinematic portrayal that are not just contents of architectural “messages”, but also their “media”.

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• Early blind individuals are not able to perform spatial bisection tasks and do not show the same ERP response mimicking the visual C1 reported in sighted people. • In late blind individuals spatial bisection abilities and neural correlates depend on blindness duration. • The deficit associated with blindness disappears if coherent temporal and spatial cues are presented to blind people. • The lack of vision may drive to the construction of multi-sensory cortical network coding space based on temporal instead of spatial coordinates. Visual modality dominates spatial perception and, in lack of vision, space representation might be altered. Here we review our work showing that blind individuals have a strong deficit when performing spatial bisection tasks (Gori et al., 2014). We also describe the neural correlates associated with this deficit, as blind individuals do not show the same ERP response mimicking the visual C1 reported in sighted people during spatial bisection (Campus et al., 2019). Interestingly, the deficit is not always evident in late blind individuals, and it is dependent on blindness duration. We report that the deficit disappears when one presents coherent temporal and spatial cues to blind people. This suggests that they may use time information to infer spatial maps (Gori et al., 2018). Finally, we propose a model to explain why blind individuals are impaired in this task, speculating that a lack of vision drives the construction of a multi-sensory cortical network that codes space based on temporal, rather than spatial, coordinates. [ABSTRACT FROM AUTHOR]

Peripersonal space can be considered as the interface between the body and the environment, where objects can be reached and which may serve as a reference for the central nervous system with regard to possible actions. Peripersonal space can be studied by assessing the perception of the reachable space, which depends on the body's physical characteristics (i.e., arm length) since their modifications have been shown to be associated with a change in peripersonal space representation. However, it remains unclear whether the representation of limb dynamics also influences the representation of peripersonal space. The present study investigated this issue by perturbing the force-field environment. A novel force field was created by rotating an experimental platform where participants were seated while they reached towards visual targets. Manual reaching performance was assessed before, during and after platform rotation. Crucially, perception of peripersonal space was also assessed, with reachability judgments, before and after platform rotation. As expected, sensori-motor adaptation to the perturbed force field was observed. Our principal finding is that peripersonal space was systematically perceived as closer to the body after force-field adaptation. Two control experiments showed no significant difference in reachability judgments when no reaching movements were performed during platform rotation or when reaching movements were performed without platform rotation, suggesting that the change in perceived peripersonal space resulted from exposure to new limb dynamics. Overall, our findings show that sensori-motor adaptation of reaching movements to a new force field, which does not directly influence arm length but results in the updating of the arm's internal model of limb dynamics, interacts with the perceptual categorisation of space, supporting a motor contribution to the representation of peripersonal space. • The link between peripersonal space and limb dynamics remains unclear. • Peripersonal space can be studied by assessing reachability judgments. • Peripersonal space is systematically modified by exposure to new limb dynamics. [ABSTRACT FROM AUTHOR]

The hippocampus plays a critical role in episodic memory: the sequential representation of visited places and experienced events. This function is mirrored by hippocampal activity that self organizes into sequences of neuronal activation that integrate spatiotemporal information. What are the underlying mechanisms of such integration is still unknown. Single cell activity was recently shown to combine time and distance information; however, it remains unknown whether a degree of tuning between space and time can be defined at the network level. Here, combining daily calcium imaging of CA1 sequence dynamics in running head-fixed mice and network modeling, we show that CA1 network activity tends to represent a specific combination of space and time at any given moment, and that the degree of tuning can shift within a continuum from 1 day to the next. Our computational model shows that this shift in tuning can happen under the control of the external drive power. We propose that extrinsic global inputs shape the nature of spatiotemporal integration in the hippocampus at the population level depending on the task at hand, a hypothesis which may guide future experimental studies. [ABSTRACT FROM AUTHOR]

Highlights • We interact with the environment occur in the space close to the body, named peripersonal space (PPS). • PPS is represented by a dedicated parieto-frontal, multisensory-motor system. • PPS shapes depending on body-objects interactions (tool-use, training, immobilization). • But also abstract interactions between the individual and the environment, including the others. • PPS underlies a self-other distinction, involved in self-consciousness. Abstract Our brain has developed a specific system to represent the space closely surrounding the body, termed peripersonal space (PPS). This space has a key functional role as it is where all physical interactions with objects in the environment occur. Here I describe how multisensory neurons in a specific fronto-parietal network map the PPS by integrating tactile stimuli on the body with visual or auditory information related to external objects specifically when they are close to the body. I show how PPS representation is not only multisensory, but actually multisensory-motor, as the PPS system interacts with motor areas to trigger appropriate responses. The extent of PPS is not fixed, but it is shaped by experience, as PPS may encompass farther portions of space, once the individual has interacted with them, (e.g., with tools), or it contracts, if interactions are limited because of external constraints, body, or brain injury. Interactions between the individual and the environment are not only physical but may also be "abstract". Recent data show that PPS adapts as a consequence of technology-mediated or social interactions. Finally, I propose that besides low-level sensory-motor representations of the space around the different parts of the body, mediating body-objects interactions, the multisensory PPS system also underlies a general representation of the self as distinct from the environment and the others. PPS thus supports self-location, contributes to bodily self-consciousness and mediates higher-level cognitive functions. [ABSTRACT FROM AUTHOR]

To better identify the distinctive characteristics of space representation in the radial dimension, we have proposed a new paradigm: the landmarks alignment task where two parallel aluminum bars were radially presented. Children had to move a landmark along one bar and place it at the same location as the reference landmark placed by the examiner on the parallel bar. The major interest of this task was its capacity to assess space representation in the radial dimension when considering a spatial landmark that oriented the subject's attention toward the orthogonal dimension. The most important result showed that in the radial dimension children with dyslexia exhibited a forward bias on the left bar, meaning a mental underrepresentation of the leftward peripersonal space and/or a mental overrepresentation of the rightward peripersonal space. Furthermore, reading discrepancies were correlated with radial forward bias on the left bar. The experiment was also conducted in the lateral axis, showing a pseudoneglect behavior in children without dyslexia. Our landmarks alignment task had the advantage of being able to assess space representation in a complex environment. The forward radial representational bias in children with dyslexia could have implications for spatial orientation in peripersonal workspace in school situations. [ABSTRACT FROM AUTHOR]

Traditionally, the standards of spatial modeling are oriented to represent the quantitative information of space. However, in recent years an increasingly common challenge is appearing: flexibly and appropriately integrating quantitative information that goes beyond the purely geometric. This problem has been aggravated due to the success of new paradigms such as the Internet of Things. This adds an additional challenge to the representation of this information due to the need to represent characteristic information of the space from different points of view in a model, such as WiFi coverage, dangerous surroundings, etc. While this problem has already been addressed in indoor spaces with the IndoorGML standard, it remains to be solved in outdoor and indoor−outdoor spaces. We propose to take the advantages proposed in IndoorGML, such as cellular space or multi-layered space model representation, to outdoor spaces in order to create indoor−outdoor models that enable the integration of heterogeneous information that represents different aspects of space. We also propose an approach that gives more flexibility in spatial representation through the integration of standards such as OpenLocationCode for the division of space. Further, we suggest a procedure to enrich the resulting model through the information available in OpenStreetMap.

When navigating in a spatial environment or when hearing its description, we can develop a mental model which may be represented in the central nervous system in different coordinate systems such as an egocentric or allocentric reference frame. The way in which sensory experience influences the preferred reference frame has been studied with a particular interest for the role of vision. The present study investigated the influence of proprioception on human spatial cognition. To do so, we compared the abilities to form spatial models of two rare participants chronically deprived of proprioception (GL and IW) and healthy control participants. Participants listened to verbal descriptions of a spatial environment, and their ability to form and use a mental model was assessed with a distance-comparison task and a free-recall task. Given that the loss of proprioception has been suggested to specifically impair the egocentric reference frame, the deafferented individuals were expected to perform worse than controls when the spatial environment was described in an egocentric reference frame. Results revealed that in both tasks, one deafferented individual (GL) made more errors than controls while the other (IW) made less errors. On average, both GL and IW were slower to respond than controls, and reaction time was more variable for IW. Additionally, we found that GL but not IW was impaired compared to controls in visuo-spatial imagery, which was assessed with the Minnesota Paper Form Board Test. Overall, the main finding of this study is that proprioception can influence the time necessary to use spatial representations while other factors such as visuo-spatial abilities can influence the capacity to form accurate spatial representations.

The right cerebral hemisphere plays a crucial rule in spatial cognition, spanning from perception of elementary features, such as location, color, line orientation or shape to representation of different spaces (3D space, allocentric, egocentric, face, personal, peri-personal, or imaginal). One important aspect of its contribution concerns the perception of space symmetry and the representation of objects and scenes, with reference to the midline or body axis. This representation results from a balance between spatial attention processes depending from the two hemispheres. Healthy participants tend to show a discrete deviation of the midline plane representation toward the left side, that is likely to result from the predominance of the activity of the right cerebral hemisphere, mainly oriented toward the contralateral side of space. The visuospatial abilities of the right hemisphere, especially for the representation of the midline plane are crucially engaged in painting and drawing processes in artists. Interestingly, the distortions created by painters of the Cubism period, characterized by an asymmetry of objects and body representations, a specific enlargement or reduction of parts of space, or even by complex distortions of 3D space are analogous to those classically reported in right-brain-damaged patients (unilateral spatial neglect, hyperschematia, constructional apraxia). Understanding the pathological mechanisms of these representation disorders provides meaningful information to apprehend visual artist creations and esthetic perception of space.

Although seeing is commonly experienced as a unitary activity, the scientific description of vision resists such an intuitive account. Both psychologists and neuroscientists are in agreement with the idea that the elaboration of visual information is distributed across several different routes provided with different functions. Importantly, these routes can be mapped onto well-identified anatomical subdivision of the visual system. Crucially, although originally based on the assumption that different visual information are elaborated via different neural channels, such a model is nowadays used as a tool for indicating a common neural basis between action and perception. The present review is aimed at providing a description of how the modular model of visual system has developed from a model where action and perception are considered as segregate to a model where action and perception are considered ass two labels of the same concept.

The paper examines the view and representation of space in Terézia Mora’s prose, primarily based on her novel entitled The Only Man on the Continent (Der einzige Mann auf dem Kontinent). In the universe of the novel the perception of space basically determines the individual’s space of action and highly influences his self-image as well as his attitude toward alterity. The city not only functions as space, but also forms a multicultural medium which becomes itself the subject of reflection and metanarration. In the novel the anthropological places and non-places, in Augé’s sense, change their function and thus the borders of referential, mental and virtual worlds are blurred, the notion of space itself is revaluated. The protagonist is the Ulysses of our days; his journeys and adventures mainly take place in his imagination. In the virtual world he loses his sense of reality, which can also be perceived in the narrative procedures of the text: the novel is in fact the protagonist’s quest for identity, his endless monologue, which is interrupted by the omniscient narrator’s comments from time to time. In the meantime the evident intertextual context also gets shape: the text maintains an ironical intertextual connection with James Joyce’s Ulysses.

The present paper approaches the axial perspective, a method of spatial representation that precedes the invention of the Renaissance geometrical perspective. Despite being typical to ancient Greek and Roman art, the axial perspective can also be identified during the Middle Ages and the early Renaissance period and it represents the first form of systematic convergence of parallel lines. At the same time, the paper presents Erwin Panofsky's theories on this spatial suggestion method. Trying to offer it a scientific foundation, the researcher builds a system that he calls "the vanishing axis perspective" and puts forward a series of arguments in favour of the existence of such a perspective. Although the axial perspectival constructions imply awkward superimpositions of planes that might seem geometrically inaccurate, this method of spatial structuring of the image constitutes an important stage in the process of identifying solutions for the faithful reproduction of concrete reality and an essential stepin the development process of thevanishing point perspective.

This paper is focused on the hierarchical perspective, one of the methods for representing space that was used before the discovery of the Renaissance linear perspective. The hierarchical perspective has a more or less pronounced scientific character and its study offers us a clear image of the way the representatives of the cultures that developed it used to perceive the sensitive reality. This type of perspective is an original method of representing three-dimensional space on a flat surface, which characterises the art of Ancient Egypt and much of the art of the Middle Ages, being identified in the Eastern European Byzantine art, as well as in the Western European Pre-Romanesque and Romanesque art. At the same time, the hierarchical perspective is also present in naive painting and infantile drawing. Reminiscences of this method can be recognised also in the works of some precursors of the Italian Renaissance. The hierarchical perspective can be viewed as a subjective ranking criterion, according to which the elements are visually represented by taking into account their relevance within the image while perception is ignored. This paper aims to show how the main objective of the artists of those times was not to faithfully represent the objective reality, but rather to emphasize the essence of the world and its perennial aspects. This may represent a possible explanation for the refusal of perspective in the Egyptian, Romanesque and Byzantine painting, characterised by a marked two-dimensionality.

When navigating in a spatial environment or when hearing its description, we can develop a mental model which may be represented in the central nervous system in different coordinate systems such as an egocentric or allocentric reference frame. The way in which sensory experience influences the preferred reference frame has been studied with a particular interest for the role of vision. The present study investigated the influence of proprioception on human spatial cognition. To do so, we compared the abilities to form spatial models of two rare participants chronically deprived of proprioception (GL and IW) and healthy control participants. Participants listened to verbal descriptions of a spatial environment, and their ability to form and use a mental model was assessed with a distance-comparison task and a free-recall task. Given that the loss of proprioception has been suggested to specifically impair the egocentric reference frame, the deafferented individuals were expected to perform worse than controls when the spatial environment was described in an egocentric reference frame. Results revealed that in both tasks, one deafferented individual (GL) made more errors than controls while the other (IW) made less errors. On average, both GL and IW were slower to respond than controls, and reaction time was more variable for IW. Additionally, we found that GL but not IW was impaired compared to controls in visuo-spatial imagery, which was assessed with the Minnesota Paper Form Board Test. Overall, the main finding of this study is that proprioception can influence the time necessary to use spatial representations while other factors such as visuo-spatial abilities can influence the capacity to form accurate spatial representations. [ABSTRACT FROM AUTHOR]

The right cerebral hemisphere plays a crucial rule in spatial cognition, spanning from perception of elementary features, such as location, color, line orientation or shape to representation of different spaces (3D space, allocentric, egocentric, face, personal, peri-personal, or imaginal). One important aspect of its contribution concerns the perception of space symmetry and the representation of objects and scenes, with reference to the midline or body axis. This representation results from a balance between spatial attention processes depending from the two hemispheres. Healthy participants tend to show a discrete deviation of the midline plane representation toward the left side, that is likely to result from the predominance of the activity of the right cerebral hemisphere, mainly oriented toward the contralateral side of space. The visuospatial abilities of the right hemisphere, especially for the representation of the midline plane are crucially engaged in painting and drawing processes in artists. Interestingly, the distortions created by painters of the Cubism period, characterized by an asymmetry of objects and body representations, a specific enlargement or reduction of parts of space, or even by complex distortions of 3D space are analogous to those classically reported in right-brain-damaged patients (unilateral spatial neglect, hyperschematia, constructional apraxia). Understanding the pathological mechanisms of these representation disorders provides meaningful information to apprehend visual artist creations and esthetic perception of space. [ABSTRACT FROM AUTHOR]

Temporal and spatial representations have been consistently shown to be inextricably intertwined. However, the exact nature of time-space mapping remains unknown. On the one hand, the conceptual metaphor theory postulates unilateral, asymmetric mapping of time onto space, that is, time is perceived in spatial terms but the perception of space is relatively independent of time. On the other hand, a theory of magnitude assumes bilateral and symmetric interactions between temporal and spatial perceptions. In the present paper, we argue that the concepts of linguistic asymmetry, egocentric anchoring, and sensory modality provide potential explanations for why evidences favoring both asymmetry and symmetry have been obtained. We first examine the asymmetry model and suggest that language plays a critical role in it. Next, we discuss the symmetry model in relation to egocentric anchoring and sensory modality. We conclude that since these three factors may jointly account for some conflicting past results regarding the strength and directionality of time-space mapping, they should be taken into serious consideration in future test designs. [ABSTRACT FROM AUTHOR]

Horizontal wind measured by wind profiling radar (WPR) is based on uniform wind assumption in volume of lateral beam. However, this assumption cannot completely meet in the real atmosphere. The subject of this work is to analyze the influence of atmospheric inhomogeneities for wind measurement. Five-beam WPR can measure two groups of horizontal wind components U and V independently, using the difference of horizontal wind components U and V can evaluate the influence of the inhomogeneity of the atmospheric motion on wind measurement. The influences can be divided into both inhomogeneous distribution of horizontal motion and vertical motion. Based on wind measurements and meteorological background information, a new means of coordinate rotation the two kinds of inhomogeneous factor was separated, and the impact in different weather background was discussed. From analysis of the wind measured by type of PB-II WPR (445MHz) during 2012 at Yanqing of Beijing, it is shown that the inhomogeneity of horizontal motion is nearly the same in U and V direction. Both the inhomogeneities of horizontal motion and vertical motion have influence on wind measurement, and the degrees of both influences are associated with changes of wind speed. In clear air, inhomogeneity of horizontal motion is the main influence on wind measurement because of small vertical velocity. In precipitation, the two influences are larger than that in clear air. [ABSTRACT FROM AUTHOR]

In this article, we present a simple agent which learns an internal representation of space without a priori knowledge of its environment, body, or sensors. The learned environment is seen as an internal space representation. This representation is isomorphic to the group of transformations applied to the environment. The model solves certain theoretical and practical issues encountered in previous work in sensorimotor contingency theory. Considering the mathematical description of the internal representation, analysis of its properties and simulations, we prove that this internal representation is equivalent to knowledge of space. [ABSTRACT FROM AUTHOR]

It is well documented that place cells and grid cells in echolocating bats show properties similar to those described in rodents, and yet, continuous theta-frequency oscillations, proposed to play a central role in grid/place cell formation, are not present in bat recordings. These comparative neurophysiological data have raised many questions about the role of theta-frequency oscillations in spatial memory and navigation. Additionally, spatial navigation in three-dimensions poses new challenges for the representation of space in neural models. Inspired by the literature on space representation in the echolocating bat, we have developed a nonoscillatory model of 3-D grid cell creation that shares many of the features of existing oscillatory-interference models. We discuss the model in the context of current knowledge of 3-D space representation and highlight directions for future research. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to describe perspective with six vanishing points. The line opened by axonometry and continued by one, two, three vanishing points and spherical perspectives, one became complete with the sixth vanishing point. Linear perspectives are often used, well known systems. Introducing new vanishing points doubles the represented part of space. The question of representing the half-space, hence the definition of the first five vanishing points can be found in literature. However, there was no useful solution for the representation of the whole space for a long time. This paper introduces a new definition of the sixth vanishing point that resulted a well applicable system. A short historical introduction looks at some of the interactions between mathematics and arts of western culture. Afterwards we formulate the new alternative perspective and give some methods of construction for notable lines and planes. Finally we write about possible applications. [ABSTRACT FROM AUTHOR]

It has been established that processes relating to ‘spatial attention’ are implemented at cortical level by goal-directed (top-down) and stimulus-driven (bottom-up) networks. Spatial neglect in brain-damaged individuals has been interpreted as a distinguished exemplar for a disturbance of these processes. The present paper elaborates this assumption. Functioning of the two attentional networks seem to dissociate in spatial neglect; behavioral studies of patients' orienting and exploration behavior point to a disturbed stimulus-driven but preserved goal-directed attention system. When a target suddenly appears somewhere in space, neglect patients demonstrate disturbed detection and orienting if it is located in contralesional direction. In contrast, if neglect patients explore a scene with voluntarily, top-down controlled shifts of spatial attention, they perform movements that are oriented into all spatial directions without any direction-specific disturbances. The paper thus argues that not the top-down control of spatial attention itself, rather a body-related matrix on top of which this process is executed, seems affected. In that sense, the traditional role of spatial neglect as a stroke model for ‘spatial attention’ requires adjustment. Beyond its insights into the human stimulus-driven attentional system, the disorder most notably provides vistas in how our brain encodes topographical information and organizes spatially oriented action – including the top-down control of spatial attention – in relation to body position. [ABSTRACT FROM AUTHOR]

To act on the environment, organisms must perceive object locations in relation to their body. Several neuroscientific studies provide evidence of neural circuits that selectively represent space within reach (i.e., peripersonal) and space outside of reach (i.e., extrapersonal). However, the developmental emergence of these space representations remains largely unexplored. We investigated the development of space coding in infant macaques and found that they exhibit different motor strategies and hand configurations depending on the objects' size and location. Reaching-grasping improved from 2 to 4 weeks of age, suggesting a broadly defined perceptual body schema at birth, modified by the acquisition and refinement of motor skills through early sensorimotor experience, enabling the development of a mature capacity for coding space. [ABSTRACT FROM AUTHOR]

The effect of the presentation of two different auditory pitches (high & low) on manual line-bisection performance was studied to investigate the relationship between space and magnitude representations underlying motor acts. Participants were asked to mark the midpoint of a given line with a pen while they were listening a pitch via headphones. In healthy participants, the effect of the presentation order (blocked or alternative way) of auditory stimuli was tested (Exp. 1). The results showed no biasing effect of pitch in blocked-order presentation, whereas the alternative presentation modulated the line-bisection. Lower pitch produced leftward or downward bisection biases whereas higher pitch produced rightward or upward biases, suggesting that visuomotor processing can be spatially modulated by irrelevant auditory cues. In Exp. 2, the effect of such alternative stimulations in line bisection in right brain damaged patients with a unilateral neglect and without a neglect was tested. Similar biasing effects caused by auditory cues were observed although the white noise presentation also affected the patient’s performance. Additionally, the effect of pitch difference was larger for the neglect patient than for the no-neglect patient as well as for healthy participants. The neglect patient’s bisection performance gradually improved during the experiment and was maintained even after one week. It is therefore concluded that auditory cues, characterized by both the pitch difference and the dynamic alternation, influence spatial representations. The larger biasing effect seen in the neglect patient compared to the no-neglect patient and healthy participants suggests that auditory cues could modulate the direction of the attentional bias that is characteristic of neglect patients. Thus the alternative presentation of auditory cues could be used as rehabilitation for neglect patients. The space-pitch associations are discussed in terms of a generalized magnitude system.

Early blind individuals can localize single sound sources better than sighted participants, even under monaural conditions. Yet, in binaural listening, they struggle with understanding the distances between three different sounds. The latter ability has never been tested under monaural conditions. We investigated the performance of eight early blind and eight blindfolded healthy individuals in monaural and binaural listening during two audio-spatial tasks. In the localization task, a single sound was played in front of participants who needed to localize it properly. In the auditory bisection task, three consecutive sounds were played from different spatial positions, and participants reported which sound the second one was closer to. Only early blind individuals improved their performance in the monaural bisection, while no statistical difference was present for the localization task. We concluded that early blind individuals show superior ability in using spectral cues under monaural conditions., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2023.)

In control engineering, a state space representation is a mathematical model of a physical system as a set of input, output and state variables related by first-order differential equations. To abstract from the number of inputs, outputs and states, the variables are expressed as vectors. Additionally, if the dynamical systems linear and time invariant, the differential and algebraic equations may be written in matrix form. The state space representation (also known as the "time-domain approach") provides a convenient and compact way to model and analyze systems with multiple inputs and outputs. With P inputs and Q outputs, we would otherwise have to write down Q x P Laplace transforms to encode all the information about a system. Unlike the frequency domain approach, the use of the state space representation is not limited to systems with linear components and zero initial conditions. "State space" refers to the space whose axes are the state variables. The state of the system can be represented as a vector within that space. [ABSTRACT FROM AUTHOR]

It is known that visual direction representation is more accurate for cardinal directions compared to oblique, a phenomenon named the 'oblique effect'. It has been hypothesized that there are two sources of oblique effect, a low level one confined to vision and a high level one extending to different modalities and corresponding to higher cognitive processes. In this study directional error (DE) was measured when normal individuals tried to align the direction of an arrow presented in the center of a computer monitor to the direction of a peripheral target located in one of 32 directions equally spaced on an imaginary circle of 60 mm radius. Task difficulty was manipulated by varying arrow length (15, 30, 45 and 60 mm). By measuring mean DE and its variance we identified two independent sources of the oblique effect. A low level oblique effect was manifested in higher accuracy or equivalently lower variance of DE in the alignment for cardinal orientations compared to oblique. A second oblique effect was manifested measuring mean DE resulting in space expansion in the vicinity of cardinal directions and space contraction in the vicinity of oblique directions. Only this latter source of oblique effect was modulated by arrow length as predicted from a theoretical model postulating that this oblique effect is produced by a cognitive process of 2-D space categorization. [ABSTRACT FROM AUTHOR]

Unilateral spatial neglect has been mainly investigated in the visual modality; only a few studies compared spatial neglect in different sensory modalities, and explored their multisensory interactions, with controversial results. We investigated the integration between vision and haptics, through a bisection task of a crossmodal length illusion, the Judd variant of the Müller-Lyer illusion. We examined right-brain-damaged patients with (n=7) and without (n=7) left unilateral spatial neglect, and neurologically unimpaired participants (n=14) in the bisection of Judd stimuli under visual, haptic, and visuo-haptic presentation. Neglect patients showed the characteristic rightward bias in the bisection of a baseline stimulus in the visual modality, but not in the haptic and visuo-haptic conditions. The illusory effects were preserved in each group and in each modality, indicating that the processing of the length illusion is independent of the presence of deficits of spatial attention and representation. Spatial neglect can be modality-specific, but visual and tactile sensory inputs are properly integrated.

Highlights: [•] Rightward bias for central location in children with dyslexia in line bisection. [•] Asymmetrical effect of line location in children with dyslexia. [•] Lateral effect towards the starting position in proprioceptive circle centering. [•] Forward (backward) effect in visuo-proprioceptive (proprioceptive) circle centering. [•] Influence of the left starting position in radial response in children with dyslexia. [Copyright &y& Elsevier]

This article examines the imagination and representation of space in everyday life from the perspective of social geography. Drawing on cultural theory, the article presents space as a multifaceted entity that is perceived, constructed, and reproduced through everyday praxis. It stresses on the situ-atedness and contextuality of the perception, construction, and representation of spatial categories and relations. To this end, three dimensions of space are discussed: (i) the representation of space in map form, one possible version of which is the concept of the route, founded on a topological representation of space; (ii) the scalar dimension of space, which involves the scaled representation of everyday space and the various socially, economically, and culturally determined scalar levels on which everyday experience occurs; (iii) the dimension of spatial continuity, which the authors discuss in conjunction with reflections on the ways in which space is represented, and next to the notion of space as an omnidirectional continuous medium they introduce a concept in which space is understood as a series of separate, meaningful entities integrated through mobile technologies to form a time-space network. This theoretical discussion is accompanied by an empirical section that draws on the spatial experiences of five users of power wheelchairs to describe examples of technologically and culturally conditioned imaginations of space. [ABSTRACT FROM AUTHOR]

In the present study we explored the effect of prismatic adaptation (PA) applied to the upper right limb on the walking trajectory of a neglect patient with more severe neglect in far than in near space. The patient was asked to bisect a line fixed to the floor by walking across it before and after four sessions of PA distributed over a time frame of 67 days. Gait path was analyzed by means of an optoelectronic motion analysis system.The walking trajectory improved following PA and the result was maintained at follow-up, 15 months after treatment. The improvement was greater for the predicted bisection error (estimated on the basis of the trajectory extrapolated from the first walking step) than for the observed bisection error (measured at line bisection). These results show that PA may act on high level spatial representation of gait trajectory rather than on lower level sensory-motor gait components and suggest that PA may have a long-lasting rehabilitative effect on neglect patients showing a deviated walking trajectory. [ABSTRACT FROM AUTHOR]

Abstract: Functional decrements associated with increasing aging may restrict daily activities and require use of tools (e.g., canes and walkers) for postural control and locomotion. Therefore, we examined older adults’ ability to plan reach movements with their arm and tools of 20 and 40cm in length. Twenty-seven participants between the ages of 55 and 92 years were divided into two groups, <75 and >76 years. The task required participants to estimate reach via use of motor imagery in regard to seven targets randomly presented in peripersonal and extrapersonal space. Each condition consisted of a block of 21 trials for the ARM and TOOL and a “switch-block” of 7 trials with the opposite condition. The procedure was repeated for both tool lengths and presented in counterbalanced order. Analysis of variance (ANOVA) results revealed a significant difference in the switch-blocks, suggesting that participants were more accurate when they switched from ARM to TOOL (extension) in comparison to TOOL to ARM (retraction). In addition, a correlation analysis indicated a negative relationship for accuracy in the 40cm tool condition and age. In view of the total sample, two findings warrant further consideration. For both tool lengths, retraction from TOOL to ARM was more difficult than extension from ARM to TOOL. And specifically to the 40cm tool, accuracy decreased as age increased. In addition to gaining information about aging of the neuro-cognitive processes associated with spatial representation, these outcomes may have implications for physical safety and rehabilitation with older persons. [Copyright &y& Elsevier]

Humans are able to mentally adopt the spatial perspective of others and represent the visual world from their point of view. Here, we present neuropsychological evidence that information inaccessible from an egocentric perspective can be accessed from the perspective of another person. Patients affected by left neglect were asked to describe arrays of objects from their own egocentric perspective, from an opposite perspective (disembodied perspective taking), and from the point of view of another person actually seated in front of them (embodied perspective taking). Although disembodied perspective-taking ameliorated neglect severity, there was an even stronger positive effect of embodied perspective-taking: items presented on the left and neglected when reported from the egocentric perspective were instead recovered when patients assumed the perspective of the other. These findings suggest that perspective-taking entails an altercentric remapping of space, i.e. remapping of objects and locations coded with reference to the other person's body. [ABSTRACT FROM AUTHOR]