Spatial Reference Frames Research Articles

Learning to ignore visual onset distractors hinges on a configuration-dependent coordinates system.

Decrement of attentional capture elicited by visual onset distractors, consistent with habituation, has been extensively characterized over the past several years. However, the type of spatial frame of reference according to which such decrement occurs in the brain remains unknown. Here, four related experiments are reported to shed light on this issue. Observers were asked to discriminate the orientation of a titled line while ignoring a salient but task-irrelevant visual onset that occurred on some trials. The experiments all involved an initial habituation phase, during which capture elicited by the onset distractor progressively decreased, as in prior studies. Importantly, in all experiments, the location of the target and the distractor remained fixed during this phase. After habituation was established, in a final test phase of the various experiments, the spatial arrangement of the target and the distractor was changed to test for the relative contribution to habituation of retinotopic, spatiotopic, and configuration-dependent visual representations. Experiment 1 indicated that spatiotopic representations contribute little, if at all, to the observed decrement in attentional capture. The results from Experiment 2 were compatible with the notion that such capture reduction occurs in either retinotopic- or configuration-specific representations. However, Experiment 3 ruled out the contribution of retinotopic representations, leaving configuration-specific representation as the sole viable interpretation. This conclusion was confirmed by the results of Experiments 4 and 5. In conclusion, visual onset distractors appear to be rejected at a level of the visual hierarchy where visual events are encoded in a configuration-specific or context-dependent manner. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A Corpus-Based Study of Spatial Frames of References in Early Child Mandarin Chinese

This study examines the developmental pattern of spatial frames of reference (FoRs) in Chinese preschoolers using the naturalistic data elicited from the Beijing Early Childhood Mandarin Corpus. Altogether, 2837 static spatial sentences were identified from the corpus, and 785 of them used FoRs; thus, they were analysed using the seven-class FoRs coding system developed from the literature review. The results indicated that: (1) six classes were produced by the Beijing preschoolers, including the direct reference (DR), geomorphic reference (GR), landmark-based reference (LBR), object-centred reference (OCR), relative reference (RR), and people-centred reference (PCR). But, the absolute reference (AR) frequently used by Beijing adults was not produced by the preschoolers; (2) significant age differences were found in the utterances with reference and demonstrative sentences and were also identified in the production of OCR, PCR, and RR; (3) there were no significant gender or gender x age effects in the production of FoRs, except for the no-frame sentences; and (4) there was a stable and consistent pattern of FoRs allocation by age, and the most frequently used was OCR. All these findings indicate interactions among language, culture, and cognition.

The Role of Spatial Reference Frame in Implicit Distractor Location Learning

The Role of Spatial Reference Frame in Implicit Distractor Location Learning

Distinct codes for environment structure and symmetry in postrhinal and retrosplenial cortices

Complex sensory information arrives in the brain from an animal’s first-person (‘egocentric’) perspective. However, animals can efficiently navigate as if referencing map-like (‘allocentric’) representations. The postrhinal (POR) and retrosplenial (RSC) cortices are thought to mediate between sensory input and internal maps, combining egocentric representations of physical cues with allocentric head direction (HD) information. Here we show that neurons in the POR and RSC of female Long-Evans rats are tuned to distinct but complementary aspects of local space. Egocentric bearing (EB) cells recorded in square and L-shaped environments reveal that RSC cells encode local geometric features, while POR cells encode a more global account of boundary geometry. Additionally, POR HD cells can incorporate egocentric information to fire in two opposite directions with two oppositely placed identical visual landmarks, while only a subset of RSC HD cells possess this property. Entorhinal grid and HD cells exhibit consistently allocentric spatial firing properties. These results reveal significant regional differences in the neural encoding of spatial reference frames.

A Hippocampal-parietal Network for Reference Frame Coordination.

Navigating space and forming memories based on spatial experience are crucial for survival, including storing memories in an allocentric (map-like) framework and conversion into body-centered action. The hippocampus and parietal cortex (PC) comprise a network for coordinating these reference frames, though the mechanism remains unclear. We used a task requiring remembering previous spatial locations to make correct future action and observed that hippocampus can encode the allocentric place, while PC encodes upcoming actions and relays this to hippocampus. Transformation from location to action unfolds gradually, with 'Came From' signals diminishing and future action representations strengthening. PC sometimes encodes previous spatial locations in a route-based reference frame and conveys this to hippocampus. The signal for the future location appears first in PC, and then in hippocampus, in the form of an egocentric direction of future goal locations, suggesting egocentric encoding recently observed in hippocampus may originate in PC (or another "upstream" structure). Bidirectional signaling suggests a coordinated mechanism for integrating map-like, route-centered, and person-centered spatial reference frames at the network level during navigation.

Spatial memory and frames of reference: How deeply do we rely on the body and the environment?

How do we mentally represent the world out there? Psychology, philosophy and neuroscience have given two classical answers: as a living space where we act and perceive, dependent on our bodies; as an enduring physical space with its feature, independent of our bodily interactions. The first would be based on egocentric frames of reference anchored to the body, while the second on allocentric frames of reference centred on the environment itself or on objects. This raises some questions concerning how deep the reliance on the body and the environment is when using these reference frames, and whether they are affected differently by the duration of time and the scale (small or large) of space. To answer these questions, I have brought empirical evidence of the effect of motor interference, blindness, environmental characteristics and temporal factors on egocentric and allocentric spatial representational capacity. The results suggest that egocentric representations are deeply rooted in the body, with its sensory and motor properties, and are closely linked to acting now in small-scale or peripersonal space. Allocentric representations are more influenced by environmental than by bodily characteristics, by visual than by motor properties, and seem particularly related to large-scale or extrapersonal space. In line with neurophysiological evidence and a Kantian perspective, it appears that we are endowed with an internal spatial representation system ready to structure environmental information for our purposes. To what extent this system is innate and pervasive in cognition and what is its relationship to the neural 'positioning' substrate discovered by O'Keefe and colleagues requires further scientific investigation.

An allocentric human odometer for perceiving distances on the ground plane.

We reliably judge locations of static objects when we walk despite the retinal images of these objects moving with every step we take. Here, we showed our brains solve this optical illusion by adopting an allocentric spatial reference frame. We measured perceived target location after the observer walked a short distance from the home base. Supporting the allocentric coding scheme, we found the intrinsic bias , which acts as a spatial reference frame for perceiving location of a dimly lit target in the dark, remained grounded at the home base rather than traveled along with the observer. The path-integration mechanism responsible for this can utilize both active and passive (vestibular) translational motion signals, but only along the horizontal direction. This asymmetric path-integration finding in human visual space perception is reminiscent of the asymmetric spatial memory finding in desert ants, pointing to nature's wondrous and logically simple design for terrestrial creatures.

Using cognitive measures from linguistic relativity research to assess thinking in Yucatec Maya-Spanish bilingual children

This article uses cognitive measures previously developed within linguistic relativity research to explore the thinking patterns of Yucatec Maya-Spanish bilingual children in the Yucatan peninsula. These measures were designed to detect cognitive patterns associated with specific language patterns. Here, these measures are used to test whether 12 Yucatec Maya-Spanish bilingual children aged 9–11 years old differ cognitively from a similar sample of monolingual Maya children (nine Yucatec Maya-speaking and three Spanish-speaking). The study assesses cognitive associations for two language domains: number marking, a structure-based contrast, and spatial frames of reference, a usage-based contrast. For both number marking and spatial frames of reference, both bilingual and monolingual children provided cognitive responses more like Yucatec Maya monolingual speakers than like Spanish monolinguals. The study also assessed whether the results were affected by factors that have emerged in other studies of bilingual cognition: language status, social community, and language of assessment (‘language mode’). For number marking, there was an effect of the language of assessment, but not of social community or language status. For spatial frames of reference, there were effects of social community and language status but not of the language of assessment. Overall, the results suggest that Yucatec Maya's cognitive habits may continue for some time during the shift from Yucatec Maya monolingualism to bilingualism but with some sensitivity to these other factors. This study offers a positive outlook for efforts to maintain and revitalize the Yucatec Maya language in the Yucatan peninsula.

Conceptual information of meaningful objects is stored incidentally.

Prior research has shown that visual working memory capacity is enhanced for meaningful stimuli (i.e., real-world objects) compared to abstract shapes (i.e., colored circles). Here, we hypothesized that the shape of meaningful objects would be better remembered incidentally than the shape of nonmeaningful objects in a color memory task where the shape of the objects is task-irrelevant. We used a surprise-trial paradigm in which participants performed a color memory task for several trials before being probed with a surprise trial that asked them about the shape of the last object they saw. Across three experiments, we found a memory advantage for recognizable shapes relative to scrambled versions of these shapes (Experiment 1) that was robust across different encoding times (Experiment 2), and the addition of a verbal suppression task (Experiment 3). Interestingly, this advantage disappeared when all objects were from the same category (Experiment 4), suggesting that people are incidentally encoding broad conceptual information about object identities, but not visual details. Finally, when we asked about the location of objects in a surprise trial, we did not observe any difference between the two stimulus types (Experiment 5). Overall, these results show that conceptual information about the categories of meaningful objects is incidentally encoded into working memory even when task-irrelevant. This privilege for meaningful information does not exhibit a trade-off with location memory, suggesting that meaningful features influence representations of visual working memory in higher-level visual regions without altering the use of spatial reference frames at the lower level. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Spatial attention in mental arithmetic: A literature review and meta-analysis.

We review the evidence for the conceptual association between arithmetic and space and quantify the effect size in meta-analyses. We focus on three effects: (a) the operational momentum effect (OME), which has been defined as participants' tendency to overestimate results of addition problems and underestimate results of subtraction problems; (b) the arithmetic cueing effect, in which arithmetic problems serve as spatial cues in target detection or temporal order judgment tasks; and (c) the associations between arithmetic and space observed with eye- and hand-tracking studies. The OME was consistently found in paradigms that provided the participants with numerical response alternatives. The OME shows a large effect size, driven by an underestimation during subtraction while addition was unbiased. In contrast, paradigms in which participants indicated their estimate by transcoding their final estimate to a spatial reference frame revealed no consistent OME. Arithmetic cueing studies show a reliable small to medium effect size, driven by a rightward bias for addition. Finally, eye- and hand-tracking studies point to replicable associations between arithmetic and eye or hand movements. To account for the complexity of the observed pattern, we introduce the Adaptive Pathways in Mental Arithmetic (APiMA) framework. The model accommodates central notions of numerical and arithmetic processing and helps identifying which pathway a given paradigm operates on. It proposes that the divergence between OME and arithmetic cueing studies comes from the predominant use of non-symbolic versus symbolic stimuli, respectively. Overall, our review and findings clearly support an association between arithmetic and spatial processing.

Privacy preserving image registration

Image registration is a key task in medical imaging applications, allowing to represent medical images in a common spatial reference frame. Current approaches to image registration are generally based on the assumption that the content of the images is usually accessible in clear form, from which the spatial transformation is subsequently estimated. This common assumption may not be met in practical applications, since the sensitive nature of medical images may ultimately require their analysis under privacy constraints, preventing to openly share the image content. In this work, we formulate the problem of image registration under a privacy preserving regime, where images are assumed to be confidential and cannot be disclosed in clear. We derive our privacy preserving image registration framework by extending classical registration paradigms to account for advanced cryptographic tools, such as secure multi-party computation and homomorphic encryption, that enable the execution of operations without leaking the underlying data. To overcome the problem of performance and scalability of cryptographic tools in high dimensions, we propose several techniques to optimize the image registration operations by using gradient approximations, and by revisiting the use of homomorphic encryption trough packing, to allow the efficient encryption and multiplication of large matrices. We focus on registration methods of increasing complexity, including rigid, affine, and non-linear registration based on cubic splines or diffeomorphisms parameterized by time-varying velocity fields. In all these settings, we demonstrate how the registration problem can be naturally adapted for accounting to privacy-preserving operations, and illustrate the effectiveness of PPIR on a variety of registration tasks.

Spatial tactile localization depends on sensorimotor binding: preliminary evidence from virtual reality.

Our brain continuously maps our body in space. It has been suggested that at least two main frames of reference are used to process somatosensory stimuli presented on our own body: the anatomical frame of reference (based on the somatotopic representation of our body in the somatosensory cortex) and the spatial frame of reference (where body parts are mapped in external space). Interestingly, a mismatch between somatotopic and spatial information significantly affects the processing of bodily information, as demonstrated by the "crossing hand" effect. However, it is not clear if this impairment occurs not only when the conflict between these frames of reference is determined by a static change in the body position (e.g., by crossing the hands) but also when new associations between motor and sensory responses are artificially created (e.g., by presenting feedback stimuli on a side of the body that is not involved in the movement). In the present study, 16 participants performed a temporal order judgment task before and after a congruent or incongruent visual-tactile-motor- task in virtual reality. During the VR task, participants had to move a cube using a virtual stick. In the congruent condition, the haptic feedback during the interaction with the cube was provided on the right hand (the one used to control the stick). In the incongruent condition, the haptic feedback was provided to the contralateral hand, simulating a sort of 'active' crossed feedback during the interaction. Using a psychophysical approach, the point of subjective equality (or PSE, i.e., the probability of responding left or right to the first stimulus in the sequence in 50% of the cases) and the JND (accuracy) were calculated for both conditions, before and after the VR-task. After the VR task, compared to the baseline condition, the PSE shifted toward the hand that received the haptic feedback during the interaction (toward the right hand for the congruent condition and toward the left hand for the incongruent condition). This study demonstrated the possibility of inducing spatial biases in the processing of bodily information by modulating the sensory-motor interaction between stimuli in virtual environments (while keeping constant the actual position of the body in space).

QSAR modelling to predict structural features of certain sulfonamide as Urokinase-type Plasminogen Activator inhibitors

The serine hydrolase family includes serine proteases. It is essential for hydrolyzing protein peptide bonds and breaking them. The urokinase-type plasminogen activator (uPA) selectively binds to the uPAR on numerous cell types, including cancer cells. Pericellular proteolysis of cell-bound proteins requires this interaction. High uPA and uPAR levels regularly worsen cancer prognoses. Thus, small chemical active-site inhibitors that block uPA may diminish cancer cell invasion and metastasis. In compliance with Organization for Economic Corporation and Development guidelines, this research performed a complete Quantitative structure activity relationship analysis of sulfonamide compounds as Urokinase-type Plasminogen Activator inhibitors. Py-Descriptors were used for this investigation. PyDescriptor uses PyMOL standards and idioms to calculate 11,145 simple molecular descriptors. This plugin calculates molecular descriptors irrespective of molecular representation properties like atom numbering or labelling, spatial reference frame, translational and rotational invariance, etc. The investigation sought to find essential and hidden structural characteristics that regulate sulfonamide-type drugs' Urokinase-type Plasminogen Activator Inhibitory action. Twenty-eight sulfonamide chemicals are used in the Quantitative structure activity relationship study to generate statistically robust and highly predictive univariate and multivariate models. All models were thoroughly evaluated and meet several statistical parameter thresholds (e.g., R2 =0.9259–0.9280, Q2Loo= 0.8579–0.8558, Q2LMO= 0.8013–0.7865). The analysis reveal that occurance of ring carbon atoms exactly at 3 A0 from carbon atom, number of negatively charged atoms from sulphur atoms within 5 bonds, presence of hydrogen atom exactly at 3 bonds from donar atoms, presence of carbon atom exactly at 4 A0 from donar atom, presence of acceptor atom exactly at 5 A0 from sulphur atom and sum of partial charges of lipo atoms within 6 bonds from sulphur atom are important pharmacophoric features for Urokinase-type Plasminogen Activator Inhibition binding affinity. Thus, the developed Quantitative structure activity relationship study has an equilibrium of quantitative and qualitative tactics. The results could be useful for future optimizations of sulfonamide analogues.

The Anterior Thalamus Preferentially Drives Allocentric But Not Egocentric Orientation Tuning in Postrhinal Cortex.

Navigating a complex world requires integration of multiple spatial reference frames, including information about one's orientation in both allocentric and egocentric coordinates. Combining these two information sources can provide additional information about one's spatial location. Previous studies have demonstrated that both egocentric and allocentric spatial signals are reflected by the firing of neurons in the rat postrhinal cortex (POR), an area that may serve as a hub for integrating allocentric head direction (HD) cell information with egocentric information from center-bearing and center-distance cells. However, we have also demonstrated that POR HD cells are uniquely influenced by the visual properties and locations of visual landmarks, bringing into question whether the POR HD signal is truly allocentric as opposed to simply being a response to visual stimuli. To investigate this issue, we recorded HD cells from the POR of female rats while bilaterally inactivating the anterior thalamus (ATN), a region critical for expression of the "classic" HD signal in cortical areas. We found that ATN inactivation led to a significant decrease in both firing rate and tuning strength for POR HD cells, as well as a disruption in the encoding of allocentric location by conjunctive HD/egocentric cells. In contrast, POR egocentric cells without HD tuning were largely unaffected in a consistent manner by ATN inactivation. These results indicate that the POR HD signal originates at least partially from projections from the ATN and supports the view that the POR acts as a hub for the integration of egocentric and allocentric spatial representations.

Association between seated trunk control and cortical sensorimotor white matter brain changes in patients with chronic low back pain.

Trunk control involves integration of sensorimotor information in the brain. Individuals with chronic low back pain (cLBP) have impaired trunk control and show differences in brain structure and function in sensorimotor areas compared with healthy controls (HC). However, the relationship between brain structure and trunk control in this group is not well understood. This cross-sectional study aimed to compare seated trunk control and sensorimotor white matter (WM) structure in people with cLBP and HC and explore relationships between WM properties and trunk control in each group. Thirty-two people with cLBP and 35 HC were tested sitting on an unstable chair to isolate trunk control; performance was measured using the 95% confidence ellipse area (CEA95) of center-of-pressure tracing. A WM network between cortical sensorimotor regions of interest was derived using probabilistic tractography. WM microstructure and anatomical connectivity between cortical sensorimotor regions were assessed. A mixed-model ANOVA showed that people with cLBP had worse trunk control than HC (F = 12.96; p < .001; ηp2 = .091). There were no differences in WM microstructure or anatomical connectivity between groups (p = 0.564 to 0.940). In the cLBP group, WM microstructure was moderately correlated (|r| = .456 to .565; p ≤ .009) with trunk control. Additionally, the cLBP group demonstrated stronger relationships between anatomical connectivity and trunk control (|r| = .377 to .618 p < .034) compared to the HC group. Unique to the cLBP group, WM connectivity between right somatosensory and left motor areas highlights the importance of interhemispheric information exchange for trunk control. Parietal areas associated with attention and spatial reference frames were also relevant to trunk control. These findings suggest that people with cLBP adopt a more cortically driven sensorimotor integration strategy for trunk control. Future research should replicate these findings and identify interventions to effectively modulate this strategy.

Playing With Spatial Frames: Altering the Body Matrix Through Multisensory Egocentric and Allocentric Body Illusions

The multifaceted nature of body experience, encompassing affective, cognitive, and perceptual components, plays a critical role in the development and persistence of conditions such as anorexia nervosa (AN). Recent research attempted to address such disturbance to improve therapeutical effectiveness, using mirror exposure (ME) and body‐swapping (BS) techniques in immersive virtual reality (VR). Procedures from a third‐person perspective—as mirror‐like experiences—were primarily used to address bodily cognitive and affective components, whereas first‐person ones—as BS—were used to correct distorted body perception. This study investigated the effect of spatial reference frame on body self‐consciousness and body perception during BS. Data revealed two main findings: Even though embodiment was significantly enhanced when participants engaged with a virtual body from a first‐person viewpoint, both egocentric and allocentric perspectives influenced body size estimation (BSE), suggesting that both spatial perspectives critically form and sustain body self‐perception. We discussed predictive coding theory to explain spatial perspective influence on body experience, highlighting the potential therapeutic benefits of incorporating first and third‐person perspectives on body illusions (BIs) for more effective interventions targeting body‐related disturbances.

Universidad sin fronteras en la Eurorregión Galicia-Norte de Portugal: una exploración desde las experiencias de estudiantes y docentes

The literature review on university cooperation in the Galicia-North Portugal Euroregion allows for the development of the script for in-depth interviews, a fundamental source of information in this study. The study explores student and academic mobility, as well as research mobility from Galicia to Northern Portugal, specifically towards the Escola Superior de Enfermagem Dr. José Timóteo Montalvão Machado for the former, and the Universidade do Minho for the latter. Emphasis is placed on understanding cross-border relations, the role of linguistic issues, how residence is addressed, and what the facilitators are. This exploratory research reveals the importance of relational capital in cooperation beyond the necessary community framework and the existence of formal structures, emphasizing the relevance of this Euroregion as a spatial frame of reference.

Effect of egocentric and allocentric reference frames on spatial-numerical associations.

From an embodied view of cognition, sensorimotor mechanisms are strongly involved in abstract processing, such as Arabic number meanings. For example, spatial cognition can influence number processing. These spatial-numerical associations (SNAs) have been deeply explored since the seminal SNAs of response code (SNARC) effect (i.e., faster left/right sided responses to small/large magnitude numbers, respectively). Although these SNAs along the transverse plane (left-to-right axis) have been extensively studied in cognitive sciences, no systematic assessment of other planes of the tridimensional space has been afforded. Moreover, there is no evidence of how SNAs organise themselves throughout the changes in spatial body-reference frames (egocentric and allocentric). Hence, this study aimed to explore how SNAs organise themselves along the transverse and sagittal planes when egocentric and allocentric changes are processed during body displacements in the environment. In the first experiment, the results revealed that, when the participants used an egocentric reference, SNAs were observed only along the sagittal plane. In a second experiment that used an allocentric reference, the reversed pattern of results was observed: SNAs were present only along the transverse plane of the body. Overall, these findings suggest that, depending on the spatial reference frames of the body, SNAs are strongly flexible.

Reflected Reality

We propose Reflected Reality: a new dimension for augmented reality that expands the augmented physical space into mirror reflections. By synchronously tracking the physical space in front of the mirror and the reflection behind it using an AR headset and an optional smart mirror component, reflected reality enables novel AR interactions that allow users to use their physical and reflected bodies to find and interact with virtual objects. We propose a design space for AR interaction with mirror reflections, and instantiate it using a prototype system featuring a HoloLens 2 and a smart mirror. We explore the design space along the following dimensions: the user's perspective of input, the spatial frame of reference, and the direction of the mirror space relative to the physical space. Using our prototype, we visualise a use case scenario that traverses the design space to demonstrate its interaction affordances in a practical context. To understand how users perceive the intuitiveness and ease of reflected reality interaction, we conducted an exploratory and a formal user evaluation studies to characterise user performance of AR interaction tasks in reflected reality. We discuss the unique interaction affordances that reflected reality offers, and outline possibilities of its future applications.

Cardinal direction judgment based on the integration of spatial reference frames in different languages

Abstract This study investigates how integrated egocentric and environmental reference frames influence direction determination and cardinal direction judgments in L1 speakers of Mongolian and Mandarin. The results show that in direction determination, Mandarin participants’ integrated frame of reference is “front-north, back-south, left-west, and right-east.” By contrast, Mongolian participants use two modes of integrated spatial representation: “front-south, back-north, left-east, and right-west” and “front-north, back-south, left-west, and right-east”. This behavior points to influences from the participants’ dominant and non-dominant languages. Mongolian and Mandarin participants showed a north advantage in cardinal direction judgment tasks with a “front-north” response configuration. Whereas Mandarin participants consistently showed a north advantage effect, Mongolian participants showed a south advantage effect in the “front-south” configuration. This suggests that in addition to the long-recognized difference in north-south/east-west axis preference, a north-south axis specification where south was the normative direction instead of north can result from cultural and linguistic influence. The results corroborate the idea that language affects the integration of spatial reference frames, lending support to linguistic relativism.