From peripersonal space to cognitive maps: An evolutionary perspective.

Because LiDAR sensors acquire point clouds with a fixed angular resolution, the resulting data can be systematically parameterized and efficiently compressed in the spherical coordinate system. Traditional spherical coordinate-based point cloud compression methods have shown strong rate-distortion (RD) performance, with the predictive geometry coding (PredGeom) method in the geometry-based point cloud compression (G-PCC) standard being a prominent example. While PredGeom includes an inter-frame prediction mode, it relies on a simple linear model, which limits its ability to capture complex motion patterns or structural dependencies. On the other hand, existing learning-based compression methods in the spherical domain do not exploit inter-frame correlations to reduce geometry redundancy. To address these limitations, we propose a learning-based inter-frame predictive coding method (Inter-LPCM). For azimuth prediction, we use a delta coding strategy based on the predefined angular resolution. To improve compression for radii, we introduce an inter-frame radius predictive (Inter-RP) model that estimates the current point's radius using neighboring points from both the current frame and the registered reference frame. In addition, we design a lightweight attention-based prediction (LAEP) model to predict elevation angles by capturing long-range geometric correlations across different coordinates. For quantization, we propose an RD-optimized method to select the quantization steps in the spherical coordinate system. For entropy coding, we design distinct models for each spherical coordinate component. These models are adapted to the statistical priors of each coordinate, which enables more accurate probability estimation. Experimental results show that Inter-LPCM, in its best RD configuration, achieved a D1-PSNR BD-rate reduction of 26.1% compared with the G-PCC lossless octree-based coding mode on SemanticKITTI, and 8.3% compared with the inter-frame prediction mode of PredGeom on Ford, using the latest G-PCC test model TMC13 v31.0. Our source code is publicly available at https://github.com/SDUChangSun/Inter-LPCM.

Collisions observed in two different reference frames

Eye-gaze synchrony-the temporal coordination of eye movements between individuals-has been widely studied in dyadic interactions, but its operationalization remains inconsistent and its extension to multi-person settings is methodologically challenging. This proof-of-concept study examines whether eye-gaze synchrony can be captured in a single triadic interaction using mobile eye tracking and proposes a reproducible workflow for doing so. Three participants wore Tobii Pro Glasses 3 during a 7-min spontaneous face-to-face conversation. Independent recordings were synchronized via a router-based setup, and gaze points were re-expressed within a common two-dimensional reference frame anchored by a fiducial marker. To illustrate how different operationalizations can be applied in this context, we compared an event-based approach quantifying discrete occurrences of mutual gaze and joint attention with an index-based approach assessing temporal alignment of gaze signals via Surrogate Synchrony methods. The two approaches yielded different descriptive patterns, suggesting that they may emphasize different features of gaze coordination in this interaction. These results support the technical feasibility of capturing gaze coordination in triadic interactions using mobile eye tracking and underscore the importance of carefully considering how synchrony is operationalized. The proposed workflow provides a foundation that future studies can evaluate and extend across interactions and contexts.

Distinct roles of hippocampus and neocortex in symbolic compositional generalization.

Pigeons lock their eyes in place during flight.

The conventional pair entropy, derived from the isotropic radial distribution function g(r), systematically underestimates structural ordering in supercooled glass-forming liquids. We argue that this failure arises because S2, constructed from the isotropic g(r), is inherently insensitive to the many-body orientational correlations that become accessible only through a four-point conditional distribution evaluated in a local particle-centered frame. To recover this information, we introduce a three-dimensional four-point structural entropy S3D, constructed from the four-point conditional distribution function g(r,θ,ϕ) evaluated in a local particle-centered reference frame, and derive its exact decomposition into a radial contribution S2 and a weighted orientational entropy SΩ. Applying this framework to the canonical KA binary mixture, we find that SΩ accounts for a substantial fraction of S3D across the full temperature range studied, reflecting genuine icosahedral and dodecahedral angular ordering present at all temperatures-as independently established by Zhang and Kob-rather than a numerical artifact. These results demonstrate that g(r,θ,ϕ) encodes angular structural information entirely invisible to the conventional g(r) and to the thermodynamic excess entropy Sex, and that S3D provides a tractable thermodynamic measure of packing-driven orientational ordering across the supercooled regime.

Harnessing and supplying off-grid single-phase power from a three-phase self-excited induction generator (SEIG) leads to a significant imbalance in stator phase voltages and currents. This paper presents a passive (capacitor-based) phase-balancing excitation scheme for supplying single-phase loads from a micro-hydro-driven three-phase SEIG. The steady-state behavior of the proposed scheme is analyzed using symmetrical component theory and two-port network representation to examine system performance under variable generator speed and different resistive (R) and resistive–inductive (RL) loading conditions. In addition, a detailed transient analysis is carried out using a stationary αβ 0 reference frame–based dynamic model to investigate voltage and current build-up, sudden load switching, and balance restoration. The results show that, for a given load, the phase-balancing capacitor values remain nearly invariant with respect to varying SEIG speed, enabling balanced operation without the use of power electronic interfaces. Simulation studies performed in the MATLAB/Simulink environment and experimental validation on a 2.2 kW laboratory prototype demonstrate near-zero voltage and current unbalance factors, along with acceptable voltage regulation of approximately 0.65% for an R load and 4.39% for an RL load at rated speed. Comparative evaluation with well-known excitation schemes further confirms the effectiveness of the proposed approach for off-grid single-phase power generation.

Object-location memory (OLM) is the ability to encode and retrieve spatial relationships between objects by using egocentric or allocentric reference frames. Critically, OLM is modulated by emotional memory systems that engage amygdala-hippocampal and arousal-related mechanisms that can bias or disrupt spatial encoding. Despite evidence that emotion shapes memory, its specific impact on OLM remains unclear, particularly in digital contexts. This systematic review examined how emotional valence, particularly stress and anxiety, modulates OLM performance in computer-based and virtual/augmented reality tasks. Following PRISMA guidelines, a systematic search was conducted in Web of Science, Scopus, PsycInfo, and PubMed. Twelve empirical studies published up to 2025 met the inclusion criteria. Results revealed sex-specific effects: anxious women tended to rely on egocentric strategies, whereas stressed men showed greater allocentric flexibility. The timing of stress exposure was critical, often disrupting encoding but occasionally facilitating retrieval. Emotional valence differentially influenced performance: positive stimuli enhanced spatial accuracy, whereas negative stimuli accelerated response times. Spatial working memory (SWM) and mental rotation emerged as key cognitive resources supporting flexible spatial learning, while physiological stress markers showed only weak associations with behavioral outcomes. Future research should standardize paradigms, explore digital and immersive environments, include diverse populations, and clarify theoretical distinctions among arousal, valence, anxiety, and stress to better understand how emotional states shape spatial memory.

Translational research investigating traditional differential reinforcement of alternative behavior (DRA) suggests that such procedures increase the persistence of target behavior relative to when the alternative behavior is first reinforced in a separate context prior to instigating the differential reinforcement procedure. One shortcoming of research on this topic is that baseline target response rates, used to calculate proportion‐of‐baseline rates as a measure of persistence, were established in the presence of reinforcement for an alternative behavior in the traditional DRA (hereafter referred to as TradDRA) condition but in isolation in the separate‐context condition (SepDRA). In our procedure, using domestic hens, we first established baseline target response rates in the TradDRA and SepDRA conditions in isolation, then introduced the two DRA interventions (with separate and concurrently trained alternative behaviors), followed by disruptor tests. The disruptor was an additional response key associated with reinforcement. The main finding from this study was that by using this improved baseline measure as a frame of reference, target behavior persistence was still lower with the SepDRA procedure relative to the TradDRA procedure, aligning with findings from previous research. The improved baseline measure resulted in smaller differences between the two procedures, but these differences may still have useful applied implications.

Dataset of integrated seismic and geodetic strain rates in the Kopeh Dagh Belt (NE Iran): Earthquake focal mechanisms (1969\u20132024) and GNSS-derived deformation parameters

Varus thrust is a multiplanar dynamic phenomenon: Evidence from three-dimensional gait analysis in a population-based cohort.

A<sc>bstract</sc>Leading models of somatosensory processing posit that integration of tactile and proprioceptive cues is essential for touch perception. Yet, such integration is not universally beneficial. While posture-dependent remapping of tactile signals is critical for guiding hand actions, discrimination of certain tactile features is enhanced when touch is represented independently of hand posture. How the brain flexibly controls the integration of tactile and proprioceptive cues based on task demands remains unclear, as most studies have only examined touch perception within a single reference frame. Here, we studied how reference frame demands shape touch perception in humans making motion judgements on a finger, while varying hand posture. Participants were cued to report motion direction relative to the finger or the sternum (i.e., the body’s midline). We found that tactile and proprioceptive cues are integrated in a task-specific manner, with hand posture biasing judgments only in the Sternum-centric task. Further, we observe that reaction times are faster for Sternum-centric judgments, with accumulation-to-bound models indicating that this advantage is driven by lower decision thresholds. Finally, we developed a Bayesian computational framework that formalizes how tactile motion signals are transformed across hand postures, advancing our understanding of how the brain maps sensory information from skin-to body-centered coordinates. Together, these findings demonstrate that reference frame task demands shape both the transformation of tactile information and speed of perceptual decisions, within a Bayesian computational framework for task-dependent coordinate transformations.

Accurate image registration is essential for successful digital dental implant planning. Surface-based registration, commonly used in clinical software, is sensitive to CBCT artifacts and relies on manual landmark selection, potentially reducing accuracy. Marker-based registration offers improved precision but is underused due to its technical complexity and time demands. The purpose of this ex-vivo study was to evaluate the accuracy of a novel marker-based registration method using limited-view CBCT reconstructions derived from two orthogonal projection images and to compare it with a conventional surface-based registration method. An ex-vivo model consisting of a maxillary arch with removable 3D-printed teeth and a radiographic guide containing radiographic markers was used to simulate five metal artifact conditions. Full-view CBCT scans were acquired for each condition. For the conventional method, three examiners independently performed dual-scan registrations using user-defined surface landmarks on full CBCT reconstructions. For the proposed method, examiners selected orthogonal projection images where markers were clearly visible and limited-view reconstructions were generated to identify marker centroids. Registration error was measured as the point-to-point distance between corresponding surface reference points, standardized to a common frame of reference. Inter-rater reliability was also assessed. Both methods maintained consistent performance across all artifact conditions. The proposed method demonstrated greater accuracy, with lower point-to-point registration errors and less spatial variation. Inter-rater reliability was excellent for the proposed method and good for the conventional approach. The proposed marker-based registration method using orthogonal projection images and limited-view CBCT reconstructions showed higher accuracy than conventional surface-based registration under controlled ex vivo conditions. Although the workflow currently requires additional examiner input, it may improve precision in dual-scan protocols for implant planning. Future clinical studies and software developments are required to support clinical implementation.

Vision enables primates to remotely map their environment using eye movements rather than physical locomotion. While view-related spatial coding is prevalent in the primate hippocampus, its origin and precise relationship to standard place coding remain largely unknown. Leveraging untethered neural recording, motion capture, and wireless eye tracking, we examined view and place coding along the parietal-retrosplenial-hippocampal pathway in macaque monkeys freely exploring an open arena. We identified opposing gradients of egocentric and allocentric spatial coding across this pathway. Acting as a critical intermediate hub, the retrosplenial cortex conjunctively encoded egocentric position and allocentric gaze direction through gain modulation. Further downstream, the hippocampus exhibited both direction-dependent and direction-invariant place coding. Notably, view responses were much more prevalent than this place selectivity and were distinctly driven and modulated by shifting gaze directions. Ultimately, our findings establish that view and place coding actively coexist to varying degrees within the primate hippocampus. These results further reveal that such complex view representations emerge from the integration of distinct spatial reference frames within the retrosplenial cortex.

Transnational family care: experiences of family carers of people with dementia among migrants from Hong Kong in Vancouver.

By examining the relevance of Sylvia Wynter's work in the context of AI, beginning with her 1992 analysis “ ‘No Humans Involved’ ” on the Rodney King beating, this article argues that her oeuvre highlights the peculiar risks of privileging and naturalization of certain public rhetorics, disciplinary frames of reference, methodologies, and epistemologies over others, especially as political interests and economic valuation drive tech design, development, and deployment. Wynter's writings also directly challenge commonplaces about AI innovations as inexorable, especially in relation to sanguine arguments about human-centered AI, the future of work, and civilization's progress. Her work in particular has important implications for civil rights and international human rights policies that risk becoming lost in current debates over humans in the loop and algorithmic taxonomies of human types.

Shock tube experiments allow interrogation of nonequilibrium thermochemistry relevant to hypersonic flow conditions. Two-dimensional effects such as shock curvature and boundary-layer growth influence shock tube flows, yet their influence on measured data is unknown. Due to shot-to-shot variability and computational limitations, a priori numerical methods are unsuitable. Existing a posteriori methods are one-dimensional, requiring correlations for problem closure. This work develops a novel method for conducting a posteriori, two-dimensional, viscous, reacting gas analysis of shock tube flows, removing the requirement for self-similar boundary-layer correlations. This method is enabled by an additional equation fixing the shock to a desired location. Using the outflow pressure as a system variable, the problem is stabilized in the shock frame of reference. Comparisons to a reference case of argon and an experimental synthetic air condition in Oxford’s T6 tunnel have excellent agreement in regions where shock trajectory effects are minimal. A 1.33 Pa 8.18 km/s synthetic air experiment in NASA EAST highlights the influence of two-dimensional effects. Peak integrated radiance is decreased by 10% due to shock curvature from the quasi-one-dimensional result, improving experimental agreement. Additionally, a 40% difference in centerline axial velocity and a 15% radiance increase are predicted when modeling two-dimensional effects.

The proper motion (also known as position drift) field of extragalactic sources at cosmological distances across our sky can be used to measure the acceleration of the Solar System through the aberration effect. If measured very precisely, the signal would also hold cosmological information, for instance about bulk flows of distant sources or the presence of tensor modes. In the Λ cold dark matter (ΛCDM) model, the acceleration of the Solar System is by far the most important contributor to the position drift signal for sources at cosmological distances, and the measurement is therefore expected to yield a constant spheroidal dipole across redshifts provided that the convergence to the cosmic rest frame has been reached. The aim of this paper is to test this hypothesis. We analyze data from the cosmic reference frame (CRF) dataset of Gaia data release 3 (DR3) focusing on constraining the dipole and quadrupole in the position drift signal, with an emphasis on redshift dependence of the signal as a consistency test of the ΛCDM model. The spheroidal dipole that we find is in mild tension, at the level of 2-3σ, with the constant-in-redshift signature expected from the local acceleration of the Solar System. We also find significant quadrupole components, that however do not have any significant evolution with redshift. The most straightforward interpretation of these findings is (unknown) systematic errors related to the Gaia instrumentation, but a cosmological origin is a possibility. Our analysis remains inconclusive on the cause of the redshift dependence of the dipole and warrants further investigations with upcoming data releases. We discuss possible implications of our results and highlight the importance of proper motion measurements for rest frame determinations in cosmology. In our discussion, we highlight interesting avenues for doing cosmology with Gaia data.

Theta activity in the RSC anchors space to the body cardinal axes.