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Visual perceptual deficits are increasingly acknowledged as a core yet underexplored feature of Major Depressive Disorder (MDD), involving impairments in contrast sensitivity, contextual modulation, and social-emotional perception. However, the underlying circuit-, neuron-, and network-level mechanisms through which depressive states influence early visual processing remain poorly understood. In this study, mice subjected to chronic restraint stress (CRS) underwent single-unit recordings in layer 2/3 (L2/3) of the primary visual cortex (V1) under light anesthesia to examine the effects of chronic stress on visually evoked neuronal responses and local network dynamics. V1 neurons in CRS-exposed mice exhibited broadened orientation tuning bandwidths, diminished surround suppression, and impaired center-surround discontinuity discrimination. At the network level, visually evoked oscillatory power in the θ, low γand high γ frequency bands was significantly attenuated in CRS mice, accompanied by a marked reduction in visual evoked potential (VEP) amplitude. These findings show that chronic stress impairs both the tuning of V1 neurons to visual stimuli and the local neural rhythms underlying early visual processing. The results uncover a multi-level physiological basis for depression-related visual deficits and provide a preclinical framework that could help develop objective sensory biomarkers for MDD.
Flexible visually guided behavior requires visual generalization, mapping diverse inputs to a common inference, and behavioral generalization, mapping one inference to multiple actions. Here, we tested whether visual neurons support both by maintaining a relatively fixed mapping between visual information amid many variations in stimuli and actions. We recorded neuronal populations in visual cortex in two male monkeys while they estimated the curvature of random 3D objects and flexibly mapped those judgments to different eye movements. Although visual responses varied substantially across objects, perceptual judgments were best explained by a common, shape-general readout of activity in V1 and V4, rather than by shape-specific strategies. V4 population activity additionally encoded impending saccades while maintaining a stable representation of stimulus curvature, allowing a single perceptual estimate to be linked to multiple behavioral outputs. Together, our findings suggest that visual cortex populations contain the ingredients necessary to implement multiple forms of flexible generalization.
Evaluation of biological significance in the visual cortex occurs along multiple parallel pathways to provide fast but coarse processing. This was critical when visual horizons were expanded by the sea-to-land transition, which meant broader visual exposure to a range of survival threats. Response latencies in the macaque cortex and postdictive effects of evolutionary-relevant stimuli in humans attest to fast visual processing.
In honeybees, foragers use the waggle dance to communicate the direction and ``a distance" to a food source from the hive to other members of the colony. Behavioral studies indicate that dancing foragers estimate this ``distance" during outward flights (from the hive to the food source) based on visual cues, in particular optic flow, even over mountain slopes. While optic flow-based biologically plausible models for the honeybee visual odometer were previously presented, their robustness with respect to uneven terrain has not yet been investigated. In this study, we present a new model for the honeybee visual odometer, called Surf, which combines vertical oscillations with the constant reorientation of the honeybee's compound eye with respect to the slope overflown. As the simulated honeybee's compound eye is typically kept level with the surface below, the direction of perception of ventral and divergent optic flow tends to remain perpendicular to the surface, enhancing the robustness of their detection across terrain irregularities. Tested in open field simulations across uneven terrain and varied wind conditions, the Surf model demonstrated greater accuracy compared to previous models evaluated under the same conditions, while keeping precision. The reliability of the Surf model accounts for the observed ``mountain slopes" (uphill and downhill) behaviors in honeybees and offers promising applications for minimalistic aerial robots navigating uneven terrain and indoor spaces.
We argue that evolutionarily conserved processing of visual information via subcortical routes persists in humans despite the emergence of cortical networks for conscious visual perception and the rapid visual control of planned actions. These cortical circuits did not replace subcortical circuits but instead evolved the capacity to preset the nested subcortical circuits to enable (or suppress) fast-as-possible actions, when required.
This study used event-related potentials (ERPs), time-frequency analysis, and multivariate pattern analysis (MVPA) to investigate how hypnosis modulates visual and auditory processing. Twenty-two highly hypnotizable participants performed an independent oddball task. Under the hypnotic suggestion of "seeing without perceiving, hearing without listening," behavioral results showed that hypnosis reduced target detection accuracy and prolonged reaction times in both modalities, while false alarm rates remained low. ERP analysis revealed no significant difference in the N100 component between hypnosis and wakefulness, but hypnosis attenuated the late cognitive evaluation reflected by the P300 component. MVPA further showed that hypnosis delayed the onset of neural decoding to 160 ms in the visual pathway and to 120 ms in the auditory pathway from a baseline of 80 ms, and also reduced the temporal stability of neural representations. Time-frequency analysis of the visual task indicated that in the wakeful state, target stimuli elicited stronger delta-band (1-4Hz) power than distractors, whereas hypnosis significantly diminished this neural representational specificity. These findings suggest that when individuals internalize hypnotic suggestions as personal goals, top-down regulatory mechanisms may alter neural temporal dynamics, reduce representational specificity, and lead to more homogeneous neural coding patterns, thereby decreasing perceptual efficiency while retaining weak decodability. This study provides neurobiological evidence for the neural mechanisms underlying perceptual dissociation during hypnosis.
Rapid and accurate mechanical detection is essential across numerous fields. However, conventional camera-based methods, which depend on computationally intensive analysis of high-frame-rate footage and predictive algorithms, are often time-consuming and can introduce interpretive errors that compromise reliability. Herein, we present a class of near-infrared stress memory emitters, allowing fast and visualized mechanical detection in ambient environments. We develop Ca(Sr)ZnOS:Yb3+/Pb2+ crystals and achieve persistent mechanoluminescence at 981 nm by combinatorial engineering of sub-bandgap states. Deliberate modulation of the persistent mechanoluminescence intensity and duration is achieved through isostructural host blending coupled with prescribed ultraviolet charging, enabling direct capture and visualization of ball impacts with short processing time (0.39 s) and high accuracy. The bright (up to 11 × 107 photons per event) and durable (up to 100 s) persistent mechanoluminescence broadens the scope of optical materials in applications such as stress sensors, human-machine interfaces, and mechano-opto-electronics.
Surgery of brain arteriovenous malformations (bAVM) and dural arteriovenous fistulas (dAVF) can be challenging due to the complex angioarchitecture. Fusing DSA images with magnetic resonance angiography (MRA) images could improve understanding and enable intraoperative navigation of DSA images. This study investigated the technical feasibility, image quality and perceived usefulness of 2D DSA-MRA fusion. Patients with bAVM or dAVF were included retrospectively. 2D-DSA injections and a time-of-flight (TOF) MRA were fused using Brainlab Elements software. Feeding vessels, draining veins and fistulous points were segmented. A survey assessed perceived usefulness among Swiss and German neurosurgeons. 96 patients with 51 bAVM and 47 dAVF were included. 145 image pairs were fused, with a success rate of 92%. Median time required for the process was 17.5 min (IQR 12.4-26.3 min; median fusion time: 2.8 min, IQR 2.0-4.0 min; median segmentation time: 11.6 min, IQR 7.9-18.5 min). Image alignment was rated as precise in 82% of cases, with 85% inter-observer agreement. Co-registration of TOF MRA and 2D-DSA sequences is feasible with reasonable time expenditure, yielding well-aligned images suitable for intraoperative navigation. DSA-MRA fusion was met with interest, emphasizing the need to develop additional tools to improve the surgical workflow for bAVM and dAVF.
We show a 90° shift in the perceived direction of a well-known motion illusion, based on the dot-pair separation in dynamic Glass patterns. The change can be explained with a cortical model incorporating extra-classical receptive fields. We employed dynamic Glass patterns: a sequence of patterns of randomly positioned, but consistently oriented dot-pairs, presented in rapid succession. Although dynamic Glass patterns contain no coherent motion, observers perceive strong motion in either direction parallel to the dot-pair orientation for small dot-pair separations (< 30 arc min). This has been attributed to the visual system interpreting the dot-pairs as motion streaks of fast-moving objects. The motion illusion has been explained by a model of the orientation selectivity of simple cells in primary visual cortex for small dot-pair separations. However, those models did not include the influence of end-stopping, an extra-classical receptive field mechanism that enhances length-selectivity to oriented bars. We incorporated end-stopping into the model and showed that increasing dot separation in Glass patterns shifts the directional preference of simple cells from parallel with the dot-pairs to the orthogonal direction. Our psychophysical experiments confirmed that Glass patterns perceived as rotating, with small dot-pair separations, were perceived as expanding/contracting with large separations (> 53 arc min). Furthermore, this shift to radial motion was eliminated when dot-pairs with opposite contrast polarities were used, consistent with our end-stopping model. The results provide new insight into the interaction between motion and form cues in the visual system, highlighting the role of extra-classical receptive fields in motion perception.
This study investigates the aerodynamic forces and moments acting on a women's discus as functions of angle of attack, freestream velocity, and spin rate about its axis of symmetry. Wind tunnel experiments were conducted to measure these aerodynamic forces and moments and to visualize the flow field using oil-flow visualization and particle image velocimetry (PIV). The results show that no significant dependence of the aerodynamic coefficients on the spin parameter was observed within the tested ranges (20-30 m/s; 0-7 rev/s). The drag, lift, and pitching moment coefficients depend strongly on the angle of attack, whereas the side force and the rolling and yawing moment coefficients remain approximately zero. The drag, lift, and pitching moment coefficients increase with angle of attack until stall occurs at approximately 28-30°, after which the lift and pitching moment decrease sharply. Stall recovery occurs at a lower angle of attack, around 25°, corresponding to a hysteresis window of approximately 4-5°. Surface static pressure measurements and flow visualizations suggest that this hysteresis is associated with the history-dependent formation and collapse of a leading-edge laminar separation bubble, which appears during increasing-angle-of-attack process with flow reattachment and disappears during the decreasing-angle-of-attack process.
Our response to commentaries further clarifies the links between visual postdictive phenomena, conscious experience, reality monitoring, and planning. We also engage with suggestions about the limits and generality of our conclusions for other sensory modalities and visually guided behavior in aquatic organisms. We conclude that the role of sensory horizons in visual consciousness offers powerful constraints on theory and generates novel testable hypotheses for consciousness science.
Elite athletes perform visually guided actions under severe temporal constraints. Reconsidering conscious versus unconscious vision, we present evidence from elite athletes that challenges the conceptualization of unconscious action guidance and propose instead distinguishing seeing-for-movement and seeing-for-thought. Elite athletes appear to use both in a coordinated manner when performing visually guided actions.
Neurofeedback, which consists of recording and visualizing neural activity in real-time, is a method currently being investigated as a supplementary treatment for Parkinson's disease (PD). By using implanted deep brain stimulation (DBS) electrodes with interleaved sensing capability, previous studies have demonstrated the efficacy of neurofeedback based on beta oscillations in the basal ganglia. Herein, for the first time, we explored short-term neurofeedback ability over the course of multiple sessions with a fully implanted DBS system. Eight patients with PD participated in the study. Neurofeedback was established with a fully internalized DBS system using beta oscillations (13-35 Hz, exceptions at 12.7 Hz and 8.78 Hz) from the subthalamic nucleus as visual feedback. Down- and upregulation tasks were performed. Three sessions were conducted on separate days. Neurofeedback induced a significant decline in beta power in the first and third session, while the regulation ability was less pronounced in the second session. In an explorative analysis, an increase in dopaminergic medication induced deterioration of downregulation performance, while stimulation improved the downregulation ability. Changes in the power of gamma oscillations were also induced through beta oscillation neurofeedback, further implying pro-kinetic changes through neurofeedback. This study demonstrated the feasibility of multiple sessions of neurofeedback training with a fully implanted DBS system over several days, however a significant improvement over the cumulative sessions remained absent. Our explorative investigation on possible influencing factors indicates potential improvements of the experimental setup and motivates the use of DBS electrode-guided neurofeedback over extended periods and possibly in an outpatient setting.
Research suggests a need for more ecologically valid assessments of emotion recognition in aggressive individuals with psychotic spectrum disorder (PSD). We employed a task featuring dynamic, multimodal (visual and auditory) expressions of a broad range of positive and negative emotions. Emotion recognition accuracy and misclassification patterns were compared between individuals with PSD and a history of interpersonal aggression (PSD+AGG; n = 79), individuals with PSD without such a history (PSD-AGG; n = 72), and healthy controls (HC; n = 86). Analyses of variance investigated effects of presentation modality (visual, auditory, multimodal), emotion category (12 emotions), valence (positive, negative), and arousal (high, low). Across analyses, the PSD+AGG group showed significantly lower accuracy than the PSD-AGG group, which in turn showed significantly lower accuracy than the HC group. Misclassification patterns revealed that the PSD+AGG group was more likely to misclassify negative emotions as positive emotions compared to the PSD-AGG group. Multiple regression analyses indicated that accuracy was most strongly predicted by fluid intelligence and semantic understanding of emotion words in individuals with PSD, with significant additional effects of gender, history of substance use disorders in remission, and educational attainment. PSD group remained a significant predictor of accuracy after controlling for these factors. In summary, individuals with PSD and a history of interpersonal aggression exhibit more pronounced deficits in emotion recognition than those with PSD alone. This underscores the potential value of incorporating emotion recognition assessment and training into clinical interventions to reduce aggression risk and improve social functioning in individuals with PSD.
Holographic displays are a transforming technology for immersive virtual and augmented reality systems. Exploring accurate yet efficient computer-generated holography (CGH) algorithms for three-dimensional (3D) content is a valuable research field. Recent advancements in layer-based CGH may exhibit limited capacity to convey comprehensive 3D information in accurately representing tilted angular spectrum and realizing realistic defocus blur. Alternative approaches based on point clouds and light fields may demand significant computational resources for preparing adequate target data for optimization. In addition, most existing CGH algorithms rely on heuristics to encode complex amplitudes into phase-only holograms for display, which can be highly ill-posed. Here we investigate an innovative CGH framework that overcomes these challenges using a unique combination of mesh-based representation, tilt-angle tailored wave propagation modeling, and complex-valued optimization, alongside a learning-empowered display calibration scheme using camera feedback. The resulting expanded hologram encoding capabilities enable the delivery of natural 3D depth cues, including smooth defocus blur and view-dependent effects. Experimental results conducted on our holographic near-eye display prototype demonstrate unprecedented full 3D visual quality, representing a significant advancement in creating immersive visualization experiences.
A strict lower limit of 400 ms is suggested for the formation of conscious vision. This processing delay could result from the need to create a unified percept over visual features processed with different time constants, and even longer intentional visual processes. Given the flexibility of these processing times, we question the need for a strict lower limit for conscious vision.
Inspired by the human brain, neuromorphic devices hold the potential to overcome the limitations of the traditional von Neumann architecture. Synapses serve as the core component of neuromorphic devices, which act as the fundamental units for signal conversion. In particular, artificial optoelectronic synapses with color perception capabilities offer significant advantages in multicolor image sensing and visual simulation. In this work, we demonstrate a Cs3Bi2I9 microplate/poly(3-hexylthiophene) (P3HT) heterojunction (CPH) as an ecofriendly and stable optoelectronic synaptic device. The device exhibits typical synaptic behaviors under optical stimulation, including excitatory postsynaptic current, paired-pulse facilitation with a maximum index of about 190%, and controllable transition from short-term to long-term memory. Notably, the CPH synapse achieves low power consumption (<90 fJ per synaptic event), outperforming traditional complementary metal oxide semiconductor-based circuits. Furthermore, the device demonstrates multi-wavelength response capabilities, enabling dual-wavelength perception and preprocessing. Our work provides a sustainable and high-performance alternative for neuromorphic vision systems, paving the way toward environmentally benign synaptic hardware.
Antibiotic-resistant Neisseria gonorrhoeae (Ng) is a WHO priority pathogen and represents a serious public health threat. This study reports the first Chilean Ng ST9363 isolate (GC11/23) exhibiting dual high-level resistance to azithromycin and fluoroquinolone, recovered from a urethral discharge sample in July 2023. Antimicrobial susceptibility was assessed using disk diffusion and MIC strip tests. Whole-genome sequencing (WGS) was performed using a hybrid approach, followed by annotation using the NCBI Prokaryotic Genome Annotation Pipeline (PGAP). In silico analyses included Staramr, MLST and NG-STAR. Phylogenetic analysis was performed on the core genome of 2,417 global ST9363 Ng isolates using IQ-TREE and visualized with TreeViewer. GC11/23 exhibited resistance to ciprofloxacin, tetracycline, penicillin, and azithromycin, while remaining susceptible only to ceftriaxone and spectinomycin. The isolate belonged to ST9363 and NG-STAR 3194. Mutations associated with fluoroquinolone resistance were identified in gyrA and parC, while high-level azithromycin resistance (HL-AziR) was linked to mutations in all four copies of the 23S rRNA gene, as well as in mtrD and mtrR. Additional resistance-associated alterations included an insertion (ins346D) in penA and a mutation in rpsJ, conferring resistance to penicillin and tetracycline, respectively. Phylogenetic analysis clustered GC11/23 with isolates from the USA and Europe collected in 2019. GC11/23 represents a multidrug-resistant Ng strain belonging to ST9363/NG-STAR 3194 and carrying mutations conferring resistance to fluoroquinolones, azithromycin, penicillin, and tetracycline. Its phylogenetic placement within a European lineage highlights the global dissemination of HL-AziR and fluoroquinolone-resistant strains.
The postdictive experimental paradigm is not superior to the direct detection paradigm, according to which the best strategy to identify the neural correlate of visual consciousness is to treat postdiction as a confounding factor. We could at most establish an equal claim to legitimacy of the two paradigms; hence, there is no puzzle about the function of a "slow" consciousness.
Floating knee injuries involving distal femoral articular fractures with concomitant segmental tibial fractures are uncommon but challenging high-energy injuries. Optimal outcomes depend on individualized fixation strategies, adequate exposure during the procedure, and preservation of soft-tissue biology. We reported a 52-year-old male sustained a road traffic accident resulting in an AO 33-C3 distal femur fracture with intra-articular extension and an ipsilateral AO 42-C2 segmental tibial fracture, classified as modified Fraser type IIb. A fragment-specific approach was undertaken. Tibial tuberosity osteotomy via the Swashbuckler approach provided improved visualization of the distal femur. Articular reduction was secured with an anteroposterior lag screw and a medial locking compression plate applied in bridging mode. The proximal tibial segments were stabilized with percutaneous lag screws, and the displaced distal shaft fragment was fixed using a limited contact dynamic compression plate through a minimally invasive percutaneous plate osteosynthesis technique. The osteotomized tuberosity was reattached with a cannulated cancellous screw. Postoperative recovery was uneventful. Early non-weight-bearing mobilization began on postoperative day 2, with protected weight-bearing allowed by 2 months and full weight-bearing by 3 months. At 6 months, radiographs confirmed solid union without implant-related complications and the patient achieved near pain-free knee motion and independent ambulation. This case highlights the value of tailored fixation and selective tibial tuberosity osteotomy to achieve anatomic reduction and stable reconstruction in complex floating knee injuries. Coordinated rehabilitation further contributed to favourable functional and radiological outcomes.