Perceptual Mechanisms Research Articles

A soft robotic system imitating the multimodal sensory mechanism of human fingers for intelligent grasping and recognition

The sensory function is crucial for achieving precise feedback control and environmental interaction in soft robots. Therefore, the multimodal sensory capabilities that mimic human fingers have always been a research hotspot. This study proposes a design method for a soft robotic gripper that can emulate the multimodal perception mechanism of human fingers and achieve high-precision recognition of grasped objects using machine learning algorithms. In addition, a finger texture structure inspired by human fingerprints is designed using a negative pressure-induced buckling method to enhance the soft gripper's ability to perceive minute surface textures. Inspired by slow adapting (SA) receptors and fast adapting (FA) receptors of human fingers, we have innovatively designed a capacitive curvature sensor (CS) and a triboelectric texture sensor (TS) to detect the size, material, and texture of objects. Furthermore, a non-contact medium identification sensor (MIS), having a sensitivity of more than 1300 times higher compared to the traditional MISs, is fabricated using the principle of electromagnetic resonance. It is shown that by employing a deep learning-based multi-channel feature fusion network, the soft grasping system with multimodal sensing has achieved a recognition accuracy of 98.43 % for different objects. This work provides an innovative approach for the application of soft robots in various fields, such as logistics sorting and food safety.

Pizza3: A general simulation framework to simulate food-mechanical and food-deconstruction problems

Current mesh-based simulation approaches face significant challenges in continuously modeling the mechanical behaviors of foods through processing, storage, deconstruction, and digestion. This is primarily due to the limitations of continuum mechanics in dealing with systems characterized by free boundaries, substantial deformations, mechanical failures, and non–homogenized mechanical properties. The dynamic nature of food microstructure and the transformation of the food bolus, in relation to its composition, present formidable obstacles in computer-aided food design. In response, the Pizza3 project adopts an innovative methodology, utilizing an explicit microstructural representation to construct and subsequently deconstruct food products in a modular, Lego-like fashion. Central to this simulation approach are “food atoms”, conceptualized from the principles of smoothed particle hydrodynamics. These units are significantly larger than actual atoms but are finely scaled to represent both solid and liquid states of food faithfully. In solid phases, food atoms interact via pairwise forces akin to bond-peridynamic methods, thus extending the capabilities of continuum mechanics to encompass large deformations and fracturing phenomena. For liquids, the model employs artificial conservative and dissipative forces, enabling the simulation of a variety of phenomena within the framework of partial compressibility. The interaction dynamics between rigid and soft objects and fluids are accurately captured through Hertzian contact mechanics, offering a versatile parameterization applicable to impermeable (but possibly penetrable) surfaces and enforcing no-slip conditions. The efficacy of this framework is showcased through the successful modeling of three time-dependent 3D scenarios, each rigorously validated against established analytical and experimental models. Advancing beyond these initial applications, the framework is further extended to more intricate cases inadequately addressed in current literature. This extension sheds light on the underlying mechanisms of in-mouth texture perception, offering new insights and tools for food engineering and design.

Dysregulation of parvalbumin expression and neurotransmitter imbalance in the auditory cortex of the BTBR mouse model of autism spectrum disorder.

Individuals diagnosed with autism spectrum disorder (ASD) frequently exhibit abnormalities in auditory perception, a phenomenon potentially attributed to alterations in the excitatory and inhibitory cells constituting cortical circuits. However, the exact genetic factors and cell types affected by ASD remain unclear. The present study investigated the balance of excitatory and inhibitory activity in the auditory cortex using BTBR T+ Itpr3tf/J (BTBR) mice, a well-established model for autism research. Our investigation unveiled a reduction in parvalbumin-positive (PV+) neurons within the AC of BTBR mice. Remarkably, in vivo magnetic resonance spectroscopy studies disclosed an elevation in glutamate (Glu) levels alongside a decrement in γ-aminobutyric acid (GABA) levels in this cortical region. Additionally, transcriptomic analysis of the mouse model facilitated the classification of several ASD-associated genes based on their cellular function and pathways. By comparing autism risk genes with RNA transcriptome sequencing data from the ASD mouse model, we identified the recurrent target gene Scn1a and performed validation. Intriguingly, we uncovered the specific expression of Scn1a in cortical inhibitory neurons. These findings hold significant value for understanding the underlying neural mechanisms of abnormal sensory perception in animal models of ASD.

Mechanisms of gravity perception and their roles in animals

Mechanisms of gravity perception and their roles in animals

Segmental Influences on the Perception of High Pitch Accent Scaling in American English.

Researchers investigating a broad array of questions in spoken language prosody routinely base their arguments on measurements taken from the F0 contours of representative speech samples. These analyses, however, frequently involve abstracting F0 contours away from the segmental strings that bear them, potentially overlooking in the process the role played by segmental qualities such as sonority or periodicity in the realization of F0 patterns by speakers and their interpretation by listeners. This paper reports the results of two experiments investigating how perception of F0 contours is affected by the segmental string over which those contours are realized. The first focuses on gaps in F0 contours created by voiceless obstruents such as stops and fricatives, while the second investigates F0 intervals spanning lower-sonority voiced segments, such as nasals and voiced fricatives. While these two scenarios might at first seem unrelated, we argue that listeners treat both with a single mechanism in perception, namely, by reducing (potentially to zero) the amount of weight accorded to those portions of the contour for determination of the speaker's intended F0 scaling level. We present an account of both effects within a unified model of F0 scaling perception called TCoG-F, with discussion of its implications for phonetic and phonological intonation research going forward.

How Attitudes Toward Evidence-Based Practice Impacts Burnout: A Sequential Mediation Model

ABSTRACT Purpose With the rapid development of China’s social work sector, the increasing job pressures, and risks of professional burnout among social workers have become more prevalent. This study examined the relationship between Chinese social workers’ attitudes toward evidence-based practice (EBP) and burnout, exploring the mediating mechanisms of evidence-based knowledge (EBK) and service quality perception (SQP). Materials and methods We applied PROCESS 4.2 macro in SPSS to analyze the data from 5,931 social workers, testing the sequential mediation effects of EBK and SQP between their attitudes toward EBP and burnout. Results The findings revealed: (1) Attitudes toward EBP had significant indirect positive effects on burnout; (2) EBK partially mediated the relationship between EBP attitude and burnout; (3) SQP partially mediated the relationship between attitudes toward EBP and burnout; (4) Attitudes toward EBP had a sequential mediated effect on burnout through EBK and SQP. Discussion The findings emphasize the need to implement targeted interventions and training programs to foster positive attitudes toward EBP, promote continuous professional development, and provide access to EBP resources. Moreover, nurturing EBK and SQP could help alleviate burnout by improving social workers’ ability to address client issues and enhance their sense of confidence and accomplishment. Conclusion This study fills a research gap by providing empirical evidence on the negative correlation between Chinese social workers’ attitudes toward EBP and burnout, while demonstrating the mediating roles of EBK and SQP.

Leveraging coevolutionary insights and AI-based structural modeling to unravel receptor–peptide ligand-binding mechanisms

Secreted signaling peptides are central regulators of growth, development, and stress responses, but specific steps in the evolution of these peptides and their receptors are not well understood. Also, the molecular mechanisms of peptide-receptor binding are only known for a few examples, primarily owing to the limited availability of protein structural determination capabilities to few laboratories worldwide. Plants have evolved a multitude of secreted signaling peptides and corresponding transmembrane receptors. Stress-responsive SERINE RICH ENDOGENOUS PEPTIDES (SCOOPs) were recently identified. Bioactive SCOOPs are proteolytically processed by subtilases and are perceived by the leucine-rich repeat receptor kinase MALE DISCOVERER 1-INTERACTING RECEPTOR-LIKE KINASE 2 (MIK2) in the model plant Arabidopsis thaliana. How SCOOPs and MIK2 have (co)evolved, and how SCOOPs bind to MIK2 are unknown. Using in silico analysis of 350 plant genomes and subsequent functional testing, we revealed the conservation of MIK2 as SCOOP receptor within the plant order Brassicales. We then leveraged AI-based structural modeling and comparative genomics to identify two conserved putative SCOOP-MIK2 binding pockets across Brassicales MIK2 homologues predicted to interact with the "SxS" motif of otherwise sequence-divergent SCOOPs. Mutagenesis of both predicted binding pockets compromised SCOOP binding to MIK2, SCOOP-induced complex formation between MIK2 and its coreceptor BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED KINASE 1, and SCOOP-induced reactive oxygen species production, thus, confirming our in silico predictions. Collectively, in addition to revealing the elusive SCOOP-MIK2 binding mechanism, our analytic pipeline combining phylogenomics, AI-based structural predictions, and experimental biochemical and physiological validation provides a blueprint for the elucidation of peptide ligand-receptor perception mechanisms.

Exploring Smartphone User Interface Experience-Sharing Behavior: Design Perception and Motivation-Driven Mechanisms through the SOR Model

This study investigates user experience (UX) sharing behaviors in the context of smartphone user interface (UI) design, emphasizing their significance for UI enhancement and effective marketing strategies. Grounded in the Stimulus–Organism–Response (SOR) framework, we examine how design perception attributes—perceived usability, novelty, enjoyment, and brand image—influence UX sharing, with a spotlight on the mediating role of individual motivation. A quantitative analysis (N = 472), Structural Equation Modeling (SEM), and mediation analysis were conducted. Our findings confirm that these components can positively impact UX sharing by bolstering personal expectations and self-efficacy in knowledge sharing, with perceived usability being an exception as it unexpectedly showed a negative association with sharing frequency. Moreover, perceived brand image and individual self-expectancy and self-efficacy enhance sharing outcomes. This research enriches our understanding of the strategic importance of user interface (UI) design in the context of smartphones, furnishing empirical grounding for devising sustainable UI design strategies and productive marketing tactics. Consequently, it bears considerable relevance to both theoretical insights and practical applications.

Exploration of the mechanism of temperature influence on bitter taste of theacrine by activating human bitter taste receptor hTAS2R14

Theacrine, a purine alkaloid derived from Camellia assamica var. kucha, has a distinct bitter taste. Our previous study found the lower recognition threshold of theacrine at 25 °C than 45 °C. This study aims to investigate the bitterness characterizations of theacrine at aforementioned temperatures and its taste perception mechanism. Sensory analysis exhibited higher bitterness intensity for theacrine at 25 °C than 45 °C. Subsequently, flow cytometry was performed to verify the above characterization at the cellular level. It revealed that theacrine could activated the bitter receptor hTAS2R14 and the calcium signal at 25 °C was higher than 45 °C. Ultimately, the interaction mechanism was studied by molecular dynamics simulations, indicating that the conformation of theacrine-hTAS2R14 had a higher binding capacity and better stability at 25 °C. Overall, temperature affected the binding of theacrine to the bitter receptor hTAS2R14, resulting in the stronger bitterness intensity of theacrine at 25 °C than 45 °C.

Visual imagery vividness correlates with afterimage conscious perception.

Afterimages are illusory, visual conscious perceptions. A widely accepted theory is that afterimages are caused by retinal signaling that continues after the physical disappearance of a light stimulus. However, afterimages have been reported without preceding visual, sensory stimulation (e.g. conditioned afterimages and afterimages induced by illusory vision). These observations suggest the role of top-down brain mechanisms in afterimage conscious perception. Therefore, some afterimages may share perceptual features with sensory-independent conscious perceptions (e.g. imagery, hallucinations, and dreams) that occur without bottom-up sensory input. In the current investigation, we tested for a link between the vividness of visual imagery and afterimage conscious perception. Participants reported their vividness of visual imagery and perceived sharpness, contrast, and duration of negative afterimages. The afterimage perceptual features were acquired using perception matching paradigms that were validated on image stimuli. Relating these perceptual reports revealed that the vividness of visual imagery positively correlated with afterimage contrast and sharpness. These behavioral results support shared neural mechanisms between visual imagery and afterimages. However, we cannot exclude alternative explanations, including demand characteristics and afterimage perception reporting inaccuracy. This study encourages future research combining neurophysiology recording methods and afterimage paradigms to directly examine the neural mechanisms of afterimage conscious perception.

Highly Robust and Self-Adhesive Soft Strain Gauge via Interface Design Engineering.

Highly robust soft strain gauges are rapidly emerging as a promising candidate in the fields of vital signs and machine conditions monitoring. However, it is still a key challenge to achieve high-performance strain sensing in these sensors with mechanical/electrical robustness for long-term usage. The multilayer structural design of sensors enhances sensing performance while the interfacial connection of heterogeneous materials between different layers is weak. Herein, inspired by the efficient perception mechanism of scorpion slit sensilla with tough interface interconnections, the synergy of ultra-high electrical performance and mechanical robustness is successfully achieved via interface design engineering. The developed multilayer soft strain gauge (MSSG) exhibits a strain sensitivity beyond 105, a lower detection limit of 8.3µm, a frequency resolution within 0.1Hz, and cyclic stability over 63000 strain cycles. Also, the tough interface improves the level of heterogeneous integration in the MSSG which allows to endure different stresses. Furthermore, an MSSG-based wireless strain monitoring system is developed that enables applications on different complex dynamic surfaces, including accurate identification of human throat activity and monitoring of rolling bearing conditions.

Pathogen elicitor peptide (pep), systemin, and their receptors in tomato: sequence analysis sheds light on standing disagreements about biotic stress signaling components

Peps are endogenous damage-associated polypeptides that evoke defense responses in plants. Like other damage-associated molecular patterns, Pep signals are transduced by receptors. PEPRs are the receptors that transduce Pep danger signals. This paper identifies new putative Peps in the Solanaceae (including Solanum spp., Nicotiana spp., and Petunia spp.) and Coffea and explores their properties. Using these newly identified Peps we derive sequence logos that present a refinement of the current understanding of the importance of specific residues in the Pep signaling molecules in Solanaceae, including several arginines, prolines that restrict peptide’s conformations, and C-terminal asparagine. We examine the degree of disorder in Pep, which is likely important to the mechanism of Pep perception. This work also calls into question some of the evolutionary relationships between Peps in Solanaceae and specific Arabidopsis Peps published in previous literature, culminating in a conclusion that SlPep should not be named SlPep6 due to the lack of conservation of protein sequences in AtPROPEP6 and SlPROPEP, and that SlPep probably does not have two receptors in tomato, based on phylogenetic analysis. Our analyses advance understanding of the Pep signaling system in Solanaceae.

Identification and Functional Analysis of Odorant Binding Proteins in Apriona germari (Hope).

Apriona germari (Hope) presents a significant threat as a dangerous wood-boring pest, inflicting substantial harm to forest trees. Investigating the olfactory sensory system of A. germari holds substantial theoretical promise for developing eco-friendly control strategies. To date, however, the olfactory perception mechanism in A. germari remains largely unknown. Therefore, we performed transcriptome sequencing of A. germari across four distinct body parts: antennae, foreleg tarsal segments, mouthparts (maxillary and labial palps), and abdomen terminals, pinpointing the odorant binding protein (OBP) genes and analyzing their expression. We found eight AgerOBPs (5, 19, 23, 25, 29, 59, 63, 70) highly expressed in the antennae. In our competitive binding experiments, AgerOBP23 showed strong binding abilities to the pheromone component fuscumol acetate, eight plant volatiles (farnesol, cis-3-hexenal, nerolidol, myristol acetate, cis-3-hexenyl benzoate, (-)-α-cedrene, 3-ethylacetophenone, and decane), and four insecticides (chlorpyrifos, phoxim, indoxacarb, and cypermethrin). However, AgerOBP29 and AgerOBP63 did not show prominent binding activities to these tested chemicals. Through homology modeling and molecular docking, we identified the key amino acid sites involved in the binding process of AgerOBP23 to these ligands, which shed light on the molecular interactions underlying its binding specificity. Our study suggests that AgerOBP23 may serve as a potential target for future investigations of AgerOBP ligand binding. This approach is consistent with the reverse chemical ecology principle, establishing the groundwork for future studies focusing on attractant or repellent development by exploring further the molecular interactions between OBP and various compounds.

Cognitive Mechanisms of Aberrant Self-Referential Social Perception in Psychosis and Bipolar Disorder: Insights from Computational Modeling.

Individuals with schizophrenia (SZ) and bipolar disorder (BD) show disruptions in self-referential gaze perception-a social perceptual process related to symptoms and functioning. However, our current mechanistic understanding of these dysfunctions and relationships is imprecise. The present study used mathematical modeling to uncover cognitive processes driving gaze perception abnormalities in SZ and BD, and how they relate to cognition, symptoms, and social functioning. We modeled the behavior of 28 SZ, 38 BD, and 34 controls (HC) in a self-referential gaze perception task using drift-diffusion models (DDM) parameterized to index key cognitive components: drift rate (evidence accumulation efficiency), drift bias (perceptual bias), start point (expectation bias), threshold separation (response caution), and non- decision time (encoding/motor processes). Results revealed that aberrant gaze perception in SZ and BD was driven by less efficient evidence accumulation, perceptual biases predisposing self-referential responses, and greater caution (SZ only). Across SZ and HC, poorer social functioning was related to greater expectation biases. Within SZ, perceptual and expectancy biases were associated with hallucination and delusion severity, respectively. These findings indicate that diminished evidence accumulation and perceptual biases may underlie altered gaze perception in patients and that SZ may engage in compensatory cautiousness, sacrificing response speed to preserve accuracy. Moreover, biases at the belief and perceptual levels may relate to symptoms and functioning. Computational modeling can, therefore, be used to achieve a more nuanced, cognitive process-level understanding of the mechanisms of social cognitive difficulties, including gaze perception, in individuals with SZ and BD.

Depth perception optimization of mixed reality simulation systems based on multiple‐cue fusion

AbstractMixed reality technology can be applied to simulation training, improve surgical performance, enhance 3D game experience, and so on, attracting extensive attention of researchers. The perception of the user about head‐mounted display MR using HoloLens is critical, especially for precision applications such as virtual hoisting. Designing and adding appropriate depth cues in MR scenes is an effective way to improve users' depth perception. In this study, taking virtual hoisting training system as an example, the depth perception strategy of multi‐cue fusion is proposed to improve the perception effect. Based on the mechanism of human depth perception, five kinds of depth cues are designed. The depth perception effect of adding single cue is studied by perceptual matching experiment. Based on the principle of fuzzy clustering, a multiple‐cue comprehensive depth optimization strategy on viewing distance scale is proposed. Finally, the perceptual matching results demonstrate the effectiveness of the multi‐cue fusion strategy, and the average error is reduced by 20.68% compared with the single‐cue strategy, which can significantly improve the spatial depth perception. This research can provide a reference for improving users' depth perception in interactive MR simulation systems.

Mechanism of key volatiles in osmanthus scented green tea on the improvement of its aroma and taste quality

The intensity of green tea's floral and sweet flavors was enhanced after being scented by osmanthus (OSGT). However, the mechanism of flavor enhancement by key volatiles remains unknown. Here, the role of key volatiles in OSGT on aroma and taste was explored by sensory experiment-guided flavor analysis. Binary mixed models of (E)-β-ionone, dihydro-β-ionone, and α-ionone showed additive interactions on floral aroma enhancement, the interactions were increased with increasing concentrations. At the concentration in OSGT, binary mixed models of (E)-β-ionone, geraniol, linalool, and γ-decalactone showed additive interactions on sweet aroma enhancement. (E)-β-ionone, geraniol, linalool, and γ-decalactone all significantly increased the perceived intensity of sweetness of sucrose solutions. Additionally, molecular docking revealed the perception mechanism of olfactory and taste receptors to the above characterized volatiles, with hydrogen bonding and hydrophobic interactions being the main interactions. This study highlights the importance of characteristic volatiles in enhancing the flavor of OSGT.

Schrödinger's Cat-Parallel experiences: exploring the underlying mechanisms of undergraduates' engagement and perception in online learning.

The emergence of e-learning had an intense, immediate, and disruptive transformation in the education system. While education aims to seek more interactions and learning engagement between teachers and students, it turns out that it takes lots of work to achieve the goal in the online classroom. This study aims to explore the underlying mechanisms and implications that emerge from the influence of the new features of online learning, drawing on students' real-life experiences, to construct a comprehensive theoretical model. From July 2023 to October 2023, 56 undergraduates, including 18 male and 38 female, participated in the data collection process either face-to-face or online. The study constructs a substantive theoretical model by employing the approaches of The Grounded Theory, three level-coding constant comparative method, theoretical sampling, core category distillation and storyline collation. (1) The elements involved in the process of online learning exhibit underlying logical correlations, driven by profound underlying factors, ultimately resulting in a parallel experience akin to Schrödinger's Cat. (2) Online features lead to students' motivation mainly depending on whether they are self-regulated. (3) Teacher-student interactions and self-regulation shape different learning contexts and types by being moderated by internal and external effects. Students had a parallel experience similar to that of Schrödinger's Cat: they were constantly dissatisfied with "rational" learning and "perceptually" satisfied with online learning. The variation in the satisfaction of the three basic psychological needs necessities college students in online learning leads to parallel experiences.

Flavor Perception and Formation Mechanism of Empty Cup Aroma in Soy Sauce Aroma Type Baijiu.

The research focused on the distinctive empty cup aroma, with the aim of identifying the key aroma compounds and the formation mechanism of empty cup aroma in soy sauce aroma type baijiu (SSB). The lasting times of SSB is significantly longer than that of other types of baijiu, with an average duration of 28 days. Key compounds such as 2,3-dimethyl-5-ethylpyrazine, phenylethyl alcohol, p-cresol, sotolon, benzeneacetic acid were identified in empty cup aroma due to their highest flavor dilution factor. Molecular dynamics (MD) simulation was performed to study the mechanism of empty cup aroma on the liquid-gas interface and solid-gas interface. The results revealed the existence of hydrogen bonding and van der Waals forces between sotolon and lactic acid, a representative nonvolatile compound, which are speculated to be an important reason for the empty cup aroma.

Posttraumatic headache: pain related evoked potentials (PREP) and conditioned pain modulation (CPM) to assess the pain modulatory function

Posttraumatic headache (PTH) is common following traumatic brain injury and impacts quality of life. We investigated descending pain modulation as one possible mechanism for PTH and correlated it to clinical measures. Pain-related evoked potentials (PREP) were recorded in 26 PTH-patients and 20 controls after electrical stimulation at the right hand and forehead with concentric surface electrodes. Conditioned pain modulation (CPM) was assessed using painful cutaneous electric stimulation (PCES) on the right hand as test stimulus and immersion of the left hand into 10 °C-cold water bath as conditioning stimulus based on changes in pain intensity and in amplitudes of PCES-evoked potentials. All participants completed questionnaires assessing depression, anxiety, and pain catastrophising. PTH-patients reported significantly higher pain ratings during PREP-recording in both areas despite similar stimulus intensity at pain threshold. N1P1-amplitudes during PREP and CPM-assessment were lower in patients in both areas, but statistically significant only on the hand. Both, PREP-N1-latencies and CPM-effects (based on the N1P1-amplitudes and pain ratings) were similar in both groups. Patients showed significantly higher ratings for anxiety and depression, which did not correlate with the CPM-effect. Our results indicate generalized hyperalgesia for electrical stimuli in both hand and face in PTH. The lacking correlation between pain ratings and EEG parameters indicates different mechanisms of pain perception and nociception.

Confrontation with others' emotions changes bodily resonance differently in those with low and high levels of depersonalization.

We present novel research on the cortical dynamics of atypical perceptual and emotional processing in people with symptoms of depersonalization-derealization disorder (DP-DR). We used electroencephalography (EEG)/event-related potentials (ERPs) to delineate the early perceptual mechanisms underlying emotional face recognition and mirror touch in adults with low and high levels of DP-DR symptoms (low-DP and high-DP groups). Face-sensitive visual N170 showed markedly less differentiation for emotional versus neutral face-voice stimuli in the high- than in the low-DP group. This effect was related to self-reported bodily symptoms like disembodiment. Emotional face-voice primes altered mirror touch at somatosensory cortical components P45 and P100 differently in the two groups. In the high-DP group, mirror touch occurred only when seeing touch after being confronted with angry face-voice primes. Mirror touch in the low-DP group, however, was unaffected by preceding emotions. Modulation of mirror touch following angry others was related to symptoms of self-other confusion. Results suggest that others' negative emotions affect somatosensory processes in those with an altered sense of bodily self. Our findings are in line with the idea that disconnecting from one's body and self (core symptom of DP-DR) may be a defence mechanism to protect from the threat of negative feelings, which may be exacerbated through self-other confusion. This article is part of the theme issue 'Sensing and feeling: an integrative approach to sensory processing and emotional experience'.