"Spicy Touch": Cross-modal associations between hand-feel touch and capsaicin-induced oral irritation.

The influence of extrinsic hand-feel touch cues on consumer experiences in food and beverage consumption is well established. However, their impact on trigeminal perception, particularly the oral irritation caused by capsaicin or spicy foods, is less understood. This study aimed to determine the existence of cross-modal associations between hand-feel touch and capsaicin-induced oral irritation. This study investigated whether these potential associations were driven by the sensory contributions of the hand-feel tactile materials (measured by instrumental physical parameters) or by affective responses (evaluated through hedonic scales and the self-reported emotion questionnaire, EsSense Profile®, by consumers). In our study, 96 participants tasted a capsaicin solution while engaging with nine hand-feel tactile materials, i.e., cardboard, linen, rattan, silicone, stainless steel, sandpaper (fine), sandpaper (rough), sponge, and towel. They subsequently rated their liking and emotional responses, perceived intensity of oral irritation, and the congruency between hand-feel tactile sensation and oral irritation. Instrumental measurements characterized the surface texture of the hand-feel tactile materials, which were correlated with the collected sensory data. The results revealed that unique cross-modal associations between hand-feel touch and capsaicin-induced oral irritation. Specifically, while sandpapers demonstrated high congruence with the sensation of oral irritation, stainless steel was found to be least congruent. These associations were influenced by both the common emotional responses ("active," "aggressive," "daring," "energetic," "guilty," and "worried") evoked by the hand-feel tactile materials and the capsaicin, as well as by participants' liking for the hand-feel tactile materials and the characteristics of the surface textures. This study provides empirical evidence of the cross-modality between hand-feel tactile sensations and capsaicin-induced oral irritation, opening new avenues for future research in this area.

A Multifunctional Tactile Sensory System for Robotic Intelligent Identification and Manipulation Perception.

Humans recognize and manipulate objects relying on the multidimensional force features captured by the tactile sense of skin during the manipulation. Since the current sensors integrated in robots cannot support the robots to sense the multiple interaction states between manipulator and objects, achieving human-like perception and analytical capabilities remains a major challenge for service robots. Prompted by the tactile perception involved in robots performing complex tasks, a multimodal tactile sensory system is presented to provide in situ simultaneous sensing for robots when approaching, touching, and manipulating objects. The system comprises a capacitive sensor owning the high sensitivity of 1.11E-2 pF mm-1, a triboelectricity nanogenerator with the fast response speed of 30 ms, and a pressure sensor array capable of 3D force detection. By Combining transfer learning models, which fuses multimodal tactile information to achieve high-precision (up to 95%) recognition of the multi-featured targets such as random hardness and texture information under random sampling conditions, including random grasp force and velocity. This sensory system is expected to enhance the intelligent recognition and behavior-planning capabilities of autonomous robots when performing complex tasks in undefined surrounding environments.

Hardness changing tactile displays for simulating the feel of organic tissues.

Physical interaction with patients, for example conducted as part of a diagnostic examination or surgical procedure, provides clinicians with a wealth of information about their condition. Simulating this interaction is of great interest to researchers in both haptics and medical education, and the development of softness changing tactile interfaces is important in recreating the feel of different soft tissues. This paper presents designs for a variety of novel electromechanical and electromagnetic mechanisms for controlling particle jamming-based, hardness changing tactile displays, intended to allow medical trainees to experience these physical interactions in a range of simulation settings such as clinical skills teaching laboratories. Each design is then subjected to a battery of mechanical tests to evaluate its effectiveness compared to the state of the art, as well as their suitability for simulating the physical hardness of different types of soft tissues, previously characterised in established literature. These results demonstrate that all of the technologies presented are able to exhibit a measurable hardness change, with Shore hardness values between 3A and 57A achieved by the most effective constriction-based device. The electromechanical devices based on constriction and compression, and the state-of-the-art pneumatic device, were able to achieve hardness changes within a range that is useful for replicating the softness of organic tissue. The electromechanical and electromagnetic devices were also found to effect their full range of hardness change in less than a second, compared to several seconds for the state-of-the-art. These results show that the performance of softness changing tactile displays can be improved with the electromechanical actuation techniques proposed in this paper, and that such displays are able to replicate the physical characteristics of soft tissues and may therefore be of benefit in medical training and simulation scenarios.

SONOICE! a Sonar-Voice dynamic user interface for assisting individuals with blindness and visual impairment in pinpointing elements in 2D tactile readers.

Pinpointing elements on large tactile surfaces is challenging for individuals with blindness and visual impairment (BVI) seeking to access two-dimensional (2D) information. This is particularly evident when using 2D tactile readers, devices designed to provide 2D information using static tactile representations with audio explanations. Traditional pinpointing methods, such as sighted assistance and trial-and-error, are limited and inefficient, while alternative pinpointing user interfaces (UI) are still emerging and need advancement. To address these limitations, we develop three distinct navigation UIs using a user-centred design approach: Sonar (proximity-radar sonification), Voice (direct clock-system speech instructions), and Sonoice, a new method that combines elements of both. The navigation UIs were incorporated into the Tactonom Reader device to conduct a trial study with ten BVI participants. Our UIs exhibited superior performance and higher user satisfaction than the conventional trial-and-error approach, showcasing scalability to varied assistive technology and their effectiveness regardless of graphic complexity. The innovative Sonoice approach achieved the highest efficiency in pinpointing elements, but user satisfaction was highest with the Sonar approach. Surprisingly, participant preferences varied and did not always align with their most effective strategy, underscoring the importance of accommodating individual user preferences and contextual factors when choosing between the three UIs. While more extensive training may reveal further differences between these UIs, our results emphasise the significance of offering diverse options to meet user needs. Altogether, the results provide valuable insights for improving the functionality of 2D tactile readers, thereby contributing to the future development of accessible technology.

Community-based, inclusive design of a 3D tactile map to enable playground navigation for children who are visually impaired and blind.

The LSU Community Playground Project (LSUCPP) collaborates with communities (especially the true experts at play, the children) to design and build playgrounds that reflect "the soul of the community." One member of the LSUCPP undertook a research project in an effort to design better playgrounds for use by children who are visually impaired or blind. A recommendation from this research was to provide a 3D-printed tactile map of each play area, such that children who were visually impaired or blind could feel the location and type of equipment and ground surfaces prior to entering a playground, which would enable them to play independently. In this paper, we tell the story of how engineering students and faculty collaborated with children with visual impairments or blindness and their teachers and professional staff to co-design and build a 3D printed tactile map at the Louisiana School for the Visually Impaired (LSVI). Specifically, we detail how we co-designed this artifact, the ways in which the artifact developed due to this inclusive approach, briefly present the design, and discuss how engineers engaged in the design of assistive technologies can put inclusive design principles and community-based design processes into action.

Effectiveness of Audio-Tactile Performance Versus Other Oral Health Education Methods in Improving Oral Health in Visually Impaired Children and Adolescents: A Systematic Review.

The aim of this study was to compare the effectiveness of audio-tactile performance (ATP) versus other oral health education methods in improving the oral health status of visually challenged children and adolescents. The review was carried out based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search was performed on the effectiveness of ATP in improving the oral health of visually impaired children. The search was conducted in Scopus, Google Scholar, PubMed, Embase, Lilacs, Web of Science, and Cochrane until December 2022. The risk-of-bias tool for randomized trials (RoB-2) was used to analyze the risk of bias. Meta-analysis was carried out for included studies that made similar comparisons and reported the same outcome measures. The initial search retrieved 368 records, of which nine studies were included for qualitative synthesis. Out of the nine included studies, five studies were included for quantitative synthesis. Two studies evaluating plaque index at 180 days (MD = -0.10; p = 0.0009; CI = -0.17 to -0.02) and five studies evaluating gingival index at 90 days (MD = -0.15; p < 0.00001; CI= -0.21 to -0.09) exhibited a significant mean difference favoring ATP. Three studies that evaluated gingival index at 30 days and 180 days showed significant mean differences (MD = -0.27; p < 0.000; CI = -0.40 to -0.15 and MD = -0.09; p = 0.01; CI= -0.15 to -0.02) favoring ATP. The ATP technique produced significant improvements in oral health when compared with other conventional techniques. However, the studies had high heterogeneity, and hence, the result must be inferred with caution.

Species groups, subgroups, and key to world species of the genus Schizotetranychus Trägårdh, 1915 (Acari, Prostigmata, Tetranychidae).

After a comprehensive taxonomic assessment of descriptions/ illustrations of all known (118) species of the spider mite genus Schizotetranychus Trägårdh (Acari: Prostigmata: Tetranychidae), five species groups are proposed based on the number of tactile setae on tibia II in female, i.e., vermiculatus with four setae (four spp.), schizopus with five setae (52 spp.), spireafolia with six setae (10 spp.), asparagi with seven setae (20 spp.), and bambusae with eight setae on tibia II (22 spp.). The species group schizopus is further divided into three species subgroups based on tactile setae on tibia I: schizopus with eight/ nine setae (21 spp.), andropogoni with seven setae (26 spp.), and taquarae with six tactile setae excluding the solenidion on tibia I (five spp.). Eight Schizotetranychus species were not assigned to any species group because of brief descriptions and/ or illustration and without information on the number of tactile setae on tibiae I and II. Moreover, two Schizotetranychus species, S.gausus Baker & Pritchard and S.luculentus Tseng that have six setae/ structures including a spinneret and a solenidion on the palp tarsus, are provisionally transferred to the genus Stigmaeopsis Banks. Finally, keys to species groups and subgroups of the world species of Schizotetranychus are provided.

Beyond self-report: Measuring visual, auditory, and tactile mental imagery using a mental comparison task.

Finding a reliable and objective measure of individual differences in mental imagery across sensory modalities is difficult, with measures relying on self-report scales or focusing on one modality alone. Based on the idea that mental imagery involves multimodal sensorimotor simulations, a mental comparison task (MCT) was developed across three studies and tested on adults (n = 96, 345, and 448). Analyses examined: (a) the internal consistency of the MCT, (b) whether lexical features of the MCT stimuli (word length and frequency) predicted performance, (c) whether the MCT related to two widely used self-report scales, (d) response latencies and accuracies across the visual, auditory, and tactile modalities, and (e) whether MCT performance was independent of processing speed. The MCT showed evidence of reliability and validity. Responses were fastest and most accurate for the visual modality, followed by the auditory and tactile. However, consistent with the idea that self-report questionnaires index a different aspect of mental imagery, the MCT showed minimal correlations with self-report imagery. Finally, relations between MCT scales remained strong after controlling for processing speed. Findings are discussed in relation to current understanding and measurement of mental imagery.

Visual and corresponding tactile dataset of flexible material for robots and cross modal perception.

Humans primarily understand the world around them through visual perception and touch. As a result, visual and tactile information play crucial roles in the interaction between humans and their environment. In order to establish a correlation between what is seen and what is felt on the same object, particularly on flexible objects (such as textile, leather, skin etc.) which humans often access by touch to cooperatively determine their quality, the need for a new dataset that includes both visual and tactile information arises. This has motivated us to create a dataset that combines visual images and corresponding tactile data to explore the potential of cross-modal data fusion. We have chosen leather as our object of focus due to its widespread usage in everyday life. The dataset we propose consists of visual images depicting leather in various colours and displaying defects, alongside corresponding tactile data collected from the same region of the leather. Notably, the tactile data comprises components along the X, Y, and Z axes. To effectively demonstrate the relationship between visual and tactile data on the same object region, the tactile data is aligned with the visual data and visualized through interpolation. Considering the potential applications in computer vision, we have manually labelled the defect regions in each visual-tactile sample. Ultimately, the dataset comprises a total of 687 records. Each sample includes visual images, image representations of the tactile data (referred to as tactile images for simplicity), and segmentation images highlighting the defect regions, all with the same resolution.

Oscillatory cortico-cortical connectivity during tactile discrimination between dynamic and static stimulation.

Fine sensory modalities play an essential role in perceiving the world. However, little is known about how the cortico-cortical distinguishes between dynamic and static tactile signals. This study investigated oscillatory connectivity during a tactile discrimination task of dynamic and static stimulation via electroencephalogram (EEG) recordings and the fast oscillatory networks across widespread cortical regions. While undergoing EEG recordings, the subject felt an electro-tactile presented by a 3-dot array. Each block consisted of 3 forms of stimulation: Spatio-temporal (dynamic), Spatial (static), and Control condition (lack of electrical stimulation). The average event-related potential for the Spatial and Spatio-temporal conditions exhibited statistically significant differences between 25 and 75, 81 and 121, 174 and 204 and 459 and 489 ms after stimulus onset. Based on those times, the sLORETA approach was used to reconstruct the inverse solutions of EEG. Source localization appeared superior parietal at around 25 to 75 ms, in the primary motor cortex at 81 to 121 ms, in the central prefrontal cortex at 174 to 204 and 459 to 489 ms. To better assess spectral brain functional connectivity, we selected frequency ranges with correspondingly significant differences: for static tactile stimulation, these are concentrated in the Theta, Alpha, and Gamma bands, whereas for dynamic stimulation, the relative energy change bands are focused on the Theta and Alpha bands. These nodes' functional connectivity analysis (phase lag index) showed 3 distinct distributed networks. A tactile information discrimination network linked the Occipital lobe, Prefrontal lobe, and Postcentral gyrus. A tactile feedback network linked the Prefrontal lobe, Postcentral gyrus, and Temporal lobe. A dominant motor feedforward loop network linked the Parietal cortex, Prefrontal lobe, Frontal lobe, and Parietal cortex. Processing dynamic and static tactile signals involves discriminating tactile information, motion planning, and cognitive decision processing.

Fatigue-Resistant Mechanoresponsive Color-Changing Hydrogels for Vision-Based Tactile Robots.

Mechanoresponsive color-changing materials that can reversibly and resiliently change color in response to mechanical deformation are highly desirable for diverse modern technologies in optics, sensors, and robots; however, such materials are rarely achieved. Here, a fatigue-resistant mechanoresponsive color-changing hydrogel (FMCH) is reported that exhibits reversible, resilient, and predictable color changes under mechanical stress. At its undeformed state, the FMCH remains dark under a circular polariscope; upon uniaxial stretching of up to six times its initial length, it gradually shifts its color from black, to gray, yellow, and purple. Unlike traditional mechanoresponsive color-changing materials, FMCH maintains its performance across various strain rates for up to 10 000 cycles. Moreover, FMCH demonstrates superior mechanical properties with fracture toughness of 3000 J m-2, stretchability of 6, and fatigue threshold up to 400 J m-2. These exceptional mechanical and optical features are attributed to FMCH's substantial molecular entanglements and desirable hygroscopic salts, which synergistically enhance its mechanical toughness while preserving its color-changing performance. One application of this FMCH as a tactile sensoris then demonstrated for vision-based tactile robots, enabling them to discern material stiffness, object shape, spatial location, and applied pressure by translating stress distribution on the contact surface into discernible images.

Tactile sensation in relation to roughness and reflection of active initial lesions in primary (deciduous) and permanent dentition in vitro.

OBJECTIVES: This study evaluated whether a relationship exist between tactile sensation, roughness and reflection intensity in active enamel lesions of primary (deciduous) and permanent dentition. METHODS: Freshly extracted teeth of the primary (n=29) and permanent (n=60) dentition of patients who underwent serial extractions under general anesthesia due to multiple deep caries lesions showing active lesions (International Caries Detection and Assessment System scores of 2) were selected. The mean linear (Ra), area-related (Sa), volume-related (Vmc) roughness and vertical reflection intensity (VRI) of sound (S) and carious (C) areas were determined by using a 3D-laser-scanning-microscope and a multi-sensor microscope with two different chromatic-confocal optics. Furthermore, two blinded examiners evaluated the roughness by tactile examination using three different explorers (S23H,405CP11, S3C). RESULTS: Mean differences (95%CI) between S and C for teeth of the primary dentition were: Ra:-1.9(-2.3;-0.4)µm, Sa:-31.8(-1.8;0.0)µm, Vmc:-1.8(-1.6;-0.0)ml/m2, VRI:29(20;43) and for teeth of the permanent dentition: Ra:-4.0(-2.5;-1.0)µm, Sa:-4.8(-3.0;-1.1)µm, Vmc:-4.6(-3.4;-0.5)ml/m2, VRI:34(19;44) differing significantly between S and C (p<0.05,Wilcoxon test). No significant difference was observed between 1st and 2nd dentition (p>0.05, Kruskal-Wallis test) as well as commercial and experimental optic (p>0.05). The highest positive predictive value (PPV) was achieved by examiner 1 with explorer S3C (1st dentition 67%;2nd dentition 100%;pooled dentition 88%)), while examiner 2 revealed the highest PPV with explorer S23H (89%;86%;88%). CONCLUSION: Differences in roughness and reflectance between sound and caries-active enamel surfaces could be evaluated in both primary and permanent dentition. These differences could also be reliably detected using three different explorers with good validity. However, the most predictive explorer seems to differ between examiners. CLINICAL SIGNIFICANCE: In both primary (deciduous) and permanent dentition active caries lesions exhibit significantly higher roughness and lower vertical reflection intensity compared with sound enamel. These differences are detectable by blind tactile examination and objective methods such as 3D-laser-scanning or multi-sensor microscopy, highlighting their utility in caries diagnosis in both dentitions.

Tactile bill-tip organs in seabirds suggest conservation of a deep avian symplesiomorphy.

Birds' bills are their main tactile interface with the outside world. Tactile bill-tip organs associated with specialized foraging techniques are present in several bird groups, yet remain understudied in most clades. One example is Austrodyptornithes, the major seabird clade uniting Procellariiformes (albatrosses and petrels) and Sphenisciformes (penguins). Here, we describe the mechanoreceptor arrangement and neurovascular anatomy in the premaxillae of Austrodyptornithes. Using a wide phylogenetic sample of extant birds (361 species), we show that albatrosses and penguins exhibit complex tactile bill-tip anatomies, comparable to birds with known bill-tip organs, despite not being known to use tactile foraging. Petrels (Procellariidae, Hydrobatidae and Oceanitidae) lack these morphologies, indicating an evolutionary transition in bill-tip mechanosensitivity within Procellariiformes. The bill-tip organ in Austrodyptornithes may be functionally related to nocturnal foraging and prey detection under water, or courtship displays involving tactile stimulation of the bill. Alternatively, these organs may be vestigial as is likely the case in most palaeognaths (e.g. ostriches and emu). Ancestral state reconstructions fail to reject the hypothesis that the last common ancestor of Austrodyptornithes had a bill-tip organ; thus, tactile foraging may be ancestral for this major extant clade, perhaps retained from a deeper point in crown bird evolutionary history.

Effects of Tactile Massage in Improving Older Residents' Psychological Health in Long-Term Care Facilities: A Randomised Controlled Trial.

BACKGROUND: Loneliness, anxiety and depressive symptoms are common among older residents in long-term care facilities (LTCFs), which can negatively impact their quality of life and increase mortality rates. Addressing these psychological health issues is an important task for nursing staff. There is a need for easy and accessible interventions to improve older residents' negative emotions. Tactile massage (TM) is a form of touch therapy that induces oxytocin, which can help individuals feel relaxed, experience pleasure and reduce anxiety. TM can also provide a sense of security and care for individuals. OBJECTIVE: This study aimed to evaluate the effects of TM in improving older residents' psychological health in LTCFs. DESIGN: In this study, we applied a two-arm randomised controlled trial research design. METHODS: We used convenience sampling to enrol 55 older residents in three long-term care facilities who were randomly assigned to an intervention group and a comparison group. The intervention group received TM by research assistants on both hands for 15 min per time, twice a week for 4 weeks and the comparison group received regular care. Data were collected before and after the intervention. Generalised estimating equations (GEEs) were used to evaluate the effectiveness of the intervention. RESULTS: There were no significant differences in loneliness, anxiety, depressive symptoms, happiness, ear temperature, heart rate or diastolic blood pressure between the two groups after the intervention. However, the intervention group had significant improvements in comfort (B = 0.86, p < 0.001), relaxation (B = 1.00, p < 0.001), respiratory rate (B = -0.16, p = 0.021) and systolic blood pressure (B = - 4.17, p = 0.002) compared to the control group. CONCLUSIONS: TM can help older residents who live in LTCFs feel relaxed and comfortable. IMPLICATIONS FOR PRACTICE: TM can be easily implemented as it requires no tools. We recommend that nursing staff and healthcare professionals incorporate TM as part of their care routines. They also can encourage family members to perform TM on residents during their visits to enhance residents' comfort and relaxation. REPORTING METHOD: The Consolidated Standards of Reporting Trials (CONSORT) checklist was used for this paper. TRIAL REGISTRATION: ClinicalTrials.gov (NCT05052138).

Test-retest and inter-rater reliability of two devices measuring tactile mechanical detection thresholds in healthy adults: Semmes-Weinstein monofilaments and the cutaneous mechanical stimulator.

INTRODUCTION/AIMS: Limitations exist in evaluating mechanical detection thresholds (MDTs) due to a lack of dependable electronic instruments designed to assess Aß fibers and measure MDTs across different body areas. This study aims to evaluate the test-retest and inter-rater reliability of the cutaneous mechanical stimulator (CMS), an electronic tactile stimulator, in quantifying MDTs. METHODS: Using a test-retest design, participants underwent assessments of MDTs using Semmes-Weinstein monofilaments (SWM) and the CMS. This study included 27 healthy volunteers (mean age 24.07 ± 3.76 years). Two raters assessed MDTs using SWM and the CMS at two stimulation sites (the left hand and foot) in two experimental sessions approximately 2 weeks apart. RESULTS: MDTs using SWM and the CMS showed excellent reliability on the hand (intraclass correlation coefficient [ICC] = .84) and foot (ICC = .90). A comparison of results obtained at the two sessions showed that MDTs on the hand displayed good reliability for both SWM (ICC = .63) and the CMS (ICC = .73), whereas MDTs on the foot displayed fair reliability for SWM (ICC = .50) and the CMS (ICC = .42). MDTs exhibited good inter-rater reliability with SWM (ICC = .66) and excellent inter-rater reliability with the CMS (ICC = .82) on the hand, as well as showing fair inter-rater reliability with SWM (ICC = .53) and good inter-rater reliability with the CMS (ICC = .60) on the foot. DISCUSSION: The CMS showed superior inter-rater reliability, indicating its potential as a valuable tool for assessing tactile sensitivity in research and clinical settings.

Investigating looming tactile takeover requests with various levels of urgency in automated vehicles.

Designing an effective takeover request (TOR) in conditionally automated vehicles is crucial to ensure driving safety when the system reaches its limit. In our study, we aimed to investigate the effects of looming tactile TORs (whose urgency is dynamically mapped to the situation's criticality as the vehicle approaches the upcoming obstacle) on takeover performance and subjective experience compared with conventional non-looming TORs (several tactile pulses with consistent inter-pulse intervals). In addition, the impact of the TOR urgency level (with urgency levels matched or unmatched to the situation's criticality) was considered. A total of 30 participants were recruited for this study. They were first asked to map the urgency of tactile signals to the criticality of takeover situations with various times to collision according to the recorded video clips. The looming TORs were constructed based on these mapping results. Then, a simulated driving experiment, employing a within-subject design, was conducted to explore the effects of the tactile TOR type (looming vs. non-looming) and urgency level (less urgency vs. matched urgency vs. greater urgency) on takeover performance and drivers' subjective experience. The results showed that the looming TOR can lead to a shorter takeover time and less maximum lateral acceleration compared with the non-looming TOR. Drivers also rated the looming TOR as more useful. Therefore, the looming TOR has great application potential for enhancing driving safety in automated vehicles. In addition, we found that as the TOR's level of urgency increased, the takeover time decreased. However, the TOR with an urgency level matched to the situation's criticality received higher usefulness and satisfaction ratings, suggesting that there was an important trade-off between the advantage of high-urgency TORs in speeding up driver responses and its cost of a poor experience. The findings of our study shed some light on the design and implementation of the takeover warning system for related practitioners.

Tactile Sensing and Rendering Patch with Dynamic and Static Sensing and Haptic Feedback for Immersive Communication.

Wearable human-machine interface (HMI) with bidirectional and multimodal tactile information exchange is of paramount importance in teleoperation by providing more intuitive data interpretation and delivery of tactilely related signals. However, the current sensing and feedback devices still lack enough integration and modalities. Here, we present a Tactile Sensing and Rendering Patch (TSRP) that is made of a customized expandable array which consists of a piezoelectric sensing and feedback unit fused with an elastomeric triboelectric multidimensional sensor and its inner pneumatic feedback structure. The primary functional unit of TSRP is mainly featured with a soft silicone substrate with compact multilayer structure integrating static and dynamic multidimensional tactile sensing capabilities, which synergistically leverage both triboelectric and piezoelectric effects. Additionally, based on the air chamber created by the triboelectric sensor and the converse piezoelectric effect, it provides pneumatic and vibrational haptic feedback simultaneously for both static and dynamic perception regeneration. With the aid of the other variants of this unit, the array shaped TSRP is capable of simulating different terrains, geometries, sliding, collisions, and other critical interactive events during teleoperation via skin perception. Moreover, immediate manipulation can be done on TSRP through the tactile sensors. The preliminary demonstration of TSRP interface with a completed control module in robotic teleoperation is provided, which shows the feasibility of assisting certain tasks in a complex environment by direct tactile communication. The proposed device offers a potential method of enabling bidirectional tactile communication with enriched key information for improving interaction efficiency in the fields of robot teleoperation and training.

Early positive tactile stimulation reverses the increase of anxiety and decrease of sociality induced by early chronic mechanical pain in mandarin voles.

Animals may experience early negative (mechanical pain: being retrieved using an incisor by parents or attacked) or positive stimulation (being licked and groomed) that may affect emotional and social behaviors in adulthood. Whether positive tactile stimulation can reverse adverse consequences on emotional and social behaviors in adulthood resulting from chronic mechanical pain and underlying mechanisms remain unclear. This study used a tail-pinching model during development to simulate mechanical pain experienced by pups in high-social mandarin voles (Microtus mandarinus). Subsequently, brush-like positive tactile stimuli were applied to the backs of the mandarin voles. Various behavioral tests were used to measure levels of anxiety, depression, and sociability. The results showed that early tail-pinching delayed the eye opening of pups, increased levels of anxiety, reduced levels of sociality in male mandarin voles, and impaired social cognition in females during adulthood. Brushing on the back reversed some of these effects. While mandarin voles that were exposed to tail-pinching during development were exposed to sub-threshold variable stress as adults, they were more likely to show a stress-induced increase of anxiety-like behavior, reduction of sociability, and impairment of social cognition, displaying heightened susceptibility to stress, particularly in males. However, back-brushing reversed some of these effects, implying that these adults display enhanced stress resilience. In addition, tail-pinching reduced levels of serum oxytocin and increased corticosterone levels in serum, but back-brushing reversed these effects. Overall, it was found that positive tactile stimulation reversed increases in anxiety and impairments of social behavior induced by negative stimulation in male mandarin voles via alteration of oxytocin and corticosterone levels.

Comparative analysis of motor skill acquisition in a novel bimanual task: the role of mental representation and sensorimotor feedback.

Introduction: This study investigates the multifaceted nature of motor learning in a complex bimanual task by examining the interplay between mental representation structures, biomechanics, tactile pressure, and performance. We developed a novel maze game requiring participants to maneuver a rolling sphere through a maze, exemplifying complex sequential coordination of vision and haptic control using both hands. A key component of this study is the introduction of cognitive primitives, fundamental units of cognitive and motor actions that represent specific movement patterns and strategies. Methods: Participants were divided into two groups based on initial performance: poor performers (PPG) and good performers (GPG). The experimental setup employed motion capture and innovative tactile sensors to capture a detailed multimodal picture of the interaction process. Our primary aims were to (1) assess the effects of daily practice on task performance, biomechanics, and tactile pressure, (2) examine the relationship between changes in mental representation structures and skill performance, and (3) explore the interplay between biomechanics, tactile pressure, and cognitive representation in motor learning. Results: Performance analysis showed that motor skills improved with practice, with the GPG outperforming the PPG in maze navigation efficiency. Biomechanical analysis revealed that the GPG demonstrated superior movement strategies, as indicated by higher peak velocities and fewer velocity peaks during task execution. Tactile feedback analysis showed that GPG participants applied more precise and focused pressure with their right-hand thumb, suggesting enhanced motor control. Cognitively, both groups refined their mental representation structures over time, but the GPG exhibited a more structured and sophisticated cognitive mapping of the task post-practice. Discussion: The findings highlight the intertwined nature of biomechanical control, tactile feedback, and cognitive processing in motor skill acquisition. The results support established theories, such as the cognitive action architecture approach, emphasizing the role of mental representation in planning and executing motor actions. The integration of cognitive primitives in our analysis provides a theoretical framework that connects observable behaviors to underlying cognitive strategies, enhancing the understanding of motor learning across various contexts. Our study underscores the necessity of a holistic approach to motor learning research, recognizing the complex interaction between cognitive and motor processes in skill acquisition.