Search Results (19)

Motion perception is a fundamental function of the tactile system, essential for object exploration and manipulation. While human studies have largely focused on discrete or pulsed stimuli with staggered onsets, many natural tactile signals are continuous and rhythmically patterned. Here, we investigate whether phase differences between “simultaneously” presented, “continuous” amplitude-modulated vibrations can induce the perception of motion across fingertips. Participants reliably perceived motion direction at modulation frequencies up to 1 Hz, with discrimination performance systematically dependent on the phase lag between vibrations. Critically, trial-level confidence reports revealed the lowest certainty for anti-phase (180°) conditions, consistent with stimulus ambiguity as predicted by the mathematical framework. I propose two candidate computational mechanisms for tactile motion processing. The first is a conventional cross-correlation computation over the envelopes; the second is a probabilistic model based on the uncertain detection of temporal reference points (e.g., envelope peaks) within threshold-defined windows. This model, despite having only a single parameter (uncertainty width determined by an amplitude discrimination threshold), accounts for both the non-linear shape and asymmetries of observed psychometric functions. These results demonstrate that the human tactile system can extract directional information from distributed phase-coded signals in the absence of spatial displacement, revealing a motion perception mechanism that parallels arthropod systems but potentially arises from distinct perceptual constraints. The findings underscore the feasibility of sparse, phase-coded stimulation as a lightweight and reproducible method for conveying motion cues in wearable, motion-capable haptic devices. Full article

The past 15 years of extensive experience teaching VR system development has taught us that haptic feedback must be more sophisticatedly integrated into VR systems, alongside the already realistic high-fidelity visual and audio feedback. The third generation of students is enhancing VR interactive experiences by incorporating haptic feedback through traditional, proven, commercially available gamepad controllers. Insights and discoveries gained through this process contributed to the development of versatile Unity custom editor tool, which is the focus of this article. The developed tool supports a wide range of use cases, enabling the visual, parametric, and descriptive creation of reusable haptic effects. To enhance productivity in commercial development, it supports the creation of haptic and haptic/audio stimulus libraries, which can be further expanded and combined based on object-oriented principles. Additionally, the tool allows for the definition of specific areas within the virtual space where these stimuli can be experienced, depending on the virtual object the avatar holds and the activities they perform. This intuitive platform allows the design of reusable haptic effects through graphical editor, audio conversion, programmatic scripting, and AI-powered guidance. The sophistication and usability of the tool have been demonstrated through several student VR projects across various application areas. Full article

Background: When engaging with the environment, multisensory cues interact and are integrated to create a coherent representation of the world around us, a process that has been suggested to be affected by the lack of visual feedback in blind individuals. In addition, the presence of voluntary movement can be responsible for suppressing somatosensory information processed by the cortex, which might lead to a worse encoding of tactile information. Objectives: In this work, we aim to explore how cross-modal interaction can be affected by active movements and the role of vision in this process. Methods: To this end, we measured the precision of 18 blind individuals and 18 age-matched sighted controls in a velocity discrimination task. The participants were instructed to detect the faster stimulus between a sequence of two in both passive and active touch conditions. The sensory stimulation could be either just tactile or audio–tactile, where a non-informative sound co-occurred with the tactile stimulation. The measure of precision was obtained by computing the just noticeable difference (JND) of each participant. Results: The results show worse precision with the audio–tactile sensory stimulation in the active condition for the sighted group (p = 0.046) but not for the blind one (p = 0.513). For blind participants, only the movement itself had an effect. Conclusions: For sighted individuals, the presence of noise from active touch made them vulnerable to auditory interference. However, the blind group exhibited less sensory interaction, experiencing only the detrimental effect of movement. Our work should be considered when developing next-generation haptic devices. Full article

Pseudo-haptics, the phenomenon of creating a simulated tactile sensation by introducing a discrepancy between a voluntary movement and its visual feedback, is well known. Typically, when inducing pseudo-haptics, the same control-display ratio (C/D ratio) is applied to all effectors. However, with the aim of expanding the potential illusions that can be presented with pseudo-haptics, we investigated how perceived sensations change when partial pseudo-haptics are applied to adjacent body parts. In this research, we examined how perceived sensations change when pseudo-haptic stimuli are applied to adjacent body parts. Specifically, we investigated the correlation between finger states and the magnitude of illusory perception during both quasi-static and dynamic movements and identified the finger that experienced discomfort during dynamic movements with pseudo-haptics. Our findings revealed that: First, the magnitude of the illusion varied based on the contact state of adjacent fingers. Second, the illusion was more pronounced during dynamic movements compared to quasi-static movements. Third, regardless of the finger receiving the pseudo-haptic stimulus, the discomfort was primarily experienced in the finger exhibiting an overall inhibitory movement. The findings contribute to the practical application of pseudo-haptics as a virtual haptic display technology. Full article

This study investigates the mutual interaction between self- and partner-induced actions in determining pressure distribution during a handshake and proposes a tele haptic handshake system based on these findings. To achieve this, experiments were conducted to examine how pressure distribution in face-to-face handshakes is influenced by mutual actions. Based on the experimental results, an interaction force model was developed to calculate stimulus intensities, incorporating region-specific weights for different parts of the hand. Additionally, a tele haptic handshake system was designed, integrating flex sensors to measure finger joint angles and a distributed haptic stimulus presentation device to provide tactile feedback. While this study lays the foundation for understanding the dynamics of handshake interactions and their application in remote environments, further validation of the system’s effectiveness in replicating real-world handshake experiences remains a subject for future work. Full article

Currently, visual Augmented Reality (AR) technology is widespread among the public. Similarly, haptic AR technology is also widely practiced in the academic field. However, conventional haptic AR devices are not suitable for interacting with real objects. These devices are often held by the users, and they contact the real object via the devices. Thus, they prevent direct contact between the user and real objects. To solve this problem, we proposed employing Electrical Muscle Stimulation (EMS) technology. EMS technology does not interfere with the interaction between the user and the real object, and the user can wear the device. First, we examined proper stimulus waveforms for EMS, in addition to pulse waveforms. At the same time, we examined the appropriate frequency and pulse width. The waveforms that we used this time were a sawtooth wave, a reverse sawtooth wave, and a sine wave. Second, to clarify the characteristic of the force presented by the EMS, we measured the relationship between the input voltage and the force presented and obtained the point of subjective equality using the constant method. Subsequently, we presented the bump sensation using EMS to the participants and verified its effectiveness by comparing it with the existing methods. Full article

Most haptic devices generate haptic sensation using mechanical actuators. However, the workload and limited workspace handicap the operator from operating freely. Electrical stimulation is an alternative approach to generate haptic sensations without using mechanical actuators. The light weight of the electrodes adhering to the body brings no limitations to free motion. Because a real haptic sensation consists of feelings from several areas, mounting the electrodes to several different body areas can make the sensations more realistic. However, simultaneously stimulating multiple electrodes may result in “noise” sensations. Moreover, the operators may feel tingling because of unstable stimulus signals when using the dry electrodes to help develop an easily mounted haptic device using electrical stimulation. In this study, we first determine the appropriate stimulation areas and stimulus signals to generate a real touch sensation on the forearm. Then, we propose a circuit design guideline for generating stable electrical stimulus signals using a voltage divider resistor. Finally, based on the aforementioned results, we develop a wearable haptic glove prototype. This haptic glove allows the user to experience the haptic sensations of touching objects with five different degrees of stiffness. Full article

Marketers and advertisers ignore new technology and diverse marketing tactics when attempting to increase product exposure, customer engagement, customer behavior and buying intention in fashion accessory marketplaces in developing countries. This research sought to discover how the Augmented Reality (AR) experience influenced consumer behavior, buying intention and pleasure when purchasing a fashion item in developing countries. This study employs positivist ideas to investigate the connections between various factors, believing that reality is unwavering, stable, and static. Experiential marketing following stimulus exposure will gather cross-sectional data. The undertaken study has developed proper experimental design (within group) from business innovation models, for instance, uses and gratification and user experience models. User experience is disclosed by its four defining characteristics: hedonic quality (identification and simulation), aesthetic quality, and pragmatic quality. After encountering an enhanced user experience, users have a more favorable attitude about purchasing; in contrast, pleasure from using the application directly impacts buying intention. It was also shown that knowledge of AR apps impacts user experience and attitude. The novelty of this research is multifarious, for instance, the smart lab was used as a marketing technology to explore a virtual mirror of the Ray-Ban products. Secondly, the augmented reality experiential marketing activities have been developed by the developers as bearing in mind the four different aspects of the user experience—haptic, hedonic, aesthetic, and pragmatic. It should be functional, simple to learn and use, symmetrical, pleasant, and appealing, while fulfilling the unconscious emotional elements of a customer’s purchase. The research is the first known study in Pakistan to evaluate the influence of augmented reality on consumer proficiency and its consequent effects on attitude and satisfaction for fashion accessory brands. The research also advances the notion that application familiarity is the most important moderator between attitude and an augmented reality-enriched user experience, contradicting the prior studies, which focus on gender and age. This research has important theoretical implications for future researchers, who may wish to replicate the proposed final model in developed and developing countries’ fashion brands. This research also has imperative managerial implications for brand managers and marketing managers, who could include the recommendations of this study in their marketing strategies. Full article

Virtual Reality (VR) can play a key role in automotive marketing research, lowering costs and shortening the time to launch a new product. However, few VR applications support automotive customers’ experiences during the early stages of product design. This study aims to identify and characterize into attributes the challenges and opportunities for the application of Virtual Reality in car clinics through a systematic review of the literature and patents. We searched PatentScout, ScienceDirect, Springer, and IEEEXplore for studies published between the databases’ inception and July 2020. Of the 77,383 patents and 336,785 articles identified, 72 and 13 were eligible, respectively. We discovered that patents are strongly concentrated by a few inventors, that the United States has the most records, and that the most prevalent applications relate to devices for automatically reading responders’ emotions in virtual environments. The articles revealed sixteen categories of challenges and opportunities: cost, location to customers, flexibility in interactions, model transportation, depth perception, haptic perception, motion, movement perception/physical collision, color and texture, sound feedback, product interaction/manipulation, visual–spatial, graphic quality, intuitiveness, cybersecurity, and cybersickness. Virtual Reality may be used for automotive marketing research but key factors such as hardware and software specification, stimulus quality, and survey objectives must be considered. Full article

Brain–computer interface (BCI) remains an emerging tool that seeks to improve the patient interaction with the therapeutic mechanisms and to generate neuroplasticity progressively through neuromotor abilities. Motor imagery (MI) analysis is the most used paradigm based on the motor cortex’s electrical activity to detect movement intention. It has been shown that motor imagery mental practice with movement-associated stimuli may offer an effective strategy to facilitate motor recovery in brain injury patients. In this sense, this study aims to present the BCI associated with visual and haptic stimuli to facilitate MI generation and control the T-FLEX ankle exoskeleton. To achieve this, five post-stroke patients (55–63 years) were subjected to three different strategies using T-FLEX: stationary therapy (ST) without motor imagination, motor imagination with visual stimulation (MIV), and motor imagination with visual-haptic inducement (MIVH). The quantitative characterization of both BCI stimuli strategies was made through the motor imagery accuracy rate, the electroencephalographic (EEG) analysis during the MI active periods, the statistical analysis, and a subjective patient’s perception. The preliminary results demonstrated the viability of the BCI-controlled ankle exoskeleton system with the beta rebound, in terms of patient’s performance during MI active periods and satisfaction outcomes. Accuracy differences employing haptic stimulus were detected with an average of 68% compared with the 50.7% over only visual stimulus. However, the power spectral density (PSD) did not present changes in prominent activation of the MI band but presented significant variations in terms of laterality. In this way, visual and haptic stimuli improved the subject’s MI accuracy but did not generate differential brain activity over the affected hemisphere. Hence, long-term sessions with a more extensive sample and a more robust algorithm should be carried out to evaluate the impact of the proposed system on neuronal and motor evolution after stroke. Full article

Emotional response to haptic stimuli is a widely researched topic, but the combination of vibrotactile and thermal stimuli requires more attention. The purpose of this study is to investigate emotional response to vibrothermal stimulation by combining spatiotemporal vibrotactile stimulus with dynamic thermal stimulus (hot or cold). The vibrotactile and thermal stimuli were produced using the Haptic Chair and the Embr wave thermal bracelet, respectively. The results show that spatiotemporal vibrotactile patterns and their duration, and dynamic thermal stimulation, have an independent effect on the emotional response. Increasing duration generally increases the valence and arousal of emotional response. Shifting the dynamic temperature from cold to hot generally decreases the valence of emotional response but has no significant effect on arousal. Nevertheless, certain spatiotemporal patterns do exhibit unique responses to changes in dynamic temperature, although no interaction effects were found. The results show the potential of designing affective haptic interfaces using multimodal vibrothermal feedback. Full article

This study focused on the associative learning of new word forms in the first language and haptic stimuli. In this study, healthy Japanese participants performed three-step tasks. First, participants made nine subjective evaluations of haptic stimuli using five-point semantic differential scales (e.g., regarding stickiness, scored from 1 (not sticky) to 5 (sticky)). Second, the participants carried out learning and recognition tasks for associative pairs of new (meaningless) word forms in their first language (Japanese) and haptic stimulus (H condition), and performed learning and recognition tasks for new (meaningless) word forms only (W condition). The order of conditions was counterbalanced among participants. Third, participants performed free recall tasks. The results of the recognition tasks showed that the proportions and response times of the W condition were better and faster, respectively, than those of the H condition. Furthermore, preference of haptic features negatively correlated with free recall scores of the H condition; however, there was no significant difference between the free recall scores of the H and W conditions. Our results suggest that new word forms were learned better than associative pairs of new word forms and haptic stimuli in a single day of learning. Furthermore, the free recall performance of word forms associated with haptic features could also be affected by their subjective evaluation (preference). Full article

This paper presents a dual-function wearable device (Tacsac) with capacitive tactile sensing and integrated tactile feedback capability to enable communication among deafblind people. Tacsac has a skin contactor which enhances localized vibrotactile stimulation of the skin as a means of feedback to the user. It comprises two main modules—the touch-sensing module and the vibrotactile module; both stacked and integrated as a single device. The vibrotactile module is an electromagnetic actuator that employs a flexible coil and a permanent magnet assembled in soft poly (dimethylsiloxane) (PDMS), while the touch-sensing module is a planar capacitive metal-insulator-metal (MIM) structure. The flexible coil was fabricated on a 50 µm polyimide (PI) sheet using Lithographie Galvanoformung Abformung (LIGA) micromoulding technique. The Tacsac device has been tested for independent sensing and actuation as well as dual sensing-actuation mode. The measured vibration profiles of the actuator showed a synchronous response to external stimulus for a wide range of frequencies (10 Hz to 200 Hz) within the perceivable tactile frequency thresholds of the human hand. The resonance vibration frequency of the actuator is in the range of 60–70 Hz with an observed maximum off-plane displacement of 0.377 mm at coil current of 180 mA. The capacitive touch-sensitive layer was able to respond to touch with minimal noise both when actuator vibration is ON and OFF. A mobile application was also developed to demonstrate the application of Tacsac for communication between deafblind person wearing the device and a mobile phone user who is not deafblind. This advances existing tactile displays by providing efficient two-way communication through the use of a single device for both localized haptic feedback and touch-sensing. Full article

It is clear that the haptic channel can be exploited as a communication medium for several tasks of everyday life. Here we investigated whether such communication can be altered in a cognitive load situation. We studied the perception of a vibrotactile stimulus presented under the foot when the attention is loaded by another task (cognitive load). The results demonstrated a significant influence of workload on the perception of the vibrotactile stimulus. Overall, we observed that the average score in the single-task (at rest) condition was greater than the overall mean score in the dual-task conditions (counting forwards, counting backwards, and walking). The walking task was the task that most influenced the perception of the vibrotactile stimulus presented under the foot. Full article

A very flexible structure with a tunable stiffness controlled by an external magnetic stimulus is presented. The proposed structure is fabricated using two magnetic-responsive materials, namely a magnetorheological elastomer (MRE) as a skin layer and a magnetorheological fluid (MRF) as a core to fill the void channels of the skin layer. After briefly describing the field-dependent material characteristics of the MRE and MRF, the fabrication procedures of the structure are provided in detail. The MRE skin layer is produced using a precise mold with rectangular void channels to hold the MRF. Two samples are produced, namely with and without MRF, to evaluate the stiffness change attributed to the MRF. A magnetic field is generated using two permanent magnets attached to a specialized jig in a universal tensile machine. The force-displacement relationship of the two samples are measured as a function of magnetic flux density. Stiffness change is analyzed at two different regions, namely a small and large deformation region. The sample with MRF exhibits much higher stiffness increases in the small deformation region than the sample without MRF. Furthermore, the stiffness of the sample with MRF also increases in the large deformation region, while the stiffness of the sample without MRF remains constant. The inherent and advantageous characteristics of the proposed structure are demonstrated through two conceptual applications, namely a haptic rollable keyboard and a smart braille watch. Full article