Human–animal interaction in virtual reality has been explored for stress relief, yet balancing practical ease of use with natural haptic experience for relaxation remains a key challenge. We investigated whether mid-air ultrasound haptics, rendering breathing and fur stroking cues without wearable haptic devices, could enhance relaxation with a virtual cat. We first conducted a perceptual study to design a tactile cue for a cat’s breathing. By synchronizing expansion–contraction of the ultrasound focal region with intensity modulation, we demonstrated the realism and expressivity of the breathing cue. Next, we conducted an application study in which participants engaged in a short relaxation session with a virtual cat. Physiological and subjective measures showed that ultrasound haptics enhanced relaxation compared to both non-haptic interaction and controller-based vibrotactile feedback. These findings suggest that ultrasound haptics can extend VR-based human–animal interaction by combining accessibility with psychological benefits, opening new opportunities for well-being and therapeutic applications.

Third-person perspective (3PP) VR can afford dual embodiment, letting users act through an in-world avatar while simultaneously operating an omniscient entity (OE) from a detached viewpoint. We investigate how the sense of body ownership (SoBO) reallocates between these two asymmetric entities during continuous play. We systematically varied macro-level design factors—avatar and OE involvement—across three maze scenes and one combat scene in a within-subjects study. After each trial, participants produced time-aligned, continuous SoBO traces for both entities; gaze and controller signals were logged, and recall interviews captured first-person explanations. This research reveals three main findings. First, SoBO is not statically fixed but dynamically reallocated between the avatar and the OE across task phases. Second, allocation follows design factors: higher OE involvement in the maze strengthened ownership toward it, while combat consistently favored the avatar. Third, moment-to-moment gaze and control intensity predict ownership allocation, with fluency and salient events emerging as additional influences. These findings provide a framework for understanding dynamic SoBO and inform the design of adaptive 3PP VR systems.

A prevailing assumption in Virtual Reality is that the perception of surface gloss attenuates with viewing distance due to the resolution limitations of head-mounted displays (HMDs). While prior work indicates that resolution loss can degrade cues such as highlight sharpness and binocular highlight consistency, the direct linkage between viewing distance and perceived gloss has not been systematically established in VR. This study systematically investigates this relationship, focusing on binocular highlight intensity asymmetry. Contrary to the common assumption, under physically based rendering, our results show no reliable decrease in perceived gloss with distance within the tested range, despite resolution limitations. Moreover, participants' gloss judgments appeared to be more strongly modulated by monocular cues (e.g., highlight luminance, contrast, and temporal information) than by the binocular asymmetry manipulation tested here under our tested conditions. Finally, we find that moderate departures from physically correct binocular highlight consistency did not, within a tested tolerance, undermine perceived realism. These findings provide a new basis for designing efficient rendering techniques that preserve gloss fidelity over distance in VR, suggesting that computational resources might be better allocated to preserving monocular cues.

Although haptic technologies that allow users to touch virtual objects have been actively researched in the academic field of haptics, they are not yet widely adopted in real-world applications. To promote broader adoption, designing haptic stimuli that elicit pleasant sensations is essential since hedonic motivation significantly drives user acceptance. However, how such pleasantness can be effectively induced through haptic stimulation during a user's active exploration remains an open question. Furthermore, it is unclear whether “pseudo-haptics”, a low-cost substitute for physical force feedback, can also serve effectively in this affective context. In this study, we investigated the relationship between the applied force during user actions and the resulting pleasantness, using a bow-dragging and arrow-shooting scenario as a case study. Specifically, we conducted three psychophysical experiments to investigate two types of force feedback. One type was a physical force that stimulated the kinesthetic sense, and the other was a pseudo force induced through visual manipulation. Our results revealed that pleasantness tended to be elicited when physical resistance force was present during bow dragging, whereas this tendency was not observed for pseudo resistance force. While there has been a general assumption that pseudo-haptics can replace physical stimuli to some extent in the rendering of haptic properties, our findings quantitatively show that in our case the two are not interchangeable for eliciting positive affect. We also found that the arrow's flying speed contributed to pleasantness as much as the physical resistance force, suggesting that pleasantness is influenced postdictively. Moreover, across all experiments, perceived pleasantness was strongly correlated with the perceived naturalness of the bow-and-arrow behavior. These findings provide valuable insights for designing pleasant interactions involving continuous force feedback, highlighting the distinct roles of physical and pseudo-haptic cues.

Humans sometimes encounter dazzling light in everyday life, such as sunlight or high-beam headlights, which often evoke instinctive biological responses like blinking and afterimages. Accurately reproducing such phenomena is essential for enhancing realism in virtual reality (VR), especially in scenarios like training simulations or entertainment experiences. While conventional methods either rely on high-luminance displays or simulate isolated perceptual effects such as glare, few approaches have explored the combination of multiple physiological responses to intensify brightness perception without using physically intense light sources. This study addresses the gap by investigating how pseudo-blinking and afterimage presentation, in addition to glare effects, can enhance the dazzling sensation in VR. We developed a novel system that synchronizes screen darkening with skin-deformation-like vibration stimuli around the eyes to simulate a blink reflex, followed by gaze-dependent afterimage presentation that dynamically transitions to complementary colors in response to user blinking. Experimental results with 19 participants revealed that both pseudo-blinking and afterimage effects significantly enhanced the perceived dazzling sensation and realism. These findings suggest that simulating involuntary physiological reactions to light in VR can evoke strong perceptual impressions, enabling safe and cost-effective glare expression.

We present a pseudo-haptic technique that modulates perceived weight in full-body virtual reality by jointly scaling virtual-hand motion and user viewpoint. Unlike prior study that manipulates the hand alone, our method leverages visual self-motion cues, extending pseudo-haptics beyond seated interactions. A threshold study isolated perceptually salient gains, and a within-subjects lifting experiment ($N=23$) crossed the two factors. Both manipulations significantly modulated perceived weight ratings ($p<.001$), and their effects combined additively. However, presence ratings declined specifically under conditions designed to produce strong lightness illusions-namely, when the virtual hand moved more than its real-world counterpart, while the virtual viewpoint moved less ($p_{\text {Holm }}<.05$). In contrast, when the virtual hand moved more slowly or matched the real hand's motion, manipulating the virtual viewpoint had relatively little impact on presence, which remained stable. Hand scaling thus serves as a low-cost primary cue and viewpoint manipulation as a complementary channel for modulating the perceived weight without sacrificing presence. The technique provides actionable guidance for VR training, rehabilitation, and exergames that demand convincing sensations of physical effort.

Impact sensation is vital for achieving high realism and immersion in virtual reality (VR) applications such as sports games. There has been substantial research focusing on the moment of impact, using methods like electrical muscle stimulation (EMS) and vibrotactile feedback. However, the size and complexity of these devices, along with concerns for user safety, limit their effectiveness in producing strong impact sensations. Additionally, less attention has been given to sensations experienced after a strong impact, like the tingling that follows a collision. This research focuses on an overlooked area: the aftereffects that emerge within the body following a physical impact. It specifically examines the tingling sensation that occurs after a strong hit, using a VR baseball bat-like device designed to deliver impulsive force, vibrotactile, and thermal feedback to the user’s hand. We conducted a user study (18 male, 6 female participants) to assess how these types of feedback affect the realism and intensity of impact sensations, as well as the tingling sensation perceived by users. The results revealed that both vibrotactile and thermal feedback as aftereffects significantly enhanced the impact sensation, confirming their ability to induce tingling sensations. Additionally, high-frequency vibrotactile stimuli particularly enhanced the tingling sensation and realism of impact. Although the sample had a gender imbalance, these findings highlight the potential for incorporating aftereffects feedback in VR systems to enhance impact sensations for entertainment and safety education purposes.

Paranormal visual effects, such as spirits and miracles, are frequently depicted in visual games and media design. However, current methods do not express paranormal experiences as aspects of the sixth sense. We propose utilizing binocular rivalry to provide a new visual presentation method by displaying different images in each eye. In this study, we conducted two experiments. Experiment 1 assessed paranormal sensation, color perception controllability, and visual discomfort caused by mismatched colors in each eye in relation to color difference. Experiment 2 assessed our proposed visual presentation method in three application scenarios. The results indicate that our proposed method improves the visual experience of more realistic paranormal phenomena. Moreover, the sensation of paranormal activity, color perception controllability, and visual discomfort increase as the color difference between the colors displayed in the two eyes increases.

This investigation proposes a novel method to enhance the perceived temperature of food, aimed at helping individuals with conditions like dentin hypersensitivity who struggle to consume foods at optimal temperatures. Conventional methods for this purpose often are impractical for sensitive individuals. This study introduces a new technique that applies external cold stimuli to the posterior neck, avoiding direct contact with oral sensory receptors. We designed a device to deliver precise cold stimuli to this area and empirical assessments were conducted using ice cream, selected for its cooling properties and variable texture. The focus was on synchronizing the cold stimuli with the swallowing process, hypothesizing that this coordination could enhance thermal and tactile perception integration without disrupting eating. The study engaged 25 participants and utilized Ura’s modification of Scheffé’s paired comparison method for statistical evaluation. The results show that this technique significantly enhances the sensation of cold in food, suggesting that external thermal stimuli can improve the dining experience without altering the food itself or affecting the taste.

In virtual environments, wind displays can reproduce the sensation of wind to enhance user experience such as presence. Enabling users to perceive strong winds can benefit several applications, such as disaster education and entertainment content. However, the large and bulky equipment required to blow strong winds across the entire body of the user limit its application. Although cross-modal effects are proposed to alter wind perceptions through multisensory stimuli, but methods to induce the perception of strong winds without generating a strong wind need further exploration. In this study, we propose a method to create an illusion of strong wind by providing tactile stimuli through clothes. We developed a compact and lightweight wearable device that vibrates the fabric by a motor to simulate its fluttering motion under a strong wi nd. Two user studies were conducted to investigate the effect of vibrating the clothes on the perceived wind velocity, realness of the wind, and presence. The results indicated that tactile stimuli provided by vibrating the clothes increased the perceived wind velocity to a similar level as the strong wind exceeding $10 \mathrm{~m} / \mathrm{s}$ while the parameters of the physical wind were unchanged. It was also revealed that the vibration of the clothes decreases the realness of the actual wind and a visual scene of the clothes of the avatar flutter increases presence. Thus, the proposed wearable device is useful for creating the experience of strong winds while keeping the wind displays compact.

Remote robot teleoperation is crucial for tasks that require human oversight, yet latency can significantly impair operator performance and result in discomfort, break inpresence and increased workload. In this paper, we propose a new robot teleoperation technique based on Virtual Reality that is expected to alleviate the negative impactson subjective experience caused by latency. The technique allows users to manipulate a virtual robot synchronized with a real one by ‘grabbing’ a virtual spring attached to it. Controller vibration is also used to simulate spring force feedback, together creating an illusion that the position discrepancy is caused by the dynamics of the spring instead of latency. We hypothesize that this approach can mitigate the negative effects of latency by making the robot’s movement appear less strange and more natural. A user study was conducted to evaluate the effectiveness of virtual spring and controller vibration separately using a $2 \times 2$ factorial design. The results suggest that the virtual spring enhanced user comfort level and the sense of presence, but the controller vibration showed no clear benefits.

Pseudo-haptics is a method that can provide a haptic sensation without requiring a physical haptic device. The effect of pseudo-haptics is known to depend on the individual, but it is unclear which factors cause individual differences. As the first study establishing a calibration method for these differences in future research, we examined the differences in the pseudo-haptic effect on mouse cursor operation in a desktop environment depending on the age and gender of the user. We conducted an online experiment and collected data from more than 400 participants. The participants performed a task of lifting a virtual object with a mouse pointer. We found that the effect of pseudo-haptics was greater in younger or male participants than in older or female participants. We also found that the effect of pseudo-haptics, which varied with age and gender, can be explained by habituation to the mouse in daily life and the accuracy of detecting the pointer position using vision or proprioception. Specifically, the pseudo-haptic effect was higher for those who used the mouse more frequently and had higher accuracy in identifying the pointer position using proprioception or vision. The results of the present study not only indicate the factors that cause age and gender differences but also provide hints for calibrating these differences.

Advances in haptic technology have led researchers and engineers to seek out killer applications in which users can enjoy an experience of touch in AR/VR spaces. Such applications will respond appropriately to human desire for haptic experiences (i.e., touch desire) and thus it is essential for researchers and engineers to understand the nature of people's touch desires as they arise in the course of daily life. In this study, we employed Twitter data analysis to investigate a diurnal pattern in touch desire. Our results showed that touch desire identified in and extracted from Twitter texts did reveal a diurnal pattern. Touch desire tended to be at its lowest in the morning and increased as the day progressed. The time at which it peaked varied with the specific target of touch desire. Touch desire in relation to other people and objects reached its peak at night, but touch desire in relation to animals reached its peak at noon. These results were confirmed not only by our Twitter text analysis but also by data from other social media and an online survey. In addition, we found that the diurnal pattern of touch desire for each target shows a strong correlation with that of visual desire for the same target. This suggests that the diurnal pattern of touch desire is not limited to the sense of touch but is common to other sensory desires for each target. Our findings suggest that researchers need to take the time of day into account when investigating touch desire. Our findings also offer valuable insights for developers into the design of haptic applications and displays that takes into account the timing of daily peaks in touch desire.

Many studies applying neural networks to the field of education have focused on student performance prediction and explainability of their decisions. While those studies introduced neural networks into educational settings, such networks cannot directly support student learnings in place of teachers. Therefore, we present a method that uses a general Transformer encoder to recommend appropriate learning actions for improving student performance. By considering the attention weight of a low-performing student to be close to that of a high-performing student, our method recommends the learning materials and actions for learning the materials. To evaluate the effectiveness of our method, we trained a deep neural network (DNN) on a private dataset of student operations (e.g., NEXT, PREV, OPEN) on digital learning materials obtained from a Japanese university. The number of operations divided by each learning material and by type of operation are input to the DNN, and the DNN outputs the student’s grade on 5-point scale. We applied our method with this trained DNN to samples that successfully predicted grades, and the number of operations increased on the basis of the recommended learning materials and actions. By re-inputting modified sample into the DNN, we then observe how the student performance changes. The results of this simple experiment indicate that more students improved their performance with both the material-based and operation-based recommendations than with random recommendations. The percentage of students whose grades improved tended to be larger for those with low grades. Specifically, the improvement ratio for students with the two lowest grades was over 90% by operation-based recommendation. This is consistent with our intuition that low-performing students are more likely to improve.

The development of methods to simulate the sensation of wind that can promote relaxation and elicit positive emotional responses has become a topic of interest with the widespread adoption of virtual and augmented reality systems. Previous studies have simulated natural wind by varying wind speed in a controlled environment or moving a large flow of air through an area. In contrast to such approaches to modulate physical airflow, the use of multisensory stimuli to alter the impression and sense of comfort provided by a simulated wind has rarely been considered in previous research. If visual and auditory stimuli affect wind comfort, a multisensory design should be considered for relaxation systems that use wind effects. Therefore, we experimentally measured wind comfort and associated emotions when participants experienced outdoor and indoor virtual environments through immersive virtual reality to investigate whether cross-modal effects of variations in audio-visual stimuli would impact the relaxation effects associated with a virtual wind. The results show that the virtual environment of an outdoor meadow and the sound of natural wind significantly improved users' subjective experience of comfort and openness associated with the wind, as well as their emotional state. Simulated natural wind reduced mental stress compared to a condition without wind, as shown by questionnaires and biometric data. The results of this study indicate that multisensory stimuli conveying natural impressions and simulated natural wind are effective for wind-based relaxation.

Although remote work has become common recently, the decrease in productivity has become a problem. Focusing on the impact of the presence of co-workers on productivity, we hypothesized that sharing work status among coworkers could improve productivity and reduce the discomfort of having work status monitored. First, more than 400 participants were surveyed to evaluate the effects of sharing work state on productivity and discomfort and to determine the factors that contribute to productivity. Based on the results, we designed a user study to examine work productivity and discomfort in non-shared, shared, and monitored work states. The results indicated that the actual work–time ratio was increased in the case of sharing work state. Furthermore, we suggested that being monitored state increases discomfort and motivation and that sharing work state reduces discomfort compared with the monitored state. These results indicated that sharing work status during remote work can improve motivation and work productivity.

Odor display has been a popular approach in virtual reality (VR) to enhance users’ multi-sensory experience. The existing multi-odor presentation methods in VR are mostly based on spatiality of scent sources to produce mixed scents, which will possibly compromise users’ olfactory experience because humans normally have poor ability to analyze distinct odorant components from a mixture. To tackle this problem, we present a VR multi-odor display approach that dynamically changes the intensity combinations of different scent sources in the virtual environment according to the user’s attention, hence simulating a virtual cocktail party effect of smell. We acquire the user’s gaze information as attention from the eye-tracking sensors embedded in the head mounted display (HMD), and increase the display intensity of the scent that the user is focusing on to simulate the cocktail party effect of smell, enabling the user to distinguish their desired scent source. We conducted a user study to validate the perception and experience of 2 ways of intensity settings in response to the user’s attention shift, which were a strong level of focused scent mixed with weak levels of non-focused scents and strong focused scent only. The results showed that both of the two intensity settings were able to improve olfactory experience in VR compared to the non-dynamic odor display method. Meanwhile, only the method of presenting strengthened focused scent while maintaining the weaker mixture of background scents showed significant improvement on simulating the olfactory cocktail party effect by giving the users an enhanced sense of their own olfactory sensitivity.

In recent years, technologies related to virtual reality (VR) have continued to advance. As a method to enhance the VR experience, we focused on loud vocalization. This is because we believe that loud vocalization can enable us to engage with the VR environment in a more interactive way. Also, as loud vocalization is an action that is thought to be closely related to stress reduction and a sense of exhilaration, the stress reduction through VR with loud vocalization is also expected. But loud vocalization itself has disadvantages for physical, mental, and social reasons. Then, we hypothesized that loud vocalization itself is not necessary for such benefits; but the sense of loud vocalization plays an important role. Therefore, we focused on a method of substituting experience by presenting sensory stimuli. In this paper, we proposed a way to present the sense of loud vocalization through vibratory stimuli to the larynx and auditory stimuli to users who are actually vocalizing quietly with the expectation for the sense of loud vocalization. Our user study showed that the proposed method can extend the sense of vocalization and realize pseudo-loud vocalization. In addition, it was also shown that the proposed method can cause a sense of exhilaration. By contrast, excessively strong vibratory stimuli spoil the sense of loud vocalization, and thus the intensity of the vibration should be appropriately determined.

While working, people often perform purposeless actions, such as spinning pens and swinging their feet. The pleasant and addictive tactile feedback generated by those actions seems to trigger them. This is based on a principle called "operant conditioning." "Operant conditioning" is a phenomenon of change in people's behavior because of a reward obtained from the purposeless action. In previous studies, operant conditioning for the behaviors of animals such as mice have been discussed, but conditioning for the behaviors of humans has had little investigation. Therefore, we designed a feedback for people's action as a reward of conditioning, especially tactile stimulation, and verified whether the stimuli can induce a simple action. We selected "tactile apparent motion" as the reward because it can provide comfort by stimulating a mechanoreceptor called C tactile afferent. We designed a wearable device that can generate tactile apparent motion from a simple input action, such as tapping the heel. Using this device, we conducted user studies. The results showed that fast tactile apparent motion is effective in inducing simple actions repeatedly. Moreover, simple actions can be induced by tactile apparent motion even in the long term.

It is important to measure the user's biological information when experiencing virtual reality (VR) content. By measuring such biological information during a VR stimulation, the body's response to the stimulation can be verified. In addition, it is possible to change the stimulation interactively by estimating the feeling from the measured biological information. However, the user load required to mount the sensor for biological information sensing under the existing VR content experience is significant, and the noise due to body movement is also a problem. In this paper, a biometric device that can be mounted on a head mounted display (HMD) was developed. Because an HMD is attached strongly to the face, it is thought to be robust to body movement and thus the mounting load of the sensor can be ignored. The developed device can simply be mounted on an HMD. A pulse waveform can be acquired from the optical pulse wave sensor arranged on the nose side of the HMD, and the respiration waveform can be acquired from a thermopile arranged in the nostril area of the HMD. We condacted the experiment to verified that a pulse wave and the respiration can be measured with sufficient accuracy for a calculation of the tension and excitement of the user. As a result of the experiment, it was confirmed that the pulse wave can be measured with an error of less than 1% in nine out of 14 users and that the respiration can be measured with an error of 0.6% if user does not move. The respiration was measured with high accuracy regardless of the type of HMD used.

In modern society, chronic stress in the workplace is a serious problem because it causes numerous diseases. To prevent chronic stress, it is necessary to continuously measurement this type of stress in the workplace. Thus, it is necessary to realize a chronic stress estimation method with small load to users. Therefore, we proposed a method to estimate chronic stress level by measuring changes of body motion patterns during desk work caused by chronic stress. For the acquisition of body motion patterns we called "Motion Pattern", a cushion-type sensor device with six pressure sensors was developed, and the changes of seat pressure distribution during desk work were measured. "Motion Pattern" was the time-series pattern of four"Motion Labels" including "Impact Label" which represented the motion that impacts the seat. We tried to estimate chronic stress level by learning the relationship between this "Motion Pattern" and the score of stress evaluation questionnaire. As a result, it was found that there was a significant difference in the interval time of "Impact Label" occurrence in all six participants. In addition, we achieved to estimate the existence and non-existence of chronic stress with an average accuracy of 87.0% using a classifier learned for each individual and achieved to estimate chronic stress level with a maximum accuracy of 70.0%for one participant. It suggests that our proposed method has potential for chronic stress monitoring in the workplace.

Playing back vibrotactile signals through actuators is commonly used to simulate tactile feelings of virtual textured surfaces. However, there is often a small mismatch between the simulated tactile feelings and intended tactile feelings by tactile designers. Thus, a method of modulating the vibrotactile perception is required. We focus on fine roughness perception and we propose a method using a pseudo-haptic effect to modulate fine roughness perception of vibrotactile texture. Specifically, we visually modify the pointer's position on the screen slightly, which indicates the touch position on textured surfaces. We hypothesized that if users receive vibrational feedback watching the pointer visually oscillating back/forth and left/right, users would believe the vibrotactile surfaces more uneven. We also hypothesized that as the size of visual oscillation is getting larger, the amount of modification of roughness perception of vibrotactile surfaces would be larger. We conducted user studies to test the hypotheses. Results of first user study suggested that users felt vibrotactile texture with our method rougher than they did without our method at a high probability. Results of second user study suggested that users felt different roughness for vibrational texture in response to the size of visual oscillation. These results confirmed our hypotheses and they suggested that our method was effective. Also, the same effect could potentially be applied to the visual movement of virtual hands or fingertips when users are interacting with virtual surfaces using their hands.

Redirected walking allows users to explore a large virtual environment while there is a limitation of the room size. Previous works tried to present users straight path in a virtual environment while they walked on a curved path in reality. We expand a previous technique to present users a various curved path in a virtual environment while they walked on a particular curved path or a straight path with/without haptics. Furthermore, we propose a novel estimation methodology to quantify walking paths which user has thought he walked in reality. The data from our experiment shows that users feel walking a various curved path in VR as same as one-to-one mapping condition.

Agents like human, such as humanoid robots or avatars can be felt as if they have and communicate and communicate due to manipulation of the bodily information. Meanwhile, as in the case of Internet bot, it is still difficult to communiate the emotion described as text, let alone empathizing due to degradation of information online. The current study proposes a method for experiencing emotion on the Internet by reproducing a mechanism of evoking emotion. This method evokes a number of emotions described on the Web, by changing of self-physiological perception with sensory stimuli. To investigate the feasibility of our method, we made a system named "Communious Mouse." This system rewrites the perception of self-skin temperature and pulse in a palm by presenting vibration and thermal stimulation through a mouse device for evoking emotion. The current paper discusses the feasibility of our method based on the obtained feedbacks through an exhibition of the system.

This paper proposes a high-definition digital display case for manipulating a virtual exhibit that has linking mechanisms. This technique enhances the understanding of dynamic exhibits. It is difficult to construct interactive contents of dynamic virtual exhibits, because measuring the mechanism invokes the risk of an exhibit's deterioration, and it takes tremendous efforts to create a fine spun computer graphics (CG) model for mechanisms. Therefore, we propose an image-based interaction method that uses image-based rendering to construct interactive contents for dynamic virtual exhibits using the interpolation between exhibit pictures with a number of deformational conditions and viewpoints. Using this method, we construct a high-definition digital showcase and exhibit the interactive content at a museum to evaluate the availability of our system.

In this paper we developed the free-viewpoint curved surface shape display, using the effect of visuo-haptic interaction. In our research, we aim to realize the simple mechanic visuo-haptic system with which we can touch various objects with our real hands. We proposed the free-viewpoint shape display system in which users can touch a virtual object with various shape through the tablet device, while walking around the object. The system figured the difference of shape between the real object and the virtual one from the current viewpoint, and calculates the amount of displacement of the touching hand image to fit to the virtual object, in real time. This modification of the movement of a hand image evokes the effect of the visuo-haptic interaction, and enable users to feel touching various shapes from various viewpoints, although actually users touch a physically static object.

In this paper, we proposed a visuo-haptic system for displaying various shapes which have curve, edge, and inclined surfaces, using a simple transmutative physical device and the effect of visuo-haptic interaction. We aim to construct a perception-based shape display system to provide users with the sensation of touching virtual objects of varying shapes using only a simple mechanism. We have confirmed that the perception of each primitive shape such as curvature and angle could be modified by displacing a user's hand image on the monitor as if s/he were touching the visual shape while actually touching another shape. In this study, we constructed the method to merge these findings for displaying more various shapes, including angular ones. We built a transmutative device, which the user touches. The device does not undergo significant transformation, but its surface can be slightly bumped in and out, and displayed various shapes with various angles, length and curvature. The results of experimental trials confirmed that our method for displaying each primitive shape can also worked as designed when we combine these findings to display more complex objects using this device which transforms slightly.

The main contribution of this paper is to develop a method for alleviating fatigue during handling medium-weight objects and augmenting our endurance by affecting our weight perception with augmented reality technology. To assist people to lift medium-weight objects without a complex structure or various costs, we focus on the phenomenon that our weight perception during handling objects is affected by visual properties. Our hypothesis is that this illusionary effect in weight perception can be applied to reduce fatigue while handling medium-weight objects without mechatronics-based physical assistance. In this paper, we propose an augmented reality system that changes the brightness value of an object in order to reduce fatigue while handling the object. We conducted two fundamental experiments to investigate the effectiveness of the proposed system. Our results suggested that the system eliminates the need to use excess energy for handling objects and reduces fatigue during the handling task.

The main contribution of this paper is to realize a method for modifying perception of satiety and controlling nutritional intake by changing the apparent size of food with augmented reality. As a possible method for decreasing rates of obesity, we focused on controlling food intake implicitly without any effort.

In our research, we aim to construct the visuo-haptic system which can give users a sense as if they were touching on virtual objects with variety of shapes, using pseudo-haptiec effects. In this paper, we focus on modifying the identification of a position of edges on a object when touching it with a pointing finger, by displacing the visual representation of the user's hand in order to construct a novel visuo-haptic system. We compose a video see-through system, which enables us to change the perception of the shape of an object a user is visually touching, by displacing the visual representation of the user's hand as if s/he was touching the visual shape, when in actuality s/he is touching another shape. We had experiments and showed participants perceived positions of edges that was the same as the one they were visually touching, even though the positions of edges they were actually touching was different. These results prove that the perceived positions of edges could be modified, and even if the ratio of the successive distance between edges is 1 : 1, we can modify the perception of this ratio from 3 : 2 to 2 : 3.