Autonomy and the ability to maintain social activities can be challenging for people with disabilities experiencing reduced mobility. In the case of disabilities that impact mobility, power wheelchairs can help such people retain or regain autonomy. Nonetheless, driving a power wheelchair is a complex task that requires a combination of cognitive, visual and visuo-spatial abilities. In practice, people need to pass prior ability tests and driving training before being prescribed a power wheelchair by their therapist. Still, conventional training in occupational therapy can be insufficient for some people with severe cognitive and/or visuo-spatial functions. As such, these people are often prevented from obtaining a power wheelchair prescription from their therapist due to safety concerns. In this context, driving simulators might be efficient and promising tools to provide alternative, adaptive, flexible, and safe training. In previous work, we proposed a Virtual Reality (VR) driving simulator integrating vestibular feedback to simulate wheelchair motion sensations. The performance and acceptability of a VR simulator rely on satisfying user Quality of Experience (QoE). Therefore, our simulator is designed to give the user a high Sense of Presence (SoP) and low Cybersickness. This paper presents a pilot study assessing the impact of the vestibular feedback provied on user QoE. Participants were asked to perform a driving task whilst in the simulator under two conditions: with and without vestibular feedback. User QoE is assessed through subjective questionnaires measuring user SoP and cybersickness. The results show that vestibular feedback activation increases SoP and decreases cybersickness. This study constitutes a mandatory step before clinical trials and, as such, only enrolled people without disabilities.

Previous studies about kinesthetic expressions of emotions are mainly based on acted expressions of emotions, which can be quite different from spontaneous expressions. This paper describes a study involving a stress induction procedure and stress perception through haptic expressions with Ntotal= 41 young men (aged 19 - 37), all right-handed. We designed a game application to collect spontaneous expressions of stress. This application involved haptic interactions and a stressful event. We observed changes in the haptic behaviors of the participants over different phases: before, during and after the stress induction. In the next step, we investigated how the collected haptic behaviors (both kinematic and force components) were haptically perceived by the other participants. The results suggest the ability of kinesthetic expressions to communicate a spontaneous stress from one person to another.

Does it feel the same when you touch an object in Augmented Reality (AR) or in Virtual Reality (VR)? In this paper we study and compare the haptic perception of stiffness of a virtual object in two situations: (1) a purely virtual environment versus (2) a real and augmented environment. We have designed an experimental setup based on a Microsoft HoloLens and a haptic force-feedback device, enabling to press a virtual piston, and compare its stiffness successively in either Augmented Reality (the virtual piston is surrounded by several real objects all located inside a cardboard box) or in Virtual Reality (the same virtual piston is displayed in a fully virtual scene composed of the same other objects). We have conducted a psychophysical experiment with 12 participants. Our results show a surprising bias in perception between the two conditions. The virtual piston is on average perceived stiffer in the VR condition compared to the AR condition. For instance, when the piston had the same stiffness in AR and VR, participants would select the VR piston as the stiffer one in 60% of cases. This suggests a psychological effect as if objects in AR would feel "softer" than in pure VR. Taken together, our results open new perspectives on perception in AR versus VR, and pave the way to future studies aiming at characterizing potential perceptual biases.

Previous studies about kinesthetic expressions of emotions are mainly based on acted expressions of affective states, which might be quite different from spontaneous expressions. In a previous study, we proposed a task to collect haptic expressions of a spontaneous stress. In this paper, we explore the effectiveness of this task to induce a spontaneous stress in two ways: a subjective feedback, and a more objective approach-avoidance behavior.

The use of virtual avatars, through facial or gestural expressions, is considered to be a main support for affective communication. Currently, different works have studied the potential of a kinesthetic channel for conveying such information. However, they still have not investigated the complementarity between visual and kinesthetic feedback to effectively convey emotion. This paper studies the relation between some emotional dimensions and the visual and kinesthetic modalities. The experimental results show that subjects used visual and kinesthetic feedbacks to evaluate the pleasure and the arousal dimensions, respectively. We also observed a link between the recognition rate of emotions expressed with the visual modality (resp. kinesthetic modality) and the magnitude of that emotion's pleasure dimension (resp. arousal dimension). These different results should help in the selection of feedbacks according to the features of the investigated emotion.

This paper deals with the haptic affective social interaction during a greeting handshaking between a human and a humanoid robot. The goal of this work is to study how the haptic interaction conveys emotions, and more precisely, how it in'uences the perception of the dimensions of emotions expressed through the facial expressions of the robot. Moreover, we examine the bene'ts of the multimodality (i.e., visuo-haptic) over the monomodality (i.e., visual-only and haptic-only). The experimental results with Meka robot show that the multimodal condition presenting high values for grasping force and joint stiffness are evaluated with higher values for the arousal and dominance dimensions than during the visual condition. Furthermore, the results corresponding to the monomodal haptic condition showed that participants discriminate well the dominance and the arousal dimensions of the haptic behaviours presenting low and high values for grasping force and joint stiffness.

Haptic expression of emotions has received less attention than other modalities. Bonnet et al. [2011] combine visio-haptic modalities to improve the recognition and discrimination of some emotions. However, few works investigated how these modalities complement each other. For instance, Bickmore et al. [2010] highlight some non-significant tendencies of complementarity between the visual and haptic modalities.

Several studies have investigated the relevance of haptics to convey various types of emotions physically. This article investigates the improvement of the recognition rate of emotions using visuo-haptic feedback compared to facial and haptic expressions alone. Four experiments were conducted in which the recognition rates of emotions using facial, haptic and visuo-haptic expressions were tested. The first experiment evaluates the recognition rate of emotions using facial expressions. The second experiment collects a large corpus of 3D haptic expressions of certain emotions and subsequently identifies the relevant haptic expression for each emotion. The third experiment evaluates the selected haptic expressions through statistical and perceptive tests to retain the ones that result in the most accurate identification of the corresponding emotion. Finally, the fourth experiment studies the effect of visuo–haptic coupling on the recognition of the investigated emotions. Generally, emotions with high amplitudes of pleasure are better recognized in the visual modality. However, emotions with high activation are better recognized in the haptic modality. These results also highlighted the finding that participants are not equally aided by each modality when recognizing emotions efficiently. Beyond the recognition rate, multimodal expressions improved the sensation of presence and expressivity.

Eliciting emotions to collect affective expressions is frequently used in studies about facial, spoken or bodily expressions of emotions. However, recent works in affective hap tics focus mostly on expressions of acted emotions. The expression of spontaneous emotions using the haptic modality remains unexplored. This paper discusses methodological considerations for designing experimental protocols to collect haptic expressions of spontaneous emotions. We highlight the main difficulties to solve, provide illustrative examples from several experiments that we conducted, and describe methodological considerations for eliciting emotions and collecting corresponding haptic expressions.

Exploring virtual environment with immersive metaphor is still largely unexplored, with the costly CAVE exception. This question takes importance in lots of fields, such as fluid mechanics, where space and time resolved dataset become more and more common. For that reason, we present an interaction design study of an window exploration metaphor, for large 3D virtual environment. The metaphor is based on the use of a tablet as a tangible and movable window on a virtual environment. Rotations in the environment are tracker-less mapped on the rotations of the tablet. Our design is inspired by fluid mechanics issues, but is build keeping generalizability in mind. The study shows that mapping three degrees of freedom onto corresponding real three degrees of freedom of space raises the transparency, the efficiency of data exploration and the space awareness of users.

Several studies have investigated the relevance of haptics to physically convey various types of emotion. However, they use basic analysis approaches to identify the relevant features for an effective communication of emotion. This article presents an advanced analysis approach, based on the clustering technique, that enables the extraction of the general features of affective haptic expressions as well as the identification of specific features in order to discriminate between close emotions that are difficult to differentiate. This approach was tested in the context of affective communication through a virtual handshake. It uses a haptic device, which enables the expression of 3D movements. The results of this research were compared to those of the standard Analysis of Variance method in order to highlight the advantages and limitations of each approach.

Several studies showed the relevance of haptics for conveying emotions to users. These studies usually cover recognition rate of emotions from haptic expressions. Surprisingly, the analysis of features of these haptic expressions is in counterpart often limited to a classical analysis of variance. However, this method suffers of several limitations for the analysis of such data. This paper investigates the complementarity of three different statistical methods for the processing of haptic expressions of emotions.