A Antal Haans

Mediated social touch: a review of current research and future directions

In this paper, we review research and applications in the area of mediated or remote social touch. Whereas current communication media rely predominately on vision and hearing, mediated social touch allows people to touch each other over a distance by means of haptic feedback technology. Overall, the reviewed applications have interesting potential, such as the communication of simple ideas (e.g., through Hapticons), establishing a feeling of connectedness between distant lovers, or the recovery from stress. However, the beneficial effects of mediated social touch are usually only assumed and have not yet been submitted to empirical scrutiny. Based on social psychological literature on touch, communication, and the effects of media, we assess the current research and design efforts and propose future directions for the field of mediated social touch.

Is This My Hand I See Before Me? The Rubber Hand Illusion in Reality, Virtual Reality, and Mixed Reality

This paper presents a first study in which a recently reported intermodal perceptual illusion known as the rubber hand illusion is experimentally investigated under mediated conditions. When ones own hand is placed out of view and a visible fake hand is repeatedly stroked and tapped in synchrony with the unseen hand, subjects report a strong sense in which the fake hand is experienced as part of their own body. In our experiment, we investigated this illusion under three conditions: (i) unmediated condition, replicating the original paradigm, (ii) virtual reality (VR) condition, where both the fake hand and its stimulation were projected on the table in front of the participant, and (iii) mixed reality (MR) condition, where the fake hand was projected, but its stimulation was unmediated. Dependent measures included self-report (open-ended and questionnaire-based) and drift, that is, the offset between the felt position of the hidden hand and its actual position. As expected, the unmediated condition produced the strongest illusion, as indicated both by self-report and drift towards the rubber hand. The VR condition produced a more convincing subjective illusion than the MR condition, although no difference in drift was found between the mediated conditions. Results are discussed in terms of perceptual mechanisms underlying the rubber hand illusion, and the illusions relevance to understanding telepresence.

The effect of similarities in skin texture and hand shape on perceived ownership of a fake limb

In the rubber-hand illusion (RHI), people attribute an artificial object to their own body. In the present study, we investigate the extent to which RHI is affected by visual discrepancies between the artificial object and a human hand. We tested Armel and Ramachandrans (2003) hypothesis that people will experience a stronger RHI when the artificial object is a skin-like textured sheet instead of a tabletop. We did not find support for their hypothesis, but the strength of the RHI diminished when the texture of a hand-shaped object did not resemble the human skin (manipulated by putting a white glove over the cosmetic prosthesis). We provide an alternative explanation for this finding, based on a skill-based sensorimotor account of perceived body ownership. Such an explanation supports Armel and Ramachandrans more general claim that discrepancies in the nature of expected and felt touch diminish the RHI.

The Virtual Midas Touch: Helping Behavior After a Mediated Social Touch

A brief touch on the upper arm increases peoples altruistic behavior and willingness to comply with a request. In this paper, we investigate whether this Midas touch phenomenon would also occur under mediated conditions (i.e., touching via an arm strap equipped with electromechanical actuators). Helping behavior was more frequently endorsed in the touch, compared to the no-touch condition, but this difference was not found to be statistically significant. However, a meta-analytical comparison with published research demonstrated that the strength of the virtual Midas touch is of the same magnitude as that of the Midas touch in unmediated situations. The present experiment, thus, provides empirical evidence that touch-like qualities can be attributed to electromechanical stimulation. This is important for the field of mediated social touch of which the design rationale is based on the assumption that mediated touch by means of tactile feedback technologies is processed in ways similar to real physical contact.

Investigating response similarities between real and mediated social touch: a first test

In this paper, we investigate whether the gender differences generally found in same and opposite sex social touch are also present in mediated situations. Participants were led to believe that a male or female stranger was remotely touching them by means of a vest equipped with vibrotactile actuators. Affective responses varied with the stimulated body location, but the effect of dyad composition was not significant. In sum, we found partial support for the assumption that mediated social touch is actually perceived of as a real touch. Possible improvements to haptic communication devices are discussed.

Individual differences in the rubber-hand illusion: predicting self-reports of people's personal experiences.

Can we assess individual differences in the extent to which a person perceives the rubber-hand illusion on the basis of self-reported experiences? In this research, we develop such an instrument using Rasch-type models. In our conception, incorporating an object (e.g., a rubber hand) into ones body image requires various sensorimotor and cognitive processes. The extent to which people can meet these requirements thus determines how intensely people experience and, simultaneously, describe the illusion. As a consequence, individual differences in peoples susceptibility to the rubber-hand illusion can be determined by inspecting reports of their personal experiences. The proposed model turned out to be functional in its capability to predict self-reports of peoples experiences and to reliably assess individual differences in susceptibility to the illusion. Regarding validity, we found a small, but significant, correlation between individual susceptibility and proprioceptive drift. Additionally, we found that asynchrony, and tapping rather than stroking the fingers constrain the experience of the illusion.

Privacy-needs in office environments : development of two behavior-based scales

Abstract. In this paper, we develop two behavior-based privacy-need measures for office environments. These two new scales are designed as objective measures, since they try to avoid introspection. One scale assesses peoples motivation to withdraw from social interaction (i.e., the Need-For-Privacy [NFP]) and the other the motivation to seek social exchange (i.e., the Need-For-Socializing [NFS]). Based on survey data from 204 bank employees, our newly-developed measures demonstrated reasonable reliabilities (> .70). Regarding construct validity, we found our NFP scale to overlap (R2 > 25%) with an established NFP measure (Kaya & Weber, 2003) and a need-for-solitude instrument (Pedersen, 1988). The results also corroborate the fact that peoples NFP and their NFS are relatively distinct motives (R2 = 10%).

Touch, Tools and Telepresence: Embodiment in Mediated Environments

We tend to think of our body image as fixed. However, human brains appear to support highly negotiable body images. As a result, our brains show a remarkable flexibility in incorporating non-biological elements (tools and technologies) into the body image, provided reliable, real-time intersensory correlations can be established, and artifacts can be plausibly mapped onto an already existing body image representation. A particularly interesting and relevant phenomenon in this respect is a recently reported crossmodal perceptual illusion known as the rubber-hand illusion (RHI). When a person is watching a fake hand being stroked and tapped in precise synchrony with his or her own unseen hand, the person will, within a few minutes of stimulation, start experiencing the fake hand as an actual part of his or her own body. In this paper, we will review recent work on the RHI and argue that such experimental transformation of the intimate ties between body morphology, proprioception and self-perception enhances our fundamental understanding of the phenomenal experience of self. Moreover, it will enable us to significantly improve the design of interactive media, including the design of avatars in virtual environments and digital games, as well as a range of human-like telerobotic devices.

Illuminating for Safety: Investigating the Role of Lighting Appraisals on the Perception of Safety in the Urban Environment:

In two studies, we took a prospect–refuge based perspective to investigate how lighting and other physical attributes (i.e., prospect, concealment, and entrapment) affect people’s judgments of the safety of urban streets during nighttime. Both studies complement existing research, which predominantly use factorial designs, with more ecologically valid correlational research using a large and representative sample of urban streets as stimulus materials. Results from Study 1 corroborate existing research demonstrating that differences in prospect, concealment, and entrapment predicted, to a large extent, variation in the perceived safety of urban streets—thus demonstrating the utility of such environmental information for making safety judgments in real-life settings. Results from a mediation analysis conducted in Study 2 showed that the relation between appraisals of lighting quality and safety judgments was completely accounted for by co-occurring variation in appraisals of prospect and entrapment. Implications for theory and methodology are discussed.