Balancing the "inner" and the "outer" self:interoceptive sensitivity modulates self-other boundaries

Distinguishing self from other is necessary for self-awareness and social interactions. This distinction is thought to depend on multisensory integration dominated by visual feedback. However, self-awareness also relies on the processing of interoceptive signals. We contrasted the exteroceptive and interoceptive models of the self to investigate the hitherto unexplored interaction between the perception of the self from the outside and from within. Multisensory stimulation between self and other was used to induce controlled changes in the representation of one’s identity. Interoceptive sensitivity predicted the malleability of self-representations in response to multisensory integration across behavioral, physiological and introspective responses, suggesting that interoception plays a key modulating role in the self-recognition system. In particular, only participants with low interoceptive sensitivity experienced changes in self-other boundaries in response to multisensory stimulation. These results support the view that interoceptive predictive coding models are used to monitor and assign the sources of sensory input either to the self or to others, as well as support the hypothesis of the insular cortex as a convergence zone in the processing and global representation of the material self given its involvement in both interoceptive feelings, multisensory integration and self-processing

Auditory-induced body distortions in children and adults

Recent studies have shown that body-representations can be altered by dynamic changes in sound. In the so-called "auditory Pinocchio illusion" participants feel their finger to be longer when the action of pulling their finger is paired with a rising pitch. Here, we investigated whether preschool children - an age group in which multisensory body-representations are still fine-tuning - are also sensitive to this illusion. In two studies, sixty adult and sixty child participants heard sounds rising or falling in pitch while the experimenter concurrently pulled or pressed their index finger on a vertical (Experiment 1) or horizontal axis (Experiment 2). Results showed that the illusion was subjected to axis and age: both adults and children reported their finger to be longer in Experiment 1, but not in Experiment 2. However, while in adults the feeling of finger elongation corresponded to a recalibration of the fingertip's felt position upwards, this was not the case in children, who presented a dissociation between the feeling of finger elongation and the perceived fingertip position. Our results reveal that the 'auditory Pinocchio illusion' is constrained to the vertical dimension and suggest that multisensory interactions differently contribute to subjective feelings and sense of position depending on developmental stage.This work was supported by Ministerio de Economía, Industria y Competitividad of Spain Grants RYC-2014–15421 and PSI2016–79004-R (“MAGIC SHOES”; AEI/FEDER, UE) to A.T., and by 2018-ATE-0038 (“Mechanisms of sensory attenuation”), University of Milano-Bicocca to E.N

Altering one's body-perception through e-textiles and haptic metaphors

Tajadura-Jiménez A, Väljamäe A and Kuusk K (2020) Altering One's Body-Perception Through E-Textiles and Haptic Metaphors. Front. Robot. AI 7:7.Technologies change rapidly our perception of reality, moving from augmented to virtual to magical. While e-textiles are a key component in exergame or space suits, the transformative potential of the internal side of garments to create embodied experiences still remains largely unexplored. This paper is the result from an art-science collaborative project that combines recent neuroscience findings, body-centered design principles and 2D vibrotactile array-based fabrics to alter one's body perception. We describe an iterative design process intertwined with two user studies on the effects on body-perceptions and emotional responses of various vibration patterns within textile that were designed as spatial haptic metaphors. Our results show potential in considering materials (e.g., rocks) as sensations to design for body perceptions (e.g., being heavy, strong) and emotional responses. We discuss these results in terms of sensory effects on body perception and synergetic impact to research on embodiment in virtual environments, human-computer interaction, and e-textile design. The work brings a new perspective to the sensorial design of embodied experiences which is based on "material perception" and haptic metaphors, and highlights potential opportunities opened by haptic clothing to change body-perception.This work was partially supported by PSI2016-79004-R Magic Shoes project grant (AEI/FEDER, UE), from Ministerio de Economía, Industria y Competitividad of Spain and the Magic Lining VERTIGO project as part of the STARTS program of the European Commission, based on technological elements from the project Magic Shoes. AT-J was supported by RYC- 2014–15421 grant from the Ministerio de Economía, Industria y Competitividad of Spain and AV was supported by the Estonian Research Council grant PUT1518

A transdisciplinary collaborative journey leading to sensorial clothing

Recent science funding initiatives have enabled participants from a diverse array of disciplines to engage in common spaces for developing solutions for new wearables. These initiatives include collaborations between the arts and sciences, fields which have traditionally contributed very different forms of knowledge, methodology, and results. However, many such collaborations often turn out as science communication and dissemination activities that make no concrete contribution to technological innovation. Magic Lining, a transdisciplinary collaborative project involving artistic and scientific partners working in the fields of e-textile design, cognitive neuroscience and human-computer interaction, creates a shared experiential knowledge space. This article focuses on the research question of how a transdisciplinary collaborative design processinvolving material explorations, prototyping, first-person-perspective and user studies, can lead to the creation of a garment that invites various perceptual and emotional responses in its wearer. The article reflects on the design journey, highlighting the transdisciplinary team's research through design experience and shared language for knowledge exchange. This process has revealed new research paths for an emerging field of 'sensorial clothing', combining the various team members' fields of expertise and resulting in a wearable prototype.This work was partially supported by the VERTIGO project as part of the STARTS program of the European Commission, based on technological elements from the project Magic Shoes (grant PSI2016-79004-R, Ministerio de Economía, Industria y Competitividad of Spain, AEI/FEDER). The work was also supported by the project Magic outFIT, funded by the Spanish Agencia Estatal de Investigación (PID2019-105579RB-I00/AEI/10.13039/501100011033). Aleksander Väljamäe’s work was supported by the Estonian Research Council grant PUT1518; and Ana Tajadura-Jiménez’s work was supported by RYC-2014–15421 grant, Ministerio de Economía, Industria y Competitividad of Spain

It Feels Like It's Me:Interpersonal Multisensory Stimulation Enhances Visual Remapping of Touch From Other to Self

Abstract Understanding other people's feelings in social interactions depends on the ability to map onto our body the sensory experiences we observed on other people's bodies. It has been shown that the perception of tactile stimuli on the face is improved when concurrently viewing a face being touched. This Visual Remapping of Touch (VRT) is enhanced the more similar others are perceived to be to the self and is strongest when viewing one's face. Here, we ask whether altering self-other boundaries can in turn change the VRT effect. We used the enfacement illusion, which relies on synchronous interpersonal multisensory stimulation (IMS), to manipulate self-other boundaries. Following synchronous, but not asynchronous, IMS, the self-related enhancement of the VRT extended to the other individual. These findings suggest that shared multisensory experiences represent one key way to overcome the boundaries between self and others, as evidenced by changes in somatosensory processing of tactile stimuli on one's own face when concurrently viewing another person's face being touched

Action sounds update the mental representation of arm dimension:contributions of kinaesthesia and agency

Auditory feedback accompanies almost all our actions, but its contribution to body-representation is understudied. Recently it has been shown that the auditory distance of action sounds recalibrates perceived tactile distances on one’s arm, suggesting that action sounds can change the mental representation of arm length. However, the question remains open of what factors play a role in this recalibration. In this study we investigate two of these factors, kinaesthesia and sense of agency. Across two experiments, we asked participants to tap with their arm on a surface while extending their arm. We manipulated the tapping sounds to originate at double the distance to the tapping locations, as well as their synchrony to the action, which is known to affect feelings of agency over the sounds. Kinaesthetic cues were manipulated by having additional conditions in which participants did not displace their arm but kept tapping either close (Experiment 1) or far (Experiment 2) from their body torso. Results show that both the feelings of agency over the action sounds and kinaesthetic cues signalling arm displacement when displacement of the sound source occurs are necessary to observe changes in perceived tactile distance on the arm. In particular, these cues resulted in the perceived tactile distances on the arm being felt smaller, as compared to distances on a reference location. Moreover, our results provide the first evidence of consciously perceived changes in arm-representation evoked by action sounds and suggest that the observed changes in perceived tactile distance relate to experienced arm elongation. We discuss the observed effects in the context of forward internal models of sensorimotor integration. Our results add to these models by showing that predictions related to action sounds must fit with kinaesthetic cues in order for auditory inputs to change body-representation

Investigating nuanced sensory experiences in textiles selection

In this study, research tools are used to investigate designers' textile selection activities and uncover the sensorial experiences that underpin those activities. Such tools were purposely introduced to disrupt the way designers generally interact with textiles and generate conversations around it. The study was conducted in a textile fair during two consecutive years with an expert audience who were in the mind-set of sourcing. This study resulted in four main themes that reveal the importance of the multisensory experience to textile selection, and the complexity of remembering and communicating such experiences in the design process, given how tacit such experiences are

Embodying an outgroup:the role of racial bias and the effect of multisensory processing in somatosensory remapping

We come to understand other people’s physical and mental states by re-mapping their bodily states onto our sensorimotor system. This process, also called somatosensory resonance, is an essential ability for social cognition and is stronger when observing ingroup than outgroup members. Here we investigated, first, whether implicit racial bias constrains somatosensory resonance, and second, whether increasing the ingroup/outgroup perceived physical similarity results in an increase in the somatosensory resonance for outgroup members. We used the Visual Remapping of Touch effect as an index of individuals’ ability in resonating with the others, and the Implicit Association Test to measure racial bias. In Experiment 1, participants were asked to detect near-threshold tactile stimuli delivered to their own face while viewing either an ingroup or an outgroup face receiving a similar stimulation. Our results showed that individuals’ tactile accuracy when viewing an outgroup face being touched was negatively correlated to their implicit racial bias. In Experiment 2, participants received the Interpersonal Multisensory Stimulation (IMS) while observing an outgroup member. IMS has been found to increase the perceived physical similarity between the observer’s and the observed body. We tested whether such increase in ingroup/outgroup perceived physical similarity increased the remapping ability for outgroup members. We found that after sharing IMS experience with an outgroup member, tactile accuracy when viewing touch on outgroup faces increased. Interestingly, participants with stronger implicit bias against the outgroup showed larger positive change in the remapping. We conclude that shared multisensory experiences might represent one key way to improve our ability to resonate with others by overcoming the boundaries between ingroup and outgroup categories

Action Sounds Informing Own Body Perception Influence Gender Identity and Social Cognition

Sensory information can temporarily affect mental body representations. For example, in Virtual Reality (VR), visually swapping into a body with another sex can temporarily alter perceived gender identity. Outside of VR, real-time auditory changes to walkers’ footstep sounds can affect perceived body weight and masculinity/femininity. Here, we investigate whether altered footstep sounds also impact gender identity and relation to gender groups. In two experiments, cisgender participants (26 females, 26 males) walked with headphones which played altered versions of their own footstep sounds that sounded more typically male or female. Baseline and post-intervention measures quantified gender identity [Implicit Association Test (IAT)], relation to gender groups [Inclusion of the Other-in-the-Self (IOS)], and perceived masculinity/femininity. Results show that females felt more feminine and closer to the group of women (IOS) directly after walking with feminine sounding footsteps. Similarly, males felt more feminine after walking with feminine sounding footsteps and associated themselves relatively stronger with “female” (IAT). The findings suggest that gender identity is temporarily malleable through auditory-induced own body illusions. Furthermore, they provide evidence for a connection between body perception and an abstract representation of the Self, supporting the theory that bodily illusions affect social cognition through changes in the self-concept.This work was supported by ESRC grant ES/K001477/1 (“The hearing body”) and by Ministerio de Economia, Industria y Competitividad of Spain Grant RYC-2014-15421 to AT-J, and by the Spanish Agencia Estatal de Investigación “MAGIC outFIT” grant (PID2019-105579RB-I00/AEI/10.13039/501100011033)

Corrigendum: Action Sounds Modulate Arm Reaching Movements

A corrigendum on: Action Sounds Modulate Arm Reaching Movements by Tajadura-Jiménez, A., Marquardt, T., Swapp, D., Kitagawa, N., and Bianchi-Berthouze, N. (2016). Front. Psychol. 7:1391. doi: 10.3389/fpsyg.2016.0139