Psychometrics of Disembodiment and Its Differential Modulation by Visuomotor and Visuotactile Mismatches

Abstract

Altered states of embodiment are fundamental to the scientific understanding of bodily self consciousness. The feeling of disembodiment during everyday activities is common to clinical conditions; however, the direct study of disembodiment in experimental setups is rare compared to the extensive investigation of illusory embodiment of an external object. Using mixed reality to modulate embodiment through temporally mismatching sensory signals from the own body, we assessed how such mismatches affect phenomenal and physiological aspects of embodiment and measured perceptual thresholds for these across multimodal signals. The results of a principal component analysis suggest that multimodal mismatches generally induce disembodiment by increasing the sense of disownership and deafference and decreasing embodiment; however, this was not generally reflected in physiological changes. Although visual delay decreased embodiment both during active movement and passive touch, the effect was stronger for the former. We discuss the relevance of these findings for understanding bodily self plasticity.

Real Bodies Not Required? Placebo Analgesia and Pain Perception in Immersive Virtual and Augmented Reality

“…While this effect will necessitate further investigation by including conditions aimed at reducing the sense of embodiment (e.g., asynchronous multisensory stimulation) [51], we speculate that an embodied approach could provide a plausible explanation for our results. Bodily perception epitomizes a foundational basis of our self: even if higher order features of consciousness are reduced, a basic sense of self embedded in a body is retained [21], emphasizing that all experience occurs from within this embodied frame of reference [19,20,22].…”

“…To measure the sense of embodiment experienced, participants completed an Embodiment Questionnaire (adapted from [9,51]) following the virtual and augmented reality sessions (Table 2). Questions were displayed within the headset visual space and were answered on a visual analog scale (VAS; values hidden from participants) from 0 (not at all) to 1 (very much) using headtracking to select and confirm answers.…”

“…The embodiment questionnaire in the PR condition was comprised only of questions emb1 and emb2. The questionnaire was adapted from commonly employed and validated [51] embodiment questionnaires in virtual bodily illusion experiments (e.g., [9]) (Table 2), and consisted of the following items: emb1. “How much did it feel like the pain you saw was caused by the stimulation on the virtual/seen arm?” (pain stimulation); emb2.…”

How Does Embodying a Transgender Narrative Influence Social Bias? An Explorative Study in an Artistic Context

“…17.12.10). A total of 43 additional individuals ( control group) were recruited at the University of Zurich in the framework of another study using a similar body illusion, which was unrelated to the theme of gender identity (unpublished work; the setup was comparable to Roel Lesur et al, 2020 ) as a control group [mean age = 22.40 (SD = 3.1); 32 women]. A Mann–Whitney comparison showed a significant difference of age between participants recorded at the museum and the laboratory ( U = 2654, p < 0.001).…”

“…For the control group, elements of this study were integrated into another embodiment-related experiment (similar to Roel Lesur et al, 2020 ) conducted at the University of Zurich in a laboratory setting. This group was included with the aim of disentangling the potential effect of retesting on both measures of bias.…”