Disembodiment

• Applicants: Professor Dr. David Dignath; Professor Dr. Roland Pfister
• Subject Area: General, Cognitive and Mathematical Psychology
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 444800539

The representation of one’s body has repeatedly been characterized as being dynamic and flexible, which is backed up by fascinating observations such as the rubber hand illusion and changes of the body representation that arise due to transformed movements (e.g., during tool use). These studies show when and how the body representation is expanded by quite literally incorporating external objects as a result of sensorimotor experience. A dynamic view, however, holds that body representations cannot only be expanded by embodying additional parts but that they can also be narrowed down by disembodying such parts later on.Current theoretical accounts explain dynamic changes of the body representation via processes of multisensory integration. These accounts also come with the tacit assumption that recently embodied entities become disembodied when multisensory signals do no longer support the embodied representation. The precise contribution of such mechanisms to disembodiment and the timescale at which disembodiment takes place have not yet been put to the direct empirical test though.The proposed project therefore targets the disembodiment of previously embodied entities. Our experimental approach builds on two tried-and-tested experimental paradigms: the active, moving rubber hand illusion and the embodiment of virtual action effects. We will instate these dynamic changes of the body representation via robust experimental methods to be able to address subsequent disembodiment as a function of sensorimotor experiences. We will specifically target gradual decay in situations without any further experiences and rapid disembodiment after experiences of non-contiguity and non-contingency of own movements and movements of an embodied entity. Disembodiment will be quantified via both, explicit judgments, and implicit measures of proprioceptive drift and cross-modal congruency effects. We will further delineate the boundary conditions that allow embodied entities to become integrated in body representations either in a stable or a flexible manner. This second focus will inform practical approaches revolving around the active control of avatars in virtual reality. The proposed project will thus contribute an innovative and unique theoretical perspective by asking how the sensorimotor mechanisms that expand the body representation in the first place may also be apt to constrain it later on.

• DFG Programme: Research Grants