Tactile information counteracts the attenuation of rubber hand illusion attributable to increased visuo-proprioceptive divergence

PLoS One. 2020 Dec 30;15(12):e0244594. doi: 10.1371/journal.pone.0244594. eCollection 2020.

Abstract

Sense of body ownership is an immediate and distinct experience of one's body as belonging to oneself. While it is well-recognized that ownership feelings emerge from the integration of visual and somatosensory signals, the principles upon which they are integrated are still intensely debated. Here, we used the rubber hand illusion (RHI) to examine how the interplay of visual, tactile, and proprioceptive signals is governed depending on their spatiotemporal properties. For this purpose, the RHI was elicited in different conditions varying with respect to the extent of visuo-proprioceptive divergence (i.e., the distance between the real and fake hands) and differing in terms of the availability and spatiotemporal complexity of tactile stimulation (none, simple, or complex). We expected that the attenuating effect of distance on illusion strength will be more pronounced in the absence of touch (when proprioception gains relatively higher importance) and absent in the presence of complex tactile signals. Additionally, we hypothesized that participants with greater proprioceptive acuity-assessed using an elbow joint position discrimination task-will be less susceptible to the illusion, but only under the conditions of limited tactile stimulation. In line with our prediction, RHI was attenuated at the farthest distance only when tactile information was absent or simplified, but the attenuation was effectively prevented by the use of complex tactile stimulation-in this case, RHI was comparably vivid at both distances. However, passive proprioceptive acuity was not related to RHI strength in either of the conditions. The results indicate that complex-structured tactile signals can override the influence of proprioceptive signals in body attribution processes. These findings extend our understanding of body ownership by showing that it is primarily determined by informative cues from the most relevant sensory domains, rather than mere accumulation of multisensory evidence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Female
  • Humans
  • Illusions / physiology*
  • Male
  • Proprioception / physiology*
  • Rubber
  • Touch / physiology*
  • Visual Perception / physiology*
  • Young Adult

Substances

  • Rubber

Grants and funding

The work in this paper was funded by National Science Centre (Poland) (https://www.ncn.gov.pl/) research grants under the decisions 2014/14/E/HS1/00803, 2020/36/T/HS6/00071 (P. L.) and 2016/23/N/HS6/02920 (P. M.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.