Brain Topography

, Volume 30, Issue 1, pp 122–135

Causal Dynamics of Scalp Electroencephalography Oscillation During the Rubber Hand Illusion

  • Noriaki Kanayama
  • Alberto Morandi
  • Kazuo Hiraki
  • Francesco Pavani
Original Paper

DOI: 10.1007/s10548-016-0519-x

Cite this article as:
Kanayama, N., Morandi, A., Hiraki, K. et al. Brain Topogr (2017) 30: 122. doi:10.1007/s10548-016-0519-x

Abstract

Rubber hand illusion (RHI) is an important phenomenon for the investigation of body ownership and self/other distinction. The illusion is promoted by the spatial and temporal contingencies of visual inputs near a fake hand and physical touches to the real hand. The neural basis of this phenomenon is not fully understood. We hypothesized that the RHI is associated with a fronto-parietal circuit, and the goal of this study was to determine the dynamics of neural oscillation associated with this phenomenon. We measured electroencephalography while delivering spatially congruent/incongruent visuo-tactile stimulations to fake and real hands. We applied time–frequency analyses and calculated renormalized partial directed coherence (rPDC) to examine cortical dynamics during the bodily illusion. When visuo-tactile stimulation was spatially congruent, and the fake and real hands were aligned, we observed a reduced causal relationship from the medial frontal to the parietal regions with respect to baseline, around 200 ms post-stimulus. This change in rPDC was negatively correlated with a subjective report of the RHI intensity. Moreover, we observed a link between the proprioceptive drift and an increased causal relationship from the parietal cortex to the right somatosensory cortex during a relatively late period (550–750 ms post-stimulus). These findings suggest a two-stage process in which (1) reduced influence from the medial frontal regions over the parietal areas unlocks the mechanisms that preserve body integrity, allowing RHI to emerge; and (2) information processed at the parietal cortex is back-projected to the somatosensory cortex contralateral to the real hand, inducing proprioceptive drift.

Keywords

Rubber hand illusion Electroencephalography Causal relationship Body ownership 

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • Noriaki Kanayama
    • 1
  • Alberto Morandi
    • 2
  • Kazuo Hiraki
    • 3
  • Francesco Pavani
    • 2
    • 4
  1. 1.Institute of Biomedical and Health SciencesHiroshima UniversityHiroshimaJapan
  2. 2.Department of Psychology and Cognitive ScienceUniversity of TrentoRoveretoItaly
  3. 3.Department of General Systems Studies in Graduate School of Arts and SciencesUniversity of TokyoTokyoJapan
  4. 4.Centre for Mind/Brain SciencesUniversity of TrentoRoveretoItaly