Re-association of Body Parts: Illusory Ownership of a Virtual Arm Associated With the Contralateral Real Finger by Visuo-Motor Synchrony.

Ryota Kondo,Michiteru Kitazaki,Yamato Tani,Maki Sugimoto,Masahiko Inami,Kouta Minamizawa

doi:10.3389/frobt.2020.00026

Ryota Kondo, Michiteru Kitazaki + Show 4 more

Open Access

https://doi.org/10.3389/frobt.2020.00026

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Abstract

Illusory ownership can be induced in a virtual body by visuo-motor synchrony. Our aim was to test the possibility of a re-association of the right thumb with a virtual left arm and express the illusory body ownership of the re-associated arm through a synchronous or asynchronous movement of the body parts through action and vision. Participants felt that their right thumb was the virtual left arm more strongly in the synchronous condition than in the asynchronous one, and the feeling of ownership of the virtual arm was also stronger in the synchronous condition. We did not find a significant difference in the startle responses to a sudden knife appearance to the virtual arm between the two synchrony conditions, as there was no proprioceptive drift of the thumb. These results suggest that a re-association of the right thumb with the virtual left arm could be induced by visuo-motor synchronization; however, it may be weaker than the natural association.

Highlights

Body ownership can be induced in real or realistic bodies and in fake or virtual bodies
We focused on the re-association of the real right thumb and a virtual left arm because the right thumb and the left arm are at different levels of the human body hierarchy, the directions of their movements are similar
We found that the participants felt as if their own right thumb had become the left arm and illusory body ownership of the virtual left arm was induced more in the visuomotor synchronous condition than in the asynchronous one

Summary

Introduction

Body ownership can be induced in real or realistic bodies and in fake or virtual bodies. Examples of such illusory body ownership include the rubber hand illusion (Botvinick and Cohen, 1998; Longo et al, 2008). In this illusion, body ownership was induced for a rubber hand by stroking a rubber hand and the observer’s hand simultaneously. The observer felt that the rubber hand belonged to his own body In this example, a visuo-tactile integration induced the illusory body ownership. The illusory body ownership is stronger in the visuo-motor synchrony method than in the passive visuo-tactile integration method (Kokkinara and Slater, 2014)

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