Body ownership causes illusory self-attribution of speaking and influences subsequent real speaking

TLDR

Agency attribution normally links actions to self, with conscious authorship of our movements. The study examines whether observing a virtual human speaking can lead participants to falsely attribute the speaking to themselves. Participants observed a virtual human speaking while receiving synchronized vibrotactile stimulation on the thyroid cartilage, creating an ownership illusion. Voice formants shifted toward the stimulus voice only when the life‑size virtual body substituted and moved with participants, showing that ownership illusion can cause self‑attribution of speaking without prior intention.

Abstract

Significance Under normal circumstances we consciously attribute authorship of our actions to ourselves, the sensation of agency. We describe an experiment where participants observed a virtual human character speak and falsely attributed the speaking to themselves. They later shifted the FF of their own voice toward the stimulus voice. This only occurred when the life-sized VB substituted their own and moved with their own movements. A further contribution to the effect was vibrotactile stimulation on the thyroid cartilage synchronized with the speaking. This suggests that agency can be self-attributed even in the absence of prior intention, feed-forward prediction, priming, and cause preceding effect. A critical contributor is the illusion of ownership over the VB that spoke.