Expectancy changes the self-monitoring of voice identity

Abstract

Self-voice attribution can become difficult when voice characteristics are ambiguous, and functional magnetic resonance imagines (fMRI) investigations of such ambiguity are sparse. We utilized voice-morphing (self-other) to manipulate (un-)certainty in self-voice attribution in a button-press paradigm. This allowed investigating how levels of self-voice certainty alter brain activation in regions monitoring voice identity areas and unexpected changes in voice playback quality. FMRI results confirm a self-voice suppression effect in the right anterior superior temporal gyrus (aSTG) when self-voice attribution was unambiguous. Although the right inferior frontal gyrus (IFG) was more active during self-generated voice compared to when passively-heard, the putative role of this region in detecting unexpected self-voice changes was not confirmed. Further research on the link between right aSTG and IFG is required and may establish a threshold monitoring voice identity in action. The current results have implications for a better understanding of an altered experience of self-voice feedback leading to auditory verbal hallucinations.