A randomised controlled trial investigating the causal role of the medial prefrontal cortex in mediating self-agency during speech monitoring and reality monitoring

• Published in: Scientific reports Vol. 14; no. 1; p. 5108
• Main Authors: Tan, Songyuan, Jia, Yingxin, Jariwala, Namasvi, Zhang, Zoey, Brent, Kurtis, Houde, John, Nagarajan, Srikantan, Subramaniam, Karuna
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.03.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 631/378/2649; 631/378/2649/1594; 631/477; Auditory stimuli; Clinical trials; Education; Excitability; Feedback; Headphones; Humanities and Social Sciences; Humans; Hypotheses; Judgment; Magnetic fields; Magnetic resonance imaging; Medial prefrontal cortex; Memory - physiology; Monitoring; multidisciplinary; Predictions; Prefrontal cortex; Prefrontal Cortex - physiology; Reality monitoring; Repetitive transcranial magnetic stimulation; Science; Science (multidisciplinary); Self-agency; Speaking; Speech; Speech monitoring; Transcranial magnetic stimulation; Transcranial Magnetic Stimulation - methods; Speech monitoring; Medial prefrontal cortex; Self-agency; Repetitive transcranial magnetic stimulation; Reality monitoring
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-55275-3

Self-agency is the awareness of being the agent of one's own thoughts and actions. Self-agency is essential for interacting with the outside world (reality-monitoring). The medial prefrontal cortex (mPFC) is thought to be one neural correlate of self-agency. We investigated whether mPFC activity can causally modulate self-agency on two different tasks of speech-monitoring and reality-monitoring. The experience of self-agency is thought to result from making reliable predictions about the expected outcomes of one’s own actions. This self-prediction ability is necessary for the encoding and memory retrieval of one’s own thoughts during reality-monitoring to enable accurate judgments of self-agency. This self-prediction ability is also necessary for speech-monitoring where speakers consistently compare auditory feedback (what we hear ourselves say) with what we expect to hear while speaking. In this study, 30 healthy participants are assigned to either 10 Hz repetitive transcranial magnetic stimulation (rTMS) to enhance mPFC excitability (N = 15) or 10 Hz rTMS targeting a distal temporoparietal site (N = 15). High-frequency rTMS to mPFC enhanced self-predictions during speech-monitoring that predicted improved self-agency judgments during reality-monitoring. This is the first study to provide robust evidence for mPFC underlying a causal role in self-agency, that results from the fundamental ability of improving self-predictions across two different tasks.