Agency and action monitoring in congruous vs. incongruous feedback condition. A rTMS study

Agency depends on our sense of being in control and causally determinant in action, and the ability to consciously monitor the external feedback produced by our own performance was a constitutive component of this sense of agency. The present research explored the mechanism underlying the monitoring system by manipulating the cortical response to different types of feedback (congruous and incongruous). The contribution of cingulate area was highlighted from a vast amount of previous research, since this brain site seems to be deputed to compare internal expectations with external cues. Subjects were required to monitor the coherence of the external spatial feedback. in response to their performance. Half of the trials were preceded by a rTMS applied to frontal areas (Fz), in order to inhibit the activity of the monitoring system. Behavioral responses (correctness and response time, RT) were effected by the rTMS in comparison with the control trials. When the frontal cortical site was stimulated, the subjects were unable to distinguish the congruous from the incongruous feedback, with similar RT for the two experimental conditions, whereas significant differences were found in normal (no rTMS) condition, that reported an increased RT in case of an incongruous feedback. The discovery of specific neural correlates of monitoring system related to our own action is discussed, and the relationship between this system with the sense of agency is better elucidated by the present research