Inhibition of monitoring mechanisms in response to erroneous or veridical feedback. “Virtual lesion” induction by an rTMS study

External feedback from contextual cues allows humans to behave appropriately in their environments. In the present study, the explicit process of feedback monitoring (an explicit response to veridical vs false feedback) was explored. In addition, the contribution of the prefrontal cortex in this monitoring process was tested by administering an rTMS inhibitory paradigm. Seventeen subjects participated in the study and were required to detect correct vs. incorrect feedback. The experimental task included three main phases: the subject's performance (spatial decisional task); the system's response to the performance (external feedback); and the subject's judgment and response to this external feedback (feedback monitoring). rTMS was performed on the DLPFC. As shown by the behavioural measures (error rate and response times), DLPFC deactivation induced worse performance (higher ER and RT) for both correct and incorrect feedback. Indeed, this prefrontal region seems to contribute to conscious monitoring functions when an explicit response is required. Possible applications to executive function analysis and rehabilitation are suggested.