During speech production, we continuously monitor what we say. In situations in which speech errors potentially have more severe consequences, e.g. during a public presentation, our verbal selfmonitoring system may pay special attention to prevent errors than in situations in which speech errors are more acceptable, such as a casual conversation. In an event-related potential study, we investigated whether or not motivation affected participants' performance using a picture naming task in a semantic blocking paradigm. Semantic context of to-be-named pictures was manipulated; blocks were semantically related (e.g., cat, dog, horse, etc.) or semantically unrelated (e.g., cat, table, flute, etc.). Motivation was manipulated independently by monetary reward. The motivation manipulation did not affect error rate during picture naming. However, the highmotivation condition yielded increased amplitude and latency values of the error-related negativity (ERN) compared to the low-motivation condition, presumably indicating higher monitoring activity. Furthermore, participants showed semantic interference effects in reaction times and error rates. The ERN amplitude was also larger during semantically related than unrelated blocks, presumably indicating that semantic relatedness induces more conflict between possible verbal responses.

Speech production long avoided electrophysiological experiments due to the suspicion that potential artifacts caused by muscle activity of overt speech may lead to a bad signal-tonoise ratio in the measurements. Therefore, researchers have sought to assess speech production by using indirect speech production tasks, such as tacit or implicit naming, delayed naming, or meta-linguistic tasks, such as phoneme-monitoring. Covert speech may, however, involve different processes than overt speech production. Recently, overt speech has been investigated using electroencephalography (EEG). As the number of papers published is rising steadily, this clearly indicates the increasing interest and demand for overt speech research within the field of cognitive neuroscience of language. Our main goal here is to review all currently available results of overt speech production involving EEG measurements, such as picture naming, Stroop naming, and reading aloud. We conclude that overt speech production can be successfully studied using electrophysiological measures, for instance, event-related brain potentials (ERPs). We will discuss possible relevant components in the ERP waveform of speech production and aim to address the issue of how to interpret the results of ERP research using overt speech, and whether the ERP components in language production are comparable to results from other fields.

The Error-Related Negativity (ERN) is a component of the event-related brain potential (ERP) that is associated with action monitoring and error detection. The present study addressed the question whether or not an ERN occurs after verbal error detection, e.g., during phoneme monitoring. We obtained an ERN following verbal errors which showed a typical decrease in amplitude under severe time pressure. This result demonstrates that the functioning of the verbal self-monitoring system is comparable to other performance monitoring, such as action monitoring. Furthermore, we found that participants made more errors in phoneme monitoring under time pressure than in a control condition. This may suggest that time pressure decreases the amount of resources available to a capacity-limited self-monitor thereby leading to more errors. IntroductionError monitoring is an important executive function, which helps to adapt, anticipate, learn, correct, and mend the consequences of actions. The neural basis of error monitoring has become a key issue in cognitive neuroscience due to its importance to the aforementioned cognitive skills. A better understanding of its working may offer new insights into the dysfunctions of self-monitoring seen in a range of clinical conditions such as schizophrenia , opiate addicts (Forman et al., 2004), and obsessive-compulsive disorder (Gehring et al., 2000). Progress in identifying the functional characteristics of the error monitoring system has been mainly achieved through the study of an electrophysiological index thought to be associated with error processing, i.e., Error-Related Negativity (ERN; Falkenstein et al., 1991;Gehring et al., 1993). The ERN is a component of the event-related potential (ERP) that has a fronto-central scalp distribution and peaks about 80 ms after an overt incorrect response (Bernstein et al., 1995;Holroyd and Yeung, 2003;Scheffers et al., 1996). The early onset latency of the ERN with respect to the incorrect response is suggestive of an error monitoring system. The generation of the ERN has been localized in the anterior cingulate cortex (ACC; Dehaene et al., 1994;Holroyd and Coles, 2002). Several hypotheses of performance monitoring have been proposed to account for the ERN, for instance, the mismatch hypothesis put forward by Falkenstein et al. (1991), the response conflict hypothesis proposed by Carter et al. (1998), and the reinforcement learning theory by Holroyd and Coles (2002).The mismatch hypothesis considers the ERN as the result of a mismatch between the intended and the actual response execution (Bernstein et al., 1995). This hypothesis assumes a comparison between the internal representation of the intended correct response, arising from ongoing stimulus processing, and the internal representation of the actual

Abstract& Speakers continuously monitor what they say. Sometimes, self-monitoring malfunctions and errors pass undetected and uncorrected. In the field of action monitoring, an event-related brain potential, the error-related negativity (ERN), is associated with error processing. The present study relates the ERN to verbal self-monitoring and investigates how the ERN is affected by auditory distractors during verbal monitoring. We found that the ERN was largest following errors that occurred after semantically related distractors had been presented, as compared to semantically unrelated ones. This result demonstrates that the ERN is sensitive not only to response conflict resulting from the incompatibility of motor responses but also to more abstract lexical retrieval conflict resulting from activation of multiple lexical entries. This, in turn, suggests that the functioning of the verbal self-monitoring system during speaking is comparable to other performance monitoring, such as action monitoring. &