The constant internal monitoring of speech is a crucial feature to ensure the fairly error-free process of speech production. It has been argued that internal speech monitoring takes place through detection of conflict between different response options or "speech plans." Speech errors are thought to occur because two (or more) competing speech plans become activated, and the speaker is unable to inhibit the erroneous plan(s) prior to vocalization. A prime example for a speech plan that has to be suppressed is the involuntary utterance of a taboo word. The present study seeks to examine the suppression of involuntary taboo word utterances. We used the "Spoonerisms of Laboratory Induced Predisposition" (SLIP) paradigm to elicit two competing speech plans, one being correct and one embodying either a taboo word or a non-taboo word spoonerism. Behavioral data showed that inadequate speech plans generally were effectively suppressed, although more effectively in the taboo word spoonerism condition. Event-related potential (ERP) analysis revealed a broad medial frontal negativity (MFN) after the target word pair presentation, interpreted as reflecting conflict detection and resolution to suppress the inadequate speech plan. The MFN was found to be more pronounced in the taboo word spoonerism compared to the neutral word spoonerism condition, indicative of a higher level of conflict when subjects suppressed the involuntary utterance of taboo words.

Persons with Tourette syndrome show altered social behaviors, such as echophenomena and increased personal distress in emotional situations. These symptoms may reflect an overactive mirror neuron system, causing both increased automatic imitation and a stronger tendency to share others’ emotions. To test this, we measured the individual level of echophenomena with a video protocol and experimentally induced empathy for pain in 21 participants with Tourette syndrome and 25 matched controls. In the empathy for pain paradigm, pictures of hands and feet in painful or neutral situations were presented, while we measured participants’ EEG and skin conductance response. Changes in somatosensory mu suppression during the observation of the pictures and pain ratings were compared between groups and correlations were calculated with the occurrence of echophenomena, self-reported empathy and clinical measures. Our Tourette syndrome sample showed significantly more echophenomena than controls, but the groups showed no behavioral differences in empathic abilities. However, controls, but not patients with Tourette syndrome, showed the predicted increased mu suppression when watching painful compared to neutral actions. While echophenomena were present in all persons with Tourette syndrome, the hypothesis of an overactive mirror neuron system in Tourette syndrome could not be substantiated. On the contrary, the Tourette syndrome group showed a noticeable lack of mu attenuation in response to pain stimuli. In conclusion, we found a first hint of altered processing of others’ emotional states in a brain region associated with the mirror neuron system.

Persons with Tourette syndrome (TS) show altered social behaviors, such as echophenomena and increased personal distress in emotional situations. These symptoms may reflect an overactive mirror neuron system (MNS), causing both increased automatic imitation and a stronger tendency to share others' emotions. To test this, we measured the individual level of echophenomena with a video protocol and experimentally induced empathy for pain in 25 participants with TS and 25 matched controls. In the empathy for pain paradigm, pictures of hands and feet in painful or neutral situations were presented, while we measured participants' EEG and skin conductance response (SCR). Changes in somatosensory mu suppression during the observation of the pictures, as well as pain ratings and SCR were compared between groups and correlated with the occurrence of echophenomena, self-reported empathy and clinical measures. Our TS sample showed significantly more echophenomena than controls, but the groups showed no behavioral differences in empathic abilities. However, controls, but not patients with TS, showed the predicted increased mu suppression when watching painful compared to neutral actions. While echophenomena were present in all persons with TS, the hypothesis of an overactive MNS in TS could not be substantiated. On the contrary, the TS group showed a noticeable lack of mu attenuation in response to pain stimuli, questioning the normal functioning of the MNS in empathy for pain situations. In conclusion, the MNS remains an important area of study for TS, but overactivity of the system could not explain echophenomena and social symptoms of TS.