General-Purpose Monitoring during Speech Production

WOS:000289063000012International audienceThe concept of "monitoring" refers to our ability to control our actions on-line. Monitoring involved in speech production is often described in psycholinguistic models as an inherent part of the language system. We probed the specificity of speech monitoring in two psycholinguistic experiments where electro-encephalographic activities were recorded. Our focus was on a component previously reported in nonlinguistic manual tasks and interpreted as a marker of monitoring processes. The error negativity (Ne, or error-related negativity), thought to originate in medial frontal areas, peaks shortly after erroneous responses. A component of seemingly comparable properties has been reported, after errors, in tasks requiring access to linguistic knowledge (e.g., speech production), compatible with a generic error-detection process. However, in contrast to its original name, advanced processing methods later revealed that this component is also present after correct responses in visuomotor tasks. Here, we reported the observation of the same negativity after correct responses across output modalities (manual and vocal responses). This indicates that, in language production too, the Ne reflects on-line response monitoring rather than error detection specifically. Furthermore, the temporal properties of the Ne suggest that this monitoring mechanism is engaged before any auditory feedback. The convergence of our findings with those obtained with nonlinguistic tasks suggests that at least part of the monitoring involved in speech production is subtended by a general-purpose mechanism

Preventing (impulsive) errors: Electrophysiological evidence for online inhibitory control over incorrect responses

International audienceIn a rich environment, with multiple action affordances, selective action inhibition is critical in preventing the execution of inappropriate responses. Here, we studied the origin and the dynamics of incorrect response inhibition and how it can be modulated by task demands. We used EEG in a conflict task where the probability of compatible and incompatible trials was varied. This allowed us to modulate the strength of the prepotent response, and hence to increase the risk of errors, while keeping the probability of the two responses equal. The correct response activation and execution was not affected by compatibility or by probability. In contrast, incorrect response inhibition in the primary motor cortex ipsilateral to the correct response was more pronounced on incompatible trials, especially in the condition where most of the trials were compatible, indicating a modulation of inhibitory strength within the course of the action. Two prefrontal activities, one medial and one lateral, were also observed before the response, and their potential links with the observed inhibitory pattern observed are discussed

Mechanisms and dynamics of cortical motor inhibition in the stop-signal paradigm: a TMS study

Abstract ■ The ability to stop ongoing motor responses in a splitsecond is a vital element of human cognitive control and flexibility that relies in large part on prefrontal cortex. We used the stop-signal paradigm to elucidate the engagement of primary motor cortex (M1) in inhibiting an ongoing voluntary motor response. The stop-signal paradigm taps the ability to flexibly countermand ongoing voluntary behavior upon presentation of a stop signal. We applied single-pulse TMS to M1 at several intervals following the stop signal to track the time course of excitability of the motor system related to generating and stopping a manual response. Electromyography recorded from the flexor pollicis brevis allowed quantification of the excitability of the corticospinal tract and the involvement of intracortical GABA B ergic circuits within M1, indexed respectively by the amplitude of the motor-evoked potential and the duration of the late part of the cortical silent period (SP). The results extend our knowledge of the neural basis of inhibitory control in three ways. First, the results revealed a dynamic interplay between response activation and stopping processes at M1 level during stop-signal inhibition of an ongoing response. Second, increased excitability of inhibitory interneurons that drives SP prolongation was evident as early as 134 msec following the instruction to stop. Third, this pattern was followed by a stoprelated reduction of corticospinal excitability implemented around 180 after the stop signal. These findings point to the recruitment of GABA B ergic intracortical inhibitory circuits within M1 in stop-signal inhibition and support the notion of stopping as an active act of control.

An ERP study of cognitive architecture and the insertion of mental processes: Donders revisited

International audienceno abstrac

How does one night of sleep deprivation affect the internal clock?

International audienceno abstrac

Simon effect in the rat: A new model for studying the neural bases of the dual-route architecture

International audienceIn humans, the Simon effect refers to the fact that choice reaction time (RT) is shorter when the stimulus corresponds spatially to the response than when it does not, albeit the location of the stimulus is irrelevant to the task. This effect has motivated innumerable empirical and theoretical studies and is considered to reflect elementary cognitive processes. We report an experiment demonstrating that rats also display a Simon effect, the dynamics of which – as assessed by factorial manipulations and RT distribution analyses – partly corresponds to those of the effect studied in human participants. The present results are consistent with the ideas that in rats, like in humans, (i) the information conveyed by the stimulus is processed via two parallel routes, one controlled and relatively slow, and one fast and automatic (dual-route architecture) and (ii) the dual-route processing is finished before the start of motor processes. The correspondence between these findings and those reported in humans open new perspectives for neurophysiological investigations of the dual-route architecture in an animal model routinely studied in neuroscience research