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

Conflict-based regulation of control in language production

Is language production dynamically regulated by cognitive control? If so, how domain-general is this process? In two experiments, we studied conflict adaptation, or conflict-driven adjustments of control, in two paradigms: Picture-Word Interference (PWI), which induces linguistic conflict, and Prime-Probe (PP), which induces visuospatial conflict. Exp. 1 tested within-task conflict adaptation separately in PWI and PP. Exp. 2 tested cross-task adaptation by alternating the two tasks in a task-switching paradigm. We found reliable within- task conflict adaptation in both PWI and PP, but neither an analysis of individual differences (Exp. 1), nor a direct manipulation of between-task conflict (Exp. 2) revealed cross- task adaptation. We further report a robust 2-back within-task adaptation in Exp. 2 to refute alternative accounts of null cross- task adaptation. These findings support models of dynamic, top-down control in language production that posit at least some degree of domain-specificity

The Use of Electroencephalography in Language Production Research: A Review

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-to-noise 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

STOP TALKING! Inhibition of speech is affected by word frequency and dysfunctional impulsivity

Speaking is a complex natural behavior that most people master very well. Nevertheless, systematic investigation of the factors that affect adaptive control over speech production is relatively scarce. The present experiments quantified and compared inhibitory control over manual and verbal responses using the stop-signal paradigm. In tasks with only two response alternatives, verbal expressions were slower than manual responses, but the stopping latencies of hand and verbal actions were comparable. When engaged in a standard picture-naming task using a large set of pictures, verbal stopping latencies were considerably prolonged. Interestingly, stopping was slower for naming words that are less frequently used compared to words that are used more frequently. These results indicate that adaptive action control over speech production is affected by lexical processing. This notion is compatible with current theories on speech self-monitoring. Finally, stopping latencies varied with individual differences in impulsivity, indicating that specifically dysfunctional impulsivity, and not functional impulsivity, is associated with slower verbal stopping

Independent distractor frequency and age-of-acquisition effects in picture-word interference: fMRI evidence for post-lexical and lexical accounts according to distractor type

In two fMRI experiments, participants named pictures with superimposed distractors that were high or low in frequency or varied in terms of age of acquisition. Pictures superimposed with low-frequency words were named more slowly than those superimposed with high-frequency words, and late-acquired words interfered with picture naming to a greater extent than early-acquired words. The distractor frequency effect (Experiment 1) was associated with increased activity in left premotor and posterior superior temporal cortices, consistent with the operation of an articulatory response buffer and verbal self-monitoring system. Conversely, the distractor age-of-acquisition effect (Experiment 2) was associated with increased activity in the left middle and posterior middle temporal cortex, consistent with the operation of lexical level processes such as lemma and phonological word form retrieval. The spatially dissociated patterns of activity across the two experiments indicate that distractor effects in picture–word interference may occur at lexical or postlexical levels of processing in speech production

Intra-Cranial Recordings of Brain Activity During Language Production

Recent findings in the neurophysiology of language production have provided a detailed description of the brain network underlying this behavior, as well as some indications about the timing of operations. Despite their invaluable utility, these data generally suffer from limitations either in terms of temporal resolution, or in terms of spatial localization. In addition, studying the neural basis of speech is complicated by the presence of articulation artifacts such as electro-myographic activity that interferes with the neural signal. These difficulties are virtually absent in a powerful albeit much less frequent methodology, namely the recording of intra-cranial brain activity (intra-cranial electroencephalography). Such recordings are only possible under very specific clinical circumstances requiring functional mapping before brain surgery, most notably in patients that suffer from pharmaco-resistant epilepsy. Here we review the research conducted with this methodology in the field of language production, with explicit consideration of its advantages and drawbacks. The available evidence is shown to be diverse, both in terms of the tasks and the cognitive processes tested and in terms of the brain localizations being studied. Still, the review provides valuable information for characterizing the dynamics of the neural events occurring in the language production network. Following modality specific activities (in auditory or visual cortices), there is a convergence of activity in superior temporal sulcus, which is a plausible neural correlate of phonological encoding processes. Later, between 500 and 800 ms, inferior frontal gyrus (around Broca’s area) is involved. Peri-rolandic areas are recruited in the two modalities relatively early (200–500 ms window), suggesting a very early involvement of (pre-) motor processes. We discuss how some of these findings may be at odds with conclusions drawn from available meta-analysis of language production studies

Response-Locked Brain Dynamics of Word Production

International audienceThe cortical regions involved in the different stages of speech production are relatively well-established, but their spatio-temporal dynamics remain poorly understood. In particular, the available studies have characterized neural events with respect to the onset of the stimulus triggering a verbal response. The core aspect of language production, however, is not perception but action. In this context, the most relevant question may not be how long after a stimulus brain events happen, but rather how long before the production act do they occur. We investigated speech production-related brain activity time-locked to vocal onset, in addition to the common stimulus-locked approach. We report the detailed temporal interplay between medial and left frontal activities occurring shortly before vocal onset. We interpret those as reflections of, respectively, word selection and word production processes. This medial-lateral organization is in line with that described in non-linguistic action control, suggesting that similar processes are at play in word production and non-linguistic action production. This novel view of the brain dynamics underlying word production provides a useful background for future investigations of the spatio-temporal brain dynamics that lead to the production of verbal responses. Citation: Riès S, Janssen N, Burle B, Alario F-X (2013) Response-Locked Brain Dynamics of Word Production. PLoS ONE 8(3): e58197

Different electrophysiological signatures of similarity-induced and Stroop-like interference in language production

Published: August 01 2023Contextual similarity between targets and competitors, whether semantic or phonological, often leads to behavioral interference in language production. It has been assumed that resolving such interference relies on control processes similar to those involved in tasks such as Stroop. This article tests this assumption by comparing the electrophysiological signatures of interference resulting from a contextual similarity versus a Stroop-like manipulation. In blocks containing two items, participants repeatedly named pictures that were semantically related, phonologically related, or unrelated (contextual similarity manipulation). In straight blocks, the pictures were named by their canonical names. In reverse blocks, participants had to reverse the names (Stroop-like manipulation). Both manipulations led to behavioral interference, but with different electrophysiological profiles. Whole-scalp stimulus-locked and response-locked analyses of semantic and phonological similarity pointed to a system with global modularity with some degree of cascading and interactivity, whereas the effect of phase reversal was sustained and of the opposite polarity. More strikingly, a representational similarity analysis showed a biphasic pattern for Stroop-like reversal, with earlier higher similarity scores for the reverse phase flipping into lower scores ~500 msec poststimulus onset. In contrast, contextual similarity induced higher similarity scores up to articulation. Finally, response-locked mediofrontal components indexing performance monitoring differed between manipulations. Correct response negativity's amplitude was lower in the phonological blocks, whereas a pre-correct response negativity component had higher amplitude in reverse versus straight blocks. These results argue against the involvement of Stroop-like control mechanisms in resolving interference from contextual similarity in language production.This work was supported in part by the Therapeutic Cognitive Neuroscience Fund at Johns Hopkins Universit

Electrophysiological correlates of error monitoring and feedback processing in second language learning

Humans monitor their behavior to optimize performance, which presumably relies on stable representations of correct responses. During second language (L2) learning, however, stable representations have yet to be formed while knowledge of the first language (L1) can interfere with learning, which in some cases results in persistent errors. In order to examine how correct L2 representations are stabilized, this study examined performance monitoring in the learning process of second language learners for a feature that conflicts with their first language. Using EEG, we investigated if L2 learners in a feedback-guided word gender assignment task showed signs of error detection in the form of an error-related negativity (ERN) before and after receiving feedback, and how feedback is processed. The results indicated that initially, response-locked negativities for correct (CRN) and incorrect (ERN) responses were of similar size, showing a lack of internal error detection when L2 representations are unstable. As behavioral performance improved following feedback, the ERN became larger than the CRN, pointing to the first signs of successful error detection. Additionally, we observed a second negativity following the ERN/CRN components, the amplitude of which followed a similar pattern as the previous negativities. Feedback-locked data indicated robust FRN and P300 effects in response to negative feedback across different rounds, demonstrating that feedback remained important in order to update memory representations during learning. We thus show that initially, L2 representations may often not be stable enough to warrant successful error monitoring, but can be stabilized through repeated feedback, which means that the brain is able to overcome L1 interference, and can learn to detect errors internally after a short training session. The results contribute a different perspective to the discussion on changes in ERN and FRN components in relation to learning, by extending the investigation of these effects to the language learning domain. Furthermore, these findings provide a further characterization of the online learning process of L2 learners