Electric source imaging of human brain functions

Michel, Christoph M.; Thut, Gregor; Morand, S.; Khateb, Asaïd; Pegna, Alan J.; Peralta, Rolando Grave de; Gonzalez, Sara; Seeck, Margitta; Landis, Théodor

doi:10.1016/s0165-0173(01)00086-8

Cited by 221 publications

(163 citation statements)

References 57 publications

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“…We used LORETA to estimate the intracerebral sources of EEG activity. While different analysing models have advantages and disadvantages (Michel et al 2001), several recent studies have successfully employed LORETA as a reliable tool for localising cortical activation in various tasks ranging from visual and auditory to complex cognitive tasks (Pizzagalli et al 2000;Vitacco et al 2002;Esslen et al 2004;Mulert et al 2004a). Interestingly, the combined use of LORETA and fMRI revealed similar cortical maps to those obtained with fMRI and LORETA separately (Vitacco et al 2002;Mulert et al 2002).…”

Section: Discussionmentioning

confidence: 99%

Neuronal Modifications During Visuomotor Association Learning Assessed by Electric Brain Tomography

et al. 2006

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Summary: In everyday life specific situations need specific reactions. Through repetitive practice, such stimulus-response associations can be learned and performed automatically. The aim of the present EEG study was the illustration of learning dependent modifications in neuronal pathways during short-term practice of visuomotor associations. Participants performed a visuomotor association task including four visual stimuli, which should be associated with four keys, learned by trial and error. We assumed that distinct cognitive processes might be dominant during early learning e.g., visual perception and decision making. Advanced learning, however, might be indicated by increased neuronal activation in integration-and memory-related regions. For assessment of learning progress, visual-and movement-related brain potentials were measured and compared between three learning stages (early, intermediate, and late). The results have revealed significant differences between the learning stages during distinct time intervals. Related to visual stimulus presentation, Low Resolution Electromagnetic Brain Tomography (LORETA) revealed strong neuronal activation in a parieto-prefrontal network in time intervals between 100-400 ms post event and during early learning. In relation to the motor response neuronal activation was significantly increased during intermediate compared to early learning. Prior to the motor response (120-360 ms pre event), neuronal activation was detected in the cingulate motor area and the right dorsal premotor cortex. Subsequent to the motor response (68-430 ms post event) there was an increase in neuronal activation in visuomotor-and memory-related areas including parietal cortex, SMA, premotor, dorsolateral prefrontal, and parahippocampal cortex. The present study has shown specific time elements of a visuomotor-memory-related network, which might support learning progress during visuomotor association learning.

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Section: Discussionmentioning

confidence: 99%

Neuronal Modifications During Visuomotor Association Learning Assessed by Electric Brain Tomography

et al. 2006

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“…In extension, it provides insights into how groups or conditions differ in terms of likely underlying neurophysiologic mechanisms (Murray et al, 2008;Michel & Murray, 2012), in addition to the temporal information about ERP differences. This method is independent of the reference electrode (Michel et al, 2001(Michel et al, , 2004) and insensitive to pure amplitude modulations across conditions (since topographies of normalized maps are compared). The spatio-temporal segmentation was applied to the group-averaged data (from picture onset to 100ms before articulation) of the four sub-groups: "matched" controls, "other" controls, "phonological-dominant" patient and "phonetic-dominant" patient sub-groups.…”

Section: This Analysis Entails a Spatio-temporal Segmentation Of The mentioning

confidence: 99%

Dynamics of phonological–phonetic encoding in word production: Evidence from diverging ERPs between stroke patients and controls

2013

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While the dynamics of lexical-semantic and lexical-phonological encoding in word production have been investigated in several event-related potential (ERP) studies, the estimated time course of phonological-phonetic encoding is the result of rather indirect evidence. We investigated the dynamics of phonological-phonetic encoding combining ERP analyses covering the entire encoding process in picture naming and word reading tasks by comparing ERP modulations in eight brain-damaged speakers presenting impaired phonological-phonetic encoding relative to 16 healthy controls. ERPs diverged between groups in terms of local waveform amplitude and global topography at ~400ms after stimulus onset in the picture naming task and at ~320-350ms in word reading and sustained until 100ms before articulation onset. These divergences appeared in later time windows than those found in patients with underlying lexical-semantic and lexical-phonological impairment in previous studies, providing evidence that phonological-phonetic encoding is engaged around 400ms in picture naming and around 330ms in word reading.Time-course of phonetic encoding 3

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“…This method is independent of the reference electrode (Michel et al, 2001(Michel et al, , 2004) and insensitive to pure amplitude modulations across conditions (topographies of normalized maps are compared). A modified hierarchical clustering analysis (Michel et al, 2001;Pascual-Marqui, Michel, & Lehmann, 1995), the agglomerative hierarchical clustering (Murray, Brunet, & Michel, 2008) was used to determine the most dominant configurations of the electric field at the scalp (topographic maps). A modified cross-validation criterion was used to determine the optimal number of maps that explained the best the group-averaged data sets across conditions.…”

Section: Topographic Pattern Analysismentioning

confidence: 99%

Comparing Electrophysiological Correlates of Word Production in Immediate and Delayed Naming Through the Analysis of Word Age of Acquisition Effects

Laganaro

Perret

2010

Brain Topogr

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Most EEG studies analysing speech production with event related brain potential (ERP) have adopted silent metalinguistic tasks or delayed or tacit picture naming in order to avoid possible artefacts during motor preparation. A central issue in the interpretation of these results is whether the processes involved in those tasks are comparable to those involved in overt speech production. In the present study we addressed a methodological issue about the integration of stimulus-aligned and response-aligned ERPs in immediate overt picture naming in comparison to delayed production, coupled with a theoretical point on the effect of word Age of Acquisition (AoA). High density EEG recordings were used and waveform analyses and spatio-temporal segmentation were combined on stimulus-aligned and response-aligned ERPs. The same sequence and duration of topographic maps appeared in the immediate and delayed production until around 350 ms after picture onset, revealing similar encoding processes until the beginning of phonological encoding, but modulations linked to word AoA were only observed in the immediate production. Considering stimulus-aligned and responsealigned ERPs together allowed to identify that a stable topography starting around 350 ms lasts 30 ms longer for late-acquired than for early-acquired words. This difference falls within the time-window of phonological encoding and its modulation can be linked to the longer production latencies for late-acquired words.3

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Electric source imaging of human brain functions

Cited by 221 publications

References 57 publications

Neuronal Modifications During Visuomotor Association Learning Assessed by Electric Brain Tomography

Neuronal Modifications During Visuomotor Association Learning Assessed by Electric Brain Tomography

Dynamics of phonological–phonetic encoding in word production: Evidence from diverging ERPs between stroke patients and controls

Comparing Electrophysiological Correlates of Word Production in Immediate and Delayed Naming Through the Analysis of Word Age of Acquisition Effects

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