Patrick Chauvel

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This paper focuses on high-frequency (gamma band) EEG activity, the most characteristic electrophysiological pattern in focal seizures of human epilepsy. It starts with recent hypotheses about: (i) the behaviour of inhibitory interneurons in hippocampal or neocortical networks in the generation of gamma frequency oscillations; (ii) the nonuniform alteration(More)
Recordings directly within the brain can establish local evoked potential generation without the ambiguities always associated with extracranial electromagnetic measures. Depth recordings have found that sensory stimuli activate primary cortex and then material-specific encoders. Sensory-specific areas remain active for long periods, but by about 200 ms are(More)
The goal of this study is to determine and localize the generators of different components of middle latency auditory evoked potentials (MLAEPs) through intracerebral recording in auditory cortex in man (Heschl's gyrus and planum temporale). The present results show that the generators of components at 30, 50, 60 and 75 msec latency are distributed(More)
Event-related potentials were recorded from 537 sites in the superior temporal plane and parietal lobe of 41 patients. Depth electrodes were implanted to localize seizure origin prior to surgical treatment. Subjects received an auditory discrimination task with target and non-target rare stimuli ("standard oddball paradigm"). In some cases, the target,(More)
Jackson (Brain 1898; 21: 580-90) observed that seizures arising in the medial temporal lobe may result in a 'dreamy state', consisting of vivid memory-like hallucinations, and/or the sense of having previously lived through exactly the same situation (déjà vu). Penfield demonstrated that the dreamy state can sometimes be evoked by electrical stimulation of(More)
In the field of epilepsy, the analysis of stereoelectroencephalographic (SEEG, intra-cerebral recording) signals with signal processing methods can help to better identify the epileptogenic zone, the area of the brain responsible for triggering seizures, and to better understand its organization. In order to evaluate these methods and to physiologically(More)
OBJECTIVE To compare the localizations of different neural sources (a) obtained from intracerebral evoked responses and (b) calculated from surface auditory evoked field responses recorded in the same subjects. Our aim was to evaluate the resolving power of a source localization method currently used in our laboratory, which is based on a recent(More)
The localization of the primary auditory cortex in man was studied by direct recordings in 150 different sites in the superior transverse gyrus, especially in Heschl's gyrus and the planum temporale. The distribution of the primary evoked responses (N13/P17/N26) was studied in 15 epileptic patients who were candidates for surgical treatment. Precise(More)
A better understanding of interstructure relationship sustaining drug-resistant epileptogenic networks is crucial for surgical perspective and to better understand the consequences of epileptic processes on cognitive functions. We used resting-state fMRI to study basal functional connectivity within temporal lobes in medial temporal lobe epilepsy (MTLE)(More)
PURPOSE To analyze and compare spectral properties and interdependencies of intracerebral EEG signals recorded during interictal periods from mesial temporal lobe structures in two groups of epileptic patients defined according to the involvement of these structures in the epileptogenic zone (EZ). METHODS Interictal EEG activity in mesial temporal lobe(More)