Auditory Functional Mapping. Validation by simultaneous depth and MEG recordings
Résumé
Epilepsy surgery requires the functional mapping of brain functions that might be affected. Recordings of evoked potentials during pre-surgical exploration by intracerebral electrodes give a very accurate information. These activities can also be obtained from non-invasive measurements (EEG or MEG). However, reconstructing the activity of a given cortical region requires the use of methods and models that are still discussed. In this study, we recorded simultaneously from intracerebral electrodes and MEG sensors the activities evoked at the level of the auditory cortex in response to verbal sounds /ba/ and /pa/, electrophysiological index of hemispherical lateralisation (Liegeois-Chauvel et al. 1999 [1] , Trebuchon et al. 2005 [2]). We used a spatial filtering technique to obtain, from the MEG measurements, the temporal time course of the evoked activities at the level of virtual electrodes defined at the location of the contacts of the intracerebral electrodes-thus allowing the comparison between these reconstructed responses and those coming from the intracerebral measurements. Reconstruction for MEG at virtual electrode H'3 similar to the SVD-sphere estimation Note the supplementary responses corresponding to the voice onset time on the left side.
Domaines
Neurosciences
Origine : Fichiers produits par l'(les) auteur(s)
Licence : CC BY - Paternité
Licence : CC BY - Paternité