Electrostimulation mapping of comprehension of auditory and visual words.
In order to spare functional areas during the removal of brain tumours, electrical stimulation mapping was used in 90 patients (77 in the left hemisphere and 13 in the right; 2754 cortical sites tested). Language functions were studied with a special focus on comprehension of auditory and visual words and the semantic system. In addition to naming, patients were asked to perform pointing tasks from auditory and visual stimuli (using sets of 4 different images controlled for familiarity), and also auditory object (sound recognition) and Token test tasks. Ninety-two auditory comprehension interference sites were observed. We found that the process of auditory comprehension involved a few, fine-grained, sub-centimetre cortical territories. Early stages of speech comprehension seem to relate to two posterior regions in the left superior temporal gyrus. Downstream lexical-semantic speech processing and sound analysis involved 2 pathways, along the anterior part of the left superior temporal gyrus, and posteriorly around the supramarginal and middle temporal gyri. Electrostimulation experimentally dissociated perceptual consciousness attached to speech comprehension. The initial word discrimination process can be considered as an "automatic" stage, the attention feedback not being impaired by stimulation as would be the case at the lexical-semantic stage. Multimodal organization of the superior temporal gyrus was also detected since some neurones could be involved in comprehension of visual material and naming. These findings demonstrate a fine graded, sub-centimetre, cortical representation of speech comprehension processing mainly in the left superior temporal gyrus and are in line with those described in dual stream models of language comprehension processing.
Pôle NeuroSciences (Neurochirurgie), Toulouse, France; CNRS - centre de Recherche Cerveau et Cognition, Toulouse, France; INSERM 825, Université de Toulouse UPS, Centres Hospitalo-Universitaires, Toulouse, France. Electronic address: franck_emmanuel.roux@yahoo.fr.
Franck-Emmanuel
FE
Roux
Department of Neurosurgery, University Hospital "St. Ivan Rilski", Sofia, Bulgaria.
Krasimir
K
Miskin
CNRS - centre de Recherche Cerveau et Cognition, Toulouse, France.
Jean-Baptiste
JB
Durand
Pôle NeuroSciences (Neurochirurgie), Toulouse, France.
Oumar
O
Sacko
Pôle NeuroSciences (Neurochirurgie), Toulouse, France.
Emilie
E
Réhault
Department of Neurosurgery, University Hospital "St. Ivan Rilski", Sofia, Bulgaria.
Rositsa
R
Tanova
Leenaards Memory Center, Department of Clinical Neurosciences CHUV & University of Lausanne, Switzerland.
Jean-François
JF
Démonet
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000368:Aged; D001288:Attention / Q000502:physiology; D001303:Auditory Cortex / Q000502:physiology; D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D002648:Child; D032882:Comprehension / Q000502:physiology*; D004192:Discrimination, Psychological / Q000502:physiology; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D019635:Neurosurgical Procedures; D010775:Photic Stimulation; D011932:Reading; D021641:Recognition, Psychology / Q000502:physiology; D013702:Temporal Lobe / Q000502:physiology; D055815:Young Adult
Auditory cortex; Brain tumour; Cortical mapping; Speech comprehension