Cerebral Cortex Advance Access originally published online on October 5, 2007
Cerebral Cortex 2008 18(6):1253-1259; doi:10.1093/cercor/bhm169
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A Discrete Area within the Left Dorsolateral Prefrontal Cortex Involved in Visual–Verbal Incongruence Judgment
1 Laboratoire de Psychologie et de Neurosciences Cognitives, FRE 2987 (CNRS/Université de Paris V René Descartes), Institut de Psychologie, 71 avenue Edouard Vaillant, 92774 Boulogne Billancourt, France, 2 Département de Neurochirurgie, Centre Hospitalier Universitaire Gui de Chauliac, Montpellier, France
Address correspondence to email: monique.plaza{at}univ-paris5.fr.
The role of the frontal lobe in cross-modal visual–auditory processing has been documented in experiments using incongruent/congruent paradigms. In this study, 4 patients with left frontal World Health Organization Grade II glioma were assessed during pre-, intra-, and postoperative sessions with picture-naming and verbal–visual task requiring judgment of congruence between pictures and words. During awake brain surgery, the naming and cross-modal tasks were coupled with electrical stimulation inactivating restricted specific regions. For all patients, focal brain stimulation in the dorsolateral prefrontal cortex elicited picture–word matching disturbances but no naming impairment, and the elicited errors exclusively appeared in incongruent and not congruent conditions. The dissociation observed between correct picture naming and disturbed cross-modal judgment shows that electrical stimulation of a discrete cortical area within the left dorsolateral prefrontal cortex can inhibit the simultaneous processing of visual–verbal information without disturbing larger networks involved in the naming process.
Key Words: electrical brain stimulation judgment left dorsolateral prefrontal cortex phonology visual–verbal incongruence