Poster E71, Monday, March 27, 2:30 – 4:30 pm, Pacific Concourse
Electrocorticographic changes at different cortical regions in sentence production
Johnathan Wu1,2, Toshimune Kambara1,3, Yasuo Nakai1, Eishi Asano1; 1Children's Hospital of Michigan, 2Wayne State University School of Medicine, 3Postdoctoral Fellowship for Research Abroad, Japan Society for the Promotion of Science
Numerous studies using picture stimuli have demonstrated that visual perception and overt responses are associated with an activation of visual and motor pathways, whereas noun and verb production is associated with left frontal activation. However, few studies have characterized the cortical dynamics of the brain before and during sentence production using methods that have both high temporal and high spatial resolution. The aim of this study is to use electrocorticography (ECoG) to examine changes in left cerebral cortical activity in sentence production. Patients were asked to describe pictures using sentences containing a noun phrase, a verb phrase, a time phrase, and a place phrase. The ECoG and sentence audio recordings were then analyzed with respect to the onset of the visual stimuli, the onset of the vocal response, and the onset of each of the four sentence elements. The results showed that immediately after the visual stimulus onset, the fusiform and inferior temporal gyri exhibited high-gamma augmentation, whereas the lingual and orbitofrontal gyri exhibited high-gamma attenuation. Immediately after the response onset, the precentral gyrus exhibited high-gamma augmentation. Prior to both time and place phrases, the pars opercularis and rostral middle frontal gyri exhibited high-gamma augmentation, whereas prior to verb phrases, the supramarginal gyrus exhibited high-gamma augmentation. These results suggest that our sentence production task activated the cortical network generally involved in noun and verb production tasks and also generate the hypothesis that specific cortical regions are differentially involved in the production of unique elements in sentences.
Topic Area: LANGUAGE: Syntax