Authors :
Presenting Author: Daniel Drane, PhD – Emory University School of Medicine
Adam Dickey, MD – Emory University School of Medicine; Emma Acerbo, PhD – Emory University School of Medicine; Nigel Pedersen, MD – UC Davis; Abed Alwaki, MD – Emory University School of Medicine; noah okada, BS – Emory University School of Medicine; Donald Bearden, PhD – Children's Hospital of Atlanta; Kimie Ono, PhD – Children's Hospital of Atlanta; Evan Brady, BS – Emory University School of Medicine; Leonardo Bonilha, MD – Emory University School of Medicine; Adam Williamson, PhD – Aix-Marseille Universite; Robert Gross, MD, PhD – Emory University School of Medicine; ammar Kheder, MD – Emory University School of Medicine
Rationale:
Recent studies suggest that auditory naming to description (AND) tasks are often dissociable from visual naming tasks in the setting of ESM, yet these findings could be seen as inconsistent with structure-function knowledge of brain processing. Semantic category disruption also appears to vary across brain regions and may be an equally critical variable interacting with modality of presentation. We examined both variables simultaneously, making sure that every visual item utilized for mapping had a corresponding AND version. We predicted that matched objects/faces would usually be impaired for both domains when naming zones in the temporal lobe (TL) were perturbed by ESM, unless we were stimulating more primary auditory processing areas (e.g., Heschl’s gyrus), as stimulation in such regions will disproportionately impair auditory comprehension. Methods:
We examined ESM data for six patients who underwent Phase II investigation at Emory University with stereoelectroencephalography (SEEG). These patients underwent ESM using a paradigm involving visual objects and famous faces, and for which an AND analog was available for each item. Each visual item was reviewed with the subject, and they were asked to generate their own verbal description for all items they could reliably name. During ESM mapping, all stimuli were counter-balanced in presentation, and whenever a deficit was made in one modality (visual vs. auditory), the same item was tested in the opposite modality over ensuing trials to explore consistency across modality. We statistically compared the proportion of errors for each region stimulated in each patient with errors classified by modality, and we compared the proportion of errors made for each modality at each site using a series of t-test comparisons.
Results:
Proportional error rates between modalities were highly similar across most TL regions assessed, with the exception of stimulation applied to Heschl’s gyrus, Wernicke’s area, and the superior temporal gyrus. At the latter locations, error rates were much greater for auditory naming to description than for visual naming (p values < .05 for these regions). No sites were found that produced visual errors but not auditory with our matched stimuli when stimulated.