B - 84 Changes in Right Pars Triangularis Network Role and Naming Errors in Post-Stroke Aphasia.

Abstract

The goal of the current study was to further clarify the role of right pars trianagularis (rPTr) in persons with aphasia (PWA) by investigating if the structural changes after stroke are associated with language deficits. We hypothesized that boundary controllability (bc), which measures the capacity of a region integrate/segregate brain regions, would be higher in rPTr for PWA than age-matched controls. We also sought to understand whether different types of naming errors corresponded to bc at rPTr. We hypothesized that bc would relate to phonological naming errors. We tested our hypothesis in 60 chronic post-stroke aphasia patients and 62 matched controls. All PWA completed the Western Aphasia Battery (WAB) and the Philadelphia Naming Test (PNT). With PNT data, we calculated the overall accuracy and proportion of error type (phonological, semantic, and mixed). Consistent with our first hypothesis, we found PWA had higher bc than age-matched controls at rPTr (t(120) = -2.52, p < 0.01). A regression model yielded a statistically significant negative relationship between bc and phonological errors that could not be accounted for by lesion volume (R2 = 0.11, F(1,48) = 6.21, p < 0.05). Our results demonstrate shift in the fundamental anatomical role of rPTr suggests the region becomes more critical for integrating and segregating communication across networks of the brain. Compared to findings in the left PTr in healthy subjects, our data suggest that homotopic recruitment may involve shifts in this anatomical property. and may relate to specific aspects of language processing.