You are viewing the SNL 2017 Archive Website. For the latest information, see the Current Website.

 
Poster A72, Wednesday, November 8, 10:30 – 11:45 am, Harborview and Loch Raven Ballrooms

Convergence of spoken and written language processing in the superior temporal sulcus

Stephen M. Wilson1, Alexa Bautista2, Angelica McCarron2;1Vanderbilt University Medical Center, 2University of Arizona

The cortical pathways for the processing of spoken and written language have been shown to converge in the superior temporal sulcus (STS). However, the STS contains numerous subdivisions with distinct cytoarchitectonic properties and connectivity profiles, and has been implicated in a wide range of linguistic processes. The overall goal of this study was to better understand the functional and anatomical details of exactly how spoken and written language processing streams converge in the STS. This depends on clarifying the functional parcellation of the STS, which is challenging because of the seamlessly integrated linguistic processes that take place in this region, and because of the inherent physical proximity of the anatomically distinct dorsal and ventral banks. To address these challenges, we quantified neural responses to spoken and written language along with unintelligible stimuli in each modality, employed univariate as well as multivariate analyses, and maximized spatial resolution by using several strategies, including hypercapnic normalization, and masking of veins identified on susceptibility-weighted imaging. We found that the posterior dorsal bank of the STS responded to intelligible and unintelligible inputs in both modalities, yet was able to discriminate between modalities based on distributed multi-voxel patterns of activity. This suggests that the posterior dorsal bank is the first site at which spoken and written inputs converge. Its response profile is consistent with a role in encoding of phonological and orthographic word forms. The anterior dorsal bank of the STS also responded to intelligible and unintelligible inputs in both modalities, yet unlike the posterior dorsal bank, it was agnostic to input modality, suggesting that this region represents abstract lexical nodes. In the ventral bank of the STS and adjacent gyri, responses to unintelligible inputs in both modalities were attenuated, while intelligible inputs continued to drive activation, indicative of higher level semantic and syntactic processing. Taken together, our results suggest that the processing of spoken and written language converges on the posterior dorsal bank of the STS, which is the first of a heterogeneous set of language regions within the STS, with distinct functions spanning several levels of linguistic processes and representations.

Topic Area: Perception: Auditory

Back to Poster Schedule