Localization of acquired deficits in oral word reading versus silent word reading in post-stroke alexia

Poster Session E - Monday, April 15, 2024, 2:30 – 4:30 pm EDT, Sheraton Hall ABC

Elizabeth H.T. Chang¹ (ec1312@georgetown.edu), Sara M. Dyslin¹, Andrew T. DeMarco¹, J. Vivian Dickens^1,2, Peter E. Turkeltaub^1,3; ¹Georgetown University Medical Center, ²University of Pennsylvania, ³MedStar National Rehabilitation Hospital

Patterns of acquired reading impairment (alexia) reflect deficits in orthographic, phonological, or semantic processing. Even though most reading in daily life is silent, prior research of post-stroke alexia primarily relies on oral word reading tasks. This study aims to dissociate the contributions of left-hemispheric brain regions to accurate oral reading versus silent visual word reading. We hypothesized that oral word reading would depend more on the dorsal phonological system, whereas silent word reading in a lexical decision task would rely more upon the ventral semantic system. Support Vector Regression Lesion-Symptom Mapping (SVR-LSM) was employed on a cohort of 68 left-hemisphere stroke survivors (age=61.5 (11.3); gender=39 M, 29 F; months since stroke: 49.4 (57.7)). Inaccurate word reading correlated with lesions in the left supramarginal gyrus and left superior temporal regions, after covarying for lexical decision performance, age, education, and lesion volume (voxelwise p<.005, cluster p<.05, 1000 permutations). Inaccurate lexical decision correlated with lesions in the left angular gyrus and left middle temporal regions after covarying for oral word reading, age, education, and lesion volume. Lesions in the left ventral occipitotemporal cortex correlated with inaccurate performance on both tasks. In line with our predictions, these findings suggest differential reliance on phonological versus semantic processing in oral versus silent reading. Specifically, inaccurate oral reading is more reflective of phonological deficits, whereas inaccurate silent word reading is more reflective of semantic deficits. Elucidating pathways for different types of reading may lead to individualized treatment tailored to specific reading deficits after stroke.

Topic Area: LANGUAGE: Other