Multimodal assessment of alexia in bilinguals with aphasia
OA Version
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Abstract
Spanish–English bilinguals with aphasia (BWA) frequently present with alexia, an acquired reading disorder that reflects disruption to shared linguistic systems shaped by bilingual experience. This dissertation integrates clinical assessment and eye-tracking measures to characterize reading impairment in BWA and to examine how lexical and contextual information are recruited during online sentence comprehension following stroke. Aim 1 examined oral reading and reading comprehension in Spanish and English to characterize the presence and severity of reading impairment in aphasia and to diagnose acquired dyslexia subtypes in 11 BWA and 20 English-speaking monolingual adults with aphasia (MWA). Across groups, reading impairment was robust for the aphasia groups relative to controls and patterned similarly in bilingual and monolingual individuals. Analyses further evaluated the relationship between spoken and written language processing, revealing phonological ability as the strongest predictor of oral reading accuracy and semantic ability as a more selective predictor of reading comprehension. In BWA, additional analyses of cross-language similarity effects indicated preserved non-selective activation during reading, consistent with disruption to shared semantic–phonological systems rather than language-specific reading mechanisms. Aim 2 used eye tracking to examine real-time sentence reading under varying levels of semantic constraint across four groups: 16 MWA, 20 English-speaking monolingual neurological controls (MNC), 8 BWA, and 10 bilingual neurological controls (BNC). Eye-movement measures revealed aphasia-related disruptions that were expressed during early-stage and late-stage processing in the MWA but only reliably during later stages of processing for the BWA. In bilingual aphasia, lexical phenomena such as cognate facilitation and homograph interference were observed but strongly context dependent and emerged primarily as delayed or distributed costs during sentence-level integration. Together, these findings demonstrate that alexia in bilingual aphasia reflects disruption to shared linguistic systems that parallels monolingual aphasia, while remaining shaped by bilingual experience and task demands. The results underscore the value of multimodal assessment for informing theory and clinical evaluation.
Description
2026