Reading Comprehension in Post-Stroke Alexia – Lexical Features and Individual Differences

PROJECT SUMMARY Reading is a crucial skill for quality of life in modern society but is impaired in at least 1.5 million Americans following stroke.1,2 Acquired reading impairments (alexia) have life-altering impact, because they prevent return to work, access to healthcare information, and maintenance of social relationships.31–35 Prior research on reading aloud overwhelmingly dominates current understanding of the role of lexical features in alexia while overlooking silent reading comprehension, despite evidence that these two reading modalities can dissociate and may rely on different mechanisms.3-8 Silent reading comprehension is the dominant reading modality in daily life and is preferred over reading aloud by adult readers,35 highlighting its significance as a healthcare priority. The proposed project aims to examine mechanisms of silent reading comprehension impairment in people with alexia applying a seminal theoretical reading comprehension framework – the Lexical Quality Hypothesis (LQH). The LQH posits that differences in reading comprehension skill can be attributed to variations in the quality of individuals’ lexical representations (i.e., word knowledge). Lexical representations can be influenced by lexical features and individual differences in bottom-up linguistic resources(e.g., phonological decoding, vocabulary size). High-quality lexical representations result in higher reading accuracy and automatic lexical retrieval, thereby facilitating integration of the individual words into the surrounding text and liberating cognitive resources for high-level linguistic skills (e.g., syntactic parsing). 9-12 This proposal applies these principles of the LQH framework to alexia to shed light on the underlying nature of silent reading comprehension impairments. Specific Aim 1 evaluates the impact of lexical features related to orthography, semantics, and phonology on silent reading comprehension accuracy and eye-movement behaviors. Specific Aim 2 explores how bottom-up linguistic skills relate to silent reading comprehension of connected texts, and how these individual differences moderate the influence of lexical features on eye-movements. Data from an archival reading assessment study and an ongoing eye-tracking while reading study will be leveraged to address these aims. This study represents the first systematic investigation on the role of lexical features and individual differences on silent reading comprehension in alexia. Results from this study will provide insight into which lexical properties can serve as predictors for item-difficulty in reading assessments and establish preliminary evidence for how to individualize silent reading comprehension interventions. Through this fellowship, the applicant will acquire scientific training, technical expertise, and professional skills that will propel her toward a career as an independent clinician-scientist specialized in alexia assessment and intervention.