34 Cognitive models of reading are also models of the brain: Identifying the neural correlates of a computational model of reading

Objectives/Goals: Many left hemisphere stroke survivors have a reading disorder (alexia), which is experienced as decreasing well-being. Therapies produce inconsistent results, demonstrating a need for treatment response predictors. We identify neural correlates of a computational model of reading, which may provide biomarkers to improve therapeutic outcomes. Methods/Study Population: Left hemisphere stroke survivors (LHSS) (n = 52) performed an oral reading task and tests of semantic and phonological processing. Artificial neural network (ANN) models, mapping between orthography (visual word form), phonology (auditory word form), and semantics (word meaning), were trained to read single words at an adult reading level. Stroke was simulated by removing percentages (in 10% intervals) of the connections into and out of semantics, phonology, and the combination thereof. The lesioned model producing the smallest average Euclidean distance over word and pseudoword reading accuracy to each LHSS was selected as the matched model. Two voxelwise lesion-symptom mapping (VLSM) analyses identified the neural correlates of the percent of phonological and semantic links removed in the matched models. Results/Anticipated Results: Model reading was correlated with LHSS reading (high-frequency regular words, r(48) = 0.96; high-frequency irregular words, r(48) = 0.94; low-frequency regular words, r(48) = 0.97); low-frequency irregular words, r(48) = 0.85; all p’s Discussion/Significance of Impact: Our results show that ANN models of reading, when closely matched to LHSS reading performance, directly connect cognitive processes to the brain. Using matched models as a precision medicine framework to predict therapy response or to identify targets for neurostimulation provides a valuable route toward improving poststroke language outcomes.