The project seeks to comprehend the intersection between bilingualism and neurological/neurodegenerative disorders, like dementia and strokes, using computational simulations. Given the wide variation in how bilingual speakers process their languages, particularly in the face of neurological disorders, the project will employ the BiLex computational model. This model has already shown promise in simulating bilingual language processing impairments post-stroke and in dementia. The research aims to enhance BiLex to better capture semantic effects (BiLex 2.0), document changes over time in recovery and decline of semantic processing abilities (BiLex 3.0), and model bilingual language selection and control (BiLex 4.0). The ultimate goal is to utilize these advanced computational models to accurately represent and predict bilingual neurological patient behaviors, facilitating the design of personalized treatments for improved outcomes.