PROJECT SUMMARY / ABSTRACT The goal of this work is to characterize changes in language system organization in the preserved hemisphere following the surgical removal of large areas of perisylvian cortex in the opposite hemisphere. Reorganization of the language system is of critical importance because functional reorganization of language abilities is limited after injury in adulthood. By examining the dynamics of plastic change in the preserved hemisphere after lobectomy in childhood, we hope to advance knowledge about the principles and constraints surrounding reorganization of the language system after injury in different stages of life. We propose a unique combination of empirical and theoretical approaches, pairing functional neuroimaging in individuals with left or right hemisphere lobectomy, and deep neural networks designed to simulate the impact of childhood seizures and cortical resection. We will characterize any accommodations in the functional mapping of language processing that may have developed in order for the sole preserved hemisphere to support an atypical burden of cognitive functions. Specifically, the functional mapping of the preserved set of perisylvian regions may reorganize to support both typically left-lateralized language functions (e.g., sentence processing) and typically right-lateralized functions (e.g., emotional prosody processing). Using a multivariate analysis approach we will identify brain areas that discriminate auditory sentence stimuli either based on the meaning of the sentence or the emotional prosody. We can apply the same approach to the learning weights of our deep neural networks trained on similar stimuli. The two aims of this proposal include a cross-sectional study of potential reorganization after cortical resection, and a longitudinal study of plasticity dynamics as this reorganization is underway. The combination of empirically measured data and theoretical modeling data will allow us to evaluate mechanisms of functional reorganization that are inaccessible with either method alone. This is a critical and unique strength of this proposal and completing this training will be an enormous benefit to Dr. Martin’s future career. Dr. Martin’s long- term career objective is to become an independent researcher in the field of developmental cognitive neuroscience. Her broad research focus is atypical organization of the language system and principles of plasticity that apply to functional reorganization in the presence of neural injury or disorder. The completion of these research aims and the training activities are tailored to fill important gaps in her knowledge and skillsets. The world-class expertise of co-sponsors Dr. Marlene Behrmann and Dr. David Plaut and the institutional resources available at the University of Pittsburgh guarantee the successful completion of these important studies and Dr. Martin’s training.