Visual cortex plasticity in cochlear implant users revealed in a visual motion detection task

•Cochlear implant users showed deepened recruitment of visual cortex for motion processing.•Visual cortex plasticity may underly compensatory strategy in hearing aided patients.•We showcase an implant-compatible objective method with potential clinical application for tracking brain plasticity. The aim of this study was to investigate brain reorganization following cochlear implantation using electroencephalography, an implant-compatible technique to record electrical brain activity. We investigated cortical plasticity in cochlear implant (CI) users using visual evoked potentials in response to visual motion changes. We estimated visual and auditory neural sources in CI users (n = 20) and normal hearing (NH) matched control participants (n = 22). Results showed intra-modal plasticity in the visual cortex of CI users, revealed by higher P1 and visual mismatch negativity amplitude, and greater contribution of the visual cortex during visual motion changes compared to NH controls. Our results suggest more efficient processing of visual information in CI users that may reflect enhanced multimodal compensatory strategies during speech processing. This study showcases an objective, implant-compatible method that could be used in a clinical setting to measure and longitudinally track cortical plastic changes, enabling a better understanding of the link between individual patterns of cortical plasticity and CI outcomes.