BCI With Virtual Reality for Stroke Rehabilitation: A Crossover Study

The goal of this clinical trial is to investigate if training sessions of motor imagery associated with brain-computer interface and motor observation through virtual reality (MI-VR-BCI) can help to improve arm and hand recovery after a stroke. The main questions to answer are: * Can adding MI-BCI-VR sessions improve upper limb movement? * Can it help stroke survivors perform daily activities more easily? * Does this type of training improve brain activity and connections related to movement? Researchers will compare this type of intervention with motor imagery associated with a standard brain-computer interface intervention (MI-BCI) to see if there are added effects to upper limb function, activity and brain connections. Participants will : * Perform two intervention periods in a random order: one with MI-VR-BCI training sessions and other with MI-BCI training sessions. Each period will involve 3 weekly sessions of training, during 6 weeks, with the intervention periods being separated by 3 weeks. * Complete four assessment sessions: one at the beginning and another at the end of each intervention period.

Inclusion Criteria: * Clinical diagnosis of stroke confirmed by neuroimaging, with resulting upper limb hemiparesis. * Time since stroke between 6 and 24 months at the time of selection. * Sufficient cognitive ability to understand and follow the intervention procedures. * Spasticity score \