BackgroundThere is numerous literature on mechanisms underlying variability of practice advantages. Literature includes both behavioral and neuroimaging studies. Unfortunately, no studies are focusing on practice in constant conditions to the best of our knowledge. Hence it is essential to assess possible differences in mechanisms of neuroplasticity between constant vs. variable practice conditions. The primary objectives of the study described in this protocol will be: to determine the brain’s structural and functional changes following constant and variable practice conditions in motor learning (...) ; to determine the EEG activation and connectivity between cognitive, sensory, and motor cerebral cortex areas in constant and variable practice conditions and as a function of practice time.MethodsThe study will follow the interventional design with two arms. Fifty participants will be randomly assigned to two groups practicing in constant and variable conditions. CG will be practicing only one pattern of step isometric contractions during unimanual index finger abduction, i.e., 90 trials in all training sessions, whereas VG will practice three different patterns. Each will be practiced 30 times per session in variable conditions. Resting-state fMRI, EEG, and motor task proficiency will be examined before and after practice.DiscussionFindings will enhance our understanding of structural and functional neural changes following practice in constant and variable conditions. Therefore, the study can be considered pure research.Clinical Trial RegistrationStudy registered at clinicaltrials.gov on 9 June 2021. Last version update: 21 December 2021.The protocol has been prepared according to the complete SPIRIT checklist, although the item order has been modified in order to comply with the manuscript structure. (shrink)