New study offers the first evidence of replay during sleep in the human motor cortex, which governs voluntary movement

Why do we sleep? Scientists have debated this question for millennia, but a new study by researchers at Massachusetts General Hospital (MGH), conducted in col-laboration with colleagues at Brown University, the Department of Veterans Affairs, and several other institutions, adds new clues for solving this mystery. Their findings, published in the Journal of Neuroscience, may help explain how humans form memories and learn, and could eventually aid the development of assistive tools for people affected by neurologic disease or injury.