Disorders of consciousness such as coma or a vegetative state caused by severe brain injury are poorly understood and their diagnosis has relied mainly on patient responses and measures of brain activity. However, new functional and imaging-based diagnostic tests that measure communication and signaling between different brain regions may provide valuable information about the potential for consciousness in patients unable to communicate. These innovative approaches are described and compared in a Review article in the groundbreaking neuroscience journal Brain Connectivity, a bimonthly peer-reviewed publication from Mary Ann Liebert, Inc., publishers. The article is available free on the Brain Connectivity website*.