After undergoing transcranial direct current stimulation, patients in a minimally conscious state exhibited signs of increased awareness and even the ability to communicate. The effect didn't last long — but the insights gleaned could lead to more effective interventions.
Patients who are in a coma cannot move or respond to their environment. But a so-called vegetative state is a bit different; it's a type of coma in which people cannot fully emerge from unconsciousness. They often give the impression that they're pulling out from a coma, but they still lack true or full awareness. That said, brain scans show that some of these people have an inner life and are able to respond to their environment.