steven's mother, gloria hawkins. what's his official diagnosis? he's in a vegetative state? >> yep.it. >> reporter: steven's current physician is dr. ken warm. he practices family medicine and admits the nursing home does not have the resources to evaluate patients for consciousness. then his diagnosis of persistent vegetative state, is it relevant? is it true still? >> it would be a lot of splitting of hairs, because he's responding in a very limited fashion. >> reporter: after the interview, i asked dr. warm to check the latest notes and diagnosis on steven's chart. >> and i went and reviewed the criteria for persistent vegetative state, and it's very clear that he doesn't fit that. >> reporter: i can't help but >> reporter: he said steven had made enough progress over the years, that now, he is more likely in a minimally conscious state. but, it's difficult to know for cetain. >> there's so much unknown about their cognitive function. >> reporter: researchers at u.c.-davis plan to have initial results of their nursing home study by the end of the year. but regardless of whether m