A man who had appeared to have been in a vegetative state for 12 years knew his name and knew where he was, Canadian researchers report in a study showing it’s possible to use MRI brain scans to establish communication with people who seem completely unconscious.

Three people tested using a special form of MRI called functional magnetic resonance imaging were able to answer simple “yes” or “no” questions, the team at Western University in London, Ontario report.

They say their findings don’t mean everyone in a coma or a persistent vegetative state is conscious, but it should help doctors find out who is and who isn’t .

“We hope to be able to reach patients who are trapped in their bodies,” says Lorina Naci, a researcher specializing in brain imaging techniques for patients with severe brain injury. “We want to give patients some autonomy in their lives.”

Naci’s team came up with a method for determining whether patients are not just hearing sounds, but able to think clearly about what those sounds mean and answer questions. Other studies have shown that up to 20 percent of patients in various vegetative states can hear and respond on at least some level.

But at least some of the responses seen could be dismissed as simple reflexes, or at best akin to someone in a dream state responding to stimuli. Naci says her team’s findings show that at least some can respond with clear conscious intent.

“The technique may be useful in establishing basic communication with patients who appear unresponsive to bedside examinations and cannot respond with existing neuroimaging methods,” the team wrote in the Journal of the American Medical Association journal JAMA Neurology.

“Although a clinical vegetative state diagnosis implies lack of consciousness and cognition, this is not necessarily always the case.”

One of the patients, a 38-year-old man in a vegetative state since a car accident 12 years before, knew his name was Steve and not Scott or Mike and was able to say he knew he was in a hospital and not a supermarket, the researchers said.

They did this with a painstaking protocol in which the patients were told to pay attention to certain words. They’d already shown that in normal, healthy people, the brain activates in a different pattern if someone is paying close attention to a certain word as opposed to simply hearing it.

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They put the patient in a scanner and asked. “Is your name Scott?” “Is your name Steven?” “Is your name Mike?” “Are you in a hospital?” and “Are you in a supermarket?”. Then they played the word “yes” and the word “no” over and over again, instructing Steven to pay attention to the correct answer.

He did. So did two other patients, to a lesser degree. Steven managed to do so twice, at two different sessions five months apart, Naci says. “This allowed us to determine the patient was quite highly cognitively preserved,” she said.

Dr. Nicholas Schiff of Weill Cornell Medical College says there’s a clear need for better methods of determining who’s conscious but severely brain damaged, and who has no consciousness at all.

“People (may) have the appearance of being in a vegetative or minimally conscious state, but through technology we have discovered some of them have been misdiagnosed,” Schiff, who was not involved in this study, said in a telephone interview.

But it doesn’t mean that some patients aren’t truly without hope. Perhaps the most high-profile case involved Terri Schiavo, who died in 2005 at the age of 41 after 15 years in a persistent vegetative state.

Her case was in the headlines because of a bitter dispute between her husband, who wanted to remove a feeding tube, and her parents, who did not. Schiavo’s fate was debated on the floor of Congress and then –president George W. Bush intervened to allow federal judges to review her case. Her husband, supported by doctors, prevailed and the tube was removed.

An autopsy confirmed Schiavo had irreversible brain damage.

Another high-profile patient, Karen Quinlan, lived for more than a decade in a vegetative state — brought on by alcohol and drugs in 1975 when she was 21; New Jersey courts let her parents take her off a respirator a year after her injury.

“It is important to keep in mind that not all persons who are not responsive fit these findings,” said Art Caplan, head of medical ethics at New York University Langone Medical Center and a frequent NBC News contributor.

“Those who have gone without oxygen for long periods of time, like Terri Schiavo, will not be mentally present inside unresponsive bodies since their brains will have been too damaged,” Caplan said.

Naci says her team has scanned seven more people in a new study aimed at finding out what proportion of patients in a vegetative or minimally conscious state have actual conscious awareness. At least some – she won’t say how many just yet – have not responded at all, she says.

It might be possible to ask people what kind of treatment they want, Naci and Caplan both said.

“For many, being trapped fully or partially conscious inside their bodies would be a horrific nightmare which they would not wish to prolong,” Caplan said. But Naci adds that it would be problematic to ask the question if there wasn’t anything doctors or other caregivers could do to help the patient.

“A lot of states and countries do not support any invasive action that would be akin to euthanasia or suicide,” she said. “We can’t ask without knowing what to do with the answer.”

However, patients might be able to play a more active role in their care, she said..

“There are a million questions one wants to ask,” Naci says. Basic questions include whether a patient is in pain, but they could even be asked whether they want to hear music or the television.

And the study shows something else. Patients may benefit from continued stimulation even if they don’t appear to be responding. Naci said the 38-year-old patient her team described had a dedicated family.

“He is being treated as if he is aware and able to communicate,” she said. “It’s probably not a coincidence that the person is like this.”

Judy Silverman contributed to this report