Neuroscientist Adrian Owen estimates that 20 percent of patients in a so-called "vegetative state" are, in fact, capable of communicating with the outside world. This is not a delusion. Using brain imaging techniques like fMRI, Owen — pictured above — has provided some remarkably compelling evidence that "non-responsive" and "unreachable" patients are often surprisingly cognizant of their surroundings. Now, he's pushing to put his methods in the hands of clinicians by making them mobile, affordable, and more reliable.
Over on Nature News, David Cyranoski recounts a number of Owen's incredible achievements, while exploring some of the ethical and moral implications of "finding" patients in a vegetative state. We've included an excerpt from the feature below, but you'll want to head over to Nature for the rest. It's a fantastic piece, and well worth reading in full.
It was June 2006. Wimbledon was on, and in a headline-stealing study, Owen took fMRI scans of a 23-year-old woman in a vegetative state while he asked her to imagine playing tennis and walking through the rooms of her house. When healthy, conscious adults imagine playing tennis, they consistently show activation in a region of the motor cortex called the supplementary motor area, and when they think about navigating through a house, they generate activity in the parahippocampal gyrus, right in the centre of the brain. The woman, who had been unresponsive for five months after a traffic accident, had strikingly similar brain activation patterns to healthy volunteers who were imagining these activities, proving, in Owen's mind, that she was conscious. The result, published in a one-page article in Science5, evoked wonder and disbelief. "I got two types of e-mail. People either said 'this is great' or 'how could you possibly say this woman is conscious?'," Owen says.
Other researchers contended that the response was not a sign of consciousness, but something involuntary, like a knee-jerk reflex. Daniel Greenberg, a psychologist at the University of California, Los Angeles, suggested in a letter to Science that "the brain activity was unconsciously triggered by the last word of the instructions, which always referred to the item to be imagined".
But Owen went on to bolster his case. Working with neurologist and neuroscientist Steven Laureys from the University of Liège, Owen showed that of 54 patients in a vegetative or minimally conscious state, five responded in the same way as the first woman. Four of them were in a vegetative state. After refining their methods, the researchers asked patient 23 to use that capability to answer yes-or-no questions: imagine playing tennis for yes, navigating the house for no. They then asked about things that the technicians scoring the brain scans couldn't possibly know.
Is your father's name Thomas? No. Is your father's name Alexander? Yes. Do you have any brothers? Yes. Do you have any sisters? No. The experiment is no easy feat for the patient. Owen's protocol demands patients maintain focus for 30 seconds then rest for 30 seconds, with lots of repetition.
In front of a computer screen showing the fMRI data, Owen traces a blue line indicating activity in the supplementary motor area - a 'yes' - as it rises during the 'answer' period. It dives during the rest periods. A red line - indicating activity in the parahippocampal gyrus - represents the 'no'. The lines are sharp and clear, and Owen, who has a taste for puns, calls the implication "a no-brainer". "You don't need to be a functional-imaging expert to appreciate what this person is telling you," he says. The patient answered five of six questions correctly. There was no discernible signal for the sixth.
Owen agrees that consciousness is not an "on-or-off thing". He sees it as an "emergent property" of many "modules" of the brain working together. Enough of these modules are at work in his exercise, he says, for responsive patients to qualify as being conscious. A person needs long-term memory to know what tennis is, short-term memory to remember the question or command and intention to give an answer. Ultimately, Owen is not concerned with pinpointing a threshold of consciousness or with providing a comprehensive definition for it. He takes a "know it if you see it" approach. Responding to commands and questions - communication - is an undeniably conscious activity, in his view. "In the end if they say they have no reason to believe the patient is conscious, I say 'fine, but I have no reason to believe you are either'," he says.