Some people stuck in "vegetative" states may be more aware than we realize, a strange new study has shown.
For the study, published in the Sept. 15 issue of the Proceedings of the National Academy of Sciences, scientists at Canada's Western University compared brain scans of 12 healthy people to the scan of a man who has been "behaviorally nonresponsive" following a brain injury 16 years ago. The scans were taken as each person watched a short Alfred Hitchcock film while inside an functional magnetic resonance imaging (fMRI) machine, which tracked their brain activity.
The film, an 8-minute condensed version of Hitchcock's "Bang! You're Dead," features a 5-year-old who plays with a revolver, unaware the gun isn't a toy.
After comparing scans of healthy brains to the scan from the brain-injured man, the researchers concluded there's "strong evidence" that the man is capable of conscious experiences. In fact, Dr. Adrian Owen, a cognitive neuroscientist at the university and one of the authors of the study, said the scans were nearly identical.
"What we saw is that his brain changed at all of those key moments in the movie in exactly the same way as a healthy volunteer," Owen told the Canadian Broadcasting Corporation. "Essentially we were getting at consciousness. We were measuring or detecting the fact that this patient was able to follow the plot."
Why Hitchcock? Owen told Nature that the filmmaker's signature suspense is perfect at grabbing the viewers' attention and making them think -- a must for the study.
“The reason Alfred Hitchcock is such a great movie-maker in this context is that his movies are filled with layers of inference and deduction, and he uses a lot of foreshadowing,” Owen told Nature. “All those things require executive processing. Those aren’t things that go on unconsciously."
A second brain-injured patient who also watched the movie showed significantly less brain activity, researchers told Science Magazine.
Lorina Naci, a postdoctoral fellow and the study's lead author, told CTV News the findings challenge our current understanding of what it means to be brain-dead.
"For the first time, we show that a patient with unknown levels of consciousness can monitor and analyze information from their environment, in the same way as healthy individuals," she said. "We already know that up to one in five of these patients are misdiagnosed as being unconscious and this new technique may reveal that that number is even higher."