When he was 18, he suffered a devastating blow to the chest. He went into cardiac arrest. Then for the next decade and a half he remained in a vegetative state — unresponsive to external stimuli and rendered completely mute. Still, his dad took him to the movies weekly, and now research is saying it may have had an effect.
A group of neuroscientists from the University of Western Ontario recently set out to test brain activity among two unconscious participants who had sustained major injuries in their youth. Their goal was simple. They wanted to learn if the brain still responded even if the face offered nothing — if someone could be home, so to speak, even if the lights were off. Such a test is rare to find when it comes to studying vegetative states, they say.
"Looking at brain activity just isn’t the standard of care," Lorina Naci, co-investigator and neuroscientist at the University of Western Ontario, in Canada, told The Verge. Too often, doctors will only go so far as asking questions and trying to elicit a verbal response.
Naci and her colleagues recruited 12 healthy participants and two unconscious ones: the first a 20-year-old woman who suffered a mysterious brain injury when she was 10, and the second the man who went into cardiac arrest when he was 18. First, they showed the healthy subjects an eight-minute clip from “Bang! You’re Dead,” a complex, irony-filled episode from Alfred Hitchcock’s television series, Alfred Hitchcock Presents. Then they showed the same clip to the unconscious subjects, monitoring their brain’s responsiveness to key plot points.
While the female patient didn’t show any signs of patterned reaction, the male subject did. His brain responded at critical moments to the video. But Naci and her team knew they needed further testing to know if those reactions meant he understood the video, or if the sensory parts of his brain were simply lighting up from the stimuli.
So, they designed two more experiments. In the first, participants alternated between clicking a button continuously and slowing down the pace, according to the research team’s instructions. All the while, subjects were watching the video. The test was designed to determine how engaged people were at crucial moments in the video: If they responded to the instructions more slowly, they were more likely engaged. If their speed stayed the same, the video probably wasn’t making an impression.
As expected, the people who were most engaged with the most tended to mess up to the same degree the brain scans showed neural activity. Even a follow-up test, where the video was scrambled and the moments disjointed, produced the same levels of response. The supreme finding, of course, was the the man who had sustained an injury 16 years prior, through all of it, responded as per the control group.
“It was actually indistinguishable from a healthy participant watching the movie,” said Adrian Owen, neuroscientist and co-author of the study.
Some are hesitant to heap on loads of praise. While reliable, fMRI isn’t perfect. Russell Poldrack, a cognitive neuroscientist at Stanford University, says the study may offer more evidence about how certain parts of consciousness work, rather than the entire experience itself. Meanwhile, he said, “the results look very solid to me, about as solid as one could hope for a case study.”
As for the future of their research, Owen pointed to the male patient’s success as evidence the field needs further attention. Not only do people who seem unconscious sometimes respond to external stimulation, measured through fMRI, but they could engage with it, too. Asking questions to judge responsiveness, then, may not be the most effective strategy.
“The fact that we can say he is enjoying these movies, he can understand these movies, says something about his quality of life,” Owen said, pointing to how the man’s father has taken him to the movies each Wednesday since his injury. “There are a lot of Wednesdays in 16 years.”
Source: Naci L, Cusack R, Anello M, Owen A. A common neural code for similar conscious experiences in different individuals. Proceedings of the National Academy of Sciences. 2014.