Patients in a persistent vegetative state may not be as unaware as their diagnosis suggests. Neuroscientists have found that 15-20 percent may be fully conscious but unable to make that known.
A new device may be able to help those individuals communicate with family, friends, and caregivers.
The device - which looks like a soft helmet with a lot of electrical wires attached - is an adaptation of functional MRI technology, as Popular Science reports:
Most brain-computer interfaces have relied on electroencephalography (EEG), which measures the electrical activity of neurons. Birbaumer and his colleagues instead measured changes in blood flow using a technique called functional near-infrared spectroscopy, which is similar to functional magnetic resonance imaging (fMRI).
“We worked for more than 10 years with neuroelectric activity [EEG] without getting into contact with these completely paralyzed people,” says Birbaumer. “Out of desperation we decided to move to a different type of brain activity and we were lucky.”
EEG did come in handy for reading whether a participant had stopped paying attention or had nodded off. But monitoring the brain’s blood flow could essentially reveal what participants were thinking.
The research team at the University of Liège in Belgium asked four test patients a series of yes or no questions with verifiable answers. Those were used to train a computer to recognize the pattern of brain activity that corresponded to a yes or no answer from each patient.
Then, they asked the all-important question: are you happy? In all cases, the answer was "yes."