(New Scientist) It can be nearly impossible to know what is happening in the mind of someone who has experienced a severe brain injury, but two new methods could offer some clues. Together, they provide not only a better indication of consciousness but also a more effective way to communicate with some vegetative people.
The way that a seemingly unconscious person behaves does not always reflect their mental state. Someone in a completely vegetative state may still be able to smile simply through reflex, while a perfectly alert person may be left unable to do so if a brain injury has affected their ability to move.
So a different way to assess mental state is needed. Marcello Massimini at the University of Milan in Italy and his colleagues have developed a possible solution by stimulating brains with an electromagnetic pulse and then measuring the response. The pulse acts like striking a bell, they say, and neurons across the entire brain continue to “ring” in a specific wave pattern, depending on how active the connections between individual brain cells are.