Many brain-damaged patients written off as vegetative are actually alert despite being immobilized. Now doctors may be able to recognize this hidden group, according to neuroscientist Melanie Boly of the Cyclotron Research Center in Belgium.
To seek the neural pattern for consciousness, Boly and her colleagues measured brain activity in vegetative, minimally conscious, and healthy subjects while playing a series of tones. Normally the brain reacts by sending information from the temporal cortex to the frontal cortex (a center of higher-order thought) and back in a loop. Boly found that the healthy and minimally conscious subjects showed neural activity throughout the complete loop, while truly vegetative ones did not. If the finding is confirmed, it could allow doctors to focus treatment on patients wrongly diagnosed as vegetative.