Brain-wave Test Challenges Vegetative-State Diagnosis

Tests using an EEG have shown unexpected cortical functioning in vegetative patients. Niels Birbaumer, a neurobiologist at the University of Tübingen, in Germany, used EEG recordings to study the brain activity of patients diagnosed as vegetative and found unexpected levels of cortical activity.

In one of the studies, Birbaumer and his colleagues looked for patterns in the brain’s electrical activity as patients listened to sentences being read aloud. In the experiment, patients listened to a series of seven-word sentences. Half the time the sentences were semantically logical. The other half of the sentences ended with a nonsensical word. As the patients listened to the words, the researchers listened to the electrical activity in their brains. With EEG data from 100 trials, the researchers pieced together a signature response for each patient who gave some indication of how he processed the errors he was hearing.

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