A、Vegetative patients are more aware. B、Vegetative patients retain some control of their eye movements. C、EEG scans may help us

Brain wave scanners might make it possible to communicate with people who are considered brain-dead, according to a new study reported in the Economist.
   A couple of recent studies have shown that a small minority of vegetative patients might be more aware than they seem. Now, Damien Cruse, with the Medical Research Council’s Cognition and Brain Sciences Unit in Cambridge, UK, thinks EEG machines will be able to help these patients communicate.
   The team asked 6 healthy volunteers to wear EEG devices, which connect electrodes to a person’s head. They were asked to respond to an audible tone by imagining that they were squeezing their right hands or wiggling the toes of both feet. The researchers found that the volunteers’ brain responses were clearly different — the hand-squeezing activated the left-hand side of the brain, and the toe wiggling produced a response in the center of the brain.
   Then they tested the procedure on a patient with locked-in syndrome, who was always completely paralyzed but retained some control of his fine movements. His brain responses were the same. Finally, they tested the procedure on a patient who had been declared vegetative 2 years earlier. They watched the EEG signals and were able to deduce which movement the patient was imagining.
   The same team had studied 23 vegetative patients for 4 years and found 4 patients were able to consistently respond to yes-or-no questions by changing their brain activity. They were asked to imagine playing tennis when they wanted to give one response or walking around the house when they wanted to give the other.
   Since the patients were responsive, they’re not technically vegetative, the researchers say. Proof that they can communicate that they’re not brain dead would have major implications for family members’ and doctors’ decisions about their care.
26. What does this talk mainly tell us?
27. For the 6 healthy volunteers, which part of the brain did the hand-squeezing imagination activate?
28. Of the 23 vegetative patients, how many were found to be able to consistently respond to yes-or-no questions?
29. What can we learn from the study on the patient declared vegetative 2 years earlier?
30. When EEG signals indicate that a vegetative patient is responsive, which of the following is NOT true?