单选题
Patients can recall what they hear while under general anesthetic even if they don"t wake up, concludes a new study. Several studies over the past three decades have reported that people can retain conscious or subconscious memories of thoughts that happened while they were being operated on. But failure by other researchers to confirm such findings has led skeptics to speculate that the patients who remembered these events might briefly have regained consciousness in the course of operations. Gitta Lubke, Peter Sebel and colleagues at Emory University in Atlanta measured the depth of anesthesia using bispectral analysis, a technique which measures changes in brainwave pattern in the frontal lobes moment by moment during surgery. "Before this study researchers only took an average measurement over the whole operation," says Lubke. Lubke studied 96 trauma patients undergoing emergency surgery. Many of whom were too seriously injured to tolerance full anesthesia. During surgery each patient wore headphones through which a series of 16 words was repeated for 3 minutes each. At the same time bisecteal analysis recorded the depth of anesthesia. After the operation Lubke tested the patients by showing them the first three letters of a word such as "limit", and asking them to complete. Patients who had had a word starting with these letters played during surgery — "limit", for example — chose that word an average of 11 per cent more often than patients who had been played a different word list. None of the patients had any conscious memory of hearing the word lists. Unconscious priming was strongest for words played when patients were most lightly anaesthetized. But it was statistically significant even when patients were fully anaesthetized when the word was played. This finding which will be published in the journal Anesthesiology could mean that operating theatre staff should be more discreet. "What they say during surgery may distress patient afterwards," says Philip Merikle, a psychologist at the University of Waterloo, Ontario.
单选题
Scientists have found that deep anesthesia______.