No one likes bad news, but for some people, no news is worse. People who are mildly neurotic are stressed by uncertainty even more than by bad news, a new study finds. Psychologists have long known that bad news grabs attention, making its recipients take notice, while good news often is given short effect in the brain. Scientists have explained the phenomenon as a survival mechanism of the brain. But researchers at the University of Toronto wanted to learn more about how people respond to uncertainty--a lack of information or information that isn't well understood. Forty-one young men and women took a test designed to assess how neurotic they were, then were fitted with electrode(电极 ) caps that measured brain activity as they completed certain tasks. As a way of monitoring stress, the investigators tracked neural activity in the anterior cingulate cortex(前扣带皮层), a part of the brain involved in conflict, uncertainty and monitoring errors. The participants later were asked to respond when they thought a second had passed since a symbol had appeared on a computer monitor. After responding, they received feedback on the monitor in the form. of a plus sign indicating a job well done, a minus sign indicating improvement was needed, or a question mark with no further explanation. The subjects who had scored higher on the neuroticism scale demonstrated more brain activity in response to uncertain feedback than to negative feedback, the researchers found. In the real world, such a heightened response might occur when an employee is up for a promotion but does not know the outcome, and a highly neurotic individual would respond less intensely to losing the promotion said Jacob Hirsh, a lead author of the paper. The opposite is true for people who are not neurotic, Hirsh added. They are not bothered by uncertainty but are very upset by negative feedback. Richard Sorrentino, a psychologist at the University of Western Ontario who also studies uncertainty, said he had conducted a similar study looking at married women who were ambivalent(有矛盾情绪的)toward their partners and not sure whether they could be trusted. 'If they were the type who preferred certainty, they were better off if they didn't trust their husbands at all than if they were uncertain about whether to trust him,' he said. Wives who preferred certainty but who were uncertain about their husbands often suffered severe symptoms, he added, including depression. As to the survival mechanism of the brain, ______.