問題詳情：
WHEN you get hungry, do you find yourself making poor decisions? Well, it turns out that this is because of a hormone called ghrelin (飢餓激素). It is released when you are hungry and has a bad effect on impulses (衝動) and making decisions, according to a recent study at Sahlgrenska Academy, part of the University of Gothenburg in Sweden. “For the first time, we have been able to show that increasing ghrelin to levels that are seen when hungry causes the brain to act impulsively and also affects the ability to make rational decisions,” Karolina Skibicka, a member of the teaching staff at Sahlgrenska Academy, told the Science Daily website. Impulsivity is complex, according to the website, but impulsive choice basically means not being able to resist the temptation to take a reward now instead of waiting until later. You may sometimes eat a bag of chips even though you know that you’re going to have dinner soon, for example. This type of problem was seen in the rats used in the study. The rats were trained to be rewarded with sugar when they did something like pressing a lever (槓桿) – or instead, they could be rewarded only when they stopped themselves from pressing the lever (“no-go”) when the right signal, like a flash of light or a buzzing sound, was given. When rats could not stop themselves from pressing the lever when the “no-go” signal was given, it was seen as a sign of impulsivity. Researchers found that rats given ghrelin directly into the brain were more likely to press the lever instead of waiting, even though it caused them to lose their reward. The ability to wait for a greater reward later measures impulsive choice. For example, you can overeat fattening foods to feel happy right now or choose to eat healthier. Researchers at Sahlgrenska Academy found that higher levels of ghrelin stopped the rats from being able to wait for the greater reward. The study also showed that increased levels of ghrelin even caused long-term genetic changes in the brain parts that are connected to impulsivity and decision making. The same type of changes can be seen in brains with attention deficit hyperactivity disorder (ADHD) (注意力缺陷多動障礙) and other psychiatric disorders (精神疾病), reported Science Daily. “The ghrelin receptors in the brain can be a possible target for future treatment,” said Skibicka.
32. According to the article, in the study at Sahlgrenska Academy, ________. A. the rats could only get their reward when they pressed a lever B. when ghrelin in the rats’ brains increased, they could wait for the right signal C. when ghrelin in the rats’ brains increased, they were more likely press the lever D. when ghrelin in the rats’ brains increased, they were eager to get the sugar
33. According to the article, impulsivity is measured by ________. A. the ability to focus on now rather than later B. the number of risks taken C. the amount of patience for waiting D. the ability to wait for a good or better reward
34. Which word is closest to the meaning of the underlined word “rational”? A. wise B. quick C. difficult D. simple
35. What’s the article mainly about? A. Impulsivity and decision-making. B. Ghrelin and impulsivity. C. Ghrelin’s increase when people are hungry. D. The way in which increasing ghrelin causes genetic changes.
【回答】
CAAB
知識點：科普環保類閱讀
題型：閱讀理解
