Some students get so nervous before a test, they do poorly even if they know the material. Sian Beilock, a psychology professor at the University of Chicago in Illinois, has studied these highly anxious test-takers. Sian Beilock says: "They start worrying about the consequences. They might even start worrying about whether this exam is going to prevent them from getting into the college they want. And when they worry, it actually uses up attention and memory resources. I talk about _ as their cognitive horsepower that they could otherwise be using to focus on the exam." Professor Beilock and another researcher, Gerardo Ramirez, have developed a possible solution. Just before an exam, highly anxious test-takers spend ten minutes writing about their worries about the test. The researchers tested the idea on a group of 20 anxious college students. They gave them two short math tests. After the first one, they asked the students to either sit quietly or write about their feelings about the upcoming second test. The researchers added to the pressure. They told the students that those who did well on the second test would get money. They also told them that their performance would affect other students as part of a team effort. Professor Beilock says those who sat quietly scored an average of 12 percent worse on the second test. But the students who had written about their fears improved their performance by an average of five percent. Next, the researchers used younger students in a biology class. They told them before final exams either to write about their feelings or to think about things unrelated to the test. Professor Beilock says highly anxious students who did the writing got an average grade of B+, compared to a B-for those who did not. The research shows that for students who are highly test-anxious, who'd done the writing intervention , all of a sudden there was no relationship between test anxiety and performance. Those students most likely to worry were performing just as well as their classmates who don't normally get nervous in these testing situations. But what if students do not have a chance to write about their fears immediately before an exam or presentation? Professor Beilock says students can try it themselves at home or in the library and still improve their performance. The purpose of the passage is  _  .
to build the confidence of the highly anxious test-takers to introduce a research about the anxious test-takers to improve the performance of the test-takers to tell something about the highly anxious test-takers