When we feel stressed, our adrenal glands release a peptide called Cortisol. Our body responds with Cortisol whether it faces ph

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问题     When we feel stressed, our adrenal glands release a peptide called Cortisol. Our body responds with Cortisol whether it faces physical, environmental, academic, or emotional danger. This triggers a string of physical reactions including depression of the immune system, tensing of the large muscles, blood-clotting, and increasing blood pressure. It’s the perfect response to the unexpected presence of a sable-toothed tiger. But in school, that kind of response leads to problems. Chronically high Cortisol levels lead to the death of brain cells in the hippocampus, which is critical to explicit memory formation.
    These physical changes are significant. Stanford scientist Robert Sapolsky found that atrophy levels in the hippocampus of Vietnam veterans with PTSD (post-traumatic stress disorder) ranged from 8 to 24 percent above the control group. Chronic stress also impairs a student’s ability to sort out what’s important and what’s not. Jacobs and Nadel (1985) suggest that thinking and memory are affected under stress. The brain’s short-term memory and ability to form long-term memories are inhibited.
    There are other problems. Chronic stress makes students more susceptible to illness. In one study, students showed a depressed immune system at test time; they had lower levels of an important antibody for fighting infection. This may explain the vicious academic cycle; more test stress means more sickness, which means poor health and missed classes, which contribute to lower test scores.
    A stressful physical environment is linked to student failure. Crowded conditions, poor student relationships, and even lighting can matter. Optometrist Ray Gottlieb says that school stress causes vision problems. That in turn impairs academic achievement and self-esteem. He says that, typically, a stressed child will constrict breathing and change how he or she focuses to adapt to the stress. This pattern hurts learning in the short and long run. Under stress, the eyes become more attentive to peripheral areas as a natural way to spot predators first. This makes it nearly impossible to track across a page of print, staying focused on small areas of print.
Stress does NOT usually result in______.

选项 A、lower atrophy levels
B、impaired ability to distinguish what is important and what is not
C、weakened thinking
D、inhibited ability to form short and long-term memories

答案A

解析 事实细节题。第二段第二句以患有创伤后应激障碍的越战老兵为例,指出他们的海马体萎缩程度比对照组高8%至24%,由此可知,压力会加深萎缩程度,故[A]项错误,为答案。第二段第三句提到,长期压力会损害学生区分事情重要与否的能力,由此排除[B]项。第二段最后两句提到,思考和记忆会受压力影响,大脑的短时记忆和形成长时记忆的能力会受到抑制,由此可排除[C]项和[D]项。
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