The decrease in responsiveness that follows continuous stimulation (adaptation) is common to all sensory systems, including olfa

admin2018-07-04  9

问题 The decrease in responsiveness that follows continuous stimulation (adaptation) is common to all sensory systems, including olfaction. With continued exposure to chronically present ambient odors, individuals’ perception of odor intensity is greatly reduced. Moreover, these perceptual changes can be profound and durable. It is commonly reported that following extended absences from the odorous environment, reexposure may still fail to elicit perception at the original intensity.
Most research on olfactory adaptation examines relatively transient changes in stimulus detection or perceived intensity—rarely exceeding several hours and often less—but because olfactory adaptation can be produced with relatively short exposures, these durations are sufficient for investigating many parameters of the phenomenon. However, exposures to odors in natural environments often occur over far longer periods, and the resulting adaptations may differ qualitatively from short-term olfactory adaptation. For example, studies show that even brief periods of odorant stimulation produce transient reductions in receptors in the olfactory epithelium, a process termed “receptor fatigue.” Prolonged odor stimulation, however, could produce more long-lasting reductions in response, possibly involving structures higher in the central nervous system pathway.
The author of the passage discusses “receptor fatigue” primarily in order to

选项 A、explain the physiological process through which long-lasting reductions in response are thought to be produced
B、provide an example of a process that subjects would probably not experience during a prolonged period of odorant stimulation
C、help illustrate how the information gathered from most olfactory research may not be sufficient to describe the effects of extended exposures to odors
D、show how studies of short-term olfactory adaptation have only accounted for the reductions in response that follow relatively brief absences from an odorous environment
E、qualify a statement about the severity and duration of the perceptual changes caused by exposure to chronically present ambient odors

答案C

解析 B.provide an example of a process that subjects would probably not experience during a prolonged period of odorant stimulation提供一个过程的例子,这个过程是研究对象在长期气味刺激中不会经历的过程。
解析:根据本文,最后两句,长期刺激和短期刺激产生的结果虽然不同,但是要接受长期刺激,意味着必然已经接受了短期刺激,所以对于接受长期刺激的研究对象来说,先发生感受器疲劳,后影响中枢神经。B选项错误。
C.help illustrate how the information gathered from most olfactory research may not be sufficient to describe the effects of extended exposures to odors帮助证明大多数嗅觉研究所得到的信息,用于描述长期气味接触有可能不够
解析:本文通过提及“感受器疲劳”说明了短期刺激和长期刺激产生的结果不同,而根据第二段第一句,大多数的嗅觉研究,研究的是短期刺激。因此“感受器疲劳”可以证明大多数的嗅觉研究是不够的。C正确。
E.qualify a statement about the severity and duration of the perceptual changes caused by exposure to chronically present ambient odors限定了一个关于接触长期存在的环境气味所导致感官变化的强度和时间的观点
解析:本文提及“感受器疲劳”这个例子只是用来说明大多数人的研究时间是不够的,但并没有限制感官变化本身的时间和强度。E错误。
转载请注明原文地址:https://kaotiyun.com/show/6djO777K
本试题收录于: GRE VERBAL题库GRE分类
0

最新回复(0)