In the study ofperceptualabilities of infants, a number of techniques are used todetermineinfants' responses to various stimuli. Because they cannot verbalize or fill out questionnaires, indirect techniques of naturalisticobservationare used as theprimarymeans of determining what infants can see, hear, feel, and so forth. Each of these methods compares aninfant'sstatepriorto theintroductionof astimuluswith itsstateduring or immediately following thestimulus. Thedifferencebetween the two measures provides the researcher with anindicationof thelevelanddurationof theresponseto thestimulus. For example, if auniformlymovingpatternof somesortis passedacrossthevisualfieldof a neonate (newborn),repetitivefollowing movements of the eyeoccur. Theoccurrenceof these eye movements providesevidencethat the movingpatternis perceived at somelevelby the newborn. Similarly, changes in theinfant's generallevelofmotoractivity—turning the head, blinking the eyes, crying, and so forth — have been used by researchers asvisualindicators of theinfant'sperceptualabilities.

Such techniques, however, have limitations. First, theobservationmay be unreliable in that two or more observers may not agree that theparticularresponseoccurred, or to whatdegreeit occurred. Second, responses are difficult toquantify. Often the rapid anddiffusemovements of theinfantmake it difficult to get anaccuraterecordof the number of responses. The third, and mostpotent,limitationis that it is not possible to be certain that theinfant'sresponsewasdueto thestimuluspresented or to a change from nostimulusto astimulus. Theinfantmay be responding to aspects of thestimulusdifferent than those identified by the investigator. Therefore, when observational assessment is used as atechniquefor studyinginfantperceptualabilities,caremust be taken not to overgeneralize from thedataor torelyon one or two studies asconclusiveevidenceof aparticularperceptualabilityof theinfant.

Observational assessment techniques have become much moresophisticated, reducing the limitations just presented. Filmanalysisof theinfant's responses, heart andrespirationratemonitors, and nonnutritive sucking devices are used aseffectivetools in understandinginfantperception. Filmanalysispermits researchers to carefully study theinfant's responses over and over and in slowmotion. Precisemeasurements can be made of the length andfrequencyof theinfant'sattentionbetween two stimuli. Heart andrespirationmonitors provide the investigator with the number of heartbeats or breaths taken when a newstimulusis presented. Numerical increases are used as quantifiable indicators of heightenedinterestin the newstimulus. Increases in nonnutritive sucking were first used as an assessmentmeasureby researchers in 1969. They devised anapparatusthat connected a baby's pacifier to a countingdevice. As stimuli were presented, changes in theinfant's suckingbehaviorwere recorded. Increases in the number of sucks were used as an indicator of theinfant'sattentionto orpreferencefor agivenvisualdisplay.

Twoadditionaltechniques of studyinginfantperceptionhave come into vogue. The first is the habituation-dishabituationtechnique, in which a singlestimulusis presented repeatedly to theinfantuntil there is a measurabledecline(habituation) in whatever attendingbehavioris being observed. At that point a newstimulusis presented, and any recovery (dishabituation) in responsiveness is recorded. If theinfantfails to dishabituate and continues to show habituation with the newstimulus, it is assumed that the baby is unable toperceivethe newstimulusas different. The habituation-dishabituation paradigm has been used most extensively with studies ofauditoryandolfactoryperceptionin infants. Thesecondtechniquerelies on evoked potentials, which are electrical brain responses that may be related to aparticularstimulusbecause of where theyoriginate. Changes in the electricalpatternof the brainindicatethat thestimulusis gettingthroughto theinfant's central nervous system and eliciting some form ofresponse.

Each of the preceding techniques provides the researcher withevidencethat theinfantcandetectordiscriminatebetween stimuli. With thesesophisticatedobservational assessment and electro-physiological measures, we know that the neonate of only a few days is far moreperceptivethanpreviouslysuspected. However, these measures are only "indirect" indicators of theinfant'sperceptualabilities.

Questions:
question_stem: Paragraph 1 indicates that researchers use indirect methods primarily to observe the
choices: tag: A
text: range of motor activity in neonates

tag: B
text: frequency and duration of various stimuli

tag: C
text: change in an infant's state following the introduction of a stimulus

tag: D
text: range of an infant's visual field
answer_key: C
explanation: 以 indirect methods 做关键词定位至第二句，说用间接方法来观察婴儿能看到什么听到什么，接下来又说与 stimulus 引入之前的状态进行对比，所以答案是 C，不管是 hear 还是 see 都是婴儿的 state，而且只有引入之后的 state 才能与之前的 state 对比得出变化。

question_stem: The word "uniformly" in the passage is closest in meaning to
choices: tag: A
text: clearly

tag: B
text: quickly

tag: C
text: consistently

tag: D
text: occasionally
answer_key: C
explanation: A uniformly: 统一地，一致地，持续地。A 是清晰地，明显地；B 是快速地；C 是持续地，一贯地，一致地；D 是偶尔地。所以答案 C 的 consistently 正确。

question_stem: Why does the author mention repetitive following movements of the eye?
choices: tag: A
text: To identify a response that indicates a neonate's perception of a stimulus

tag: B
text: To explain why a neonate is capable of responding to stimuli only through repetitive movements

tag: C
text: To argue that motor activity in a neonate may be random and unrelated to stimuli

tag: D
text: To emphasize that responses to stimuli vary in infants according to age
answer_key: A
explanation: 功能目的题，修辞点所在的句子上题已经读过，只是在叙述一个例子，而且 for example 进一步说明这句话只是例子。往前看，前句说两种方法的不同告诉研究人员新生儿对刺激的不同反应的 level 和 duration，所以 A 是答案。B 的 only 原文没说；C 的 unrelated 与原文相反；D 的 age 原文没说。

question_stem: Which of the following is NOT mentioned in paragraph 2 as a problem in using the technique of direct observation?
choices: tag: A
text: It is impossible to be certain of the actual cause of an infant's response.

tag: B
text: Infants' responses, which occur quickly and diffusely, are often difficult to measure.

tag: C
text: Infants do not respond well to stimuli presented in an unnatural laboratory setting.

tag: D
text: It may be difficult for observers to agree on the presence or the degree of a response.
answer_key: C
explanation: EXCEPT 题，本应该排除法，但原文中非常清楚地写到第一第二第三三个局限性，也就是三个正确答案，所以也可以直接选的。第一对应 D，正确，不选；第二对应对应 B，正确，不选；第三对应 A，正确，不选；所以 C 错，选。

question_stem: The word potent in the passage is closest in meaning to
choices: tag: A
text: artificial

tag: B
text: powerful

tag: C
text: common

tag: D
text: similar
answer_key: B
explanation: B potent: 有效的，强有力的。A 是人工的；B 是强有力的；C 是常见的，普通的；D 是相似的。所以 B 的 powerful 正确。

question_stem: Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.
choices: tag: A
text: Researchers using observational assessment techniques on infants must not overgeneralize and must base their conclusions on data from many studies.

tag: B
text: On the basis of the data from one or two studies, it seems that some infants develop a particular perceptual ability not observed in others.

tag: C
text: To use data from one or two studies on infant's perceptual abilities, it is necessary to use techniques that will provide conclusive evidence.

tag: D
text: When researchers fail to make generalizations from their studies, their observed data is often inconclusive.
answer_key: A
explanation: A 原句的主要逻辑是条件状语从句，而主句中的逻辑是并列。原句的结构是当 blabla 的时候（条件），必须仔细以防止：1）overgeneraize 2) rely on one or two studies。原文中隐含的主语是我们防止。A 正确，其余三个答案把原句的主干完全改变。B 说婴儿怎么怎么样，后半句话完全瞎编，原文的我们防止彻底没了；C 的内容完全错误，胡乱搭配；D 主句和从句都跟原文不一样。

question_stem: What is the authors primary purpose in paragraph 3?
choices: tag: A
text: To explain why researchers must conduct more than one type of study when they are attempting to understand infant perception

tag: B
text: To describe new techniques for observing infant perception that overcome problems identified in the previous paragraph

tag: C
text: To present and evaluate the conclusions of various studies on infant perception

tag: D
text: To point out the strengths and weaknesses of three new methods for quantifying an infant's reaction to stimuli
answer_key: B
explanation: 问第三段整段的目的，看中心句，也就是本段首句。说通过越来越先进的技术可以减少上文中提到的局限性，所以答案是 B。

question_stem: The word quantifiable in the passage is closest in meaning to
choices: tag: A
text: visual

tag: B
text: permanent

tag: C
text: meaningful

tag: D
text: measurable
answer_key: D
explanation: D quantifiable: 可计数的，可测量的。A 是视觉的；B 是永久的；C 是有意义的；D 是可测量的。所以 D 的 measurable 正确。

question_stem: Paragraph 3 mentions all of the following as indications of an infant's heightened interest in a new stimulus EXCEPT an increase in
choices: tag: A
text: sucking behavior

tag: B
text: heart rate

tag: C
text: the number of breaths taken

tag: D
text: eye movements
answer_key: D
explanation: EXCEPT 题，排除法。A 的 sucking 做关键词定位至最后两句，正确，不选；B 的 heart rate 和 C 的 breaths 做关键词定位至第五句，都正确，不选，所以 D 是答案.

question_stem: According to paragraph 4, which of the following leads to the conclusion that infants are able to differentiate between stimuli in a habituation-dishabituation study?
choices: tag: A
text: Dishabituation occurs with the introduction of a new stimulus.

tag: B
text: Electrical responses in the infant's brain decline with each new stimulus.

tag: C
text: Habituation is continued with the introduction of a new stimulus.

tag: D
text: The infant displays little change in electrical brain responses.
answer_key: A
explanation: 本来可以用 habituation-dishabituation 做关键词的，但发现多次出现，改用动词 differentiate，但被替换成形容词 different，定位至第四句，说如果婴儿没有显出对新刺激的不适应而继续表现出适应性，就说明他们不能区分，所以答案是 A.

question_stem: In paragraph 4, what does the author suggest about the way an infant's brain perceives stimuli?
choices: tag: A
text: An infant's potential to respond to a stimulus may be related to the size of its brain.

tag: B
text: Changes in the electrical patterns of an infant's brain are difficult to detect.

tag: C
text: Different areas of an infant's brain respond to different types of stimuli.

tag: D
text: An infant is unable to perceive more than one stimulus at a time.
answer_key: C
explanation: 以 brain 做关键词定位至倒数第二句，说另一种技术依靠激发潜能，大脑不同区域对不同刺激有反应，注意从句 where they originate 指的是大脑的反应产生的地方，所以答案是 C，不同区域对不同刺激有反应。其他答案都没提到。

question_stem: Paragraph 5 indicates that researchers who used the techniques described in the passage discovered that
choices: tag: A
text: infants find it difficult to perceive some types of stimuli

tag: B
text: neonates of only a few days cannot yet discriminate between stimuli

tag: C
text: observational assessment is less useful for studying infant perception than researchers previously believed

tag: D
text: a neonate is able to perceive stimuli better than researchers once thought
answer_key: D
explanation: D，原文很短，可以快速扫过，问题问得出什么结论，本段第二句：With these sophisticated observational assessment and electro-physiological measures, we know that the neonate of only a few days is far more perceptive than previously suspected.