Most developmental scientists now agree that both nature (genetics) andnurture(environment) areessentialfor the normaldevelopmentofperception. However, there is still muchdisputeabout theextentto which either nature ornurtureis the more importantfactor. Points of view on thisissueare more than just philosophical musings, theyaffectthe kinds of experiments that are undertaken. Iarguehere that classifyingparticularaspects ofperceptualdevelopmentas eitherinnateor learned presents us with anoverlypassiveview in which either genes or environment imposes structure on the developing brain. Incontrast, I suggest thatperceptualdevelopmentis better characterized as an activity-dependentprocessinvolvingcomplexandsubtleinteractions at many levels.

To begin toillustratemy point, let'sconsidersome recentneurobiologicalwork on theprenatal(before-birth)developmentof the brain in rodents. Neurons arespecializedcells thattransmitimpulses or messages to other neurons, glands, and muscles. The neurons studied in these experiments are those involved in binocularvision. Experiments show that theprenataltuning (training) of these neurons arisesthroughtheirresponseto internally generated waves of electricalactivity. In other words, theresponseproperties of thesevisualneurons are shaped by a "virtual environment" generated by cells elsewhere in the brain and eye. Although theterm"innate" can be stretched to cover this example ofdevelopment, we could equally welldescribethisprocessas the cells "learning" from the input provided. Further, after birth the same neurons continue to be tuned in the same way, except that now their input also reflects the structure of the world outside. When we examinedevelopmentindetail, it becomes harder toargue, as some theorists do, that "innateknowledge" is fundamentally different from learning.

Another example of the role of activity-dependent processes inperceptualdevelopmentcomes from theabilitytodetectandrecognizefaces. Because regions of the human brain arespecializedfor processing faces, some researchers have argued that thisabilityisinnate. However, experiments with infantsreveala morecomplexstory. Thetendencyfor newborns to look more toward faces turns out to be based on a veryprimitive, reflexlike system that is triggered by astimulusas simple as three high-contrast blobs in theapproximatelocations of the eyes and mouth. This simplebiasissufficientto ensure that newborns look much more at faces than at other objects and patterns over the first weeks of life. Oneconsequenceof this is that developing circuits on thevisualrecognitionpathway of the brain get more input related to faces and thus are shaped by experience with thisspecialtype ofvisualstimulus. We can now study thisprocessby using new brain-imaging methods. Such studies have shown that the brains of young infants show less-localized and less-specialized processing of faces than do the brains of adults. It is not until they are one year old that infants show the same patterns of brainspecializationfor processing faces as do adults, by which time they have had as much as a thousand hours ofexposureto human faces.

Another example comes from the study of infants' eye movements tovisualtargets. Although newborns arecapableof someprimitivereflexive eye movements, only much later in the first year can they make most of the kinds ofcomplexandaccurateeye movements seen in adults. One view is that the very limitedabilitypresent in newborns is justsufficientto allow them to practice and develop new brain circuits for the morecomplexintegrationofvisualandmotorinformation necessary for adult eye movements. Once again, it appears that infants activelycontributeto their ownsubsequentdevelopment.

These considerations should make usskepticalabout the many claims that are made forinnateperceptualabilities based on experiments with babies of four months and older. In fact, when the same experiments were done with younger infants, quite different results have often been obtained, suggestingdramaticchanges inperceptualabilities over the first few weeks and months after birth.

Infants are not passively shaped by either their genes or their environment. Rather,perceptualdevelopmentis an activity-dependentprocessin which, during postnatal life, theinfantplays an active role in generating the experience it needs forsubsequentdevelopment.

Questions:
question_stem: The word "overly" in the passage is closest in meaning to
choices: tag: A
text: unlikely

tag: B
text: automatically

tag: C
text: apparently

tag: D
text: excessively
answer_key: D
explanation: 词汇题
overly adv.过度地，极度地，与 excessively 同义。
故选 D。

question_stem: According to paragraph 2, how does the tuning of visual neurons in rodents change after birth?
choices: tag: A
text: Tuning now occurs in response to internally generated electrical activity.

tag: B
text: Tuning now occurs in response to a "virtual environment" generated by cells in the brain and eye.

tag: C
text: Tuning now becomes innate because the "virtual environment" disappears.

tag: D
text: Tuning now includes responses to outside stimuli.
answer_key: D
explanation: 题干提问“啮齿类动物的视觉神经元的调节在出生后是如何改变的”。
定位第2段倒数第2句 after birth the same neurons continue to be tuned in the same way, except that now their input also reflects the structure of the world outside. （出生后，同样的神经元继续以同样的方式被调节，只是现在它们的输入也反映了外部世界的结构。）其中 their input also reflects the structure of the world outside 对应选项 D 表述。
故选 D。

question_stem: According to paragraph 3, why have some people argued that processing faces is innate?
choices: tag: A
text: Babies are attracted to patterns that resemble the human face.

tag: B
text: Babies have a primitive, reflexlike reaction to faces.

tag: C
text: Some parts of the brain are devoted specifically to the recognition of faces.

tag: D
text: Studies show that the brains of infants are less specialized than those of adults.
answer_key: C
explanation: 题干提问“为什么有些人认为面部信息处理是天生的”。
定位第3段第2句 Because regions of the human brain are specialized for processing faces, some researchers have argued that this ability is innate.其中 Because regions of the human brain are specialized for processing faces（由于人类大脑的某些区域是专门处理面部信息的），对应选项 C 表述。
故选 C。

question_stem: In paragraph 3, why does the author discuss babies' recognition of faces?
choices: tag: A
text: To contrast the development of newborns and rodents in terms of the roles of nature and nurture

tag: B
text: To provide additional evidence for the argument that perceptual development is dependent upon activity

tag: C
text: To provide additional support for the idea that nature influences development more than nurture

tag: D
text: To describe how regions of the human brain become specialized during development
answer_key: B
explanation: 题干提问“作者为什么讨论婴儿面部识别”。
定位第3段第3句 However, experiments with infants reveal a more complex story.开始讨论 babies' recognition of faces，其 however 否定了前一句 processing faces is innate 的观点，进而证实了第1句 activity-dependent processes。可以理解为 babies' recognition of faces 作为证据，佐证了第1句观点，对应选项 B 表述。
故选 B。

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

tag: B
text: distinction

tag: C
text: understanding

tag: D
text: achievement
answer_key: A
explanation: integration n.结合，整合，一体化，与 union 同义。
故选 A。

question_stem: What example discussed in the passage leads to the conclusion it appears that infants actively contribute to their own subsequent development?
choices: tag: A
text: Babies achieve more complex eye movements through repeated practice.

tag: B
text: Babies learn some eye movements by imitating the eye movements they see in adults.

tag: C
text: Focusing on visual targets may make it more difficult for babies to develop adult eye movements.

tag: D
text: Infants are motivated to retain some primitive reflexive eye movements.
answer_key: A
explanation: 题干提问“以下哪个例子可以得出婴儿对他们自己随后的发展做出了积极的贡献的结论”。
定位第4段倒数第2句 the very limited ability present in newborns is just sufficient to allow them to practice and develop new brain circuits for the more complex integration of visual and motor information necessary for adult eye movements.（新生儿的能力非常有限，足以让他们练习和开发新的大脑回路，以便更复杂地整合成人眼球运动所需的视觉和运动信息。）对应选项 A 表述。
故选 A。

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: Different experiments on younger children often yield similar results about perceptual ability.

tag: B
text: Varying the visual stimuli in the same experiment has been shown to change the perceptual ability of younger children.

tag: C
text: The results of experiments on perceptual ability suggest younger infants change less dramatically than do older infants.

tag: D
text: Experiments show that perceptual ability changes significantly in the weeks and months after birth.
answer_key: D
explanation: 定位第5段高亮句，三个信息点：（1）when the same experiments were done with younger infants, （2）quite different results have often been obtained, （3）suggesting dramatic changes in perceptual abilities over the first few weeks and months after birth.提取主干内容为（2）different results 及（3）suggesting dramatic changes in perceptual abilities over the first few weeks and months after birth.对应选项 D 表述。
故选 D。

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

tag: B
text: permanent

tag: C
text: basic

tag: D
text: independent
answer_key: A
explanation: subsequent adj.随后的，后来的，与 later 同义。
故选 A。