科普五班 推荐文章
2020-03-02 06:00:08 来源：范文大全收藏下载本文
科普五班 09210808 张泓 推荐文章：
By 1950, the results of attempts to relate brain procees to mental experience appeared rather discouraging.Such variations in size, shape, chemistry, conduction speed, excitation threshold, and the like as had been demonstrated in nerve cells remained negligible in significance for any poible correlation with the manifold dimensions of mental experience.Near the turn of the century, it had been suggested by Hering that different modes of sensation, such as pain, taste, and color, might be correlated with the discharge of specific kinds of nervous energy.However, subsequently developed methods of recording and analyzing nerve potentials failed to reveal any such qualitative diversity.It was poible to demonstrate by other methods refined structural differences among neuron types; however, proof was lacking that the quality of the impulse or its condition was influenced by these differences, which seemed instead to influence the developmental patterning of the neural circuits.Although qualitative variance among nerve energies was never rigidly disproved, the doctrine was generally abandoned in favor of the opposing view, namely, that nerve impulses are eentially homogeneous in quality and are transmitted as “common currency” throughout the nervous system.According to this theory, it is not the quality of the sensory nerve impulses that determines the diverse conscious sensations they produce, but rather the different areas of the brain into which they discharge, and there is some evidence for this view.In one experiment, when an electric stimulus was applied to a given sensory field of the cerebral cortex of a conscious human subject, it produced a sensation of the appropriate modality for that particular locus, that is, a visual sensation from the visual cortex, an auditory sensation from the auditory cortex, and so on.Other experiments revealed slight variations in the size, number, arrangement, and interconnection of the nerve cells, but as far as psychoneural correlations were concerned, the obvious similarities of these sensory fields to each other seemed much more remarkable than any of the minute differences. However, cortical locus, in itself, turned out to have little explanatory value.Studies showed that sensations as diverse as those of red, black, green, and white, or touch, cold, warmth, movement, pain, posture, and preure apparently may arise through activation of the same cortical areas.What seemed to remain was some kind of differential patterning effects in the brain excitation: it is the difference in the central distribution of impulses that counts.In short, brain theory suggested a correlation between mental experience and the activity of relatively homogeneous nerve-cell units conducting eentially homogeneous impulses through homogeneous cerebral tiue.To match the multiple dimensions of mental experience psychologists could only point to a limitle variation in the spatiotemporal patterning of nerve impulses. 翻译: 至1950 年，试图将大脑过程（brain proce）和心理体验（mental experience）联系起来的研究努力，其结果令人甚是灰心丧气。正如由科学家在神经细胞中所证明的那样，尺寸、形状、化学过程、传输速度、兴奋阈值、以及诸如此类的种种差异，对于任何有可能的与心理体验形形色色诸多方面的内容加以联系起来的做法，在意义上仍是微足道。在十九世纪与二十世纪濒临交替转折之际，率先由赫林（Hering）提出，不同的感觉方式（mode of sensation），诸如痛若、味觉、以及色彩等，或许可与特异种类的神经能量（nervous energy）的释放联系起来。然而，随后所发展起来的用于记录和分析神经潜能（nerve potential）的方法没能揭示任何这类性质的差异。人们倒是可以通过其它方法来证明在诸神经元（neuron）种类之间，存在着细微的结构差异；但是，人们缺乏证据以证明神经冲动的性质或其传输受这些结构差异所影响。恰恰相反，这些结构差异所影响的似乎是神经网络（neural circuit）的发展性组合排列（developmental patterning）。虽然神经能量之间存在性质差异的观点从没有遭到严格的驳斥，但该学说普遍被抛弃，人们转而采纳了与之相对立的一个观点，即神经冲击从根本上来说在性质上是毫无二致的，并仿佛象“通用货币”（common currency）一样在神经系统中传输。按此理论，并非是感觉的神经冲动的性质在决定着它们所产生的不尽相同的有意识感觉，而是神经冲动所释放入其中的不同的大脑区域在起着决定性作用。对于这一观点，不乏某些证据。在某个实验中，当电流刺激联通到一个有意识的人类测试者大脑脑皮层（cerebral cortex）某一特定感觉区域时，它便产生了一种与那个特定区位相应的感觉形式（modality），亦即是说，自视觉脑皮层产生一视觉的感觉，自听觉脑皮层产生一听觉的感觉，以此类推。其它实验揭示出神经细胞在尺寸、数量、排列、以及相五联系这些方面的微弱差异，但就心理—神经的关系而言，这些感觉区域彼此间的明显共同点要比任何彼此间细小的差异似乎予人印象深刻得多。
然则，大脑区位理论就其本身而言亦最终证明几乎不具有任何解释价值。研究表明，像红色、黑色、绿色和白色，或者触觉、寒冷、温暖、运动、痛苦、姿势以及压力等如此大相径庭的感觉，显然有可能来自对相同脑皮层区域的刺激。所剩下的似乎是某种性质的大脑兴奋的不同组合排列效果：正是神经冲动中心分布这方面的差异才起着举足轻重的作用。简而言之，大脑理论暗示出在心理体验与相对同质的神经—细胞单位的活动之间存在着某种联系，而这些相对同质的神经—细胞单位则又通过同质的大脑组织传输着根本上同质的冲动。为了将心理体验的多重侧面对应起来，心理学家只能将注意力投向神经冲动在时空（spatiotemporal）组合排列方面无穷尽的差异。
推荐理由：这篇文章是我在练习GRE阅读的时候遇到的，当时对于文章的把握不是很好，但是反复读文章以及译文，我觉得它应该属于一类典型的科技文，虽然GRE的词汇难度可能稍微大一些。
区别于以往的科技文阅读，它的中心不是介绍某种技术，而是一个医学研究和结论，文章的结构为分总，推动文章发展是以时间为轴，研究实验过程和结论，难于把握的原因在于段落中心不容易明确，关于专业研究过程表述可能很多，但一旦抓住文章结构，好多内容是可以不用可以理解的。所以我觉得这类文章可以通过先阅读结论，在根据时间点，不同实验分析文章的方式解决阅读问题。
此外，文章中有非常多典型的句型，各种表达转折或者承接的词或者词组，科技文阅读逻辑性还是很强的，这些句型和介词副词的掌握对于文章分层，理解文章还是挺重要的。综上，我推荐这篇文章。
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