Penfield's homunculus: a note on cerebral cartography.
Penfield's homunculus: a note on cerebral cartography.
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彭菲尔德的小人：关于大脑制图的注释。
DOI：
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发表时间：
1993
影响因子：
11
通讯作者：
G. Schott
中科院分区：
文献类型：
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作者：
G. Schott
1937年，彭菲尔德和博尔赫斯发表了一篇具有重大意义的论文。“他们描述了他们对刺激人类大脑皮层的影响的研究，这些程序是作为探索性操作来进行的，以描绘出随后手术干预的适当区域。他们证实了皮质定位的精确地形，并能够将大脑离散部分的刺激与影响身体特定部位的运动和感觉现象联系起来。虽然这些现在的经典研究证实并大大扩展了早期对清醒的人类和动物实验的观察结果，但他们的研究结果的呈现方式是显着的。这是人们第一次尝试用图画的方法来说明大脑皮层的表征;因此，这是一个全新的概念，但它也是一个被证明是一种奇怪的说明方法，并引起了许多意想不到的问题。彭菲尔德和博尔赫斯着手说明感觉运动带中的“顺序和比较范围”。“为了呈现他们观察的地形，作者偏离了对大脑刺激效果的严格文本描述，并实现了一个非凡的概念飞跃：一位艺术家，H. P.坎特利夫人，被雇用来绘制一个感觉和运动侏儒-下面讨论的术语。这第一个被创造出来的侏儒（图1）被描述为“大脑皮层区域的大小和顺序的视觉图像”。它的形状是对称的，同时展示了运动和感觉的特征;然而，实际上所代表的是模糊和混乱的。提交人说，各部分的大小“与其说是由答复的数量决定的.。而是通过当这些响应对于同一部分是多个时每个部分的表示的表观垂直范围”。“垂直”的意思没有说明，从随后的评论中变得更加不清楚：“拇指和嘴唇的大尺寸表明在个别情况下专门用于这些部分的罗兰皮层的垂直范围非常大”。目前还不清楚“垂直”是否与“垂直”相同，以及这些术语是否意味着在皮层表面上纵向，或深，因为作者还刺激大脑的深层后，切除区域摘除异常的大脑。提到对同一部分有多个反应也很难解释，因为这可能意味着多个部位在引起反应方面是有效的，或者只有在某些区域才真正刺激了多个部位。虽然侏儒看起来与长度而不是宽度有关，但实际上所示的部分在两个维度上都被放大了。同样值得注意的是，为了表现的目的，反应已经被转移到大脑的同一侧，从图示中无法区分皮层刺激的单侧和双侧效应。13年后，彭菲尔德和拉斯穆森在他们题为《人类大脑皮层》的专著中又一次试图说明皮层的代表性。
In 1937, Penfield and Boldrey published a paper of major importance.' They described their work on the effects of stimulation of the cerebral cortex in man, the procedures being carried out as exploratory manoeuvres to delineate the appropriate area for subsequent surgical intervention. They confirmed the precise topography of cortical localisation, and were able to relate stimulation of a discrete part of the brain with motor and sensory phenomena affecting a particular part of the body. Whilst these now classical studies confirmed and greatly extended what had been known from earlier observations in awake humans and from experiments in animals, the manner of presentation of their findings was remarkable. It was the first time pictorial means of illustrating cortical representation had been attempted; it was thus an entirely new concept, but it was also one which has proved a curious method of illustration and one which gives rise to a number of unforseen problems. Penfield and Boldrey set out to illustrate "the order and comparative extent" occupied in the sensorimotor strip.' To represent the topography of their observations, the authors departed from the rigorous textual description of the effects of stimulation of the brain and achieved an extraordinary conceptual leap: an artist, Mrs H P Cantlie, was employed to draw a sensory and motor homunculus-a term discussed below. This first homunculus to be created (fig 1) was described as giving "a visual image of the size and the sequence of the cortical areas". It was symmetrical in shape and illustrated both motor and sensory features together; what actually was represented, however, was ambiguous and confusing. The authors state that the size of the parts was determined "not so much by the number of responses...but by the apparent perpendicular extent of representation of each part when these responses were multiple for the same part". What is meant by "perpendicular" is not stated, and it becomes even less clear from the subsequent comment: "that the large size of the thumb and the lips indicates the vertical extent of Rolandic cortex devoted to those parts in individual cases is very large". It is unclear whether "vertical" is the same as "perpendicular", and whether these terms mean longitudinal over the cortical surface, or deep-since the authors also stimulated deeper layers of the brain after having resected areas for extirpation of abnormal brain. The referral to responses which were multiple for the same part is also difficult to interpret, since it could imply multiple sites were effective in eliciting responses, or that only in certain areas were multiple sites actually stimulated. Whilst the homunculus appears to relate to length rather than width, the parts illustrated are in fact enlarged in both dimensions. Also noteworthy is that responses have been transposed to the same side of the brain for the purposes of representation, and it is not possible from the illustration to distinguish unilateral from bilateral effects of cortical stimulation. Thirteen years later, in their monograph entitled The cerebral cortex of man, Penfield and Rasmussen made another attempt to illustrate cortical representation.2 This was preceded by a diagram of a cross-section of the cere-