LB 060-063 勝芬 T

LB 060-063
(Thanks for the typing from YUCEBEY & ALEKSANDRA)

Penfield and Roberts state that not every stimulation in the critical area interferes with speech. However, they have not published maps of the ineffectual stimulations.

潘菲爾(Penfield)和羅勃茲(Roberts)聲明並不是每一種在關鍵區裡的刺激都會干涉語言，但他們仍未發表無效刺激的對應圖(map)。


If we survey the collected evidence, we cannot fail to be puzzled. Why do patients who had normal brain function up to the time of catastrophe sometimes have aphasia from lesions in relatively uncharted areas, whereas Penfield’s patient who had abnormal brain function have aphasic symptoms when stimulated in the “orthodox” speech areas? Why is there, in Penfield’s patients, such a relatively poor correlation between the stimulation points (where transient aphasia can be produced) and the cortical excisions in the vicinity of the same areas? Could this discrepancy be an artifact resulting from the indiscriminate pooling of cases for the construction of the map? If there were so, we would have to conclude that there is a great deal of individual variation.

如果我們研究收集而來的證據，我們依然非常困惑。為什麼當腦部功能正常的病患受到腦部損傷時，有的時候其失語症是來自相對的未標記區塊；反之，潘菲爾所研究的腦部功能不正常的病患，其失語症狀是來自「正統」的語言區塊？為什麼潘菲爾的病患就有這種現象，刺激點（短暫失語症能被觸發）和同個區塊的表皮切除之間的關係如此薄弱？這樣的差異是否來自不加區分案例的人為結果，就為了對應圖的建構？如果是這樣，我們能下的結論是這關乎個體的變異。


Penfield and Roberts have also published distribution of stimulation points arranged according to the type of aphasic symptom produced: complete arrest of speech, hesitation and slurring, distortion and inability to name objects with retained ability to speak. There is no evidence, however, that any one of these symptoms is correlated with any sharply delimited cortical area.

潘菲爾(Penfield)和羅勃茲(Roberts)根據失語症狀的類型，也發表了刺激點的分布區域：完全無法說話；口吃和口齒不清；扭曲和無法使用保有的語言來命名。然而，還沒有證據來說明任何一樣症狀跟皮質區域明確的界定有交互關係。


Direct stimulation of the cortex may sometimes do more than simply interfere with ongoing speech. It may also elicit fractions of the motor speech act. Penfield and Roberts show a region in which stimulation would occasionally cause the patient to vocalize, namely, either margin of the left (and also the right) Rolandic fissure. The sounds are described as a vowel, and the vocalization will last for the duration of the stimulation; if the patient runs out of breath, he will quickly inhale and continue. The patient is usually aware that he is making sounds, but he is unable to bring this under voluntary control. Besides voicing, pursing of the lips and movements of tongue and jaw may be observed. These movements are not caused by random contraction of one or the other muscle but are well-integrated components such as might enter into chewing, speaking, or swallowing activities.

腦皮層的直接刺激不僅單單妨礙語言的進行，有時候甚至影響更多，這種刺激也可能會引發片斷的運動性言語障礙(motor speech)。潘菲爾和羅勃茲指出能讓病患間歇發聲的區域，就在中央溝(或稱羅蘭度氏裂 Rolandic fissure)右側或左測的邊緣，而刺激發出的聲音是我們所稱的母音，刺激的期間都能持續發聲，若病患氧氣不足時，他會趕緊吸氣再繼續發聲，病患通常會意識到自己在發出聲音，但是他無法隨意控制自己的發聲。除了聲音之外，雙唇的縮攏開合，舌頭和下顎的動作也都能觀察得到，但是這些動作並不是任意由某種肌肉就能做到，而是需要各種肌肉良好的合作，像是咀嚼、說話、吞嚥等動作。


Interesting as the stimulation experiments are, their relevance to our understanding of the speech mechanism is only limited. Stimulation is a thoroughly abnormal interference with brain function; here nervous activity is initiated on the surface of the cortex from a single anatomic location. In the normal state, however, neuronal activity for speech may consist of modulation of ongoing activity in various parts of the left parietal and frontal cortex.

就如同這個有意思的刺激實驗一般，其相關性對於我們對語言機制的了解其實是被限制住的，刺激對大腦功能來說，完全是種不正常的干擾，神經活動是從單一結構的腦皮質表面開始，然而，在正常的情況下，說話的神經活動是由左顱頂骨(left parietal)和額葉皮質(frontal cortex)裡，各種區域正在進行的模組所組成。


a) Summary: Language and Cortex. The discussion leads us to the following conclusions.

摘要：語言與腦皮質。這些討論帶給我們以下的結論。


Cortical maps of language disorders vary, depending to some extent on the mapping method and on the types of lesions adduced as basic source material.

根據對應方法和語言損害案例的實驗素材，語言障礙的腦皮質對應圖會有所改變。


There is no evidence for an “absolute” language area, but the language function may be localized in statistical terms. Although there is no one area which is necessarily, and exclusively involved in language disturbances in all individuals, there are some regions which are very frequently so involved and other regions which are never involved in either speech or language.

沒有任何證據顯示語言在腦部的絕對對應位置，但是語言功能卻可能由統計術語來局部化分，雖然說沒有任一區域是必要或絕對的牽涉語言混亂，但是就有些區域會經常性的牽涉其中，而有些區域則永遠不會。


Lesions on either margin of the left Rolandic fissure and convolutions anterior to it frequently interfere with speech production. Comprehension of language is primarily interrupted through lesions in the left parietal lobe and the rostral aspects of the temporal lobe (Wernicke’s area).

在左羅蘭度氏裂的邊緣和其前部迴旋的損害，經常會妨礙語言的產出(language production)，而在左頂葉(left parietal lobe)和顳葉(temporal lobe)吻部(韋尼克區(Wernicke’s area))的損傷，主要會干擾語言的理解。


There is no clear-cut evidence that Broca’s area is more specifically related to speech than areas adjacent to it.

相較於波卡區(Broca’s area)的鄰近區域，我們也沒有明確的證據指出波卡區和語言有更為特別的關連。


The “language maps,” established on a statistical basis, are not histologically homogeneous. There is no cytoarchitectural pecularity of the cortical areas involved in language.

以統計為本所建構的語言對應圖，並不是組織同質性，而牽涉語言的皮質區域亦沒有細胞建構的特性。


Broca’s area consists of large cells in the third and fifth cortical layer, but it is doubtful that this is relevant to language.

波卡區是由第三和第五皮質層的大細胞所組成，不過是否和語言有所關聯仍須存疑。


The histological maps of cerebral cortices of subhuman primates have somewhat different lines of demarcation than man. This is true or cortical areas which in man have relevance to language; it is also true of Broca area. The cytoarchitecture of Broca’s is also found in some roughly homologous areas in the cortices of some subhuman primates.

近似人類的靈長類，其大腦皮質的細胞分布約略和人類有不同的界線，從人類皮質區域跟語言的相關性以及波卡區就可看出，不過在靈長類的波卡區細胞建構中，也可以找到大致與人類同源的皮質區域。


It would be circular or meaningless to state that only man has a cortical speech area, because cortical language maps are based on observation of behavior. We cannot observe language interference in an animal that does not speak. Such an animal, by definition, lacks speech areas.

聲稱只有人類有語言皮質區是種迂迴或無意義的的說法，因為語言皮質分布是建立在行為觀察的基礎之上，我們無法觀察不會說話動物的語言干擾，在這種定義下的動物是缺乏語言區域的。


(1) Subcortical Structures Traditionally, all intellectual functions including speech and language have been through to be located in the cerebral cortex, and more speculations have been directed to this thin sheet of tissue than toward any other cerebral component. However, there are many other structures that are demonstrably connected with the cortex and with each other (often only by circuitous routes). Every structure of the brain is physiologically active and at least some of the structures have been hypothesized to play a part in the same intellectual functions that are more frequently imputed to the cortex. These speculations have been going on for over a generation. As an example, we may cite Campion and Elliot-Smith (1934) who proposed that thought consisted of corticothalamic circulation of impulses. Penfield has suggested the existence of a centrencephalic integrating system, which he has definedas that central system within the brain stem which is responsible for integration of varied specific functions from different parts of the hemispheres. Occasionally, he has defined it even more loosely as that system which includes all those areas of subcortical gray matter, together with their connecting tracts, serving the purpose of intra- and interhemispheral integration. This formulation, as it stands, would include all gray matter beneath the cortex. It reflects our lack of knowledge regarding the cognitive functions of the subcortical ganglia, a state of affairs for which we can hardly hold Penfield responsible. Recently, Penfield has attributed a major role in the execution of speech to a certain part of the centrencephalic system. “It is proposed,” he writes (Penfield and Roberts, 1959, p. 207) “as a speech hypothesis, that the function of all three cortical speech areas (that is, Broca’s, Wernicke’s, and the supplementary motor speech area) in man are coordinated by projections of each to parts of the thalamus, and that by means of these circuits, the elaboration of speech is somehow carried out.” Penfield finds evidence for this supposition (a) in the fact that the superficial excisions performed by him do not cause permanent aphasia, whereas deep trauma and cerebro-vascular accidents do cause aphasia, both as a rule affecting subcortical structures; and (b) in the demonstration of fiber tracts running from the so-called speech areas to part of the thalamus. It is well to bear in mind, however, that it has never been demonstrated that all lesions causing irreversible language disorders interrupt those particular cortico-thalamic connections to subcortical centers.

(1)皮質下組織 依慣例來說，所有智力功能包含說話和語言能力，就遍佈在大腦皮質的區域之中，更多的推測直接表示，這些功能就落在這層薄如紙片的組織之上，而非其他的大腦物質。然而還有很多其他的組織與腦皮層相連結或相互連結 (通常只有迴圈路徑)。大腦每一種組織在生理上都很活躍，而且至少有一部分被假定成為在同一種智力功能中扮演了某種角色，更常歸因於皮質層。這些特性已經有好幾十年了，讓我們引用Campion and Elliot-Smith (1934) 提出的論點為例，他們認為思考是由皮質丘腦(corticothalamic)的刺激循環所造成，潘菲爾提出中央頭部(centrencephalic)統合系統的存在，他把這個系統定義成腦幹的中央系統，負責不同大腦半球中各種特殊功能的整合，潘菲爾的說法使得這個系統的定義更為鬆散，以潘菲爾的定義來說，這個系統包含所有皮質下的灰色神經組織(subcortical gray matter)和其間的連接通道，並負責大腦半球內部的整合。若以這種想法來看，皮質層底下就會包含所有灰色神經組織，這反映了我們對於認知功能的皮質下神經節(subcortical ganglia)的知識缺乏，因此我們很難對潘菲爾提出疑問。最近潘菲爾認為中央腦部系統是說話能力執行的主要角色，他寫道(Penfield and Roberts, 1959, p. 207)：「我們提出一個說話能力的假說，那就是三個說話能力區域(波卡氏區、韋尼克氏區、次要運動性語言障礙區)的功能，是由丘腦(thalamus)的各個部分所調節，而藉由這種迴路，語言能力的精巧就這樣呈現了。」潘菲爾所找到證據來支持他的論點 (a)事實上，他將皮質表面的切除發現並不會產生永久性的失語症，而深層的創傷和腦血管的傷害則會產生失語症，兩者皆有影響皮質下組織的慣例。 (b)纖維管道從語言能力區到一部分丘腦的運作，也是一種證據。然而，值得我們銘記在心的是，仍沒有證據說明所有的損傷所引起的不可逆語言障礙，會阻礙特定皮質丘腦(cortico-thalamic)和皮質下中心(subcortical centers)的連結。


The exact cortico-thalamic correspondences in man are not fully known (Feremutsch, 1963; Clark, 1932; Walker, 1938). Our conceptions are based on extrapolations from research on monkeys and apes. According to the most recent and reliable investigations the lateroventral nucleus of the thalamus sends fibers into those cortical sectors which are most clearly involved with motor speech (together with other motor functions). The temporo-parietal regions of the cortex which are implicated in nonmotor aspects of language are connected by fibers to the latero-posterior nucleus of the thalamus and the pulvinar.(see Fig 2.23).

人類皮質丘腦到底如何連繫仍然未知(Feremutsch, 1963; Clark, 1932; Walker, 1938)，我們的概念是建立於猴子和人猿的實驗之上。根據最新且最可靠的研究，丘腦的腹側腺核(lateroventral nucleus)會發送纖維進入皮質區域，最明顯的就是牽動了運動性言語障礙 (同時牽動其他運動功能)，皮質層牽連非運動性言語的顳頂區(temporo-parietal regions) 會藉由纖維連接丘腦的側後核(latero-posterior nucleus)與丘腦後結節(pulvinar)。