Let us focus on the species-specificities of behavior. There are certain cerebral functions that mediate between sensory input and motor output which we shall call generically cognitive function. The neurophysiology of cognitive function is largely unknown but its behavioral correlates are the propensity for problem solving, the formation of learning sets, the tendency to generalize in certain directions, or the facility for memorizing some but not other conditions. The interaction or integrated patterns of all of these different potentialities produces the cognitive specificities that have induced von Uexkuell, the forerunner of modern ethology, to propose that every species has its own world-view. The phenomenological implications of his formulation may sound old-fashioned today, but students of animal behavior cannot ignore the fact that the differences in cognitive processes (1)are empirically demonstrable and (2) are the correlates of species-specific behavior.
讓我們把焦點放在特定物種的行為上。在知覺的輸入與我們一般認為的認知功能之間還有某種的腦部功能做為中介。認知功能方面的神經生理學目前還不為人所知，但行為上的研究依然與問題解決、學習的形成、一些方向的歸納傾向或是為了記憶而有設備有關。這些不同的互動與綜合的型式的潛能會產生出認知獨特性。Von-Uexkuell—現代人類學的先驅。他假設每種物種都有它獨特的世界觀。他所推測的這些現在可能落伍了，但研究動物行為的學生仍不能忽略認知過程不同的這個事實。
(ii) Specific properties of cognitive function are replicated in every member of the species.
Although there are individual differences among all creatures, the members of one species resemble each other very closely. In every individual a highly invariable type of both form and function is replicated. Individual differences of most characteristics tend to have a normal (Gaussian) frequency distribution and the differences within species are smaller than between species. (We are disregarding special taxonomic problems in species identification.) The application of these notions to (i) makes it clear that also the cognitive processes and potentialities that are characteristics of a species are replicated in every individual. Notice that we must distinguish between what an individual actually does and what he is capable of doing. The intraspecific similarity holds for the latter, not the former, and the similarity in capacity becomes striking only if we concentrate on the general type and manner of activity and disregard such variables as how fast or how accurately a given performance is carried out.
(ii) 認知功能的特定特性會反映在每個物種中。
雖然生物之間有個別的差異，但同一物種之下的成員彼此之間還是十分相似。
每一個物種都有複製了不變的型態與功能。大部分個體的差異傾向於正常頻率分布和物種自己的差異小於物種之間的差異。(我們不考慮在物種定義中的分類的特殊問題。) 這些觀念運用在
(i)讓物種的認知過程與潛力更加清楚，這也是每種個體都有的物種的特徵。注意我們必須分辨個體確實做了甚麼與個體有能力去做甚麼。至於intraspecific的相似性我們之後再探討。只有我們專注於活動一般的種類與方式和不顧這些表現執行的多快與多正確的變數，這些相似性才會變得驚人。
(iii) Cognitive processes and capacities are differentiated spontaneously with maturation.
This statement must not be confused with the question of how much the environment contributes to development. It is obvious that all development requires an appropriate substrate and availability of certain forms of energy. However, in most cases environments are not specific to just one form of life and development. A forest pond may be an appropriate environment for hundreds of different forms of life. It may support the fertilized egg of a frog or a minnow, and each of the eggs will respond to just those types and forms of energy that are appropriate to it. The frog’s egg will develop into a frog and the minnow’s egg into a minnow. The pond just makes the building stones available, but the organismic architecture unfolds through conditions that are created within the maturing individual.
(iii) 認知過程與潛力不同於自然的成熟。
這個陳述與環境如何發展有關的問題並不會令人困惑。很明顯的所有的發展都需要適當的底層與力量的一種形式。 然而，大部分的例子中環境並不是指生活的形式和發展。森林中的池塘可能很適合數以百計不同生命形態所生活的環境。池塘會養育青蛙的受精蛋或是小魚，但每一種蛋都是適合這個環境的力量型式的一種。青蛙蛋會生出青蛙與小魚的蛋會生出小魚。池塘指示一個建造出的石頭但這有機的建築展現出可以創造出成熟個體的環境與條件。
2009年1月4日 星期日
2008年12月22日 星期一
LBT 057-060
The most painstaking histological investigations of Broca’s area were carried out by Kreht (1936), who followed the tradition of the Vogts with their careful description of every detail and variation in cell density and size. Von Bonin’s and Bailey’s observations were essentially the same as Kreht’s, but the latter also occasionally found larger cells in layer VI. The fourth layer in all cortices examined was noticeably sparsely populated with cells. Kreht observed that Broca’s area always tended to be different from surrounding areas, but that the cytoarchitecture itself in this region varied greatly from brain to brain. Kreht also investigated homologous areas in brains of a few apes and monkeys and found that the cortices of these animals had areas with similar cytoarchitecture as that found in Broca’s area. Thus the microscopic anatomical detail does not contribute to our search for histological correlates of speech and language.
有關Broca’s area 所做的最艱苦的歷史研究是由 Kreht (1936)所擔任的。他是一位跟隨Vogts的腳步，細心的描述有關細胞密度與大小的所有細節與變化。Von Bonin’s 和Bailey’s 的觀察就跟Kreht 的觀察一樣的重要。 但Kreht 偶爾會發現到在第五層有較大的細胞。被發現到在第四層的所有皮層間只分布了稀疏的細胞。Kreht 觀察到Broca’s area 與其周圍的區域都有所不同。但在這個區域的細胞結構本身根據不同的腦袋而有很大的改變。Kreht 也調查到在一些人猿與猴子的腦袋中有類似的區域且發現這些動物的皮層都有與Broca’ area 相似的區域。所以，這些精微的解剖細節就我們研究語音與語言相關的歷史並沒有很大的貢獻。
Behavioral Maps. The mapping of speech areas is based on observations of behavioral derangement in the presence of (α) internal brain disease; (β) of penetrating head injuries (trauma); (γ) surgical excision; and (δ) observations of behavior during electrical stimulation of the exposed cortex during surgery.行為地圖
語音區域的地圖是以有關目前出現的行為擾亂的觀察為基礎。
(α)內部腦部疾病
(β)尖銳的腦部傷害(外傷)
(γ)外科手術的切除
(δ) 在手術期間對於暴露在外的皮層做電擊的刺激的行為觀察。
(α). From a heuristic point of view, the first type of observation ids the most unsatisfactory one because of many cases in which the exact location of the lesion is only a matter o speculation, and even if these brains should become available for postmodern examination the patient may have died of more widespread disease and destruction in the brain than the lesion which first caused aphasia.
從啟發式的觀點看來，第一種的觀察也是最令人不滿意的一種。因為在確切損害部位的很多例子只是種推測。即使這些大腦經過後現代的檢驗，病人死於腦袋有大規模的疾病或傷害而不是由於死於失語症。
Nevertheless, the vast majority of aphasia patients owe their speech disturbance to internal brain disease, particularly cerebro-vascular accidents, commonly known as strokes. Tissue is destroyed or function is temporarily interrupted because of insufficient blood supply caused by a clot in or rupture of a vessel. The artery most often implicated is the left middle cerebral artery, which runs along the sylvian fissure and sends out branches through the entire lateral face of the hemisphere, as shown in Fig. 2.21. It is precisely because of the vast territorial extent of this artery that behavioral derangement resulting from interference with it gives us the least specific information concerning the localization of the speech and language function. Even when the vascular insufficiency is demonstrated by x-rays of the vascular tree, the exact location of the actual dysfunction remains largely a matter of speculation.
雖然如此，但大部分失語症的病人是有他們腦內疾病的語言障礙，特別是腦血管疾病，也就是中風。因為由於血脈的結塊或是破裂而造成血液供應的不足，會造成Tissue的破壞或是功能暫時性的影響。動脈通常是腦部左邊中間的要道，通常沿著裂縫已及經過整個半腦的側臉來傳送出分支。如 表2.21.顯示。這是十分精確的因為大部分此要道之所以導致行為錯亂是因為此要道只給我們有關語音及語言作用的局佈最少的特定資訊造成了干擾。即使經由x光可以呈現出血脈的不足或缺乏，但確切機能有障礙的區域依舊需要去進一步探索。
(β). Inferences from traumatic lesions have been drawn repeatedly (Goldstein, 1942, Luria, 1947, Conrad, 1954, Russell and Espir, 1961), resulting in various maps. The extent of the lesion can be determined more accurately in these cases than in internal brain disease, but the fact is frequently overlooked that trauma also causes secondary pathology (particularly hemorrhage and edema) which may have deleterious effects on tissue far beyond the visibility destroyed areas. In Fig. 2.22 the centers of penetrating head injuries to the left hemisphere are shown with indications of those injuries which caused lasting aphasia and which did not. The subjects were veterans of Word War II. To make Russel’s and Espir’s material comparable to Conrad’s, the diagrams had to be redrawn, and in this process some distortions are inevitable because neither the original drawings nor the present mode of representation can be read unequivocally. The distortions, however, occur primarily around the outer margins of these diagrams and are due to the shortened perspective of the curved surfaces. Nevertheless, it is clear that the resulting maps are not identical although correspondences exit. In Conrad’s material, motor-speech deficits predominate on both margins of the central sulcus and extend frontally; linguistic sensory and amnestic deficits predominate in the parieto-occipital areas, but there are few cases which do not conform to this distribution. Russel and Espir do not indicate the nature of the language deficit in their original data. In both cases we cannot fail to be impressed with the random-appearing scatter of lesions and with the overlap between aphasia-producting and aphasia-free lesions. The most striking findings of these recent studies are that there seems to be no more than a statistical relationship between Broca’s area and the resultant deficit.
(β).有關外傷區域的推論一直被持續關注，導致了多樣的情況。在這些例子受傷領域可以比腦內疾病更準確的做出決定，但事實是，通常忽略了傷口也會引起第二種病狀，像是出血或浮腫，這些可能會對tissue造成有害的影響而非只是單單可見的受傷的區域。在表2.22中顯示出滲透腦部傷害中心到左半腦指出傷害有些會引起永久的失語症，有些不會。我們研究的主體是在第二次世界中的老兵。比較Russel與Espir 的Conrad的物質，這個圖表必須要重新畫，且在這過程中一些曲解使無法避免的，因為原本的畫與現在的呈現模式都沒有辦法明確的解讀。一開始由於透視這些曲線的表面，會造成發生在這些圖表的外邊緣的扭曲。然而，很明顯的，造成的地圖已經不是一樣的雖然跟出口相符。
在Conrad的物質中，言語的不足主要在sulcus中間的區域以及擴張到前部。語言感官以及amnestic的不足主要在parieto-occipital 區域。但有一些例子跟這樣的分布並不一樣。Russel以及Espir在它們的原始區域並沒有指出有語言上的不足。在這兩個例子，我們對隨機出現的受傷的傳播已及產生失語症或沒有產生失語症的傷口有了印象。最令人吃驚的發現是，現今的研究指出Broca’s area與結果上的不足只是一種統計上的關係。
(β).有關外傷區域的推論一直被持續關注，導致了多樣的情況。在這些例子受傷領域可以比腦內疾病更準確的做出決定，但事實是，通常忽略了傷口也會引起第二種病狀，像是出血或浮腫，這些可能會對tissue造成有害的影響而非只是單單可見的受傷的區域。在表2.22中顯示出滲透腦部傷害中心到左半腦指出傷害有些會引起永久的失語症，有些不會。我們研究的主體是在第二次世界中的老兵。比較Russel與Espir 的Conrad的物質，這個圖表必須要重新畫，且在這過程中一些曲解使無法避免的，因為原本的畫與現在的呈現模式都沒有辦法明確的解讀。一開始由於透視這些曲線的表面，會造成發生在這些圖表的外邊緣的扭曲。然而，很明顯的，造成的地圖已經不是一樣的雖然跟出口相符。
在Conrad的物質中，言語的不足主要在sulcus中間的區域以及擴張到前部。語言感官以及amnestic的不足主要在parieto-occipital 區域。但有一些例子跟這樣的分布並不一樣。Russel以及Espir在它們的原始區域並沒有指出有語言上的不足。在這兩個例子，我們對隨機出現的受傷的傳播已及產生失語症或沒有產生失語症的傷口有了印象。最令人吃驚的發現是，現今的研究指出Broca’s area與結果上的不足只是一種統計上的關係。
(γ). Surgical excision of limited cortical tissue is a fairly common occurrence in clinical neurology. Pefield and Roberts (1959) have described the outcome of such operations performed on 273 patients who had suffered from focal cerebral seizures caused by earlier injuries, infection, or anoxia of the brain. Over the years, examples of ablations on every part of the cortex have been accumulated, although Broca’s area was only excised once and this happened to be a patient with an atypical early history. In all of this material from which tumor cases are excluded, there are few cases in which the removal of cortical tissue resulted in more than a temporary dysphasic condition, with language function restored within a matter of days or weeks. Many operations in the critical areas had no language disturbance. This is puzzling in view of the consequences of traumatic lesions and cerebro-vascular accidents. We might have expected that in many more cases permanent aphasia had resulted. The explanation must be due to some important differences between the surgical cases and others. First, patients who come to surgery have had histories of years of abnormally functioning brains manifested by recurrent and uncontrollable seizures. We cannot be sure of the effect that this might have had on localization (using the world here in its loosest terminology). Penfield and Roberts believe that the epileptogenic focus is not the location of the lesion but is adjacent to it. The lesion itself constitutes an irritant which induces abnormal function in structurally healthy tissue. Thus, there may be a systematic “bias” in the localization of function in these brains. The tissue that is surgically removed probably had not been participating in speech function for some years. 。However, this explanation begs the basic question: why does sudden destruvtion of tissue interfere irrevocably with language in adult patients, whereas language often remains essentially unaffected in cases where similar destructions were preceded by years (sometimes a lifetime) of sporadic, short, physiological interferences?
(γ). 手術切除有限的外部皮質在臨床神經學是常常發生的。Pefield 和Roberts (1959) 有討論到因為之前的受傷，感染或是腦部缺氧而遭受腦部疾病的273位病人經過切除有限的外部皮質的手術後的結果。
這幾年來，皮層每一部切除的例子持續的增加。雖然 Broca’s area曾被排除，而這也發生在早期不合規則的歷史上。所有這些物質都把腫瘤排除，有很少的例子是移除皮層的組織導致幾天或是幾個禮拜後，短暫的語言功能重置。 很多在關鍵區域的手術都會有語言錯亂的現象。就外傷與腦部血管意外的結果來看是很令人困惑的。 我們可能預期會造成更多永久的失語症的例子。這個解釋也是由於一些有關手術例子之間的重要不同。
首先，來動手術的病人必須證明有週期性並且無法控制的腦部功能反常的病例。我們無法確定局部化(就世界來說是最大概的術語)會有的效應與影響。Penfield和Roberts相信epileptogenic的焦點不是受傷的確切地方而是其鄰近的部分。而傷口本身構成刺激，而起刺激是由於在結構健全的tissue之下激發反常的作用。因此，可能會有有系統的偏差在這些腦部的作用的局部化。 這個手術移除掉的tissue可能會影響語言功能的作用有幾年之久。然而，這個解釋產生一些基本的問題: 像是為何這些突然的tissue的destruvtion會無法阻止的干擾成人病人的語言?反之，語言通常是重要的且不受影響的，但是萬一相似的構造持續好幾年(可能是一輩子)都會有不定時，短暫的且生理上的干擾呢?
(γ). 手術切除有限的外部皮質在臨床神經學是常常發生的。Pefield 和Roberts (1959) 有討論到因為之前的受傷，感染或是腦部缺氧而遭受腦部疾病的273位病人經過切除有限的外部皮質的手術後的結果。
這幾年來，皮層每一部切除的例子持續的增加。雖然 Broca’s area曾被排除，而這也發生在早期不合規則的歷史上。所有這些物質都把腫瘤排除，有很少的例子是移除皮層的組織導致幾天或是幾個禮拜後，短暫的語言功能重置。 很多在關鍵區域的手術都會有語言錯亂的現象。就外傷與腦部血管意外的結果來看是很令人困惑的。 我們可能預期會造成更多永久的失語症的例子。這個解釋也是由於一些有關手術例子之間的重要不同。
首先，來動手術的病人必須證明有週期性並且無法控制的腦部功能反常的病例。我們無法確定局部化(就世界來說是最大概的術語)會有的效應與影響。Penfield和Roberts相信epileptogenic的焦點不是受傷的確切地方而是其鄰近的部分。而傷口本身構成刺激，而起刺激是由於在結構健全的tissue之下激發反常的作用。因此，可能會有有系統的偏差在這些腦部的作用的局部化。 這個手術移除掉的tissue可能會影響語言功能的作用有幾年之久。然而，這個解釋產生一些基本的問題: 像是為何這些突然的tissue的destruvtion會無法阻止的干擾成人病人的語言?反之，語言通常是重要的且不受影響的，但是萬一相似的構造持續好幾年(可能是一輩子)都會有不定時，短暫的且生理上的干擾呢?
The surgical cases do not differ only from traumatic and vascular lesions in terms of abnormal function. The surgical lesion is always different from the other lesions; it is usually shallower, there is no uncontrolled bleeding, it does not follow the distribution of the vascular tree, and the healing process is histologically and morphologically different from the events that follow the cerebro-vascular accidents and trauma. With this many differences between the surgical cases and other cases, it is fair to say that surgical lesions are not commensurable, and the difference in effects cannot yet be interpreted. However, there is one lesson we may learn from cortical excisions. The narrow localization theory which holds that engrams for words or syntactic rules are stored in certain aggregates of cells cannot be in accord with the clinical facts.
這個手術的例子與其他沒有甚麼不同只有外傷與血脈也就是不正常的作用。手術的傷口總是與其他的傷口不同。它通常比較淺，沒有不可控制的出血，不會照血脈的分布且痊癒的過程有邏輯得且型態上與跟腦血管意外與外傷是不同的。
手術與其他例子得很多不同，我們可以說手術的傷口不是可計量的，且影響上的不同不是可以解釋的。然而，我可以從皮層的切除學到寶貴的一課。較窄的局部化理論表示字的記憶或是句型規則是被儲存在細胞的集合體，並非根據臨床的事實。
(δ) Electrical stimulation of the exposed cortex during neurosurgery is another source of evidence for cortical function-maps. It is again Penfield and Roberts who have systematized their findings. 。For instance, they have published (1959) a cortical map showing points of stimulation affecting motor speech. From this map it is difficult to discern any sharply circumscribed area of functional representation.
Roughly, the stimulation map corroborates the impression gained from the maps of Fig. 2.22 although it does seem as if there were at least statistical discrepancies between the two types of source-material for such maps.
Roughly, the stimulation map corroborates the impression gained from the maps of Fig. 2.22 although it does seem as if there were at least statistical discrepancies between the two types of source-material for such maps.
(δ)在神經外科對於暴露的皮層給與電的刺激是另外一種皮層作用地圖的證據來源。又是Penfield 和Roberts 曾將他們的發現系統化 例如，它們出版了皮層地圖指出刺激影響動態語音。從這個地圖，很難去分辨任何功能代表的明顯的限制。 大體上，刺激的地圖印證了表2.22的意念，雖然似乎好像在這兩種來源物質上有少量的統計的差異。
2008年12月14日 星期日
LB 057-060T
(α). From a heuristic point of view, the first type of observation ids the most unsatisfactory one because of many cases in which the exact location of the lesion is only a matter o speculation, and even if these brains should become available for postmodern examination the patient may have died of more widespread disease and destruction in the brain than the lesion which first caused aphasia.
從啟發式的觀點看來，第一種的觀察也是最令人不滿意的一種。因為在確切損害部位的很多例子只是種推測。即使這些大腦經過後現代的檢驗，病人死於腦袋有大規模的疾病或傷害而不是由於死於失語症。
Nevertheless, the vast majority of aphasia patients owe their speech disturbance to internal brain disease, particularly cerebro-vascular accidents, commonly known as strokes.
2008年12月2日 星期二
LB 057-060T
The most painstaking histological investigations of Broca’s area were carried out by Kreht (1936), who followed the tradition of the Vogts with their careful description of every detail and variation in cell density and size. Von Bonin’s and Bailey’s observations were essentially the same as Kreht’s, but the latter also occasionally found larger cells in layer VI. The fourth layer in all cortices examined was noticeably sparsely populated with cells. Kreht observed that Broca’s area always tended to be different from surrounding areas, but that the cytoarchitecture itself in this region varied greatly from brain to brain. Kreht also investigated homologous areas in brains of a few apes and monkeys and found that the cortices of these animals had areas with similar cytoarchitecture as that found in Broca’s area. Thus the microscopic anatomical detail does not contribute to our search for histological correlates of speech and language.
有關Broca’s area 所做的最艱苦的歷史研究是由 Kreht (1936)所擔任的。他是一位跟隨Vogts的腳步，細心的描述有關細胞密度與大小的所有細節與變化。Von Bonin’s 和Bailey’s 的觀察就跟Kreht 的觀察一樣的重要。 但Kreht 偶爾會發現到在第五層有較大的細胞。被發現到在第四層的所有皮層間只分布了稀疏的細胞。Kreht 觀察到Broca’s area 與其周圍的區域都有所不同。但在這個區域的細胞結構本身根據不同的腦袋而有很大的改變。Kreht 也調查到在一些人猿與猴子的腦袋中有類似的區域且發現這些動物的皮層都有與Broca’ area 相似的區域。所以，這些精微的解剖細節就我們研究語音與語言相關的歷史並沒有很大的貢獻。
有關Broca’s area 所做的最艱苦的歷史研究是由 Kreht (1936)所擔任的。他是一位跟隨Vogts的腳步，細心的描述有關細胞密度與大小的所有細節與變化。Von Bonin’s 和Bailey’s 的觀察就跟Kreht 的觀察一樣的重要。 但Kreht 偶爾會發現到在第五層有較大的細胞。被發現到在第四層的所有皮層間只分布了稀疏的細胞。Kreht 觀察到Broca’s area 與其周圍的區域都有所不同。但在這個區域的細胞結構本身根據不同的腦袋而有很大的改變。Kreht 也調查到在一些人猿與猴子的腦袋中有類似的區域且發現這些動物的皮層都有與Broca’ area 相似的區域。所以，這些精微的解剖細節就我們研究語音與語言相關的歷史並沒有很大的貢獻。
Behavioral Maps. The mapping of speech areas is based on observations of behavioral derangement in the presence of (α) internal brain disease; (β) of penetrating head injuries (trauma); (γ) surgical excision; and (δ) observations of behavior during electrical stimulation of the exposed cortex during surgery.
行為地圖
行為地圖
語音區域的地圖是以有關目前出現的行為擾亂的觀察為基礎。
(α)內部腦部疾病
(β)尖銳的腦部傷害(外傷)
(γ)外科手術的切除
(δ) 在手術期間對於暴露在外的皮層做電擊的刺激的行為觀察。
2008年11月24日 星期一
Broca's area
Broca's area is a section of the human brain that is involved in language processing, speech or sign[1] production, and comprehension. Broca's area is named after the 19th-century physician Paul Broca. The concept of Broca's Area was originally produced with the intent to explain how speech production was inhibited in the learning of communication by the deaf; however, it is currently used to describe many anatomical aspects of psychological processing mechanisms.
Contents[hide]
1 Description
1.1 Parts
2 Aphasia
3 Evolution of human language[9]
4 See also
5 References
[edit] Description
Broca's area is located in the opercular and triangular sections of the inferior frontal gyrus of the frontal lobe of the cortex. Broca's and Wernicke's areas are found unilaterally in the brain (dominant hemisphere, usually left hemisphere). It is supplied by the superior division of the Left Middle Cerebral Artery.
Broca's area comprises Brodmann area 44[2] and (according to some authorities) Brodmann area 45.[3][4][5] Broca's Area is connected to Wernicke's area by a neural pathway called the arcuate fasciculus. The corresponding area in macaque monkeys is responsible for high-level control over orofacial actions.[6]
[edit] Parts
Broca's area has two main parts, which express different roles during language comprehension and production:
Pars triangularis (anterior), which is thought to support the interpretation of various 'modes' of stimuli (plurimodal association) and the programming of verbal conducts
Pars opercularis (posterior), which is thought to support the management of only one kind of stimulus (unimodal association) and the coordination of the speech organs for the actual production of language, given its favorable position close to motor-related areas
[edit] Aphasia
People suffering from damage to this area may show a condition called Broca's aphasia (sometimes known as expressive aphasia, motor aphasia, or nonfluent aphasia), which makes them unable to create grammatically-complex sentences: It's often described as telegraphic speech and contains little but content words. Patients are usually aware that they cannot speak properly. Comprehension in Broca's aphasia is relatively normal, although many studies have demonstrated that Broca's aphasics have trouble understanding certain kinds of syntactically-complex sentences.[7]
For example, in the following passage, a Broca's aphasic patient is trying to explain how he came to the hospital for dental surgery:
"Yes... ah... Monday... er... Dad and Peter H...and Dad.... er... hospital... and ah... Wednesday... Wednesday, nine o'clock... and oh... Thursday... ten o'clock, ah doctors... two... an' doctors... and er... teeth... yah."[8]
This type of aphasia can be contrasted with Wernicke's aphasia, named for Carl Wernicke, which is characterized by damage to more posterior regions of the left hemisphere in the superior temporal lobe. Wernicke's aphasia manifests as a more pronounced impairment in comprehension. Because speech production retains a natural-sounding rhythm, and remains relatively normal grammatically, it is nonetheless often roundabout, vague, or meaningless. It is therefore also known as receptive aphasia.
Positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) have found decreases in activity in the Broca's area in stuttering. There is greater activation of the right hemisphere homologue of the Broca's area (area of Ross), which is believed to be a compensatory response to the hypoactivity in the Broca's area proper. Volumetric magnetic resonance imaging (VMRI) has shown that the pars triangularis is smaller in people that stutter.
[edit] Evolution of human language[9]
Broca's area is considered a marker for the development of language in the evolution of humans. The paleontological record of species leading to modern humans, Homo sapiens, finds that this part of the neural structure of the brain is present in fossils of Homo sapiens, and of Homo habilis, whereas the presumed precursors of these early humanoids, australopiths, lacked this area of the brain (note that this information depends on the analysis of skulls where the presence of Broca's area can be determined).
Whereas Broca's area is unique in its linguistic role to humans, it is present in animals, although it performs other similar roles that were adapted to language in humans.
The fossil record cannot, of course, give firm data about the beginning of language, which is one of the critical factors contributing to the evolution of Homo sapiens into the species that we have become. However, the association of Broca's area with language in modern man may guide further analysis of this evolution.
[edit] See also
arcuate fasciculus
cortex
expressive aphasia
human brain
language
pars opercularis
pars triangularis
Wernicke's area
[edit] References
^ Horwitz B, Amunts K, Bhattacharyya R, Patkin D, Jeffries K, Zilles K, Braun AR. "Activation of Broca's area during the production of spoken and signed language: a combined cytoarchitectonic mapping and PET analysis," Neuropsychologia. 2003; 41(14): 1868-76.
^ Mohr JP in Studies in Neurolinguistics (eds. Witaker H & Witaker NA) 201–235 (Academic, New York, 1976)
^ Penfield W & Roberts L Speech and Brain Mechanisms (Princeton Univ Press, Princeton, 1959)
^ Ojemann GA, Ojemann JG, Lettich E, Berger MS (1989). "Cortical language localization in left, dominant hemisphere. An electical stimulation mapping investigation in 117 patients". J Neurosurg 71: 316–26. doi:10.1038/nature03628.
^ Duffau H et al. (2003). "The role of dominant premotor cortex in language: a study uding intraoperative functional mapping in awake patients". Neuroimage 20: 1903–14. doi:10.1016/S1053-8119(03)00203-9.
^ Petrides M, Cadoret G, Mackey S (2005). "Orofacial somatomotor responses in the macaque monkey homologue of Broca's area". Nature 435: 1235–38. doi:10.1038/nature03628.
^ Caramazza A & Zurif E (1976). "Dissociation of algorithmic and heuristic processes in language comprehension: evidence from aphasia". Brain and Language 3: 572–82. doi:10.1016/0093-934X(76)90048-1.
^ Goodglass H & Geschwind N. Language disorders. In E. Carterette and M.P. Friedman (eds.) Handbook of Perception: Language and Speech. Vol II (New York, Academic Press, 1976)
^ Watson, Peter "Ideas: A History of Thought and Invention from Fire to Freud", Harper, New York 2006 [ISBN]0-06-093564-2], Chapter 2
Contents[hide]
1 Description
1.1 Parts
2 Aphasia
3 Evolution of human language[9]
4 See also
5 References
[edit] Description
Broca's area is located in the opercular and triangular sections of the inferior frontal gyrus of the frontal lobe of the cortex. Broca's and Wernicke's areas are found unilaterally in the brain (dominant hemisphere, usually left hemisphere). It is supplied by the superior division of the Left Middle Cerebral Artery.
Broca's area comprises Brodmann area 44[2] and (according to some authorities) Brodmann area 45.[3][4][5] Broca's Area is connected to Wernicke's area by a neural pathway called the arcuate fasciculus. The corresponding area in macaque monkeys is responsible for high-level control over orofacial actions.[6]
[edit] Parts
Broca's area has two main parts, which express different roles during language comprehension and production:
Pars triangularis (anterior), which is thought to support the interpretation of various 'modes' of stimuli (plurimodal association) and the programming of verbal conducts
Pars opercularis (posterior), which is thought to support the management of only one kind of stimulus (unimodal association) and the coordination of the speech organs for the actual production of language, given its favorable position close to motor-related areas
[edit] Aphasia
People suffering from damage to this area may show a condition called Broca's aphasia (sometimes known as expressive aphasia, motor aphasia, or nonfluent aphasia), which makes them unable to create grammatically-complex sentences: It's often described as telegraphic speech and contains little but content words. Patients are usually aware that they cannot speak properly. Comprehension in Broca's aphasia is relatively normal, although many studies have demonstrated that Broca's aphasics have trouble understanding certain kinds of syntactically-complex sentences.[7]
For example, in the following passage, a Broca's aphasic patient is trying to explain how he came to the hospital for dental surgery:
"Yes... ah... Monday... er... Dad and Peter H...and Dad.... er... hospital... and ah... Wednesday... Wednesday, nine o'clock... and oh... Thursday... ten o'clock, ah doctors... two... an' doctors... and er... teeth... yah."[8]
This type of aphasia can be contrasted with Wernicke's aphasia, named for Carl Wernicke, which is characterized by damage to more posterior regions of the left hemisphere in the superior temporal lobe. Wernicke's aphasia manifests as a more pronounced impairment in comprehension. Because speech production retains a natural-sounding rhythm, and remains relatively normal grammatically, it is nonetheless often roundabout, vague, or meaningless. It is therefore also known as receptive aphasia.
Positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) have found decreases in activity in the Broca's area in stuttering. There is greater activation of the right hemisphere homologue of the Broca's area (area of Ross), which is believed to be a compensatory response to the hypoactivity in the Broca's area proper. Volumetric magnetic resonance imaging (VMRI) has shown that the pars triangularis is smaller in people that stutter.
[edit] Evolution of human language[9]
Broca's area is considered a marker for the development of language in the evolution of humans. The paleontological record of species leading to modern humans, Homo sapiens, finds that this part of the neural structure of the brain is present in fossils of Homo sapiens, and of Homo habilis, whereas the presumed precursors of these early humanoids, australopiths, lacked this area of the brain (note that this information depends on the analysis of skulls where the presence of Broca's area can be determined).
Whereas Broca's area is unique in its linguistic role to humans, it is present in animals, although it performs other similar roles that were adapted to language in humans.
The fossil record cannot, of course, give firm data about the beginning of language, which is one of the critical factors contributing to the evolution of Homo sapiens into the species that we have become. However, the association of Broca's area with language in modern man may guide further analysis of this evolution.
[edit] See also
arcuate fasciculus
cortex
expressive aphasia
human brain
language
pars opercularis
pars triangularis
Wernicke's area
[edit] References
^ Horwitz B, Amunts K, Bhattacharyya R, Patkin D, Jeffries K, Zilles K, Braun AR. "Activation of Broca's area during the production of spoken and signed language: a combined cytoarchitectonic mapping and PET analysis," Neuropsychologia. 2003; 41(14): 1868-76.
^ Mohr JP in Studies in Neurolinguistics (eds. Witaker H & Witaker NA) 201–235 (Academic, New York, 1976)
^ Penfield W & Roberts L Speech and Brain Mechanisms (Princeton Univ Press, Princeton, 1959)
^ Ojemann GA, Ojemann JG, Lettich E, Berger MS (1989). "Cortical language localization in left, dominant hemisphere. An electical stimulation mapping investigation in 117 patients". J Neurosurg 71: 316–26. doi:10.1038/nature03628.
^ Duffau H et al. (2003). "The role of dominant premotor cortex in language: a study uding intraoperative functional mapping in awake patients". Neuroimage 20: 1903–14. doi:10.1016/S1053-8119(03)00203-9.
^ Petrides M, Cadoret G, Mackey S (2005). "Orofacial somatomotor responses in the macaque monkey homologue of Broca's area". Nature 435: 1235–38. doi:10.1038/nature03628.
^ Caramazza A & Zurif E (1976). "Dissociation of algorithmic and heuristic processes in language comprehension: evidence from aphasia". Brain and Language 3: 572–82. doi:10.1016/0093-934X(76)90048-1.
^ Goodglass H & Geschwind N. Language disorders. In E. Carterette and M.P. Friedman (eds.) Handbook of Perception: Language and Speech. Vol II (New York, Academic Press, 1976)
^ Watson, Peter "Ideas: A History of Thought and Invention from Fire to Freud", Harper, New York 2006 [ISBN]0-06-093564-2], Chapter 2
2008年11月17日 星期一
LBT 443-446
Language has been thought of as being the expression of man’s reason, the result of onomatopoeia, invented as a means of communication, considered basic to the formation of society, or simply a gift of God. Each of these definitions of language has been used in the construction of a multitude of language theories[1]. We shall not be concerned with the development of these theories, but limit ourselves to a discussion of the recurrent emergence of the thoughts on the biological basis of language.
語言被認為是人類理性的一種表達方式，也被認為是一種為了社會形成而去溝通所發明出擬聲詞的結果。或是被認為是神的禮物與恩賜。各種語言的定義被使用來形成了多種的語言理論。 我們不應只關心這些理論的發展過程，而限制了我們去討論經常出現的關於生物基礎語言方面的想法。
語言被認為是人類理性的一種表達方式，也被認為是一種為了社會形成而去溝通所發明出擬聲詞的結果。或是被認為是神的禮物與恩賜。各種語言的定義被使用來形成了多種的語言理論。 我們不應只關心這些理論的發展過程，而限制了我們去討論經常出現的關於生物基礎語言方面的想法。
The idea that language is one of man’s inherent characteristics, like vision or hearing, is found in some myths on the creation of man[2]. In these myths, language is given to man in conjunction with his senses, so that apparently it was considered one of them, and not part of man’s cultural or social functions ( which are also described as given or taught by the gods). By no means can these assertions of a divine origin be considered antithetical to a natural origin of language; on the contrary, everything natural to man was God’s gift to him.
語言是人類與生俱有的特色的想法，就像是視覺或是聽覺。都被發現是有關一些人類起源的神話。在這些神話,語言是跟感官一起給予人類的,所以,語言被認為是感官之一，而非人類文化或社會作用的一部份。(也被認為語言是由神給予或教導的)。這些有關神的起源的主張並不被認為是與語言自然的起源是對立的，相反的，每種人類的天賦都可以說是神的禮物。
Between the realm of mythology and science stands the experiment of the Egyptian King Psammetichos of the seventh century B.C. and related by Herodotus ( fifth century B.C.). Psammetichos suppossedly tried to have two children raised by shepherds who never spoke to them in order to see what language they would develop [3]. This experiment is relevant to our discussion in so far as its design implies the belief that children left to themselves will develop language. Psammetichos thought he would be able to demonstrate which language was the oldest, but apparently did not doubt that even untutored children would speak.
在神話和科學的領域之間存在著西元七世紀前的埃及的國王Psammetichos的實驗，Psammetichos的實驗也和希羅多德有關(西元前五世紀)。 Psammetichos 試著觀察由牧羊人飼養的兩個小孩，在牧羊人不曾跟他們說話的情況下，他們的語言會如何發展。這項實驗跟我們到目前為止的討論有關,到目前為止,他的信仰意味著認為兒童將自己會發展語言。Psammetichos認為他能証明哪一種語言是最古老的,但也顯然堅信即使沒受過教育的兒童仍會說話。
Language first became the subject of discussion by the presocratic philosophers in the latter part of the sixth century B.C. The setting up of antitheses, typical for Greek philosophy, was also applied to the problems which language posed. But discussions of language were limited to a mere consideration of naming and were purely secondary outgrowths of the philosopher’s search for general truths. In order to understand the statements on language made by the Greek philosophers, it is essential to give an idea of the context in which they were made and briefly describe the evolution of the meaning of the two everrecurring terms nomos and physis in which language was to be discussed. Nomos was later replaced by theses and was often wrongly translated as convention while physis has been incorrectly equated with nature.
在西元前六世紀後期，語言已經變成前蘇格拉底哲學家所討論的主題。這種典型的希臘哲學對立的命題也運用到討論語言方面的問題。但有關語言的討論大多侷限於命名的討論，其次哲學家才是在尋找真理。為了瞭解希臘哲學家對語言所做出的陳述，對於去了解他們針對語言所討論到兩個重複出現的術語nomos and physis的意義是很重要的。Nomos也可以說是theses但通常被錯譯為convention，physis也並完全不等於nature.
For Herakleitos (ca. 500 B.C.), nomos was the order regulating the life of society and the individual, but he did not see it as a product of society[4].The nomos of society was valid, but not absolute. Similarly names were valid as they reflected some aspect of the object they named. (Apparently, he did not consider them physis as had been thought)[5]. Physis would have implied that names are an adequate expression of reality or of the true nature of things, an idea to which Herakleitos did not subscribe.
對Herakleitos而言，nomos是由社會與個人所規範的秩序，但他並不了解它也是社會的產物。社會的nomos是正確的但不是絕對的。相似的，名字也是反映出它所命名的物體。(明顯的，他沒有考慮到physis這方面。)Physis可以說是事物的事實或是真實的本質的一種適當的表達方式。這個觀念是Herakleitos不贊成的。
在西元前六世紀後期，語言已經變成前蘇格拉底哲學家所討論的主題。這種典型的希臘哲學對立的命題也運用到討論語言方面的問題。但有關語言的討論大多侷限於命名的討論，其次哲學家才是在尋找真理。為了瞭解希臘哲學家對語言所做出的陳述，對於去了解他們針對語言所討論到兩個重複出現的術語nomos and physis的意義是很重要的。Nomos也可以說是theses但通常被錯譯為convention，physis也並完全不等於nature.
For Herakleitos (ca. 500 B.C.), nomos was the order regulating the life of society and the individual, but he did not see it as a product of society[4].The nomos of society was valid, but not absolute. Similarly names were valid as they reflected some aspect of the object they named. (Apparently, he did not consider them physis as had been thought)[5]. Physis would have implied that names are an adequate expression of reality or of the true nature of things, an idea to which Herakleitos did not subscribe.
對Herakleitos而言，nomos是由社會與個人所規範的秩序，但他並不了解它也是社會的產物。社會的nomos是正確的但不是絕對的。相似的，名字也是反映出它所命名的物體。(明顯的，他沒有考慮到physis這方面。)Physis可以說是事物的事實或是真實的本質的一種適當的表達方式。這個觀念是Herakleitos不贊成的。
相關連結
2008年11月11日 星期二
LB Chapter 2 p056-060 威鈴
LB Chapter 2 p56-60
The most painstaking histological investigations of Broca’s area were carried out by Kreht (1936), who followed the tradition of the Vogts with their careful description of every detail and variation in cell density and size. Von Bonin’s and Bailey’s observations were essentially the same as Kreht’s, but the latter also occasionally found larger cells in layer VI. The fourth layer in all cortices examined was noticeably sparsely populated with cells. Kreht observed that Broca’s area always tended to be different from surrounding areas, but that the cytoarchitecture itself in this region varied greatly from brain to brain. Kreht also investigated homologous areas in brains of a few apes and monkeys and found that the cortices of these animals had areas with similar cytoarchitecture as that found in Broca’s area. Thus the microscopic anatomical detail does not contribute to our search for histological correlates of speech and language.
Behavioral Maps. The mapping of speech areas is based on observations of behavioral derangement in the presence of (α) internal brain disease; (β) of penetrating head injuries (trauma); (γ) surgical excision; and (δ) observations of behavior during electrical stimulation of the exposed cortex during surgery.
(α). From a heuristic point of view, the first type of observation ids the most unsatisfactory one because of many cases in which the exact location of the lesion is only a matter o speculation, and even if these brains should become available for postmodern examination the patient may have died of more widespread disease and destruction in the brain than the lesion which first caused aphasia.
Nevertheless, the vast majority of aphasia patients owe their speech disturbance to internal brain disease, particularly cerebro-vascular accidents, commonly known as strokes. Tissue is destroyed or function is temporarily interrupted because of insufficient blood supply caused by a clot in or rupture of a vessel. The artery most often implicated is the left middle cerebral artery, which runs along the sylvian fissure and sends out branches through the entire lateral face of the hemisphere, as shown in Fig. 2.21. It is precisely because of the vast territorial extent of this artery that behavioral derangement resulting from interference with it gives us the least specific information concerning the localization of the speech and language function. Even when the vascular insufficiency is demonstrated by x-rays of the vascular tree, the exact location of the actual dysfunction remains largely a matter of speculation.
(β). Inferences from traumatic lesions have been drawn repeatedly (Goldstein, 1942, Luria, 1947, Conrad, 1954, Russell and Espir, 1961), resulting in various maps. The extent of the lesion can be determined more accurately in these cases than in internal brain disease, but the fact is frequently overlooked that trauma also causes secondary pathology (particularly hemorrhage and edema) which may have deleterious effects on tissue far beyond the visibility destroyed areas. In Fig. 2.22 the centers of penetrating head injuries to the left hemisphere are shown with indications of those injuries which caused lasting aphasia and which did not. The subjects were veterans of Word War II. To make Russel’s and Espir’s material comparable to Conrad’s, the diagrams had to be redrawn, and in this process some distortions are inevitable because neither the original drawings nor the present mode of representation can be read unequivocally. The distortions, however, occur primarily around the outer margins of these diagrams and are due to the shortened perspective of the curved surfaces. Nevertheless, it is clear that the resulting maps are not identical although correspondences exit.
In Conrad’s material, motor-speech deficits predominate on both margins of the central sulcus and extend frontally; linguistic sensory and amnestic deficits predominate in the parieto-occipital areas, but there are few cases which do not conform to this distribution. Russel and Espir do not indicate the nature of the language deficit in their original data. In both cases we cannot fail to be impressed with the random-appearing scatter of lesions and with the overlap between aphasia-producting and aphasia-free lesions. The most striking findings of these recent studies are that there seems to be no more than a statistical relationship between Broca’s area and the resultant deficit.
(γ). Surgical excision of limited cortical tissue is a fairly common occurrence in clinical neurology. Pefield and Roberts (1959) have described the outcome of such operations performed on 273 patients who had suffered from focal cerebral seizures caused by earlier injuries, infection, or anoxia of the brain. Over the years, examples of ablations on every part of the cortex have been accumulated, although Broca’s area was only excised once and this happened to be a patient with an atypical early history. In all of this material from which tumor cases are excluded, there are few cases in which the removal of cortical tissue resulted in more than a temporary dysphasic condition, with language function restored within a matter of days or weeks. Many operations in the critical areas had no language disturbance. This is puzzling in view of the consequences of traumatic lesions and cerebro-vascular accidents. We might have expected that in many more cases permanent aphasia had resulted. The explanation must be due to some important differences between the surgical cases and others. First, patients who come to surgery have had histories of years of abnormally functioning brains manifested by recurrent and uncontrollable seizures. we cannot be sure of the effect that this might have had on localization (using the world here in its loosest terminology). Penfield and Roberts believe that the epileptogenic focus is not the location of the lesion but is adjacent to it. The lesion itself constitutes an irritant which induces abnormal function in structurally healthy tissue. Thus, there may be a systematic “bias” in the localization of function in these brains. The tissue that is surgically removed probably had not been participating in speech function for some years. However, this explanation begs the basic question: why does sudden destruvtion of tissue interfere irrevocably with language in adult patients, whereas language often remains essentially unaffected in cases where similar destructions were preceded by years (sometimes a lifetime) of sporadic, short, physiological interferences?
The surgical cases do not differ only from traumatic and vascular lesions in terms of abnormal function. The surgical lesion is always different from the other lesions; it is usually shallower, there is no uncontrolled bleeding, it does not follow the distribution of the vascular tree, and the healing process is histologically and morphologically different from the events that follow the cerebro-vascular accidents and trauma. With this many differences between the surgical cases and other cases, it is fair to say that surgical lesions are not commensurable, and the difference in effects cannot yet be interpreted. However, there is one lesson we may learn from cortical excisions. The narrow localization theory which holds that engrams for words or syntactic rules are stored in certain aggregates of cells cannot be in accord with the clinical facts.
(δ) Electrical stimulation of the exposed cortex during neurosurgery is another source of evidence for cortical function-maps. It is again Penfield and Roberts who have systematized their findings. For instance, they have published (1959) a cortical map showing points of stimulation affecting motor speech. From this map it is difficult to discern any sharply circumscribed area of functional representation. Roughly, the stimulation map corroborates the impression gained from the maps of Fig. 2.22 although it does seem as if there were at least statistical discrepancies between the two types of source-material for such maps.
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