Minggu, 14 April 2013

MAKALAH A. COMPONENT OF LANGUAGE



CHAPTER I
INTRODUCTION


          Linguistic study involves a search for patterns in the way speakers use language; linguists aim to describe these patterns by reducing them to a set of rules called a grammar. As Edward Sapir once commented, however, “All grammars leak” (1921, 38). Over time linguists came to recognize a growing number of language components; each new component was an attempt to plug the “leaks” in an earlier grammar, to explain what had previously resisted explanation. The following discussion pinpoints the various leaks linguists have recognized (as well as their attempts to plug the leaks) and demonstrates how culture and language influence each othe
r.
Before going into the details of language and its processing one should have a rough idea of “what the various brain parts are? “ It is common knowledge that the brain controls muscular activity in human body. It is clear that the brain is also the seat of conscious thought. Indeed we can all agree that when we have an idea, make the unconscious decision to convey it in language and subsequently actually produce some utterances in our language; the brain is involved at every step along the way. Here we will take a look at the important parts of brain as far as language is concerned.

Frontal Lobe: This is the front part of our brain. The frontal lobes are considered our emotional control center and home to our personality. The frontal lobes are involved in motor function, problem solving, spontaneity, memory, language, initiation, judgments, impulse control, and social and sexual behavior.
Parietal Lobe: The parietal lobes can be divided into two functional regions. One involves sensation and perception and the other is concerned with integrating sensory input, primarily with the visual system.
Occipital Lobe: The posterior lobe of each cerebral hemisphere, having the shape of 3 sided pyramid. It contains the visual center of the brain.
Temporal Lobe: The lower lateral lobe of either cerebral hemisphere, located in front of occipital lobe. It contains the visual center of the brain.
Cerebrum: It is the largest part of the brain as a whole. It is here that things like perception, imagination, thought, judgment, and decision occur.
Cerebellum: Cerebellum is involved in coordination of movement and motor learning.
Broca’s area: Region located anteriorly in the left hemisphere in the left frontal lobe operculum. It is responsible for production of words and sentences. This area is named after Paul Broca (in 1861).
Wernicke’s area: Region located posteriorly in the left hemisphere in the superior temporal gyrus. It is responsible for comprehension of spoken words and sentences. This area is named after Carl Wernicke (in 1874)


CONTENT

1.      CHAPTER I: INTRODUCTION ....................................................  1
2.      CONTENT........................................................................................ 3
3.      CHAPTER II: DISCUSSION.......................................................... 4
A.    COMPONENT OF LANGUAGE.............................................. 4
B.     LANGUAGE PROCESSING.................................................... 8
4.      CONCLUSION ............................................................................... 15
5.      REFERENCES ................................................................................ 16
   







CHAPTER II
DISCUSSION

A.    COMPONENT OF LANGUAGE
Phonology: Sounds
          The study of the sounds of language is called phonology. The sounds of human language are special because they are produced by a set of organs, the speech organs, that belong only to the human species. The actual sounds that come out of our mouths are called phones, and they vary continuously in acoustic properties. However, we hear all the phones within a particular range of variation as functionally equivalent allophones of the same phoneme, or characteristic speech sound, in the language. Part of the phonologist"s job is to map possible arrangements of speech organs that human beings may use to create the sounds of language. Another part is to examine individual languages to discover the particular sound combinations they contain and the patterns into which those sound combinations are organized. No language makes use of all the many sounds the human speech organs can produce, and no two languages use exactly the same set. American English uses only 38 sounds. Most work in phonology has been done from the perspective of the speaker, who produces, or articulates, the sounds of language using the speech organs.
            Although all languages rely on only a handful of phonemes, no two languages use exactly the same set. Furthermore, different speakers of the same language often differ from one another in the way their phonemes are patterned, producing "accents," which constitute one kind of variety within a language. This variety is not random; the speech sounds characteristic of any particular accent follow a pattern. Speakers with different accents are usually able to understand one another in most circumstances, but their distinctive articulation is a clue to their ethnic, regional, or social-class origins. The sound changes that occur over time within any particular phonemic system (accent) are equally orderly.
Morphology: Word Structure
            Morphology, the study of how words are put together, developed as a subfield of linguistics as soon as linguists realized that the rules they had devised to explain sound patterns in language could not explain the structure of words.
What is a word? English speakers tend to think of words as the building blocks of sentences and of sentences as strings of words. But words are not all alike: some words (book) cannot be broken down into smaller elements; others (bookworm) can. The puzzle deepens when we try to translate words from one language into another. Sometimes expressions that require only one word in one language (préciser in French) require more than one word in another (to make precise in English). Other times, we must deal with languages whose utterances cannot easily be broken down into words at all. Consider the utterance nikookitepeena from Shawnee (an indigenous North American language), which translates into English as "I dipped his head in the water" (Whorf 1956, 172). Although the Shawnee utterance is composed of parts, the parts do not possess the characteristics we attribute to words in, say, English or French.
            To make sense of the structure of languages such as Shawnee, anthropological linguists needed a concept that could refer to both words (like those in the English sentence above) and the parts of an utterance that could not be broken down into words. This led to the development of the concept of morphemes, traditionally defined as "the minimal units of meaning in a language." The various parts of a Shawnee utterance can be identified as morphemes, and so can many English words. Describing minimal units of meaning as morphemes, and not as words, allows us to compare the morphology of different languages.
Morphemic patterning in languages like Shawnee may seem hopelessly complicated to native English speakers, yet the patterning of morphemes in English is equally complex. Why is it that some morphemes can stand alone as words (sing, red) and others cannot (-ing, -ed)? What determines a word boundary in the first place? Words, or the morphemes they contain, are the minimal units of meaning. Thus, they represent the fundamental point at which the arbitrary pairing of sound and meaning occurs.

Syntax: Sentence Structure
            A third component of language is syntax, or sentence structure. Linguists began to study syntax when they discovered that morphological rules alone could not account for certain patterns of morpheme use. In languages like English, for example, rules governing word order cannot explain what is puzzling about the following English sentence: "Smoking grass means trouble." For many native speakers of American English, this sentence exhibits what linguists call structural ambiguity. That is, we must ask ourselves what trouble means: the act of smoking grass (marijuana) or observing grass (the grass that grows on the prairie) that is giving off smoke. In the first reading, smoking is a gerund working as a noun; in the second, it is a gerund working as an adjective.
            We can explain the existence of structurally ambiguous sentences if we assume that the role a word plays in a sentence depends on the overall structure of the sentence in which the word is found and not on the structure of the word itself. Thus, sentences can be defined as ordered strings of words, and those words can be classified as parts of speech in terms of the function they fulfill in a sentence. But these two assumptions cannot account for the ambiguity in a sentence like "The father of the girl and the boy fell into the lake." How many people fell into the lake? Just the father or the father and the boy? Each reading of the sentence depends on how the words of the sentence are grouped together. Linguists discovered numerous other features of sentence structure that could not be explained in terms of morphology alone, leading to a growth of interest in the study of syntactic patterns in different languages. Although theories of syntax have changed considerably since Chomsky"s early work, the recognition that syntax is a key component of human language structure remains central to contemporary linguistics.

Semantics:Meaning
            Semantics, the study of meaning, was avoided by linguists for many years because meaning is a highly ambiguous term. What do we mean when we say that a sentence means something? We may be talking about what each individual word in the sentence means or what the sentence as a whole means or what I mean when I utter the sentence, which may differ from what someone else would mean even if uttering the same sentence. In the 1960s, formal semantics took off when Chomsky argued that grammars needed to represent all of the linguistic knowledge in a speaker"s head, and word meanings were part of that knowledge. Formal semanticists focused attention on how words are linked to each other within a language, exploring such relations as synonymy, or "same meaning" (old and aged); homophony, or "same sound, different meaning" (would and wood); and antonymy, or "opposite meaning" (tall and short). They also defined words in terms of denotation, or what they referred to in the "real world."
            The denotations of words like table or monkey seem fairly straightforward, but this is not the case with words like truth or and. Moreover, even if we believe a word can be linked to a concrete object in the world, it may still be difficult to decide exactly what the term refers to (a challenge to which Hockett"s design feature of "semanticity" draws attention). Suppose we decide to find out what monkey refers to by visiting the zoo. In one cage we see small animals with grasping hands feeding on fruit. In a second cage are much larger animals that resemble the ones in the first cage in many ways, except that they have no tails. And in a third cage are yet other animals who resemble those in the first two cages, except that they are far smaller and use their long tails to swing from the branches of a tree. Which of these animals are monkeys?
            To answer this question, the observer must decide which features of similarity or difference are important and which are not. Having made this decision, it is easier to decide if the animals in the first cage are monkeys and whether the animals in the other cages are monkeys as well. But such decisions are not easy to come by. Biologists have spent the last 300 years or so attempting to classify all living things on the planet into mutually exclusive categories. To do so, they have had to decide, of all the traits that living things exhibit, which ones matter.
            This suggests that meaning must be constructed in the face of ambiguity. Formal linguistics, however, tries to deal with ambiguity by eliminating it, by "disambiguating" ambiguous utterances. To find a word"s "unambiguous" denotation, we might consult a dictionary. According to the American Heritage Dictionary, for example, a pig is "any of several mammals of the family Suidae, having short legs, cloven hoofs, bristly hair, and a cartilaginous snout used for digging." A formal definition of this sort does indeed relate the word pig to other words in English, such as cow and chicken, and these meaning relations would hold even if all real pigs, cows, and chickens were wiped off the face of the earth. But words also have connotations, additional meanings that derive from the typical contexts in which they are used in everyday speech. In the context of antiwar demonstrations in the 1960s, for example, a pig was a police officer.
            From a denotative point of view, to call police officers pigs is to create ambiguity deliberately, to muddle rather than to clarify. It is an example of metaphor, a form of figurative or nonliteral language that violates the formal rules of denotation by linking expressions from unrelated semantic domains. Metaphors are used all the time in everyday speech, however. Does this mean, therefore, that people who use metaphors are talking nonsense? What can it possibly mean to call police officers pigs?
            We cannot know until we place the statement into some kind of context. If we know, for example, that protesters in the 1960s viewed the police as the paid enforcers of racist elites responsible for violence against the poor and that pigs are domesticated animals, not humans, that are often viewed as fat, greedy, and dirty, then the metaphor "police are pigs" begins to make sense. This interpretation, however, does not reveal the "true meaning" of the metaphor for all time. In a different context, the same phrase might be used, for example, to distinguish the costumes worn by police officers to a charity function from the costumes of other groups of government functionaries. Our ability to use the same words in different ways (and different words in the same way) is the hallmark of openness, and formal semantics is powerless to contain it. This suggests that much of the referential meaning of language escapes us if we neglect the context of language use.

B.      LANGUAGE PROCESSING
            Language processing refers to the way human beings use words to communicate ideas and feelings, and how such communications are processed and understood. Thus it is how the brain creates and understands language. Most recent theories consider that this process is carried out entirely by and inside the brain. This is considered one of the most characteristic abilities of the human species - perhaps the most characteristic. However very little is known about it and there is huge scope for research on it.
            Most of the knowledge acquired to date on the subject has come from patients who have suffered some type of significant head injury, whether external (wounds, bullets) or internal (strokes, tumors, degenerative diseases). Studies have shown that most of the language processing functions are carried out in the cerebral cortex. The essential function of the cortical language areas is symbolic representation. Even though language exists in different forms, all of them are based on symbolic representation.
            Much of the language function is processed in several association areas, and there are two well-identified areas that are considered vital for human communication: Wernicke's area and Broca's area. These areas are usually located in the dominant hemisphere (the left hemisphere in 97% of people) and are considered the most important areas for language processing. This is why language is considered a localized and lateralized function. However, the less-dominant hemisphere also participates in this cognitive function, and there is ongoing debate on the level of participation of the less-dominant areas.Other factors are believed to be relevant to language processing and verbal fluency, such as cortical thickness, participation of prefrontal areas of the cortex, and communication between right and left hemispheres.



Wernicke's area
http://upload.wikimedia.org/wikipedia/commons/thumb/3/33/Gray726-Brodman.png/220px-Gray726-Brodman.png

Lateral surface of the brain with Brodmann's areas numbered.
            Wernicke's area is classically located in the posterior section of the superior temporal gyrus of the dominant hemisphere (Brodmann area 22), with some branches extending around the posterior section of the lateral sulcus, in the parietal lobe.[4]
            Considering its position, Wernicke's area is located relatively between the auditory cortex and the visual cortex. The former is located in the transverse temporal gyrus (Brodmann areas 41 and 42), in the temporal lobe, while the latter is located in the posterior section of the occipital lobe (Brodmann areas 17, 18 and 19).[4]
            While the dominant hemisphere is in charge of most of language comprehension, recent studies have demonstrated that the less dominant (right hemisphere in 97% of people) homologous area participates in the comprehension of ambiguous words, whether they are written or heard.[5]
            Receptive speech has traditionally been associated with Wernicke's area of the posterior superior temporal gyrus (STG) and surrounding areas. Current models of speech perception include greater Wernicke's area, but also implicate a "dorsal" stream that includes regions also involved in speech motor processing.[6]
            First identified by Carl Wernicke in 1874, its main function is the comprehension of language and the ability to communicate coherent ideas, whether the language is vocal, written, signed.[2]
Broca's area
            Broca's area is usually formed by the pars triangularis and the pars opercularis of the inferior frontal gyrus (Brodmann areas 44 and 45). It follows Wernicke's area, and as such they both are usually located in the left hemisphere of the brain.[4]
            Broca's area is involved mostly in the production of speech. Given its proximity to the motor cortex, neurons from Broca's area send signals to the larynx, tongue and mouth motor areas, which in turn send the signals to the corresponding muscles, thus allowing the creation of sounds.[4]
            A recent analysis of the specific roles of these sections of the left inferior frontal gyrus in verbal fluency indicates that Brodmann area 44 (pars opercularis) may subserve phonological fluency, whereas the Brodmann area 45 (pars triangularis) may be more involved in semantic fluency.[7]
Arcuate fasciculus
http://upload.wikimedia.org/wikipedia/commons/thumb/a/a8/DTI_Brain_Tractographic_Image_A_panal.jpg/220px-DTI_Brain_Tractographic_Image_A_panal.jpg


            Diffusion tensor imaging image of the brain showing the right and left, also shown are the right and left superior longitudinal fasciculus and tapetum of corpus callosum. Image provided by Aaron G. Filler, MD, PhD.
            Arcuate fasciculus is a bundle of nerves that is believed to connect the posterior part of the temporal-parietal junction with the frontal lobe in the brain, which roughly translates into connecting Wernicke's area with Broca's area, thus becoming an important association area.[8]
New research demonstrates that the arcuate fasciculus instead connects posterior receptive areas with motor areas, and not to Broca's area in particular. Since some branches of the arcuate fasciculus extend further into the parietal lobe, it is believed that it has an important role in attention.[8]




Other brain areas involved in language processing

Along with the Broca’s area and Wernicke’s area, many other brain parts are involved in language related tasks. These areas include both LH and RH parts.
LH parts:
Anterior temporal lobe: It is not directly involved in processing the syntactic or semantic structure of sentence but is primarily responsible for the initial encoding of word. It causes atleast semantic information to stay longer active.
Motor activations:
Left inferior frontal gyrus Traditional Broca’s area as well as motor cortex are generally involved for the syntactic complexity.
Right cerebellum It is assumed that the cerebellum forms part of an articulatory rehearsal mechanism. It has been activated during various verbal fluency tasks. Cerebellum plays an important role in the cognitive aspects of motor learning and planning. Also it is activated with error detection tasks.
Left superior frontal gyrus, This was also found to be activated with above mentioned areas for syntactic ambiguity and some error handling tasks.
Superior frontal gyrus Syntactically ambiguous sentences caused activation in this area. It was also found to be activated with semantic evaluation of complex sentences.
RH parts:
Auditory speech processing activates RH as much as LH. Reading words may also activate some parts of RH.
Right anterior temporal lobe, More activated for sentences than for words.
Right superior temporal gyrus, Activations were experienced for sentence comprehensions.
Frontal lobe of RH Comprehension, of lexical semantic ambiguities. Also it found some role in constructing other kind of alternative interpretations; primarily semantic.
            Effective use of lexical semantics in sentence comprehension may be partially dependent on RH particularly right anterior temporal lobe. Right anterior temporal lobe has an access to lexical information which may not be available to LH. The normal language comprehension involves a much wider network of Brain areas carrying out different components of processing, than was earlier assumed. Broca’s area appears to be more important in maintaining information about both lexical items and phrases. The motor areas are recruited during the processing of more demanding sentences. When semantic processing becomes more difficult additional areas of left and right frontal lobe are activated.
Studies on sign language users
Sign languages (such as ASL) encompass the same abstract capabilities as spoken languages and contain different levels of linguistic representation such as phonology, morphology, syntax, semantics and pragmatics. Such structural similarities between signed and spoken languages predict that the left hemisphere language areas should also be recruited during sign language processing. The two forms of language differ in their input-output modalities. By this view left hemisphere should not be fully recruited. Right hemisphere plays a greater role in visual spatial processing.
Some observations show that LH plays a crucial role in supporting sign language. Hickok, Bellugi and Klima [2001] mentioned in their paper such observation. Deaf signers with comprehension difficulties had damage to areas that include Wernicke’s area and Patient with trouble in making signs had damage that involved Broca’s area. Studies showed that most impaired signers had damage to brain’s left temporal lobe, where Wernicke’s area is located. Various results establish that LH language areas are recruited by language system, independent of modality and surface properties of the language. The organization of brain doesn’t appear to effect particularly by the way in which language is perceived and produced. One exception to LH’s monopoly on language production is creation of a coherent discourse. RH seems to have a role in the comprehension of extended discourse, but deciphering the meaning of words and sentences seems to take place primarily in the LH. Speakers with right hemisphere lesions show more subtle deficits when tested. Most severe impairments of spatial abilities occur more commonly following damage to RH. There is a greater participation of RH during the comprehension of signs. Areas included are Right Temporal areas, Right Posterior areas and
Right Superior Temporal Lobe. Right parietal cortex was seen to be active to depict spatial scenes. While RH appears strongly tuned towards semantic interpretation and global meaning; LH seems necessary for fine aspects of on line sentence processing and literal meaning. Imaging results have shown activation of Broca’s area : in hearing patients when they speak and in deaf patients when they are signing. Signing activated left supramarginal gyrus, which was not been greatly implicated in phonological retrieval for spoken languages. Activation was seen in the left parietal cortex which was similar to that seen in English speakers when they try to produce prepositions. Various studies suggest different final organization of the brain system for language in speakers and signers. The standard LH language areas may be included to all natural languages but the final organization appears to be determined by the exact language experience of the individual. The lesion studies are making it clear that if differences exist between spoken and sign languages, they are likely to be subtle and language specific. They share a great deal of neural territory at the more central and higher level of brain systems but diverge at the more peripheral levels of processing.
Study of Bilingual Brain
Some researchers believe that language acquisition radically alters the brain through some kind of symmetry breaking i.e. fixation of one of the possible values of each parameter, so that brain ultimately get tuned to one language. Just consider the case of bilinguals (or polyglots), what happen if acquisition of language L1 and L2 (different languages) require different values for the same parameter.
Earlier there were hypotheses suggesting that all languages known to a bilingual (or polyglots) are localized in the same cerebral areas and that there is no basis for postulating a separate cerebral organization for different languages in the bilingual’s brain. Then came many hypotheses opposing earlier one which suggest, the brain areas recruited for L1 learning and processing are different from those involved for L2. Many studies supported the later hypothesis. One such study was mentioned by Monika Ekiert. In this some patients showed Broca’s aphasia for L1 and Wernicke’s aphasia for L2. A large series of recent studies led the researchers to formulate the hypothesis that different languages are organized partly in common areas and partly in specific and separate areas of the brain. Stimulation in central region of Broca’s or Wernicke’s area tends to disrupt functions of both the languages, but some areas’ stimulation disrupts only either of the two. The difference in cerebral representation has been attributed to a neural variability in the linguistic ability of individuals. The anatomical separation of grammar and phonology in bilinguals varies according to age and manner of language acquisition. In early bilinguals (who adopted L1 and L2 from childhood) no exhibition of different areas for different languages was shown, while in late bilinguals (who adopted L2 in adult age) L1’s grammar and phonology motor maps had developed a closed proximity and L2 developed in separate area.     Evans et al [2002] found that for participants from a dual language environment, both early and late acquisition of a second language resulted in a LH localization of L2. Their data revealed increased RH involvement for later learned L2 in a single language environment.
            Illes, Francis, Desmond (and many others) [1999] examined brain activation of bilinguals of English and Spanish language users. The participants became fluent in their L2’s (English or other way round) a decade after acquisition of L1, but were proficient in both. They found that
the semantic activation for both the languages occurred in the same cortical location. They inferred that learning a new language, even after a decade, does not require the addition of a new semantic processing system or the recruitment of a new cortical region. Such evidences suggest a common cortical representation for L1 and L2 when levels of proficiency in both languages are comparable.

















CONCLUSION

Comparison of the views of co evolution of language processing and brain has a two sided result. On one hand brain has been shaped by and for language and has become “brain of the language”, and on the other hand, language has changed to better suit communicative demands offered by the users and learning acquisition of children and has become “language of the brain”. Babies’ brain is primed to learn language and it does this by making pathways and stronger connections, which may extend upto the age of 10 years.
The two classical language areas, Broca’s and Wernicke’s, are important brain areas for language processing but many other LH and RHparts of the brain are involved in the task. The  usage of these parts depend on language used, task performed (name or recognize), conceptual category of items (unique, common, familiar), modularity of input and output (spoken language or sign language) and number of languages known to individual. For optimal retrieval of words of different categories different anatomically separable regions are involved, while for concept retrieval some regions are consistently associated. This says partial segregation of different categories. The LH is found to be dominant in language processing with many tasks affected by LH lesions. But overall composition of language, in some sense, is distributed over the two hemispheres. LH is generally related to fine aspects of sentence processing and literal meaning and RH to visual spatial abilities. The standard LH areas may be common to all natural languages but the final organization of language system appears to be determined by the exact language experience of the individual. In case of bilinguals the age of acquisition of language and language environment seems to effect the language organization. Different brain areas may be recruited for different languages. But when proficiency is kept constant, age of acquisition doesn’t seem to have much effect.
From various studies and results mentioned, it can be concluded that language is not a function restricted to one hemisphere of the brain, but both the Left and the Right hemispheres have their own vital role in language processing. When the parts of the two hemispheres perform their respective tasks, some areas of brain take the charge of leader and lead them to the completion of task successfully. The overall organization of language in brain depends upon the individual and the proficiency and the way he had acquired the language.


References

-Brain and language: A perspective from sign language; Bavelier, Corina and Neville.
-Building baby’s brain: Learning Language; web page.
-How does the Human Brain process language? : New studies of deaf and signers, hint at an answer: Hickok, Bellugi, Klima.
-Neural System behind word and concept retrieval: H Damasio, Tranel, Grabowski, Adolphs and A Damasio.
-Rethinking the Neurological basis of Brain: Stowe, Haverkort and Zwarts.
-The Bilingual Brain; Monika Ekiert
-The co evolution of Language and the Brain: A review of the contrastive views; Ken Ramshoj Christensen.
-The Neural correlates of the spatial language in English and American Sign Language:   a PET study with hearing Bilinguals; Emmorey, Grabowski, McCullough, Ponto, Hichwa
and H Damasio.
-The Neural Systems underlying language: Insights from sign language research; Karen
Emmorey.

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