NEUROLINGUISTICS

Linguistic has always been to give a full account of how language works, and this account must include an explanation of how the human brain operate to generate language. Another subfield of linguistic is neurolinguistic, it is concerned principally with the intersection of linguistic theory and brain structure. Today, neurolinguistics concern themselves with the number of issues that relate to the neurological basis of language: the brain’s anatomy, the species-specificity of language, and the relationship between language and consciousness.

A.    The Human Brain

The brain is the most complex organ of the body. It lies under the skull and consists of approximately 10 billion nerve cells (neurons) and billions of fibers that interconnect them. The surface of the brain is the cortex, often called “Gray Matter”, consisting of billions of neurons. The cortex is the decision-making organ of the body. It is the storehouse of our memories. Somewhere, in this Gray Matter resides the grammar that represents our knowledge of language.

The brain is composed of cerebral hemispheres, one on the right and one on the left, joined by the corpus callosum, a network of two million fibers, the corpus callosum allows the two hemispheres of the brain to communicate with each other. Without this system of connections, the two hemispheres would operate independently. In general, the left hemisphere controls the right side of the body and the right hemisphere controls the left side. If you point with your right hand, the left hemisphere is responsible for your action. Similarly, sensory information from the right side of the body like right ear, right hand, right visual field. Is received by the left hemisphere of the brain, and sensory input to the left side of the body is received by the right hemisphere. This is referred to as contralateral brain function.

gambar bagian otak.

B.      Localization, Brain and Language

In the early nineteenth century, Franz Joseph Gall proposed the theory of Localization, which is the idea that different human cognitive abilities and behaviors are localized in specific parts of the brain. In light of our current knowledge about the brain, some of Gall’s particular views are amusing. For example, he proposed that language is located in the frontal lobes of the brain because as a young man he had noticed that the most articulate and intelligent of his fellow students had protruding eyes,  which he believed reflected overdeveloped brain material. Gall’s view that the brain is not uniform mass, and that linguistic and other cognitive capacities are function of localized brain areas, has been upheld by scientific investigation of Aphasia and other disorders, and more recently by functional brain imaging.

 Specific locations of the brain are involved with specific aspects of speech or language. Linguistics are very cautious about asserting that any of the areas of the brain are actually associated with language. Although they are obviously associated with speech. A strong possibility exists that language rules depend on activity in deeper areas of the brain, and that the speech complex that includes Broca’s (represent some sort of interruption in the actual production of speech sounds) and wernicke’s areas is made up of relatively superficial pathway for turning language into Speech.

1.      Aphasia

The study of aphasia has been an important area of research in understanding the relationship between brain and language. Aphasia is the name for a variety of speech losses and speech problems that are related to dysfunctions of the brain itself. Aphasia is the neurological term for any language disorder that results from brain damage caused by disease or trauma.

2.      Types of Aphasia

a.       Broca’s Aphasia

In 1864 the French surgeon Paul Broca proposed that language is localized to the left hemisphere of the brain, and more specifically to the front Part of the left hemisphere called Broca’s Area. At a scientific meeting in Paris, he claimed that we speak with the left hemisphere. Broca’s Finding was based on a study of his patients who suffered language deficits after brain injury. In 1865, Broca’s Further claimed that Aphasia results only when damage occurs on the left side of the brain.

Patient with injuries to Broca’s area may have Broca’s aphasia. Broca’s aphasia is characterized by labored speech and certain kinds of word finding difficulties, but it’s primarily a disorder that affects the person’s ability to form sentence with the rules of syntax. One of the most notable characteristics of Broca’s aphasia is that the language is often agrammatic, meaning that it frequently lack articles, prepositions, pronouns, and auxiliary verbs. For now, Broca’s aphasics also typically omit inflections such as the past tense suffix –ed or the third person singular verb ending –s. here is an excerpt of a conversation between a patient with Broca’s aphasia and a doctor.

Example:

Doctor: “could you tell me what you have been doing in the hospital?”

Patient: “Yes, Sure. me go, er, uh, P.T (physical  therapy) none o’cot, speech…. two times…. read… r… ripe… rike… uh write….practice….get…ting… better.

b.      Wernicke’s Aphasia

In 1874, Carl Wernicke a German neurologist announced the discovery of a second major speech area. Now called Wrenicke’s area it has since been determined that Broca’s and Wernicke’s are connected by a long track of nerves. Wernicke’s Aphasia is markedly different from Broca’s. Speech is fluent. Pronunciation is unimpaired, and speech sounds more or less normal until it’s meaning is considered. Wernicke’s area, language then, is lateralized to the left hemisphere. Lateralization is the term used to refer to any cognitive function that is localized primarily on one side of the brain or the other.

Wernicke’s aphasia produce fluent speech with good intonation, and they may largely adhere to the rules of syntax. However, their language is often semantically incoherent. People with damage to wernicke’s area difficulty naming objects presented to them and also in choosing words in spontaneous speech. They may make numerous lexical errors (word substitutions), often production Jargon and nonsense words, as in the following example:

 “The only thing that I can say again is madder or modder fish sudden fishing sewed into the accident to miss in the purdles”.

The kinds of word substitutions that aphasic patients produce also tell us about how words are organized in the mental lexicon. Sometimes the substituted words a similar to the intended words in their sounds, for example: Pool might be substitute for tool, sable for table, or crucial for crucible.

c.       Hescl’s Area

Hescl’s area is principally associated with the nerve pathways of hearing. And damage to it results in what is called word deafness a form of Aphasia in which the listener cannot understand words spoken to him or her. The damage to Heschl’s area has apparently prevented sounds from entering the speech complex at the right point or in the right way. Speech cannot be understood, even though it may be “heard” as sound. People suffering from word deafness may have no difficulty at all in understanding written language.

3.      Speech and Species

Researchers have compared the human brain to the chimpanzee’s to determine whether the chimpanzee is equipped for speech. The chimpanzee’s brain is similar enough to the human brain for psychologists to have considerable trouble telling them apart. In several respects, however, differences exist that relate directly to the capacity for speech.

Chimpanzees have no perceptible Broca’s area: the area equivalent to Wernicke’s area is small and symmetrical in both hemisphere, and there are no nerves bridges to  connect the two. In other word, the chimpanzee apparently lacks entirely what in the human are known to be the major speech areas of the brain. This is not to say that chimpanzees are incapable of vocalizations. Chimpanzee, like other animals, are capable of a wide range of communicative noises, each of which may be associated with different types of message. 

Humans are directly uniquely equipped for speech with a brain that contains anatomical specializations found in no other species. Even though they lack human unique capacity for speech because the neurolinguist has no idea of what the anatomical correlates of language organization might be, the matter must rest there for the moment

4.      Language and Consciousness

·          Figure 17-2, The left visual field of both eyes is connected to the right hemisphere. And the right visual field  to the left hemisphere. and the right visual field to the left hemisphere.

Optic connections

LEFT FIELD

RIGHT FIELD

 

RIGHT HEMISPHERE

OPTIK NERVE CROSSING

LEFT HEMISPHERE

·         Figure 17-3 the left field is perceived solely with right eye through the right visual area and the right field is seen only with the left eye through the left visual area.

Optic connections after severing the opticcrossing between the two sides of the brain.

RIGHT FIELD

LEFT FIELD

 

·         Figure 17-4 saw the word band only because the brain had been split so that the two halves were independent of each other, hat could not be transmitted to the left side, where speech is produced, and so hat could not be talked about.

Perception of Hatband with optic crossing severed

BAND

HAT

 

BAND

HAT

NEUROLINGUISTCS

By 13 group :

SYAHRAENI FITRIAH ARSYAD

20400115054

YULIANA IBRAHIM

20400115077

English Education Department

Tarbiyah and Teaching Faculty

State Islamic University of Alauddin Makassar

2016/2017irthHSTCS1

07/08/17