PSYCHOLINGUISTICS

Presented byDr. Mac Aditiawarman, M.Hum.

Psycholinguistics is the study of relationship between Language and the mind. As such, psycholinguistics search for answers to thre basic question:1. How is language represented in the mind?2. What are the mental processes involved in

the production and comprehension of speech?

3. How does a person acquire language?

PSYCHOLINGUISTICS

These questions are difficult to answer, partially because our limited knowledge about the brain, the repository of our linguistics knowledge. Yet, if we want to make claims about the psychological reality of our linguistic theory. ( e.g., a claim that certain linguistic rules like flapping have some physical manifestation in the brain), then we must find answers to these question.

One area in which psycholinguists look for these answer is in the study of child language acquisition. As early 1887, ethnologist Horatio Hale claimed that language was instinctive. If his claim were correct, then language would be simply be another biological function like breathing. While no linguist would want to accept this claim in its strongest form, we must accept a curtain degree of innateness, because of the fact that children acquire language in an imperfect environment.

Total innateness would imply one of two sequences. Either all children would acquire the same language, or children from different nationality, say Chinese and American, would have different biological make ups to account for the fact that they speak different languages. We know that the second one is false because children of, say, Mexican parents grow up in the United State speaking perfect native English.

Thus, they have a Mexican biology but the English language. It is not people’s biological heritage which determines the language that they will acquire. We also know, however, that the language cannot be acquire simply on the basis of experience since the linguistic environment is imperfect. The language that the child hears everyday contains ill-formed sentences, with pauses and slips of the tongue, yet the child acquire a correct grammar. The language stimulus that a child receives is finite, yet he is able to construct a grammar that can produce a countless number of novel grammatical sentences. These ‘poverty of stimulus’ facts argue for the innateness of grammar. Thus, we must view language as arising from an interaction between innateness and experience.

A number of theories have been posited regarding the role of experience in language acquisition. One of the more prominent theories, the reinforcement theory, suggests that children learn language by having selected utterances reinforced by their parents. When we first consider the relationship between parent and child, this theory may seem correct. Imagine a father coming home from work and hearing his baby babbling in the crib. Out of the numerous noises the child makes, he picks out the sequence ’d-a-d-a’, at which point he might say: “ That’s right, Dada. Dada’s home”.

Then he would rush off to tell the child’s mother that the baby said first word, before returning to the child and practicing this great accomplishment. However, the reinforcement theory suffers from several serious flaws. First, the theory cannot account for a child’s initial utterances. The child must say something before it can be reinforced. Secondly, adult do not necessarily reinforce on the basis of grammaticality.

Some ill-formed utterances are reinforced because they are true:Child : Mama isn’t boy, he a girl.Parent: That’s right.Other utterances, though grammatically correct, are not reinforced because they are untrue:Child : There’s farmhouse.Parent: No that’s a lighthouse

Another prominent theory, suggest that the children learn language through imitation. While children do imitate, one study finding that imitated utterances range from 6% to 27% of a child’s total utterances, they also produce new and unique utterances:Parent : Did you like the doctor?Child : No, he took a needle and shotted my arm.

No child will hear an adult say ‘shotted’, therefore, the child must have some creative, linguistic capacity, which allow for creation of words like ‘shotted’ and which imitation cannot account for.

Though psycholinguists do not support either the reinforcement or imitative theories of language acquisition, the do realize the importance of studying children and their utterance. By studying the way that the children acquire their language, psycholinguists try to determine the nature of grammatical rules children develop as they acquire their phonology, morphology, syntax and semantics.

In this way, linguists can find answers not only to question 3, but also question 1. Other areas of psycholinguistics include the study of adult production and comprehension, and neurolinguistics, the study of the relationship between language and the physical structure of the brain. Here we can find answer to 1and 2, discovering the relationship between proposed linguistics structure, the physical composition of the brain, and comprehension and production patterns.

LANGUAGE AND THE BRAIN

To fully appreciate the amazing human ability for language it is necessary to know something about the way the brain controls language. Because the human brain is complex and our knowledge of its inner working is somewhat limited, there are many aspects of brain function which are simply not understood at this time.

PHYICAL FEATURES OF THE BRAINA summary of some of the anatomy of the brain will help you follow the discussion later in this file. One of the first noticeable physical feature of the brain is the fact that it is divided into two halves. These two halves are called the right and the left hemisphere. The two hemispheres are connected by a bundle of nerve fibers called the corpus callosum. This bundle of nerve fibers (plus a few other interhemispheric connection) make it possible for the two hemispheres to communicate with each other. The hemispheres are covered by a ¼ inch membrane called the cortex.

The surface of the hemispheres is not flat; rather, there are bumps and depression on it. The bumps in hemispheres are called gyri and depressions are called fissures. The fissures in particular serve as physical boundaries for the identification of section of the brain.

The connection between the brain and the body are contralateral. What this means is that the right side of the body is controlled by the left hemisphere, while left side of the body controlled by the right hemisphere. It is also important to realize that contralateral connection also means that sensory information from the right side of the body is received by left hemisphere, while sensory information from the left side of the body is received by the right hemisphere.

LATERALIZATIONNot surprisingly, nether of the hemispheres

in adult duplicates the function carried out by another; rather; each side of the brain performs specific functions. Lateralization refers to this specialization of each of the hemispheres of the brain for different cognitive functions. Paul Broca, in the 1860’s, was one of the first physicians to observe that damage to the left side of the brain resulted in impaired language ability while damage to the right side of the brain did not influence language ability.

Since that time the researchers have observed that approximately 70% of the people with damage to the left hemisphere experience aphasia, an inability to perceive, process or produce language because of physical damage to the brain. Hemispherectomies, operation in which one hemisphere or part of one hemisphere is removed from the brain, also provide evidence for lateralization. Performed on people who experience severe seizures, this operation affects the patient’s behavior and ability to think.

It has been found that hemispherectomies involving the left hemisphere result in aphasia much more frequently than those involving the right hemisphere. This indicates in most people the left side of the brain is used to process language while the right side has much less to do with language processing.

Further evidence for lateralization comes from split-brain patients. Normally, the two hemispheres are connected by the corpus callosum. In certain kinds of serve epilepsy, the corpus callosum is cut, preventing thr two hemispheres from transmitting information to each other.

Also, since the connections from the brain to the rest of the body are contralateral, various experiments can be formed on these split-brain patients which help to identify the cognitive characteristics of the two hemispheres. For example, in one experiment a patient is blind-folded and an object is placed in his/her right hand. The patient can say the name of the object. If an object is placed in the left hand, the patient usually cannot identify the object verbally.

The result of this kind of experiment indicate that language is lateralized: that the left hemisphere is the location of those abilities which are used in producing language while the right hemisphere is essentially devoid of such cognitive abilities. When the object is in the subject’s right hand the left hemisphere is experiencing the heightened sensory activity associate with holding the object. When object is placed in subject’s left hand only the right hemisphere experience the sensory feedback associate with holding the object. Because the subject in this situation in unable to state the name of the object, we infer that the cognitive abilities and memory store needed to name the object are not available to the right hemisphere.

Primary areas of human brain are thought to be located in the left hemisphere, because only rarely does damage to the right hemisphere, cause language disorders. Broca’s area, result which adjacent to the region of motor cortex that controls the movement of muscles of lips, the jaw, the tongue, the soft palate and the vocal cords, apparently incorporates programs for the coordination of these muscles in speech. Damage to Broca’s area results in slow and labored speech, but comprehension of language remains intact.

Wernike’s area lies between Heschl’s gyrus, which is the primary receiver of auditory stimuli, and the angular gyrus, which acts as away station between the auditory and visual regions. When Wernike’s area is damaged, speech is fluent but has little content and comprehension is usually lost. Wernike and Broca areas are joined by a nerve bundle called the arcuate fasciculus. When it is damage, speech is fluent but abnormal, and patients can comprehend words but cannot repeat them.

THE CITICAL PERIODThe critical period from birth to puberty is sometimes called the critical period. A child must learn a language during this period to gain normal, native competence in the language. Some of the properties of the brain which we have discussed up to this point may provide an explanation of the critical period. We have seen the left hemisphere is normally location of the abilities needed for the use of language in adults. Language lateralization indicates that there is something about the left hemisphere that causes this predisposition is not known, but the fact that there is a predisposition is important for an understanding of the critical period.

The predisposition of the left hemisphere for language is an indication that in children the left hemisphere is open to language learning. As the child’s brain matures and patterns of neutral activity become set, the readiness for language learning which was once present become less and less available. This loss of flexibility can have two results. This first and most common result is that it becomes much more difficult to learn a second language after the critical period than it was a child. Most American college students who take up a second language fell the effects of this loss of flexibilities.

On the other hand, children who learn two or more languages during the critical period usually can speak the languages without an accent. The second, result is that if a child is not exposed to language during childhood it may become impossible to later learn language. Genie, a child who was discovered at the age of 13 in 1970, is an example of this second, tragic result. She received virtually no linguistic stimulation from ages 1 to 13. Even after 11 years of intense instruction her language ability was not normal.

APHASIAAphasia is an impairment of language abilities because of physical damage to the brain. One type of aphasia is called Broca’s aphasia. Broca’s aphasic suffer from an inability to plan the motor sequences used in speech. When they attempt to speak, they speak haltingly and have a hard tone getting the words out. There is also a tendency for telegraphic speech (i.i. they leave out small function words and inflections) although the basic word order is correct.

EXAMPLE 1 : Broca’s AphasiaExaminer : Tell me, what did you do before retired?Aphasic : Uh, uh, uh, pub, par, partender, no, Examiner : Carpenter?Aphasic : (Shaking head yes) Carpenter, tuh, tuh, tenty year.Broca’s aphasia seems to result in primary expressive disorders. Comprehension of the speech of others doesn’t see to be a problem for Broca’s aphasic. Damage to the Broca’s ares will result in Broca’s aphasia.

Broca’s aphasia results in primarily expressive disorders, Wernike’s aphasia results in primarily receptive disorders. A patient which Wernike’s aphasia doesn’t not find it hard to speak, but there is a tendency for Wernike’s aphasic to produce semantically incoherent speech, as you can see in example 2.

EXAMPLE 2 : Wenike’s AphasiaExaminer : Do you like here in Cansas City?Aphasic : Ye, I am. Examiner : I’d Like you tell me something about

your problem.Aphasic : Yes. I ugh can’t hill of my way. I can’t talk all of the things I do, and part of the part I can go alright, but I can’t tell from the other people. I usually most of things. I know what can I tell and know what they are, but I can’t always come back even though I know they should be in, and I know should something eely I should know what I’m doing.

THE ACQUISITION OF PHONOLOGYWhen an eighteen-month child attempts to pronounce the word water, he might say ww, falling considerably short of the adult pronunciation; or his pronunciation of that may sound dƐϮ. Errors like these may persist for some time, despite constant drilling by the child parents, and despite the child’s own realization that his pronunciation is less than perfect. All children make mistakes these before they have master the phonological system of their native language. Yet such errors reveal that they have already learned a great deal, and in another two and-a-half years or so, their speech will resemble that of their parents in all important respects.

Linguists interested in the acquisition of phonology attempt to trace its development from baby talk to mature adult pronunciation. In doing so, they try to answer two central questions in child-language research:1. Why does children’s speech differ from

that of adult? and2. Why does the evidence from acquisition

of phonology bear on the claim that the capacity of human language is innate?