Brain Mapping and Bilingualism - Essay Example

Running Head: BRAIN MAPPING AND BILINGUALISM Brain mapping for bilingualism: does the brain use different areas for processing of bilingual speech? Author: College: November 29, 2014 Table of Contents 1. Introduction 5 1. Introduction 5 2. Background 7 2. Background 7 3. Logic 13 3. Logic 13 4. Experiments 13 4. Experiments 13 5. Conclusions 17 5. Conclusions 17 References 21 References 21 1. Introduction Bilingualism, the gift of speaking two languages, has interested researchers since different areas of the brain help a person to develop these skills. The complex structure of the brain means that only non-invasive techniques can be used to study the speech recognition and processing patterns. The development of Positron emission tomography (PET) scanner, and functional magnetic resonance imaging (fMRI) scanners, allow brain scans to be conducted to analyse speech patterns. Findings indicate that separate areas of the brain are used in bilingualism (Abutalebi et al. 2001). However, the studies until now have been unitary in nature, and have not studied the lexicon of related languages, the differences in the languages, and if this difference has an impact on the brain processing areas. The research until now has not examined in detail if there are differences in brain activity for different languages. This becomes crucial since, foreign languages have different phonetics, and lexicon, and it is expected that different areas of the brain are activated when one speaks Hindi, Arabic, or Chinese. These are crucial aspects of brain mapping since a focussed research of this nature, helps to bring more details into brain mapping for bilingualism. This proposal focuses on this aspect and the thesis statement is "Brain mapping for bilingualism: does the brain use different areas for processing of bilingual speech?" The proposed research will use PET scanners to identify the patterns in brain processing by administering tests to bilingual subjects. It is expected that the research will help to develop a better understand of brain activity for bilingual speech processing. 2. Background The availability of neuroimaging techniques helps in understanding the brain mechanisms of how two languages, L1 and L2 are organised. The techniques help to understand the manner in which the brain recognises the two languages, manages, and processes the thought processes, without mixing them. Functional neuroimaging studies indicate the presence of language related areas in the perisylvian cortex of the left hemisphere (Mouthon et al. 2013). Other studies have shown the presence of these areas in the middle and inferior temporal gyri, the temporal pole, the insila, middle prefrontal areas lingual, and in fusiform gyri (Indefrey & Levelt, 2000). Lesion studies indicate that these areas are regarded as language related areas of the brain, and they appear to provide specific components for language processing such as language semantics (Alexander et al. 1989). Neville and Bavelier (1998) indicate that the function role of the language related brain areas, have linguistically different systems for language characteristics such as syntax, phonology, and lexical semantics. A study by Petersen, van Mier, Fiez and Raichle (1998) showed that when the task and experimental design become constant, the increased familiarity of the tasks lead to changes in the brain activation. The scientists used PET techniques to investigate the influence of practice on a verbal task. The findings indicate that a difference is seen in the processing sequence, varying from high and low performance of verb generation, and further showed decreasing brain activity in the left prefrontal cortex. These findings are supported by research from Petersson et al. (1999) and Raichle et al. (1994) who report that the prefrontal brain areas remained active in the first instance of the task, but showed decreased activity in the well-practiced automatic condition. Hence, this aspect of the study will be verified in the research. Chee et al. (1999) reported findings from their research in language comprehension for English and Mandarin languages, by using sentence comprehension for the subjects. The study indicates that there was significant activity in the left inferior and middle frontal gyri, left superior and middle temporal gyri, the anterior supplementary motor area, the bilaterally, superior parietal regions, and occipital regions. Some amount of overlapping brain activity was reported in the studies. These studies were supported by research from Price et al (1999), who studied six subjects using PET tests. Lexicon of the languages is important in this research. The term lexicon refers to repository of the languages words. It uses bound morphemes, which cannot be used as standalone words. Many words from English do not have exact translations into Chinese, Arabic, and Hindi. Hence, Neologisms or loan words are used. These are English words, borrowed in other languages. As an example, words such as computers, internet are nouns, name words, and they do not have any other similar words in other languages (Gleason & Ratner, 1998). However, verbs, adjectives, pronouns, and other components can be loosely translated to give a meaning. Some examples are innovate, imply, or phrases such as nail in the coffin, between the devil and the deep blue. Such words are translated to give contextual meanings, while the exact translation may give misleading results. The issues for bilingual lexical access are more complex, since it involves mental processing to find an equivalent word in L2 (Grainger & Beauvillain, 1987). Certain control mechanisms of the brain are used in the signal processing. Chinese, Hindi, and Arabic, have different phonetics, sound, pronunciation, and grammar. The tasks of reading, which involve word naming, lexical decision, and word priming, are different for these languages. A person who speaks these languages would develop or acquire different patterns of the brain to process the languages (Costa & Navarrete, 2006). Studies by Klein (et al. 1994) show that the semantics of same words in different languages can affect brain activities and area of activation. Word generation activities such as speaking rhymes, synonyms, and translation to other languages, help to understand lexical semantics. Word generation is seen to create activation in the Brodmann zones 9, 45, 46, 47 of the left dorsolateral frontal cortex. Some level of selective activation is seen in the area of the left putamen during word generation in L2. It is also seen that the phonemic verbal fluency produces a bigger foci of brain activation in a person who has less fluency in other languages. Activation is seen in the inferior frontal, precentral gyri, and middle frontal areas of the left prefrontal cortex. Activation is also seen the parietal lobe and the supplementary motor areas. If a person has increased familiarity with a language, the brain activation is reduced (Yetkin et al, 1996). Musso et al. (2003) point out that the Broca region is linked with learning L1. When a person begins learning grammar aspects of L2, this region shows increased activation. These findings are of interest since many L1 languages do not have an exact translation in L2 language, and the use of neuroimaging, helps to understand the lexicon and semantics in such instances. This aspect will be assessed through research in this project. 3. Logic Based on the literature review from the previous section, the following hypotheses are framed. These will be tested in the research. H1: Difference in brain activity exists for bilinguals when they speak two phonetically different languages H2: Different areas of the brain are activated when bilinguals speak different languages. H3: When a word in L1, which does not have a literal translation in L2 is spoken, different areas of the brain are activated. 4. Experiments A laboratory experiment is proposed for the research and details of the experiments are given as follows (Fernandez,, 2011; Jonides , 2007; Forster & Bednall, 1976). Subjects: The subjects for the research will be six individuals who can speak two languages, with some amount of fluency. I plan to enrol my colleagues at the university, and other students, acquaintances I know personally. The subjects will be arranged in pairs, with two of them having bilingual skills in English/ Hindi; English/ Chinese, and English/ Arabic. The subjects will have a similar education of a bachelors or Masters degree, they will have spent at least four years in UK, but speak and read their native language, and they will belong to the age group of 22-26 years. These conditions will eliminate any errors due to demographics, period of stay in UK, age, and other factors. The reason for selecting this combination of languages is because the languages are phonetically different and unique, and they have different lexicons. English will be the L1 language, and remain the common language among the students while Chinese, Hindi, and Arabic will be L2, L3, and L4 languages respectively. Materials: These will include PET scanners, which I can access in my hospital. The required permissions will be obtained, and consent of the respondents will be procured for their participation. For the test, a script of 250 words will be prepared in English from a technical/ scientific publication. The text will have complex sentence structures, and avoid the use of technical jargon. Services of experts in L2, L3, and L4 languages will be used for translation. Procedures: The subjects will be invited to the test individually, and at different times, so that they do not meet and speak with each other. They will be fitted into the machines, and care will be taken to remove any stress caused by seeing the machines, so that they calm down. The they will be first given the English script and asked to read it aloud, and brain maps will be recorded by the machine. Next, they will be given the script in their native languages, and they will be given the script to read it aloud, and brain maps will be recorded. These tests will help to verify H1 and H2. It is also proposed to have another test where a list of complex phrases in English, that do not have an exact translation in L2, L3, L4, will be created. These will be translated into the respective native languages, to give a literal meaning. Subjects will be asked to read out the English phrase first, then asked to form a translation in their mind, and speak it aloud. They will then be given a translated phrase and asked to speak it aloud. The changes in brain activity will be monitored in all the cases. This test will help to verify H3. The procedure will be repeated for all the six subjects. At the end of the session, we will have 36 sets of recordings of the brain maps, and these will be studied for differences in patterns of brain activity. Expected results: It is anticipated that there will be differences in the brain map scans between the three pairs of respondents. This means that the maps will indicate that different areas of the brain will be used during the sessions for the three pairs. However, it is anticipated that a pair of respondents who speak the same language, will have identical brain activity maps. Another expected result is that when the subjects read the complex phrase, translate it, a change in the brain activity will be seen. It will be possible to understand the specific areas of the brain which are activated for the two languages. 5. Conclusions It is apparent that different areas of the brain are exercised when bilinguals speak different languages. The findings indicate that such an activity can be measured and mapped using PET techniques, and the resulting brain maps can help to identify different patterns of brain activity. Three hypotheses were framed and a research method was designed to carry out the tests. Six subjects will be tested using PET techniques to test the three hypotheses. The six subjects will be arranged in pairs and tested for three language combinations namely, English/ Arabic, English/ Hindi, and English/ Chinese. Care is taken to ensure that the subjects have a common background, and that they speak the native language at home. The results from the research will prove to be very valuable since till date, extensive research into the differences in brain activity for different languages is not available. One cannot assume that the same areas of the brain are activated when different phrases of L1, that do not have a direct translation into foreign language, are translated using literal translations. The research has certain limitations and causes for errors since the subjects, who are college students, could be well conditioned involuntarily. It is possible that they would have been exposed or read the complex English phrases earlier and know their translations. This issue will be handled by using phrases that do not occur often, and are not in common use. The help and guidance of language experts will be taken to frame such phrases. In addition, the subjects will not be shown the test questions, hence, the repetition aspect and automation element is not possible. References Abutalebi. J., Cappa, S. 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