پردازش واژگانی-معنایی در افراد مبتلا به بیماری آلزایمر: شواهدی از تکلیف نامیدن تصویر در دوزبانه های ایرانی تورکی آذربایجانی-فارسی (مقاله علمی وزارت علوم)
درجه علمی: نشریه علمی (وزارت علوم)
آرشیو
چکیده
مطالعات آسیب شناختی ذهن با رویکردی زبان شناختی برروی دوزبانه های مبتلا به اختلالات زبانی ناشی از بیماری آلزایمر زمینه پژوهشی بین رشته ای گسترده ای را در سال های اخیر برای پژوهشگران فراهم آورده است. با این حال، علیرغم وجود این واقعیت که زوال زبان یکی از علائم غالب بیماری آلزایمر است اختلالات زبانی در دوزبانه ها در ارتباط با بیماری آلزایمر به صورت کافی مورد بررسی تجربی واقع نشده است. این پژوهش آزمون محور با هدف بررسی چگونگی تأثیر نام پریشی ناشی از بیماری آلزایمر بر روی مهارت های واژگانی- معنایی زنان دوزبانه تورکی آذربایجانی و فارسی ایرانی صورت گرفته است. به این منظور یک گروه تجربی شامل 20 فرد 55-82 ساله که نمره آزمون کوتاه تعیین وضعیت شناختی آن ها بین 19-23 بود با یک گروه کنترل شامل 20 فرد دچار اختلال شناختی خفیف و با نمره آزمون کوتاه تعیین وضعیت شناختی 23-30 از نظر سن، سن آشنایی با زبان فارسی و تحصیلات رسمی همتا شدند. تولیدات شفاهی زبان هر دو گروه به وسیله تکلیف زبان پریشی دوزبانه نامیدن تصاویر در دو زبان تورکی آذربایجانی و فارسی به طور جداگانه بررسی شد. مقایسه میانگین زمان واکنش به تصاویر محرک در دو زبان نشان داد که بیماری آلزایمر زبان غیرغالب (فارسی) را با شدت بیشتری نسبت به زبان غالب (تورکی آذربایجانی) دچار اختلال کرده است. نتیجه این پژوهش در راستای تأیید فرضیه سه انباره در چارچوب انگاره عصب-زبان شناختی پارادی است که بیان می کند دوزبانه ها از دو زیرنظام زبانی با دستور و واژگان مستقل و جداگانه و یک نظام غیرزبانی شناختی برخوردارند.Lexico-semantic processing in individuals with Alzheimer’s disease: Evidence from picture naming task in Iranian Azerbaijani Turkish-Persian bilinguals
Adopting a linguistic approach to the pathology of the mind on bilinguals afflicted with aphasia caused by Alzheimer's disease (AD) has given rise to a wide array of interdisciplinary research in recent years. However, bilinguals’ language impairments in AD have not been appropriately experimentally investigated while language deterioration has always been a frequent symptom of AD. A task-based research in this study has been conducted to investigate the effect of Anomic Aphasia caused by AD on the lexico-semantic skills of Iranian Azerbaijani Turkish-Persian bilingual women. To this end, the experimental group (AD) with 20 participants with Mini-Mental State Examination (MMSE) test scores in the range of 19 and 23 were matched in terms of age, age of familiarity with Persian language, and formal education. There was also a control group consisting of 20 participants with Mild Cognitive Impairment (MCI) and having MMSE test scores in the range of 23 and 30. The verbal productions of both groups were evaluated by the Bilingual Aphasia Picture Naming Task (BAT) in the Azerbaijani Turkish and Persian languages separately. Comparing the average reaction times (RTs) to the stimulus pictures in two languages showed that AD affected the nondominant language (Persian) more severely than the dominant language (Azerbaijani Turkish). The results of this research are consistent with the three-store hypothesis in the framework of the Neurolinguistic Notion of Bilingualism maintaining that bilinguals have two language subsystems, each of which has an independent and separate grammar and vocabulary, and a non-linguistic cognitive system.Keywords: Alzheimer’s diseases, Azerbaijani Turkish-Persian Bilinguals, Lexico-Semantic Processing, Picture naming Task, Task-Based Analysis IntroductionLanguage processing is a complex cognitive operation that involves various linguistic and neurological mechanisms in the brain. Brain diseases such as Alzheimer's disease, which affect the cognitive abilities of affected individual to varying degrees, have been the subject of extensive research in cognitive sciences, including psycholinguistics. One of the cognitive consequences of Alzheimer's disease is language disorders. One aspect of language processing that has been studied on individuals with language disorders caused by Alzheimer's disease is lexico-semantic processing or access to vocabulary and retrieval of meanings from the mental vocabulary. In recent years, there has been a lot of research in the field of bilingual pathology, but there has been scant attention directed towards languages such as Persian and Azerbaijani Turkish that belong to different linguistic families with distinctive syntactic and morphology characteristics. The present study took a descriptive and task-oriented approach to examine how and to what extent Alzheimer's disease affects the first and second languages of Azerbaijani Turkish-Persian bilinguals. In so doing, armed with neurolinguistic view of bilingualism theory (Paradis, 2004), we had 40 Azerbaijani Turkish-Persian bilinguals participate in control and experimental groups based on Mini-Mental State Examination (MMSE) scores. We also had our participants undergo Bilingual Aphasia Task (BAT) via DMDX. MethodThe research process began with the collection of demographic information from Azerbaijani Turkish-Persian bilingual females Which included: age, education, age of familiarity with Persian, computer literacy, clinical background check, medications used, visual and auditory status, and coding to subjects. The statistical population of the research was from Tabriz and its sample size was 40 participants who were categorized into control and experimental groups. Twenty participants with an age-related decrease in cognitive ability (according to a neurologist) with a score 23 or above in MMSE and the age range of 55-82 were categorized within the control group. Besides, 20 Azerbaijani Turkish-Persian bilingual female participants with Alzheimer's disease (according to the neurologist) who scored between 19-23 in MMSE and the age range of 55-82 were placed in the experimental group.Firstly, a researcher-made bilingualism proficiency test was constructed. The test was administered on a cognitively healthy sample before being administered on research participants. During the test, Azerbaijani Turkish, and Persian languages were separately assigned a level for each of the spoken, audible, readable, and written skills. This qualitative test, along with the relative trust in the self-assessment of the participants, was conducted on each language and for each of the skills. The results were categorized into four levels: weak, medium, good, and excellent for each individual.Next, MMSE was administered as an Alzheimer’s disease screening test. This test examines the repetition of naming announcements, attention and calculation, recall, language, ability to follow simple commands, and orientation of thinking (Tuijl et al., 2012). The test is used to separate attributable mental illnesses from acquired ones (Folstein et al., 1957). In this study, the Azerbaijani Turkish translation of the test was conducted by the Azerbaijani Turkish-Persian examiner.Finally, the BAT was carried out. The words considered for the picture of the task were related to organs, plants, animals, objects, and natural events that did not evoke cultural and ethnic events. The vocabulary items of the pictures of BAT were selected based on the criterion of familiarity history up to the age of seven or at most eight years. Furthermore, the criteria of imaginability, low ion rate, and cultural familiarity were controlled. The pictures were divided into three blocks with five-minute intervals and each block consisted of twenty items. The task was run on DMDX version 6.3.2.4 to record reaction time (RT) to picture stimuli. Results and ConclusionThis study aimed to examine the effect of anomic aphasia caused by Alzheimer's disease on the lexico-semantic skills of Azerbaijani Turkish-Persian bilinguals and experimentally tested the hypothesis of unparalleled deterioration in both languages in aphasia by using BAT. The results showed that the RT was much shorter for Azerbaijani Turkish than for Persian in the control group. In other words, the speed of access or retrieval of the Azerbaijani Turkish vocabulary was faster than the speed of access to Persian vocabulary in the control group. The average RT of the control group in two languages showed a significant difference (W=3.02, p<.01). Based on this finding, the hypothesis of the study that predicted no significant difference between the speed of access to first and second language vocabularies in the control group was rejected. Also, the finding does not confirm Juncos-rabadán & Iglesias’s (1994) findings that with growing age, the cognitive operation of both languages decreases parallelly. However, it should be taken into account that the research of Juncos-rabadán & Iglesias (1994) was done on languages from the same language family, where cognates could have possibly played a role. The current research was done on different language families, where the issue of the cognate status of words was not present.Also, the results showed that the speed of access to Azerbaijani Turkish (dominant language) vocabulary was much shorter than the speed of access to Persian (nondominant language) vocabulary in the experimental group (W= 3.88, p<.001) aligning with the research of Ivanova et al. (2014) that showed nondominant language is more severely impaired than dominant language. Golan et al. (2010), who also took the dominant language test for Spanish-English languages, concluded that nondominant language, especially in people prone to dementia, is more likely to be affected by language disorders. This is also consistent with the findings of the present study. Also, the results of the between-group comparisons showed that the participants in the experimental group faced longer pauses than the participants in the control group in accessing vocabulary and expressing the target words in the first language (U=78, p<.01) and the second language (U=37.5, p<.01).The analysis of lexico-semantic deterioration in this study showed that anomic aphasia caused by Alzheimer's disease impairs a person's second language (the language that a person has less mastery than his first language) more than the first language (the language that a person learned in childhood and used continuously in daily life). This finding is consistent with Paradis's (2004) theory showing that the language learned after the first language is more affected by cognitive deterioration. The fact that the dominant language has a stronger association with semantic representations in mind compared to the nondominant language in bilinguals can be a reason for the greater impact of cognitive diseases such as Alzheimer's disease on the nondominant language (see Costa et al., 2012). A comprehensive pathological study to determine the deterioration patterns of cognitive disease requires further interdisciplinary research by linguists, language sociologists, psychologists, and neuropsychologists. An important point to consider in evaluating bilingual language disorders would be that diachronic studies of young bilingual populations can give a clearer and more accurate result of acquired linguistic damage such as Alzheimer's disease.
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