Chinese is the most widely spoken language worldwide. In the United States alone, it is estimated that there are about 3.6 million speakers of Chinese, making it the second most widely spoken non-English language in the nation after Spanish (U.S. Census Bureau, 2008, 2003). And, based on a 3% prevalence estimate of stroke (Centers for Disease Control and Prevention, 2007), there are up to 40,000 Chinese speakers with language impairment living in the United States at a given time.
However, the paucity of assessment tools for Chinese speakers with neurogenic communication disorders can make diagnosing aphasia among Chinese speakers a challenging job for U.S. speech-language pathologists. Meanwhile, a particular challenge for researchers working with Chinese-speaking people with aphasia is objectively quantifying discourse production.
The following summary of existing aphasia assessment tools available for Chinese speakers and procedures for evaluating narrative production in this group may help SLPs who are working with them.
Language Differences and Testing
There are seven major dialect groups in China, including Mandarin (Putonghua), Wu, Xiang, Gan, Yue, Min, and Kejia. Although these dialect groups share uniform grammar, they differ significantly in pronunciation and vocabulary. Putonghua is the official language in China and is widely spoken across the northern, central, and western regions of China. Cantonese is the second-most spoken dialect in the Yue group after Putonghua and is mainly spoken in Southern Chinese provinces of Guangdong, Guangxi, and Hong Kong (Matthews & Yip, 1994).
Chinese and English differ in terms of dialect, orthography, phonetics, and grammar. While dialects of English are largely mutually intelligible, Chinese dialects differ significantly from one another in syllable pronunciation and vocabulary and therefore are not understood across Chinese speakers. Chinese employs a logographic writing system, and all Chinese languages are syllabic. In contrast to the alphabetic writing system in English, no letters or graphemes represent phonemes in any Chinese dialect.
Chinese syllables are depicted in print using radicals (semantic or phonetic in nature) that represent the morpheme (a unit of meaning), and hence the whole syllable, making the script morpho-syllabic in nature (Leong & Mulchay, 1987). The figure above shows the Chinese character "," which means "a disorder." It consists of a semantic radical on the left, bearing a morpheme of its semantic information of "pathology," and a phonetic radical on the right, bearing another morpheme with its phonological information. As a tonal language, Chinese also employs pitch change to contrast lexical meanings. The character "" uses tones three and four in Cantonese and Putonghua, respectively. Together with the characters "," meaning "to lose" and "," meaning "a language," the compound word "" (aphasia) is formed.
Compared with English and other Indo-European languages, Chinese is an analytic language due to its lack of inflectional or derivational morphology. Grammatical meanings are often conveyed through word order, adverbials, or grammatical particles (such as aspect markers or sentence final particles). Chinese also permits omission of most subjects and objects if they can be understood from the context. As a result, elliptical sentences can be considered correct and grammatical in Chinese, especially in connected speech or conversations, as long as there is a mutual understanding between a speaker and a listener. Given these significant differences, SLPs cannot simply translate an English test to be used with a Chinese speaker with aphasia. Adoption of existing assessment materials in English to Chinese also requires careful selection and modification of stimuli items in relation to cultural appropriateness.
Aphasia Assessment Batteries
Mandarin and Cantonese are the two most common Chinese dialect groups internationally. Two Chinese standardized aphasia assessment batteries have been published, namely the Taiwan Mandarin version of the Boston Diagnostic Aphasia Examination (M-BDAE) and the Cantonese version of the Western Aphasia Battery (CAB). The format of both tests, which include language subtests for auditory comprehension, verbal expression, fluency, naming, repetition, reading, and writing, generally follows that of the original test. These two batteries have been widely used in Taiwan and Hong Kong, respectively.
The Bilingual Aphasia Test (BAT), developed in the 1980s, also is suitable for testing Chinese speakers with aphasia. Part A of the BAT establishes the language history of a speaker by obtaining information on the premorbid state of bilingualism and contexts of language acquisition. Part B—the major part of the test—includes 428 items to evaluate a speaker's proficiency and impairment across modalities. Part C examines a speaker's skills to recognize, produce, and provide grammatical judgment of translated language pairs. Part A and B of the Mandarin and Cantonese BAT are available; Part C can be administered in three translation versions: Cantonese-Mandarin, Mandarin-English, and Mandarin-French. Given the BAT's length, clinicians tend to select a subset for diagnosing bilingual speakers with aphasia.
Quantifying Discourse Production
Another critical component of assessment for individuals with aphasia is discourse—a language unit whose organization supersedes any single word or sentence (Olness, 2006) and that is composed of a series of connected sentences for conveying a message (Cherney, 1998). Common elicitation tasks include describing single or sequential pictures, reporting procedural events, telling or retelling stories, and conducting monologues or conversations.
Clinicians should be sure to select client-relevant stimuli when probing for language samples. It has been widely reported in cross-linguistic studies that culturally inappropriate pictures, topics, or stories can affect the validity of the assessment. For example, using a picture depicting cookie theft was found to be problematic in the Chinese population (Kong, 2006). In particular, speakers wrongly identified the kitchen scene as a living room and could not recognize the theme of stealing cookies from the cookie jar. Similarly, the fairy tale "Cinderella" fails to elicit discourse from elderly Chinese speakers, but culturally appropriate stories such as Aesop's "Cry Wolf" or "The Tortoise and the Hare" do. Use of culturally inappropriate stimuli is likely to result in an overestimation of aphasia severity due to the lack of relevant content obtained from the person being assessed.
Objective measurement of aphasic discourse as a part of a comprehensive assessment has been promoted by ASHA (2004) and the Royal College of Speech and Language Therapists (2005). However, it is often not done in clinical settings because the process of data transcription and analysis is time-consuming. The M-BDAE and CAB, however, contain only brief rating scales for subjective evaluation of post-sentential language skills. Clinicians who need to perform more systematic, objective analysis of aphasic narrative production in Chinese can refer to three published systems in Cantonese, two of which are more clinically oriented.
One of these is the Cantonese Linguistic Communication Measure (CLCM), developed by Kong and Law (2004) to objectively analyze Chinese aphasic descriptions of a picture. The CLCM uses indices that evaluate contents (such as lexical diversity and counts of informative words and errors); grammatical support; degree of elaboration; and efficiency (such as rate of producing informative words).
More recently, Kong (2009, 2011) proposed a rule-based quantification system, the Main Concept Analysis (MCA), to capture the presence, accuracy, and completeness of oral narrative content and its production efficiency among Chinese speakers with aphasia. An important characteristic of the CLCM and MCA is the use of pictures that are culturally appropriate for Chinese people.
Researchers who need a more sophisticated system to quantify Chinese narratives can look to the modified Quantitative Production Analysis, proposed by Law (2001). This assessment uses a storytelling task to elicit language samples. It contains detailed procedures for extracting narrative words in Chinese and for classifying words into Chinese parts of speech. It also includes sensitive criteria for analyzing Chinese compound words and degree of embedding, such as the use of complex sentences and embedded clauses.
Compared with the large number of aphasia tests available in English, there is a paucity of standardized assessment tools for the Chinese population. Bilingual clinicians also have limited resources for testing bilingual or multilingual speakers of Chinese. Given that most research related to Chinese aphasiology has been conducted in the Cantonese-speaking population, more investigations in different Chinese dialects are warranted.