Aphasia is an acquired language disorder that emerges across modalities including receptive and expressive domains. It is caused by brain damage and can coexist with other neurogenic disorders such as motor speech disorders, although cognitive disorde...
Aphasia is an acquired language disorder that emerges across modalities including receptive and expressive domains. It is caused by brain damage and can coexist with other neurogenic disorders such as motor speech disorders, although cognitive disorders are excluded when diagnosing aphasia (McNeil & Pratt, 2001). Linguistic symptoms may differ by language, and aphasic symptoms are likely to be affected by unique linguistic features of the language that individuals with aphasia used premorbidly. Considering that the language-specific features could influence individual symptoms of aphasia, it is important to investigate the language-specific differences among aphasic symptoms as well as how these differences affect syndromes of aphasia.
The competition model accounts for aphasic symptoms based on the unique linguistic characteristics of the language that aphasic individuals used premorbidly rather than syndrome-based differences across the types of aphasia. According to the competition model, instances of the same type of aphasia may demonstrate different linguistic features across languages (Bates & Wulfeck, 1989). The current study performed crosslinguistic comparisons in Korean and English, given that these two languages have contrasting syntactic structures. Korean is a verb-final language, following the word order of Subject–Object–Verb (SOV). As long as the predicate is retained at the end, other linguistic constituents can be scrambled freely within a sentence (Sohn, 2001). In contrast, English follows a word order of Subject–Verb–Object (SVO), and word order information is a critical factor in interpreting thematic relations of a sentence in English (Bates, Friederici, & Juarez, 1988). On the other hand, grammatical morphology, such as case markers, plays a critical role in denoting thematic roles in languages with a relatively free word order such as Korean.
The purpose of the current study is to examine crosslinguistic differences in personal narratives and picture description tasks between Korean- and English-speaking individuals with aphasia. Spontaneous speech is one of the most commonly used elicitation measures in evaluating syndromes and severity of aphasia because it demonstrates a wide range of communication abilities. Many studies have examined spontaneous speech in aphasia patients to examine symptoms. However, few studies have conducted crosslinguistic studies in aphasia using elicited tasks. Crosslinguistic studies in aphasia could give an implication of language-specific effects across language, given that aphasic individuals’ premorbidly used language breakdown would provide a basis for applying the competition model. The measures most frequently used to elicit spontaneous speech include narrative tasks and picture description tasks. These two different ways of eliciting spontaneous speech may tap into different cognitive and linguistic domains. Researchers have reported that a picture description task may place greater demands on the individual than narrative tasks do, as the picture description paradigm is presented in a more constrained way (Deloche, Jean-Louis, & Seron, 1979).
Twenty-nine individuals with aphasia with a single, left-hemisphere stroke participated in this study. Participants consisted of fourteen Korean-speaking individuals with aphasia and fifteen English-speaking individuals with aphasia. Data for the English group are taken from the “Aphasia Bank Project” (MacWhinney, Fromm, & Holland, 2011). Personal narratives and sequential picture description tasks were used in the present study. The experimental materials were obtained from the Aphasia Bank Protocol. For the Korean participants, the English protocols were translated into Korean. In personal narratives tasks, participants were asked about the current status of their speech, how they suffered stroke, and their recovery from stroke. Troubleshooting questions were asked to encourage them when participants struggled. For the sequential picture description task, six cuts of the sequential story of a boy refused an umbrella were used. Linguistic outcome measures included total number of utterances, total number and different numbers of nouns and verbs, number of nouns per utterance, number of verbs per utterance, tokens for verb-to-noun ratio (VNR), and types for VNR.
Two-way mixed ANOVAs were conducted to analyze differences between the Korean- and English-speaking groups depending on the type of elicitation tasks (personal narratives and sequential picture description tasks). The results revealed, first, that the Korean speaking individuals with aphasia rated higher in different number of verbs, number of nouns per utterance, number of verbs per utterance, tokens for VNR, and types for VNR. However, the English-speaking group had higher total numbers of utterances in both personal narratives and sequential picture description tasks.
Second, there were significant task-type differences in total number of utterances, total number and different numbers of nouns and verbs, number of verbs per utterance, and tokens and types for VNR. Both Korean- and English-speaking individuals with aphasia generated more linguistic units in utterances, nouns, and verbs in personal narratives than in the sequential picture description task.
Third, the two-way interactions were significant in number of nouns per utterance and number of verbs per utterance. The interactions in number of nouns per utterance are due to the fact that the Korean-speaking group produced more nouns in the sequential picture descriptions than in the personal narrative tasks, while the opposite was observed for the English-speaking group. In terms of the interaction for the number of verbs per utterance, the Korean group generated more numbers of verbs in the sequential picture description tasks than the personal narrative tasks compared to the English group.
The interactions in number of verbs per utterance occurred because the Korean-speaking group produced more verbs in the sequential picture descriptions than in the personal narrative tasks, while the English-speaking group performed similarly in both personal narratives and the sequential picture description tasks.
The current study found that Korean individuals with aphasia produced more numbers and a greater variety of verbs than the English individuals with aphasia did. The results are consistent with the prediction that Korean speakers with aphasia are less vulnerable to producing verbs than English speakers are, given that Korean is a verb-salient language. In addition, many samples in a wide range of communication situations could be acquired by evaluating different types of spontaneous speech. Personal narratives tasks and sequential picture description tasks were used in this study to analyze an aphasic individual’s spontaneous language. This study revealed that the participants produced more utterances, nouns, and verbs in the personal narrative task than the sequential picture description task. The results are consistent with the prediction that personal narrative tasks are easier for aphasic individuals than describing a sequential picture. This is because the picture description tasks need more combined cognitive process than personal narrative tasks do. Further research in elicited spontaneous speech across types of aphasia could be useful.