Effect of Chinese Verb Network Strengthening Treatment in Mandarin-English Bilinguals with Aphasia

• ¹ Boston University, United States

The current study adopted the Verb Network Strengthening Treatment (VNeST; Edmonds, Nadeau, & Kiran, 2009) in Chinese to improve verb retrieval ability in Mandarin-English bilingual patients with aphasia (BPWA). The goals were to investigate: 1) the treatment effect of Chinese VNeST, 2) its within-language generalization to semantically-related items, 3) its cross-language generalization to the untrained language, and 4) its generalization to lexical retrieval in broader language tasks. Two Mandarin-English speaking individuals (Table 1) with chronic aphasia due to stroke participated in this study. Mandarin was their first language and English was their second. Eighteen pairs of semantically-related verb stimuli in Chinese (e.g., weigh and measure) were divided into two sets. One was used for treatment for P1 and the other was used for P2. A third, control set consisted of ten adjective words (e.g., on). A multiple baseline approach across participants (Connell & Thompson, 1986) included four phases: 1) three baselines for each language, 2) treatment, 3) three post-treatment probes for each language, and 4) 1-month maintenance. Additionally, language outcomes were measured before and after treatment. Each participant was trained in Chinese VNeST twice per week for two hours for a total of 20 sessions over 10 weeks. They were administered probes for the trained, semantically-related untrained items, and control items in sentence production in both languages. Treatment reliability and probe scoring were conducted for 25% of all sessions. Logistic mixed-effects model and generalized linear model were applied for statistical analysis, and effect sizes were obtained with Cohen’s d (Cohen, 1988). Error analysis of probe responses was additionally conducted. Response accuracies were shown in Figure 1. Statistical analysis for P2 revealed a significant main effect of Chinese trained items (p < 0.01) and a significant interaction between Chinese trained by session (p < 0.01), indicating higher response accuracy on the Chinese trained items over time, but no significant effect was observed in the English data. For P1, there was no significant effect due to the lack of variance in the control set. There was a large effect size for P1 for the Chinese trained, Chinese untrained, and English untrained from pre- to post-treatment, and there was no change for control items. For P2, there was a medium effect size for Chinese trained and a small effect size for English untrained from pre- to post-treatment. There was an additional medium effect size for the Chinese control and a large effect size for the English control. Improvements were observed in a variety of language measurements. Speech errors in Chinese sentence probes for P1 showed increase in phonological errors and neologisms from baseline to maintenance, but decrease in semantic, morphosyntactic, lexical, cross-language, and tonal errors. Error analysis of English sentence probes showed increase in phonological, morphosyntactic, cross-language, and no response errors, but decrease in semantic, neologism, and lexical errors. This study provides evidence suggesting that treatment in Chinese VNeST can improve verb retrieval in sentences for Mandarin-English BPWA. The effect sizes implied within-language and between-language generalization effects with some variations across patients.