調整動詞輸入的頻率及範例變異性對發展性語言障礙兒童的語法學習之影響

發展性語言障礙(Developmental Language Disorder, DLD)兒童的語法學習以複雜句和動詞論元結構最為困難。DLD兒童的內隱學習缺陷不僅使其難以擷取文法規則，也比典型發展同儕需要更多語言刺激。文獻指出，高頻和高範例變異的語言輸入分別可以改善DLD兒童學習語法的表現。本研究探討同時調整動詞輸入的頻率及範例變異性是否更能促進發展性語言障礙兒童學習語法的表現。本研究採非隨機實驗控制組前後測設計。受試者為12位發展性語言障礙學童（均齡87.75個月），並分派至高變異組或混合組。兩組兒童的生理年齡、非語言智力及被動句前測表現皆無顯著差異（p值均>.05）。介入活動為六週一對一繪本共讀，每週一次40分鐘課程，以被動句為目標句。六週介入共選擇48個最常使用於被動句的動詞（每週16句）。高變異組每週聽到由16個相異動詞組成的被動句（每一動詞1句，高變異輸入）；混合組則聽到6個相異動詞的被動句（每一動詞1句）和2個相異動詞的被動句（每一動詞5句，高頻輸入)。其餘共讀內容兩組大致相同。研究結果顯示，混合組在共讀課節間被動句問題回應正確率高於高變異組，且於介入後的標準化語法測驗表現、故事重述自發使用被動句的比例和平均語句長度均顯著提升。兩組兒童介入後的被動句促發表達皆有進步，不只可類化至無介入動詞之被動句，也有短期維持的成效。但是兩組在被動句圖片指認的表現上則無顯著進步。本研究結果支持語言治療師進行語法介入時，選擇較常出現在目標句的動詞範例，並以高頻和多元（高變異）的呈現，可有效促進發展性語言障礙兒童的語法學習。

Previous studies have indicated that the most common grammatical difficulties in children with DLD are complex syntax and verb argurment structure. Researchers have found that frequency and variability of language input contribute to syntactic learning in these children, respectively. In this study, we investigated whether frequency and variabilities of verb exemplars could jointly facilitate learning of passive structure in children with DLD.We conducted our study with a non-randomized control-group pretest-posttest design. Twelve school-aged children with DLD (mean age 7;3) participated in a 6-week intervention, with shared book reading as primary activity and passive structure as intervention target (16 exposures for the structure per week). Children were evenly assigned to High Variability (HV) group or Mixed group. Out of the 16 exposures, the children in the HV group heard 16 verbs for once in passive structure, whereas the children in the Mixed group heard 2 verbs, repeated 5 times each, and 6 verbs for once. Our results showed that children in both groups improved on producing passive structures in a syntactic priming task, and also showed significant change in untrained verbs (p<.05). However, there were no group difference on picture pointing task after the intervention. More importantly, in story retell, children in the Mixed group not only produced more spontaneous uses of passive structures, but also showed greater gains on standardized test of syntax and MLU, suggesting learning and generalization of complex syntax. Consistent with previous studies, shared book reading could enhance syntactic complexity in story retelling in both groups. Our findings inform SLPs that frequency and variabilities of verb exemplars manipulation in a target structure could facilitate syntactic learning in school-aged children with DLD. The benefit of applying these input strategies in a syntactic form may boost treatment efficiency compared to simply increasing the input frequency of sentences.