探討「非立即性增強」以及「打斷行為反應和重新引導」兩種策略對自閉症幼童的語言固著行為之成效

Effects of “Noncontingent Reinforcement Plus Differential Reinforcement of Alternative Behavior” and “Response Interruption and Redirection” on a Child's Vocal Stereotypy Maintained by Automatic Reinforcement

自閉症是終身殘疾，其特徵包含在社會互動、溝通及行為方面的缺陷，自閉症兒童並時常展現重複和非功能性的固著行為（stereotypic behaviors）。固著行為可能藉由本身感官所產生的反應，而導致自動增強（automatic reinforcement）。同時，固著行為會干擾聽覺處理、無法區別學習，以及有困難展現適切的社會行為。因為固著行為會影響孩童發展，目前針對自閉症幼童此行為有其相關研究策略。然而，目前相對少的研究文獻針對自閉症兒童的語言固著行為（vocal stereotypy）進行探討。先前研究提出「打斷行為並重新引導」（response interruption and redirection ） 策略可以降低語言固著行為。另一策略是藉由非立即性增強（noncontingent reinforcement），孩子將其注意力放在可替代的刺激上而異常反應（例如：語言固著行為），這樣替代性刺激可以有效的取代異常反應。然而這兩種策略都有其限制。本研究的目的在探討行為策略的介入，是否可以有效改善一位五歲自閉症幼童的語言固著行為。採用功能分析檢視幼童的語言固著行為的由來。結果顯示「自動增強」為語言固著行為產生的原因。除了非立即性增強外，應用區別性增強替代行為（differential reinforcement of alternative behavior）策略去提升適切語言溝通的機會。根據行為功能分析的結果，實驗設計為ABCACBA，使用兩種行為策略（打斷行為並重新引導以及非立即性增強以及替代行為增強）並分成階段進行介入，以比較兩種策略的成效。研究結果顯示，使用「非立即性增強以及替代行為增強」策略不僅顯著降低不適切的語言固著行為，並顯著提高適切語言行為的使用。

In this study, the authors investigated the effective treatment of repetitive and noncontextual vocal behaviors of a 5-year-old child (John) with an autism spectrum disorder. Background: Autism is a life-long disability characterized by deficits in social interactions, communication, and behavior. Children with autism often display stereotypic movements that are characterized by their repetitive and nonfunctional nature. Although it is believed that stereotypic behaviors might be automatically reinforced by the sensory consequences produced by engaging in the response, some evidence also shows that stereotypy can be related to social or demand consequences. Meanwhile, stereotypic behaviors can interfere with auditory processing, discrimination learning, and appropriate social behaviors. The focus of a treatment for frequent engagement in stereotypic movements by children with autism has been examined because this type of behavior may hamper children's development. Non-contextual vocalization is one stereotypic behavior that children with autism often display. However, there has been relatively limited research focused on the treatment of vocal stereotypy for children with autism. Specifically, it is difficult to treat if vocal stereotypy is self-reinforcing (i.e., automatic reinforcement). An approach to treating vocal stereotypy maintained by automatic reinforcement is response interruption and redirection (RIRD). To block vocal stereotype, RIRD treatment may involve teachers initiating vocal demands with whichthe child readily complies Previous research revealed the positive effects of RIRD on reducing the level of vocal stereotype. Another approach to developing treatment for automatic reinforcement has focused on noncontingent access to preferred items (NCR). According to operational definition of NCR, it is hypothesized that if the child chooses to spend more time with the alterative stimuli, rather than engage in the aberrant response (e.g., vocal stereotype), these stimuli can effectively compete with the aberrant response. But, both approaches (RIRD and NCR) have their own limitations. The treatment of RIRD is labor-intensive while NCR alone was not effective as a treatment. Method: Functional analyses (FA) were implemented to identify the function of John's stereotypical behavior. Using the methods described by Iwata and his colleagues (1982/1994), vocal stereotype was assessed in four specific conditions (i.e., attention, demand, alone, control/play) to determine which specific consequences (e.g., attention, escape, or sensory) were maintaining the behaviors. According to previous preference assessment, a cookie served as strong reinforcement for John, and could be used to promote the use of appropriate language. In addition, differential reinforcement of alternative behavior (DRA) was included to eliminate the limitation of NCR as well as strengthen appropriate communication (e.g., request). Following FA, two treatment packages, “RIRD” and “NCR plus DRA,” were implemented in an ABCACBC design to determine whether either RIRD or NCR plus DRA could reduce John's vocal stereotypy. Findings: The results of FA suggested that vocal stereotypy was maintained by automatic reinforcement. The findings suggested that NCR plus DRA can significantly reduce the behavior of noncommunicative vocalization maintained by automatic reinforcement. The findings also revealed that NCR plus DRA produced levels of appropriate vocal behaviors more thanthose observed in both baseline and RIRD phases. Conclusions/Implications: This study suggests that highly preferred stimuli may compete with engagement in automatically reinforced challenging behaviors. Implications of this study are also discussed in this paper.