由因果關係網路看漢語高功能自閉症兒童的敘事連貫能力

Abstract

兒童透過敘事表達自己，並藉此與外界溝通互動；有關兒童敘事能力的研究，可提供我們關於其發展歷程多方面的豐富訊息。是以，發展心理學家不僅透過敘事能力的研究探討正常兒童的語言發展，亦藉之檢視發展異常兒童的語言障礙。由於溝通上質的缺陷是自閉症的核心障礙之一，而敘事表達可反映出敘事者對社會人際知識、對情緒的瞭解，及其對語言的理解、組織與表達方式，因此，敘事能力被視為有助於評估自閉症患者的溝通障礙。敘事時除語彙的掌握得當外，敘事連貫性的呈現，亦為成功表達的關鍵要素。敘事連貫性奠基於對敘事中故事整體主軸的掌握及事件間的關聯。國內外針對自閉症患者敘事能力的研究普遍認為：患者與正常對照組在語言能力本身的差異不大，兩組的差異常顯現在對故事內容、結構及敘事觀點處理上的不同；患者對事件因果關係的鋪陳及對故事主軸的掌握能力較弱，過於著重局部細節，且有較多不相干的內容，以致其敘事連貫統合能力有不足之虞。國內近年針對自閉症患者敘事能力的研究，或聚焦於敘事結構與指涉方式，或探討敘事能力與其他因素間的相關性，對於患者於故事連貫性的統整能力，及其於因果關係的鋪陳表達，著墨較少。是以，本計畫擬檢視漢語高功能自閉症兒童敘事連貫能力的表現，藉此以期對前人所提出自閉症患者於故事整體掌握不佳的評述，能作更進一步的探討。研究者指出敘事的連貫性即為故事在時間及因果向度上的架構。此連貫性為故事整體意義及關連性的展現，其維繫在於將事件間的因果關係充分聯結。是以，敘事連貫能力與因果脈絡間關係密切。關於自閉症患者敘事連貫能力的研究，有的學者透過故事文法分析患者的故事結構組織；有的則著眼敘事中因果關係脈絡的呈現。一般認為Trabasso 等人(1985)提出的因果關係網路，比故事文法更能有效鑑別患者的敘事連貫能力。Trabasso 等人的因果關係網路除考量事件的不同類別屬性外，更進一步將事件串連成因果關係鏈以及因果關係連結，此兩者經組織形成因果關係網路。而事件間的因果關係連結依其特質，再經細分為六種因果關係次分類。此因果關係網路的研究模式，不僅適用於敘事的回憶研究，亦可用以檢視敘事者如何建構故事及如何連貫事件情節；此模式除有清晰可循的步驟可賴以分析敘事語料，其心理學效度亦已在多類題裁的研究中建立。鑑於此，本計畫擬藉由因果關係網路的模式，檢視漢語高功能自閉症兒童與正常對照組，於敘事中因果關係鏈及因果關係連結的呈現，並據此探討兩組兒童於敘事連貫能力上的異同。關於自閉症的溝通障礙，學者們試圖由心智理論與中央連貫理論等不同論述角度思考。近二十年來，針對自閉症與心智理論缺陷之關係的探討，著述甚豐。然自閉症的成因極其複雜，心智理論固然對自閉症患者社交溝通障礙提供了部份解釋，但對其他方面認知能力的障礙，甚至其優勢能力，未能給予充足的論證。Happé 等研究者認為自閉症敘事連貫能力的不足，無法由心智理論提供充分解說，他們主張此缺陷源於患者整體處理能力不足，故與中央連貫理論的關係緊密。研究者由感應知覺、音樂、語意連貫等多方面測驗，證實自閉症患者的中央連貫統整能力薄弱。鑑於此，本計畫試圖檢驗中央連貫理論用於解釋自閉症患者敘事連貫能力的適切性。本世紀以來國內外自閉症的出現率迅速攀升，對自閉症之障礙與成因的研究，實有臨床與理論方面的迫切需要。儘管國際學界透過各種途徑檢視自閉症的溝通障礙，國內對其溝通表達能力的探討尚嫌不足，透過長篇敘事語料的分析研究更屬鳳毛麟角。鑑於此，本計畫擬藉由跨領域合作的方式，剖析漢語高功能自閉症兒童敘事連貫能力之表現。我們以Frog, where are you?為題材，並參酌 Trabasso 等人提出的因果關係網路架構，將敘事連貫能力依因果關係鏈與因果關係連結的概念分析，並予以編碼量化。我們透過因果關係鏈、因果關係連結、故事完整性以及人物內在目標的掌握等指標，檢視高功能自閉症兒童與正常對照組於因果關係網路架構及統整連貫主軸事件能力上之差異，並比較兩組孩童在因果關係次類型的使用分布上之異同。此外，我們將探討敘事連貫能力與智力、語文能力、與認知上的中央連貫能力等各變項間的關係，俾使對國內自閉症兒童的敘事表達有進一步認識，從而提供臨床介入實務之參考。如此，不僅可為國內自閉症兒童在這個研究場域中留下珍貴語料，亦利於將研究結果作跨語文的對應比較。藉本計畫之實證研究，我們可進而檢驗因果關係網路模式以及中央連貫理論，在解釋自閉症兒童敘事連貫表達上之適切性，以藉此增進理論內涵的完整性，並強化理論之普遍性。

Children express themselves and build up connections with others through narratives. Given its potential to illuminate not only linguistic capacities, but also cognitive and social knowledge, developmental psychologists increasingly analyze narrative ability as a means of exploring language development of typical children and of measuring pragmatic language abilities of children with autism spectrum disorders (ASDs). A substantial amount of studies indicate that children with ASDs have intact phonological, morphological and syntactic development, but are qualitatively different from normally-developing children in narrative structure. As reported, autistic children are more likely to produce incomplete episodes, but less likely to use causal explanations. They show little regard for the relevance of events and appear to have difficulty representing the gist of stories and thus fail to link important events coherently in their narrative production. Similar observations have been noted in recent studies on Mandarin-speaking children with ASDs. These investigations mainly focus on narrative components, referring terms or correlations between narrative ability and various related factors. Autistic children’s ability in maintaining narrative coherence, however, fails to gain much attention. It is thus the goal of the present study to investigate Mandarin-speaking high-functioning children with ASDs with regard to their ability of establishing narrative coherence. Narrative coherence refers to a global representation of story meaning and connectedness. Karmiloff-Smith (1985) defined coherence as the temporal and causal structure of a story. Although earlier studies have adopted the paradigm of story grammar to assess narrative coherence of children with ASDs, an alternative, perhaps more promising and more justifiable, method is to evaluate the causal relationships between linguistic units in a narrative. Trabasso and colleagues develop a system that uses causal connections and causal chains to establish a causal network, which not only quantifies the relative importance of particular events, but also identifies the gist of a narrative. As Diehl et al.(2006) suggest, the causal network model provides a methodology that examines not only story recalls, but also illustrates how children with ASDs construct their narratives. This model provides researchers with a clear and concrete method to follow and its validity has been widely established through various studies. The abilities of making causal links between narrative events are based on proper cognitive abilities. To unmask the complex connection between language and cognition, a variety of cognitive psychologists thus try to investigate atypical children’s ability in making causal inferences in narrative production. To the similar end, we consider causal network in our pursuit to assess how typical and atypical children achieve narrative coherence and to further explore the interrelatedness between language and cognition. A variety of accounts in developmental psychology have been proposed to explain pragmatic impairments of children with ASDs. Among them, ‘theory of mind’ and ‘central coherence theory’ are the two most influential endeavors. Since ASDs have defied all simple explanations, feasible accounts should address both social and non-social facets of such disorders. While the accounts based on theory of mind, specifically social accounts, find limitations when faced with puzzling non-social features of autism, central coherence theory, in terms of a cognitive style, provides insights into both social and non-social aspects of the disorders and explains very parsimoniously the assets and deficits in ASDs. Many researchers believe that the central coherence account of ASDs can predict skills as well as failures in various cognitive domains, ranging from perceptual processes, visuospatial construction, to verbal-semantic coherence tasks. Regarding narrative processing, several studies suggest that the narratives of individuals with ASDs are marked by deficiencies in organization and coherence. It is thus the goal of the present work to examine relationship between central coherence ability and narrative coherence in high-functioning children with ASDs. Given the fact that prevalence of ASDs has increased significantly in recent years,internationally as well as nationally, and that impairment in pragmatic aspects, including communicative intention, narrative production, and social discourse, is considered one of the defining characteristics of this population, the studies of their difficulties with narrative coherence may have theoretical and therapeutic implications. In light of this, the present study aims to explore narrative coherence of Mandarin-speaking high-functioning children with ASDs, by examining narrative production based on Frog, where are you. Following frameworks of earlier research on causal network, we quantify children’s narrative coherence by calculating causal connections and causal chains in their narrative productions. By measuring causal chains, causal connections, story components, hierarchical goal plan, we attempt to uncover, with regard to narrative coherence, similarities and differences between normally-developing children and children with ASDs. We also examine interrelatedness between variables such as abilities in achieving narrative coherence, intelligence quotient, language ability, and central coherence ability. In addition, we endeavor to discuss the applicability of Trabasso and colleagues’ causal network and the validity of Frith and Happé’s central coherence theory in accounting for narrative coherence of children with ASDs. Related explanations in cognitive psychology will also be considered in our discussion. The outcome of the study, thus, may advance our understanding of narrative ability of children with ASDs, provide empirical evidence for examining the validity of related theories in this field, and, more significantly, have implications for therapeutic practices.