語意在句法處理中的角色：中文關係子句的眼動閱讀研究

本文以兩個眼動閱讀實驗探討語意訊息 (semantic cues) 和句法訊息 (syntactic cues) 如何在中文關係子句的處理中運作及交互作用。實驗一旨在研究兩種動詞與論元之間的合理性關係 (plausibility) 是否會影響讀者理解不同結構的關係子句。結果顯示，當兩個論元都是合理施事者 (agent) 時，論旨角色的指派 (thematic roles) 有歧義，較難理解；而當只有一個論元是合理的施事者時，讀者趨向指派正確的論旨角色，且較快整合句法上的困難。此外，因中文句法結構特殊，讀者在關係詞之前就處理主語關係子句 (subject relative clauses) 的歧義，在主要動詞上則會遇到賓語關係子句 (object relative clauses) 的理解困難。此發現解決了Hsiao & Gibson (2003) 和 Lin (2006) 的歧見，證明中文讀者在不同位置會遇到不一樣的困難。實驗二所關注的語意訊息為論元的生命性 (animacy)，關係子句中的兩個論元分屬有生命的 (animate) 及無生命的 (inanimate) 名詞。結果發現論旨角色的指派和生命性相互關聯，有生命性的論元較傾向當施事者，而無生命的論元傾向當受事者。讀者仍在關係詞之前遇到主語關係子句的理解困難，但在主要動詞，讀者主要依循生命性的引導來指派論旨角色，句法訊息的影響並不顯著。因此語意訊息在中文的語句處理扮演重要的角色，結果大致上與Traxler (2002)的研究相符。讀者同時受到當下的句法訊息以及語意訊息影響，在不同的位置會遇到不一樣的歧義性，而產生花園路徑效果 (garden-path effect)。

Two eye movement experiments were conducted to investigate how semantic cues and syntactic structural cues function and interact in Mandarin Chinese relative clause (RC) processing. Mandarin Chinese is unique in combining head-final RCs with a VO basic order (Dryer, 1992, 2003) and also in relying solely on word order as structural cues, without case marking or agreement. However, Mandarin Chinese still preserves flexibility in word order that is motivated by pragmatics. Semantic cues, including the plausibility of the argument-verb relation and argument animacy within RCs, may be crucial to sentence processing in Mandarin Chinese. Experiment 1 aims to examine whether the meaning of the verb allowing only one of the two animate arguments to be a plausible agent may lead to reduction of ORC difficulty (cf. Traxler, 2002). The results showed that the plausibility effects were robust at the head noun and the main verb. A bias of thematic role assignment in the irreversible relation leads readers to correct interpretations, while the reversible relation does not elicit such a bias. The results also solved the discrepancy between the two previous studies (Hsiao and Gibson, 2003 & Lin, 2006) by unveiling a dynamic process in which readers encounter diverse ambiguities at different positions for different structures. Chinese readers disambiguate SRCs earlier due to their non-canonical word order and have trouble integrating the main verb in ORCs owing to perspective shifting. The interaction between plausibility and RC type on re-reading rate suggested that plausibility cues were used to solve syntactic ambiguity. Experiment 2 manipulated contrastive argument animacy in order to investigate whether thematic role assignment correlates with animacy. The results confirmed the hypothesis that while animate entities bias towards agent roles, inanimate ones incline towards patient roles (c.f., Valin & LaPolla, 1997). Besides, inanimate entities are conceptually less accessible than animate ones. Contrastive animacy shows its impact on syntactic processing with robust interactions at different positions. The findings of interactions between semantic cues and RC types in two experiments suggest that semantic cues play an important role in Chinese relative clause processing. Semantic plausibility and argument animacy can influence the process of thematic role assignment. The semantic cues that accord with the biases of thematic role assignment then would ease the syntactic ambiguities. Not only syntactic cues but also semantic cues are utilized by readers in sentence comprehension. In this thesis, the eye movement data provide clear evidence indicating that readers solve various temporary ambiguities syntactically and semantically at different positions of the sentence with relative clauses.