本論文進行兩個眼動實驗，探討語境及多義特性在一詞多義處理歷程中扮演的角色。Frazier與Rayner(1990)認為一詞多義由於詞義間有重疊的語義屬性(sense overlap)，因此處理詞義之初，會先以部分語義(partial specification)來理解，不需立即進行完整詞義的解讀，支持部分語義解讀假設(Immediate Partial Interpretation Hypothesis)。在Frisson 與Pickering(2001)所提出詞義未定模型(Underspecification Model)中，進一步說明語境在一詞多義中扮演的角色，認為一詞多義的語義提取會先以未定意義(underspecified meaning)解釋，在語義提取完畢後，語境才會介入詞義的選擇。本論文操弄語境導引和詞義重疊性，來探討一詞多義的詞義提取與選擇歷程。實驗一操弄句子中目標詞的語境預測力(可預測語境vs.不可預測語境)與詞義數量(單詞義vs.多詞義)，記錄並分析目標詞與目標詞後區域的凝視時間。結果顯示：目標詞上的凝視時間多詞義顯著短於單詞義，支持部分語義解讀假設。然而，實驗一在目標詞後區域並未看到多詞義因延遲語義解讀(delayed semantic commitments)而造成抑制或競爭效果。實驗二就此現象與「一詞多義本身的詞義重疊程度」與「語境對一詞多義有無發生語義解讀的必要性」進行進一步探討。實驗二(同實驗一)操弄目標詞的語境預測力，與詞義的重疊程度(單義詞vs.中度詞義重疊vs.高度詞義重疊)，並控制語境偏向次要詞義的情形。結果顯示：目標詞上的晚期眼動指標在中度詞義重疊(中vs.單)與高度詞義重疊(高vs.單)皆看到與語境預測力發生交互作用，顯示語境預測力的影響在晚期階段發生；目標詞後區域觀察到中度與高度詞義重疊(中vs.單；高vs.單)皆在不可預測語境下發生詞義抑制效果，符合詞義未定模型預期之延遲語義解讀效果，並在目標詞晚期眼動指標看到中度詞義重疊效果與高度詞義重疊效果(單-中 vs. 單-高)受語境影響有不同的效果，顯示詞義重疊會影響詞義選擇的必要性。總結本論文的結果：首先，一詞多義的語義提取符合部分語義解讀的假設，而語境介入的影響支持詞義未定模型的看法，即語境在語義提取之初並未介入影響，在語義未定的情況下，若語境內容有進行語義解讀之必要時，則會發生延遲語義解讀。其次，詞義的促進效果與一詞多義的詞義數量多寡有關，詞義數量減少時，詞義促進效果也隨之消失。最後，當語境偏向一詞多義的次要詞義時，延遲語義效果才會發生。 / This thesis conducted two eye movement experiments with the aim to investigate the role of context and multi-sense feature in processing polysemy. Frazier and Rayner (1990) suggested that, at the beginning of semantic processing, polysemy is comprehended with partial specification. There is no immediate need to process the complete word sense due to the sense overlap between senses. This viewpoint supports the Immediate Partial Interpretation Hypothesis. In Frisson and Pickering’s (2001) Underspecification Model, further elaboration were made on the role of context in the process of retrieving and selecting one of the word senses of a polysemy. The sense that is first retrieved from a polysemy is considered to be an underspecified meaning. It is after the semantic retrieval is finished that context is involved in selecting a word sense. This thesis manipulated context guidance and sense overlap, to further research on processing polysemy in terms of word sense retrieval and selection. Experiment One manipulated contextual predictability (predictable context vs. unpredictable context) and number of senses (one-sense, monosemy vs. many-sense, polysemy) of the target words in sentences. Fixation times of the target words and post-target areas were recorded and analyzed. Results showed that the fixation times on target words were significantly shorter for polysemy than for monosemy, supporting the Immediate Partial Interpretation Hypothesis. However, in Experiment One, there is no inhibitory or competitive effect on the post-target area, indicating that there is no effect of delayed semantic commitments while comprehending polysemy. In Experiment Two, we further investigated how this phenomenon is connected with the degree of sense overlap and whether context is necessary to activate semantic commitment for polysemy. Contextual predictability of target words and the degree of sense overlap (monosemy vs. moderate-sense-overlap vs. high-sense-overlap) were manipulated, with the former designed as in Experiment One. Specifically, the context was controlled to bias toward the subordinate sense. The results showed that there were interactions of sense overlap degree (both moderate-sense-overlap vs. monosemy and high-sense-overlap vs. monosemy) and contextual predictability on target words for later-stage indices. This suggests that contextual predictability effects at later stages. On the post-target areas, there were inhibitory effects found for moderate-sense-overlap vs. monosemy and for high-sense-overlap when the context is unpredictable. This finding supports the delayed effect of semantic commitments in the Underspecification Model. Moreover, effects of sense overlap (polysemy-moderate vs. polysemy-high) were modulated by contextual predictability on target words for later-stage processing, showing that sense overlap affects the necessity of semantic commitments. In conclusion, the semantic retrieval of polysemy can be best explained by the Immediate Partial Interpretation Hypothesis and the involvement of contextual constraint supports the Underspecification Model. That is, context does not affect the beginning phase of semantic retrieval. Since the senses are underspecified, delayed semantic commitment occurs if it is necessary to make semantic commitment in the context. Furthermore, the facilitation of senses is related to the number of a polysemy’s senses. As number of senses decreases, facilitation of senses wanes and disappears. Finally, delayed semantic commitment occurs only when the context biases towards a subordinate sense of the polysemy.

兩種語句處理模型曾被提出以解釋閱讀句子時語法及語意資訊的互動。句法優先模型(syntax-first models)認為詞性判斷必定先於語意分析，而制約滿足模型(constraint-satisfaction models)則認為不同的資訊在語句理解的過程中會同時被處理。本研究檢驗兩種語句處理模型能否解釋語句中的詞彙歧義解困(lexical ambiguity resolution)。 許多眼動研究曾發現詞彙歧義詞的次要語義偏向效應(subordinate bias effect)，顯示語意偏向次要語義的語境能加速激發歧義詞的次要語義並且產生語義競爭。然而，語境的語法在詞彙歧義解困中扮演的角色並不清楚。因而，不同語義分屬不同詞性的詞性歧義詞便提供我們一個媒介以檢驗詞彙歧義解困中詞性及語意限制的互動。 本研究的目的有二：(一) 檢驗詞性限制能否決定中文詞性歧義詞的語義解困；(二) 檢驗中文歧義詞語義的詞性是否會影響次要語義偏向效應。實驗一我們將四種不同類型的中文非均勢同形異義詞置於語法及語意皆為次要語義偏向的句子裡；實驗二則將四種不同類型的中文非均勢同形異義詞置於語法為次要語義偏向但語意中立的句子裡。受試者閱讀句子時的眼動表現會即時被記錄。 實驗一的結果發現：(一) 四類型歧義詞的次要語義偏向效應只反映在目標詞後區域的二次閱讀指標上；(二) 就效果量而言，NV歧義詞的次要語義偏向效應在目標詞及目標詞後兩個區域都比VN歧義詞來得大。實驗二的結果則發現：(一) VN歧義詞的次要語義偏向效應從目標詞區的首次閱讀指標就出現，並且持續至目標詞及目標詞後兩個區域的二次閱讀指標；(二) 另外三類型歧義詞的次要語義偏向效應直到所有分析區域的二次閱讀指標才反映出來；(三) NV歧義詞的次要語義偏向效應比VN歧義詞出現得更晚也更不明顯。整體而言，本研究的結果顯示詞性限制並不是影響中文詞性歧義詞語義解困的唯一因素。此結果支持制約滿足模型，並反對句法優先模型的預測。 / Two primary sentence processing models have been proposed to account for the interaction between syntactic and semantic information in reading sentences: Syntax-first models assume that syntactic-category assignment must precede semantic analysis, while constraint-satisfaction models propose that information from different sources is processed and weighed at the same time during sentence comprehension. The present study examined whether these sentence processing models, which assume different contribution of syntactic category and semantic context, can explain the resolution of lexical ambiguity in sentences. Several eye movement studies have demonstrated the subordinate bias effect (SBE) for lexical-semantic ambiguous words (i.e., NN/VV homographs), indicating that a subordinate-biased semantic context can boost the activation of the subordinate meaning of ambiguous words and causes meaning competition (Duffy, Morris, & Rayner, 1988). However, the role of syntactic context in lexical ambiguity resolution is less clear. Syntactic category ambiguous words (i.e., SCA words; VN/NV homographs), whose alternative meanings differ in syntactic category (e.g., watch in English), serve as a means of examining the interaction between syntactic category and semantic constraints during lexical ambiguity resolution. The purpose of the present study was twofold: (a) to examine whether the syntactic category constraint can determine the semantic resolution of Chinese SCA words, and (b) to investigate whether syntactic category of alternative meanings of Chinese homographs can influence the SBE during lexical ambiguity resolution. Four types of Chinese biased homographs (NN, VV, VN, and NV) were embedded into syntactically and semantically subordinate-biased sentences (Experiment 1) and into syntactically subordinate-biased but semantically neutral sentences (Experiment 2). Participants’ eye movements were recorded as they read each sentence. In Experiment 1, the results showed: (1) The SBE for the four types of homographs was significant only in the second-pass reading on the post-target words. (2) Numerically, the NV homographs revealed a larger effect size of SBE than VN homographs on both target and post-target words. In Experiment 2, the results showed: (1) The SBE for VN appeared from the first-pass reading on the target words and lasted to the second-pass reading on the target and post-target words. (2) The SBE for the other types of homographs did not occur until the second-pass reading in all analyzed regions. (3) The SBE for NV occurred much later and less obviously than that for VN. In general, our findings support the constraint-satisfaction models and reject the prediction of the syntax-first models, suggesting that the syntactic category constraint is not the only factor influencing the semantic resolution of SCA words.

過去二十多年來，心理語言學研究關注詞彙歧義解困 (lexical ambiguity resolution)歷程發生時，語義脈絡與多義詞的語義頻率之間的交互作用。許多研究發現，當語境支持非均勢同形異義詞 (unbalanced homograph) 的次要語義時，同形異義詞的凝視時間長於與其有相同字形頻率的單義詞 (unambiguous control)，此為次要語義偏向效應 (subordinate bias effect)。根據再排序觸接模型 (reordered-access model)，次要語義偏向效應來自於主要語義與次要語義的競爭；相對地，選擇觸接模型 (selective access model)則認為只有與語境相關的語義被激發，因此，次要語義偏向效應是因為提取到一個使用頻率較低的語義。本論文進行兩個眼動實驗。實驗一檢視中文多義詞的次要語義偏向效應以區辨兩種詞彙歧義解困模型分別提出的解釋。本實驗的材料使用了低頻同形異義詞、低頻單義詞、以及高頻單義詞。結果顯示，當使用的單義詞與多義詞字形頻率相同時，在目標詞及後目標詞上(目標詞後一個詞)皆發生了次要語義偏向效應。實驗二利用口語理解─視覺典範中透過受試者理解語音訊息時同步記錄眼動的作業方式來探究次要語義偏向效應是否來自於主要語義的激發。當口語句子中的目標詞被唸出後，會計算出隨著時間增加眼睛落在四個雙字詞的凝視比例。結果發現次要語義因為語境的選擇在聽到目標詞後大約500毫秒時就可被激發，主要語義則在一聽完多義詞後被激發。因此，多義詞的兩個語義在聽到目標詞後大約900至1300毫秒時(相當於在後目標詞時)發生競爭。整體而言，本研究顯示即使語境支持多義詞的次要語義，主要語義依然會被激發。因此，次要語義偏向效應是由兩個語義競爭後所造成的結果，符合再排序觸接模型的解釋。 / Research in psycholinguistics throughout the last two decades has focused on the interaction between linguistic context and meaning dominance during lexical ambiguity resolution. Many studies demonstrated the subordinate bias effect when the preceding context biased for the subordinate meaning (i.e. infrequent meaning) of an unbalanced homograph. According to the reordered access model, the SBE is due to competition between the dominant and subordinate meanings. On the contrary, the selective access model assumes only the context-relevant meaning is activated and the SBE is a result of access to a low frequent meaning. Two eye tracking experiments of sentence reading and sentence listening were conducted. Experiment 1 examined the SBE of Chinese homographs to differentiate the two accounts. We utilized low frequency homographs along with their matched low and high-frequency unambiguous words. The results showed the SBE emerging in fixation durations of the target region and post-target region (i.e. next two words of the target), when unambiguous controls were matched to the word-form frequency of ambiguous words. Experiment 2 used visual world paradigm to explore temporal dynamics of dominant meaning activation responsible for the SBE in an instructional eyetracking-during-listening task. Fixation probabilities on four disyllabic printed words were analyzed during a time period after a target word was uttered in a spoken sentence. The results supported the reordered access model. The subordinate meaning was activated by contextual information at about 500 ms after the onset of acoustic homograph at the time when context penetrated to make its favored meaning available. Soon after the offset of homograph, the dominant meaning became active. Both meanings associated with the homograph were activated during the time windows of 901 ms to 1300 ms, which approximately corresponding to the acoustic onset of post target. In sum, our studies demonstrate that the dominant meaning is activated even when the contextual information biases to the subordinate meaning of a homograph. The subordinate bias effect is the result of competition from two meanings, conforming to the reordered access model.