Chapter 5 General Discussion
5.2 Syntactic category constraint
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combination of content words, not providing any semantics for sentence comprehension. It remains possibility that readers employ different reading strategies when they encounter the SCA words in sentences using different kinds of
“semantically-neutral” context.
To sum up, our findings in both experiments support constraint-satisfaction models and disagree with syntax-first models. The dominant meaning can be activated even if it is not favored by the preceding contexts. The syntactic category constraint alone cannot determine the semantic resolution of SCA words. Semantic constraint, meaning frequency, and inherent processing difficulty are primary sources determining ambiguity resolution.
5.2 Syntactic category constraint
The functional primacy of syntactic category assignment has been supported by research on English and Indo-European languages (Frazier, 1979, 1987, 1989; Frazier
& Rayner, 1982; Friederici, 1995, 2002; Friederici et al., 1996; Friederici et al., 1999;
Rayner et al., 1983). For example, when a target word violates both syntactic category and semantic constraints from the preceding context, N400 was not observed; instead, ELAN was found around 100-300 ms after target word onset (Friederici et al., 1999).
These studies suggested that syntactic analysis precedes semantic analysis during
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sentence comprehension. Does syntactic category constraint play a role in Chinese sentence comprehension? Under the assumption of constraint-satisfaction models, the answer is definitely yes. However, syntactic category constraint seems less influential than probabilistic constraints during Chinese sentence comprehension. On the one hand, both Experiment 1 and Experiment 2 demonstrated that the SBE for SCA words cannot be successfully eliminated by syntactic category constraint, suggesting that the dominant meaning can still be activated though being inconsistent with the preceding syntactic category bias. Thus, this finding rejects the functional primacy of syntactic category assignment and supports the influence of probabilistic constraints. On the other hand, both Experiment 1 and Experiment 2 revealed unequal effect sizes of the ambiguity effect for VN and NV homographs. If the syntactic category constraint indeed played a very influential role in the semantic resolution of SCA words, the subordinate meaning would be selectively activated either in the case of VN or NV homographs. The difference between VN and NV homographs indicates that the syntactic category of alternative meanings is more influential than the preceding syntactic category constraint. Our Experiment 2 demonstrated the SBE for strongly-biased VN, indicating that the probabilistic constraints are more influential than the syntactic category constraint during Chinese sentence comprehension.
In addition, several eye-movement and ERP studies have also revealed that the
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functional primacy of syntactic category assignment was not so obvious in Chinese as compared to in Indo-European languages (Li, 1998; Wang et al., 2013; Yu & Zhang, 2008; Zhang et al., 2013; Zhang et al., 2010). Instead of using SCA words as probes, these studies employed the violation paradigm in which the target word / character either conforms to or violates the preceding context with regard to semantic and syntactic category constraints. Eye movement research showed that the violation effect in both the pure semantic violation condition and the semantic + syntactic violation one did not differ from each other in terms of the appearance time (Yang et al., 2009), indicating that the syntactic processing does not precede the semantic processing in Chinese reading. Similarly, ERP research demonstrated a larger N400 for the semantic + syntactic violation condition in comparison with the pure syntactic violation condition (Zhang et al., 2010), indicating that the semantic integration is not blocked by the syntactic category violation. The authors suggest the lack of syntactic primacy in Chinese might result from language-specific characteristics. Unlike some Indo-European languages (e.g., French, German), Chinese has few morpho-syntactic markers and vague boundary of syntactic category, so it is possible that readers rely on the syntactic category constraints to a less degree during Chinese reading.
In sum, although constraint-satisfaction models allow syntactic category constraints to be considered in Chinese sentence comprehension, some
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language-specific properties reduce its availability.
5.3 Semantic constraint
The present study verifies that semantic constraint plays an influential role during ambiguity resolution. For lexical-semantic ambiguous words (NN/VV), both Experiment 1 and 2 showed the SBE was absent on the first-pass measures for the target and present on the second-pass measures. Our findings seem inconsistent with those in the previous studies (Duffy et al., 2001; Duffy et al., 1988; 盧怡璇, 2012), in
which the SBE for NN and VV was obviously observed on the measures of initial processing in the target region. One possible reason is that the preceding semantic constraint we used in Experiment 1 might be so strong that the subordinate meaning could be selectively activated. A comparison of the first-pass duration measures between Experiment 1 and 2 may shed light on the strength of semantic constraint (see Table 29). First, regardless of ambiguity, the durations were increased in Experiment 2, indicating readers needed more time to access a word when the preceding context provided no semantic information. Second, Experiment 1 showed a reverse pattern for the ambiguity effect (A < UA), but this pattern was eliminated in Experiment 2. This finding also indicated that the semantic constraint in Experiment 1 was strong enough to lead readers to activate the subordinate meaning of homographs sooner than to access the unambiguous meaning. This facilitatory effect for the
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subordinate meaning of homographs might be because the context was more semantically related to the subordinate meaning of homographs compared to the unambiguous word. To test this explanation, a norming study of semantic relatedness between the context and the target words should have been conducted.
Table 29
A comparison of means of first-pass duration measures between Experiment 1 and 2 Measures Type Ambiguity Experiment 1 Experiment 2
FFD
Note. A = ambiguous words; UA = unambiguous words
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As for syntactic category ambiguous words (VN/NV), Experiment 1 demonstrated that the SBE was absent until the second-pass reading in the post-target region, while Experiment 2 obtained the SBE instantly on the measures of initial processing in the target region. These findings are in agreement with the suggestion of Lee and Federmeier (2009) that semantic information is also important to the semantic resolution of SCA words. In their electrophysiological study, a sustained frontal negativity (200-700 ms), elicited by the NV-homographs in the syntactic prose sentences, was largely reduced when additional semantic information was available in contexts. Our findings accord with theirs in a way that the SBE for SCA words was elicited when the preceding strong semantic constraint was eliminated. In addition, they also found NV-homographs elicited larger N400 than did unambiguous words only when context was biased toward the subordinate meaning of homographs, indicating the automatic activation of the dominant meaning of NV-homographs in the subordinate-biased contexts. Our experiments also demonstrated the SBE for SCA words on the second-pass measures.