Language, admittedly, is ubiquitous and plays a crucial role in our life. People may suppose that comprehending words or sentences is an inherent ability, which is quick and effortless most of the time. However, the complex underlying mechanism about how syntactic and semantic information interact and integrate in human’s brain have always been discussed.
Ambiguity is one of the robust examples since it is so prevalent at either word or sentence level in language. In English, for example, it is estimated that over 80 percent of high-frequency words have more than one meaning (Twilley, Dixon, Taylor & Clark, 1994; Rodd et al., 2002). Chinese, likewise, has a large number of word-class ambiguous words. According to the Modern Chinese Dictionary, nearly 80% of the monosyllables in Chinese are ambiguous between various meanings, and 55% have five or more homophones. Moreover, an estimate indicated that regardless of frequency, between 13%
and 29% of Chinese monosyllabic and disyllabic words can be used as nouns and as verbs (Hu, 1996). On the one hand lexical ambiguity makes language rich and flexible, but on the other hand it complicates language, creates processing load and somehow increases the chance of confusion or misunderstanding. With such distinctive feature that one-to-many meaning mapping, how to pick out the most appropriate meaning swiftly among many possible interpretations and thus reach an effective communication is a primary issue for psycholinguists and neuropsychologists.
When it comes to lexical ambiguity, most of the time, it can refer to either polysemy or homonymy. To be specific, polysemy denotes a word possesses multiple different but related meanings as shown in the case of foot (e.g., “my left foot” and “at the foot of the mountain”), while homonymy contains several meanings which are semantically
unrelated like bank (river bank and financial bank). As for the former, both meanings are related but not literally the same; for the latter, both meanings share a single orthographic form but semantically unrelated concepts. According to a number of prior neurolinguistic studies, homonymy and polysemy are vindicated psychological distinct and being processed differently (Frazier & Rayner, 1990; Pickering & Frisson, 2001; Rodd, Gaskell,
& Marslen-Wilson, 2002). Due to the distinctiveness, the present study is exclusively concerned with homonymy, the so-called homophonic homographs, to avoid making confounding (Cruse, 1986; Lyons, 1977).
Two competing hypotheses of lexical ambiguity resolution have been proposed in the past decades from psychological and linguistic perspectives. Context-dependent account declares that the context that precedes an ambiguous word can offer help to access only the contextually appropriate meaning, assuming that language processing is operated by an interactive mechanism in which information among different linguistic subsystems like lexical or grammatical levels can flow both bottom-up and top-down simultaneously in ongoing language processing (McClelland, 1987). In contrast, context-independent account postulates that language subsystems are operated independently of other cognitive systems; namely, language processing must be completed in each language subsystem before information is transferred. This view is based upon the premise that language processing is a modular, bottom-up approach in which non-lexical, sentential information does not penetrate lexical access (Fodor, 1983). These hypotheses, in fact, provide a basis for researchers to extend various models of language processing as well as highlight the importance of underlying cognitive architecture of language processing.
To demonstrate the influence of contextual information, a great many researchers have investigated it across languages via various experimental paradigms, and most focus on either semantic or syntactic constraints. A majority of findings suggest that semantic
information of context is able to facilitate word processing (Marslen-Wilson & Tyler, 1980; Van Petten & Kutas, 1990; Van Petten & Kutas, 1991), help access appropriate meaning and even reduce selection demands related to ambiguity though it seems not to operate independently but interact with meaning frequency (Duffy, Morris, & Rayner, 1988; Rayner & Frazier, 1989; Rayner, Pacht, & Duffy, 1994; Lee & Federmeier, 2009).
On the other hand, past research into the effects of syntactic context on word processing has also been studied yet yielded inconsistent results (Marslen-Wilson & Tyler, 1980;
Seidenberg et al., 1982; Tanenhaus, Leiman, & Seidenberg, 1979; Folk & Morris, 2003;
Lee & Federmeier, 2006, 2009, 2011; Chen, 2014). Some support that syntactic context information can affect word processing, whereas some concludes such the information alone is insufficient to eliminate the lexical ambiguity indexed by a frontal negativity.
Under discrepant basis, this issue has not reached a consensus unanimously. Moreover, previous neurolinguistic research has been widely conducted in English and other Indo-European languages such as German, Italian and French, but there are relatively few studies to explore the syntactic context information during Chinese processing.
In addition to context, the role of meaning dominance is also one of the essential factors in lexical ambiguity resolution. Meaning dominance refers to alternative meanings of an ambiguous word have different frequency of uses. In comparison to the subordinate meaning, the dominant meaning is much easier to reach a high activation level (Simpson
& Burgess, 1985; Burgess & Simpson, 1988; Hogaboam & Perfetti, 1975; Simpson, 1981). However, the alternative meanings of an ambiguous word will reach a high activation level at the same time and keep competing with each other if the frequency of uses of both meanings are equal. (Duffy, Morris, & Rayner, 1988; Rayner & Duffy, 1986;
Sereno, Pacht, & Rayner, 1992).
Since most of the previous research associated meaning dominance with semantic
issue; that is, they indeed manipulated two distinct meanings of ambiguous words but seemed to overlook the distinctiveness of dominant and subordinate meanings of experimental materials respectively, especially when the alternative meanings of ambiguous words fell in different word classes. The relevant studies were much less with respect to syntactic context. Despite the fact that some have asserted to inspect the meaning dominance under only the syntactic constraint, some did not control the equal numbers of syntactic category ambiguous words, some just used balanced homographs.
For example, Folk and Morris (2003) have investigated the function of syntactic context in lexical ambiguity resolution by embedding balanced NN- and NV-homographs in sentences which were syntactically instantiated either the dominant or the subordinate meaning of the homographs. Yet, the prior context contained syntactic information that disambiguated the NV ambiguous words, specifying the noun interpretation was intended only. Under the circumstance, meaning dominance did not be examined comprehensively.
Therefore, the current study is regarded as a pilot study, aiming to not only organize the materials in Chinese homographs but set up a protocol to approach the following issues regarding how syntactic information affect meaning access and aid lexical ambiguity resolution in Chinese biased homographs as well as what the role of meaning dominance is under such a context. Based on this consideration, a large body of this study will emphasize the material selection, in which we made efforts to verify the validity of the materials on various linguistic features. Despite the fact that we have done preliminary experiments through the established design by using the materials, the numbers of participants in this experiment was relatively small. In addition, the data was unexpectedly variable among participants. As the variation among participants was quite salient, we conducted a simple group-level statistical analysis, and most part of the current study focused on explaining the source of the inter-individual variance. Follow-up
analysis and testing was conducted to verify these speculations. Although the results of the present study are not conclusive, we hope that the stimuli and testing protocol would provide a basis for future research.
Chapter 2 Literature review