维吾尔族与汉族的大学生在汉语歧义词消解中的语境促进效应及反应抑制效应

词汇歧义是语言的普遍现象。在汉语中, 歧义词的种类繁多, 是少数民族学生汉语学习困难的重要原因之一。通过两个实验, 考察在不同加工时间条件下维吾尔族和汉族的大学生在汉语歧义词消解中的语境促进效应及抑制效应。结果发现, 两个民族的大学生均出现了语境促进效应, 但在短时加工条件下, 汉族大学生的语境促进效应显著大于维吾尔族大学生, 在长时加工条件下, 两个民族的大学生的语境促进效应并无显著差异。在短时加工条件下, 仅汉族大学生可以有效地抑制无关信息的干扰; 在长时加工条件下, 两个民族的大学生均可以有效地抑制无关信息的干扰。整个研究表明, 在汉语歧义词消解中, 随着加工时间增加, 维吾尔族大学生的语境促进效应和对无关信息的抑制均可以达到与汉族大学生相近的水平。     

University of Alberta norms of relative meaning frequency for 566 homographs

For many models of lexical ambiguity resolution, relative frequency of the different meanings of homographs (words with more than one meaning) is crucial. Although several homograph association norms have been published in the past, none has involved a large number of subjects responding to a large number of homographs, and most homograph norming studies are now at least a decade old. In Experiment l, associations to 566 homographs were collected from an average of 192 subjects per homograph. Frequency of occurrence for the three most common meanings is reported, along with the corresponding associates, and a measure of the overall ambiguity of each homograph. Homographs whose meanings differed in part of speech were more ambiguous overall than homographs whose different meanings belonged to a single grammatical class. Homographs whose pronunciation depended on meaning (heterophones) were no more ambiguous than nonheterophones, and word frequency was unrelated to overall ambiguity. Estimates of homograph balance across different norming studies were compared, and homographs with two meanings of approximately equal relative meaning frequency (balanced homographs) and homographs with one clearly dominant meaning (polarized homographs) were identified. In Experiment 2, reliability of meaning categorizations was measured for a subset of the homographs in the first experiment. Meaning categorizations were shown to be highly reliable across raters.     

Effects of syntactic category assignment on lexical ambiguity resolution in reading: an eye movement analysis

Readers' eye movements were monitored as they read sentences containing lexically ambiguous words whose meanings share a single syntactic category (e.g., calf), lexically ambiguous words whose meanings belong to different syntactic categories (e.g., duck), or unambiguous control words. Information provided prior to the target always unambiguously specified the context-appropriate syntactic-category assignment for the target. Fixation times were longer on ambiguous words whose meanings share a single syntactic category than on controls, both when prior context was semantically consistent with the subordinate interpretation of a biased ambiguous word (Experiment 1) and when prior context was semantically neutral as to the intended interpretation of a balanced ambiguous word (Experiment 2). These ambiguity effects, which resulted from differences in difficulty with meaning resolution, were not found when the ambiguity crossed syntactic categories. These data indicate that, in the absence of syntactic ambiguity, syntactic-category information mediates the semantic-resolution process.     

Meaning resolution processes for words: A parallel independent model

Lexical ambiguity research over the last two decades is reviewed, with a focus on how that literature applies to understanding the resolution of meaning for words. Early models of ambiguity processing dealt almost exclusively with the time course of the effects of context on lexical access, in order to address the issue of modularity of lexical access. Newer models of ambiguity processing accommodate recent findings of early context effects that are contingent on both strength of context and meaning frequency. The most important contribution of these newer models of ambiguity processing is not to the modularity debate, but to investigation of the range of parameters affecting the entire meaning resolution process, including meaning access as well as the integration of meanings into context. As an example of this approach, we describe a simple quantitative model of meaning resolution that subsumes many other models as parametric variations.     

Accessing lexical ambiguities during sentence comprehension: Effects of frequency of meaning and contextual bias

Two hypotheses concerning the nature of lexical access, the exhaustive access and the terminating ordered search hypotheses, were examined in two separate studies using a crossmodal lexical priming task. In this task, subjects listened to sentences that were biased toward either the primary interpretation (a meaning occurring 75% or more of the time) or a secondary interpretation (a meaning occurring less than 25% of the time) of a lexical ambiguity that occurred in each sentence. Simultaneously, subjects made lexical decisions about visually presented words. Decisions to words related to both the primary and secondary meanings of the ambiguity were facilitated when presented immediately following occurrence of the ambiguity in the sentence. This effect held under each of the two biasing context conditions. However, when they were presented 1.5 sec following occurrence of the ambiguity, only visual words related to the contextually relevant meaning of the ambiguity were facilitated. These results support the exhaustive access hypothesis. It is argued that lexical access is an autonomous subsystem of the sentence comprehension routine in which all meanings of a word are momentarily accessed, regardless of the factors of contextual bias or bias associated with frequency of use.     

汉语同形歧义词歧义消解的两半球差异

实验探讨汉语同形歧义词(homographs)歧义消解的过程及大脑两半球的差异。被试为华中科技大学96名大学生,实验采用词汇判断任务。句子语境呈现在被试的视野中央,探测词在SOA(stimulus onset asynchronism)为100毫秒或400毫秒时呈现在左视野或右视野。结果发现,(1)当SOA为100毫秒时,在左视野(右半球)上,与语境一致的同形歧义词的主要意义得到激活,与语境不一致的次要意义也有一定程度的激活。在右视野(左半球)上,只有与语境一致的同形歧义词的主要意义得到激活。(2)当SOA为400毫秒时,在左、右视野(两半球)上,与语境一致的同形歧义词的主要意义和次要意义都得到激活。结果表明,大脑左半球对汉语歧义词的歧义消解具有一定的优势,语境敏感模型可以较好地解释本实验的结果。     

Selection mechanisms in reading lexically ambiguous words

Readers' eye movements were monitored as they read sentences containing lexically ambiguous words. The ambiguous words were either biased (one strongly dominant interpretation) or nonbiased. Readers' gaze durations were longer on nonbiased than biased words when the disambiguating information followed the target word. In Experiment 1, reading times on the disambiguating word did not differ whether the disambiguation followed the target word immediately or occurred several words later. In Experiment 2, prior disambiguation eliminated the long gaze durations on nonbiased target words but resulted in long gaze durations on biased target words if the context demanded the subordinate meaning. The results indicate that successful integration of one meaning with prior context terminates the search for alternative meanings of that word. This results in selective (single meaning) access when integration of a dominant meaning is fast (due to a biasing context) and identification of a subordinate meaning is slow (a strongly biased ambiguity with a low-frequency meaning).     

Interpretive cues and ambiguity in generalized anxiety disorder

The current study investigated whether generalized anxiety disorder (GAD) individuals rely on antecedent information to interpret ambiguity and whether reliance on such preceding cues persists in the absence of potential threat. Twenty-six GAD and 23 nonanxious control college students performed a lexical decision task, using homographs (i.e. words with multiple meanings) as ambiguous primes. In half the trials, a homograph prime that possessed both threat-related, as well as neutral meanings was followed by a target word related to one of these two meanings. In addition, each ambiguous prime was immediately preceded by a series of four antecedent words that were either: (a) associated with the threatening meaning of the prime; (b) associated with the neutral meaning of the prime; or (c) unrelated to either meaning of the homograph, as well as the target. Homographs for which both meanings were neutral in valence comprised the other half of the trials. Effect size statistics suggest that GAD participants utilized the antecedent words to interpret the homograph primes with threat-related meanings, unlike their nonanxious counterparts (p<0.06). When both meanings of the homograph prime were neutral in valence, the GAD group appeared deficient in the use of preceding information to interpret the ambiguous prime.     

Idiom literality judgments in younger and older adults: age-related effects in resolving semantic interference

To study age effects in the resolution of idiomatic semantic ambiguity, we focus on decomposability, the extent to which a literal reading of an idiom's words shares meaning with its figurative interpretation. Younger and older adults judged whether decomposable and nondecomposable idioms and nonidioms had a literal interpretation. Older adults were slower at making literality judgments and more sensitive to conflicts between literal and figurative meanings. The results support claims of decompositional analysis of idioms during later processing stages and of obligatory activation of figurative meanings. They also lend support to research that has shown age-related effects in ambiguity resolution.     

Sublexical ambiguity effect in reading Chinese disyllabic compounds

For Chinese compounds, neighbors can share either both orthographic forms and meanings, or orthographic forms only. In this study, central presentation and visual half-field (VF) presentation methods were used in conjunction with ERP measures to investigate how readers solve the sublexical semantic ambiguity of the first constituent character in reading a disyllabic compound. The sublexical ambiguity of the first character was manipulated while the orthographic neighborhood sizes of the first and second character (NS1, NS2) were controlled. Subjective rating of number of meanings corresponding to a character was used as an index of sublexical ambiguity. Results showed that low sublexical ambiguity words elicited a more negative N400 than high sublexical ambiguity words when words were centrally presented. Similar patterns were found when words were presented to the left VF. Interestingly, different patterns were observed for pseudowords. With left VF presentation, high sublexical ambiguity psudowords showed a more negative N400 than low sublexical ambiguity pseudowords. In contrast, with right VF presentation, low sublexical ambiguity pseudowords showed a more negative N400 than high sublexical ambiguity pseudowords. These findings indicate that a level of morphological representation between form and meaning needs to be established and refined in Chinese. In addition, hemispheric asymmetries in the use of word information in ambiguity resolution should be taken into account, even at sublexical level.     

Semantic diversity: A measure of semantic ambiguity based on variability in the contextual usage of words

Semantic ambiguity is typically measured by summing the number of senses or dictionary definitions that a word has. Such measures are somewhat subjective and may not adequately capture the full extent of variation in word meaning, particularly for polysemous words that can be used in many different ways, with subtle shifts in meaning. Here, we describe an alternative, computationally derived measure of ambiguity based on the proposal that the meanings of words vary continuously as a function of their contexts. On this view, words that appear in a wide range of contexts on diverse topics are more variable in meaning than those that appear in a restricted set of similar contexts. To quantify this variation, we performed latent semantic analysis on a large text corpus to estimate the semantic similarities of different linguistic contexts. From these estimates, we calculated the degree to which the different contexts associated with a given word vary in their meanings. We term this quantity a word’s semantic diversity (SemD). We suggest that this approach provides an objective way of quantifying the subtle, context-dependent variations in word meaning that are often present in language. We demonstrate that SemD is correlated with other measures of ambiguity and contextual variability, as well as with frequency and imageability. We also show that SemD is a strong predictor of performance in semantic judgments in healthy individuals and in patients with semantic deficits, accounting for unique variance beyond that of other predictors. SemD values for over 30,000 English words are provided as supplementary materials.     

Multiple semantic encoding of homophones and homographs in contexts biasing dominant or subordinate meanings

The resolution of lexical ambiguity was studied in two experiments. While subsequent selection would appear to limit longer term storage to one meaning of an ambiguous word, multiple initial encoding of homophones and homographs was indicated by the intrusion of their alternative meanings across trials in a Brown-Peterson paradigm. In Experiment 1 subjects heard four words and then engaged in a 10osec distractor task. Written recall was then demanded. On context trials a homophone with two distinct alternative meanings was presented with other words biasing either a dominant or subordinate meaning, for example, look, stare,peer, glance. On the next trial words related to an alternative meaning were presented, for example, dock, wharf, quay, jetty. Intrusions of the graphic forms of alternative meanings le.g.,PIER) into critical trial recall occurred whether the dominant or subordinate meaning of the homophone had been biased by context. Experiment 2 employed visual presentation of homographs, for example, GOLD, IRON,LEAD, and oral recall, but was logically similar to Experiment 1. Intrusions of the alternative codings of homographs across trials again occurred, for example, GUIDE, DIRECT,lead, regardless of the meaning originally biased by context.     

Global context effects on processing lexically ambiguous words: Evidence from eye fixations

Readers' eye movements were monitored as they read biased ambiguous target words in the context of a short paragraph. Two aspects of context were manipulated. The global context was presented in the topic sentence of the paragraph and instantiated either the dominant or the subordinate meaning of biased ambiguous target words (those with highly dominant meanings). Local contextual information either preceded or followed the target word and was always consistent with the subordinate interpretation. Consistent with prior research, we obtained a subordinate bias effect wherein readers looked longer at the ambiguous words than control words when the preceding context instantiated the subordinate meaning. More importantly, the magnitude of the subordinate bias effect was the same when global context alone, local context alone, or local and global context combined were consistent with the subordinate meaning of the ambiguous word. The results of this study indicate that global contextual information (1) has an immediate impact on lexical ambiguity resolution when no local disambiguating information is available, (2) has no additional effect when it is consistent with local information, but (3) does have a slightly delayed effect when inconsistent with local information.     

不同认知方式个体抑制歧义词不适当意义的机制

本试验采用固定速的移动窗口范式和意义适合性判断任务,考察场依存、场独立个体抑制句子中歧义词不适当意义的机制以及歧义词歧义消解的进程。结果表明：不同认知方式个体在抑制句子中歧义词不适当意义的时间进程上存在差异,与场依存者相比,场独立者能够较早地抑制歧义的干扰;同时,本研究证明歧义词的多个意义首先激活,然后与语境不一致的意义得到抑制,研究结果支持词汇歧义消解的多重通达模型。     

Probing Lexical Ambiguity: Word Vectors Encode Number and Relatedness of Senses

Lexical ambiguity—the phenomenon of a single word having multiple, distinguishable senses—is pervasive in language. Both the degree of ambiguity of a word (roughly, its number of senses) and the relatedness of those senses have been found to have widespread effects on language acquisition and processing. Recently, distributional approaches to semantics, in which a word's meaning is determined by its contexts, have led to successful research quantifying the degree of ambiguity, but these measures have not distinguished between the ambiguity of words with multiple related senses versus multiple unrelated meanings. In this work, we present the first assessment of whether distributional meaning representations can capture the ambiguity structure of a word, including both the number and relatedness of senses. On a very large sample of English words, we find that some, but not all, distributional semantic representations that we test exhibit detectable differences between sets of monosemes (unambiguous words; N = 964), polysemes (with multiple related senses; N = 4,096), and homonyms (with multiple unrelated senses; N = 355). Our findings begin to answer open questions from earlier work regarding whether distributional semantic representations of words, which successfully capture various semantic relationships, also reflect fine-grained aspects of meaning structure that influence human behavior. Our findings emphasize the importance of measuring whether proposed lexical representations capture such distinctions: In addition to standard benchmarks that test the similarity structure of distributional semantic models, we need to also consider whether they have cognitively plausible ambiguity structure.     

The study of inhibitory processes in aging with the Faust et al. paradigm (1997): methodological issues

Information provided by a word activates various potential meanings. Comprehension involves the suppression of inappropriate meanings of ambiguous words in order to finetune the intended meaning of sentences. If older adults become less efficient at inhibiting contextually irrelevant information, then multiple meanings of ambiguous words would be activated regardless of contextual bias. An alternative to multiple access was that older adults activate only the most dominant meaning of ambiguous words. According to this reservation, support for an inhibition deficit would require evidence that older adults activated the multiple meanings of ambiguous words. The effects of aging on both activation and inhibition of different meanings of ambiguous words were studied using Faust et al. (1997) paradigms. Results showed that both activation and inhibition response latency differed for the dominant and subordinate target and that the dominant meaning for one subject was not the same for another one. The implication of these results is that studies of inhibition should take dominance meaning of ambiguous word for each subject into account.     

An on-line investigation of lexical ambiguity processing in schizophrenia

The processing of lexical ambiguity in context was investigated in eight individuals with schizophrenia and a matched control group. Participants made speeded lexical decisions on the third word in auditory word triplets representing concordant (coin-bank-money), discordant (river-bank-money), neutral (day-bank-money), and unrelated (river-day-money) conditions. When the interstimulus interval (ISI) between the words was 100 ms, individuals with schizophrenia demonstrated priming consistent with selective, context-based lexical activation. At 1250 ms ISI, a pattern of nonselective meaning facilitation was obtained. These results suggest an attentional breakdown in the sustained inhibition of meanings on the basis of lexical context.     

LIFG-based attentional control and the resolution of lexical ambiguities in sentence context

The role of attentional control in lexical ambiguity resolution was examined in two patients with damage to the left inferior frontal gyrus (LIFG) and one control patient with non-LIFG damage. Experiment 1 confirmed that the LIFG patients had attentional control deficits compared to normal controls while the non-LIFG patient was relatively unimpaired. Experiment 2 showed that all three patients did as well as normal controls in using biasing sentence context to resolve lexical ambiguities involving balanced ambiguous words, but only the LIFG patients took an abnormally long time on lexical ambiguities that resolved toward a subordinate meaning of biased ambiguous words. Taken together, the results suggest that attentional control plays an important role in the resolution of certain lexical ambiguities - those that induce strong interference from context-inappropriate meanings (i.e., dominant meanings of biased ambiguous words).     

Ambiguity Advantage Revisited: Two Meanings are Better than One When Accessing Chinese Nouns

This paper revisits the effect of lexical ambiguity in word recognition, which has been controversial as previous research reported advantage, disadvantage, and null effects. We discuss factors that were not consistently treated in previous research (e.g., the level of lexical ambiguity investigated, parts of speech of the experimental stimuli, and the choice of non-words) and report on a lexical decision experiment with Chinese nouns in which ambiguous nouns with homonymic and/or metaphorical meanings were contrasted with unambiguous nouns. An ambiguity advantage effect was obtained—Chinese nouns with multiple meanings were recognized faster than those with only one meaning. The results suggested that both homonymic and metaphorical meanings are psychologically salient semantic levels actively represented in the mental lexicon. The results supported a probability-based model of random lexical access with multiple meanings represented by separate semantic nodes. We further discuss these results in terms of lexical semantic representation and how different experimental paradigms result in different ambiguity effects in lexical access.