Garden-path utterances and relevance

An appropriate account of how the interpretation process of garden-path utterances develops should include an analysis of those psycholinguistic aspects related to the recovery of the semantic representations of the utterance as well as a pragmatic explanation of how those representations are used in the construction of a final interpretation. To investigate how lexical access could take place in the case of ambiguous words, two psycholinguistic models are briefly reviewed: the selective model and the exhaustive model. An argument is put forward for the exhaustive model, that is, for a modular view of the lexical processing system. Thus, we argue that in the processing of a garden-path utterance, upon encountering an ambiguous word, all of its meanings are initially activated. Once access has been completed and the selection phase reached, pragmatic factors come into play, in the process of selecting one of the possibilities and building an interpretation from it. Relevance theory, a cognitive-pragmatic account of communication, explains why a given interpretation is initially selected, why it is later rejected as contextually inappropriate and why the processor tries a second line of interpretation which will finally produce the desired results

Context effects and lexical ambiguity processing: an activation-based account

Many studies have been conducted to test the effects of ambiguous words in sentence processing. There are two views: the modularity hypothesis and the interactive hypothesis that dominate this field of study. The effect of ambiguity has been tested in many ways, including gating, cross-modal priming, naming, and self-paced reading. This utilizes the methods of self paced reading with lexical decision and naming tasks to examine the hypotheses as they relate to the access period of lexical differentiation. Results indicate that context has an immediate effect, after which participants look to other factors to discern meaning of a sentence. Details are discussed according to a time course activation model

Settling Into Semantic Space: An Ambiguity-Focused Account of Word-Meaning Access

Most words are ambiguous: Individual word forms (e.g., run) can map onto multiple different interpretations depending on their sentence context (e.g., the athlete/politician/river runs). Models of word-meaning access must therefore explain how listeners and readers can rapidly settle on a single, contextually appropriate meaning for each word that they encounter. I present a new account of word-meaning access that places semantic disambiguation at its core and integrates evidence from a wide variety of experimental approaches to explain this key aspect of language comprehension. The model has three key characteristics. (a) Lexical-semantic knowledge is viewed as a high-dimensional space; familiar word meanings correspond to stable states within this lexical-semantic space. (b) Multiple linguistic and paralinguistic cues can influence the settling process by which the system resolves on one of these familiar meanings. (c) Learning mechanisms play a vital role in facilitating rapid word-meaning access by shaping and maintaining high-quality lexical-semantic knowledge throughout the life span. In contrast to earlier models of word-meaning access, I highlight individual differences in lexical-semantic knowledge: Each person's lexicon is uniquely structured by specific, idiosyncratic linguistic experiences

Advances and Issues in Lexical Ambiguity Research

Lexical ambiguity is one of the major themes in psycholinguistic research over the past two decades. The purpose of this paper is to review the advances and issues in lexical ambiguity research after mid-80s. The central topic in this area is context effects on disambiguation processes. Using crossmodal priming paradigm and other experimental methods, psychologists have studied the on-line processes of resolving lexical ambiguity. Although multiple access model and selective access model are traditionally two major models, hybrid models which include activation of multiple meanings, context-sensitivity, and frequency-dependency are needed, and connectionism is a promising framework. We also examine findings about processing of isolated ambiguous words. Although work on lexical ambiguity has focused more on processing, we must also study the structure and learning mechanism of ambiguity itself

GARDEN-PATH UTTERANCES AND RELEVANCE

AbstractAn appropriate account of how the interpretation process of garden-path utterances develops should include an analysis of those psycholinguistic aspects related to the recovery of the semantic representations of the utterance as well as a pragmatic explanation of how those representations are used in the construction of a final interpretation. To investigate how lexical access could take place in the case of ambiguous words, two psycholinguistic models are briefly reviewed: the selective model and the exhaustive model. An argument is put forward for the exhaustive model, that is, for a modular view of the lexical processing system. Thus, we argue that in the processing of a garden-path utterance, upon encountering an ambiguous word, all of its meanings are initially activated. Once access has been completed and the selection phase reached, pragmatic factors come into play, in the process of selecting one of the possibilities and building an interpretation from it. Relevance theory, a cognitive-pragmatic account of communication, explains why a given interpretation is initially selected, why it is later rejected as contextually inappropriate and why the processor tries a second line of interpretation which will finally produce the desired results

The Relative Contribution of Top-down and Bottom-up Information During Lexical Access

The research reported in this thesis examines the relative contributions of top-down and bottom-up information during lexical access. I evaluate the Cohort Model of lexical access (Marslen-Wilson and Welsh, 1978; Marslen-Wilson and Tyler, 1980; and Marslen-Wilson, 1987) which specifies that the first stage in lexical access is fully autonomous and that during this stage all processing proceeds in terms of analysis of the acoustic-phonetic input. Implicit in this model is the assumption that bottom-up processing is immune to any effects of contextual or top-down information. I examine the extent to which listeners ever rely exclusively on bottom-up information during lexical access and investigate this issue empirically, by measuring effects of context on both the production and the perception of words in various contexts. I test the hypothesis that a word uttered in a constraining context will be acoustically indistinguishable from its competitors by, first, measuring one acoustic parameter (VOT) across constraining and non-constraining contexts and, then, examining the intelligibility of tokens of that parameter taken from the varyingly constraining contexts. The data from these experiments suggest that the realization of VOT is not an aspect of bottom-up information which would create problems for a bottom-up processor in terms of providing ambiguous acoustic-phonetic information. I then investigate whether bottom-up processing during lexical access is immune to effects of context. Following Grosjean (1980) and Tyler (1984), I utilize the Gating Paradigm. Using incongruous contexts, I argue that direct assessment of the contributions made by different information sources during lexical access can be made. By presenting bottom-up information which is inappropriate to the contextual (topdown) information, I evaluate the extent to which one information source is given priority over the other. I vary both the contextual constraints available to the listener and the acoustic clarity of bottom-up information. The observed pattern of listeners' identifications of the words suggested that whilst bottomup information was given priority, top-down information was available and was utilized during lexical access. I present data which support the working structure of the Cohort Model of lexical access. I conclude, however, that the model places disproportionate emphasis on initial bottom-up processing. It appears that top-down information is not prohibited from contributing to processing during the initial stage of lexical access

Listeners normalize speech for contextual speech rate even without an explicit recognition task

Speech can be produced at different rates. Listeners take this rate variation into account by normalizing vowel duration for contextual speech rate: An ambiguous Dutch word /m?t/ is perceived as short /mAt/ when embedded in a slow context, but long /ma:t/ in a fast context. Whilst some have argued that this rate normalization involves low-level automatic perceptual processing, there is also evidence that it arises at higher-level cognitive processing stages, such as decision making. Prior research on rate-dependent speech perception has only used explicit recognition tasks to investigate the phenomenon, involving both perceptual processing and decision making. This study tested whether speech rate normalization can be observed without explicit decision making, using a cross-modal repetition priming paradigm. Results show that a fast precursor sentence makes an embedded ambiguous prime (/m?t/) sound (implicitly) more /a:/-like, facilitating lexical access to the long target word "maat" in a (explicit) lexical decision task. This result suggests that rate normalization is automatic, taking place even in the absence of an explicit recognition task. Thus, rate normalization is placed within the realm of everyday spoken conversation, where explicit categorization of ambiguous sounds is rare

Parsing with parallelism : a spreading-activation model of inference processing during text understanding

The past decade of reseatch in Natural Language Processing has universally recognized that, since natural language input is almost always ambiguous with respect to its pragmatic implications, its syntactic parse, and even its lexical analysis (i.e., choice of correct word-sense for an ambiguous word), processing natural language input requires decisions about word meanings, syntactic structure, and pragmatic inferences. The lexical, syntactic, and pragmatic levels of inferencing are not as disparate as they have often been treated in both psychological and artificial intelligence research. In fact, these three levels of analysis interact to form a joint interpretation of text.ATLAST (A Three-level Language Analysis SysTem) is an implemented integration of human language understanding at the lexical, the syntactic, and the pragmatic levels. For psychological validity, ATLAST is based on results of experiments with human subjects. The ATLAST model uses a new architecture which was developed to incorporate three features: spreading activation memory, two-stage syntax, and parallel processing of syntax and semantics. It is also a new framework within which to interpret and tackle unsolved problems through implementation and experimentation

When orthography is not enough: the effect of lexical stress in lexical decision.

Three lexical decision experiments were carried out in Italian, in order to verify if stress dominance (the most frequent stress type) and consistency (the proportion and number of existent words sharing orthographic ending and stress pattern) had an effect on polysyllabic word recognition. Two factors were manipulated: whether the target word carried stress on the penultimate (dominant; graNIta, seNIle 'slush, senile') or on the antepenultimate (non-dominant) syllable (MISsile, BIbita 'missile, drink'), and whether the stress neighborhood was consistent (graNIta, MISsile) or inconsistent (seNIle, BIbita) with the word\u2019s stress pattern. In Experiment 1 words were mixed with nonwords sharing the word endings, which made words and nonwords more similar to each other. In Experiment 2 words and nonwords were presented in lists blocked for stress pattern. In Experiment 3 we used a new set of nonwords, which included endings with (stress) ambiguous neighborhoods and/or with low number of neighbors, and which were overall less similar to words. In all three experiments there was an advantage for words with penultimate (dominant) stress, and no main effect of stress neighborhood. However, the dominant stress advantage decreased in Experiments 2 and 3. Finally, in Experiment 4 the same materials used in Experiment 1 were also used in a reading aloud task, showing a significant consistency effect, but no dominant stress advantage. The influence of stress information in Italian word recognition is discussed