Representation Of Word Meaning Research Articles

A professional development initiative for developing approaches to vocabulary instruction with secondary mathematics, art, science, and english teachers

During a yearlong collaborative effort to enhance vocabulary instruction in secondary classrooms, high school teachers and university faculty developed and implemented a variety of approaches to support students in building rich representations of word meanings as well as an understanding of word features such as roots, affixes, and parts of speech. This article describes those approaches and provides specific examples.

Phonological and conceptual activation in speech comprehension

We propose that speech comprehension involves the activation of token representations of the phonological forms of current lexical hypotheses, separately from the ongoing construction of a conceptual interpretation of the current utterance. In a series of cross-modal priming experiments, facilitation of lexical decision responses to visual target words (e.g., time) was found for targets that were semantic associates of auditory prime words (e.g., date) when the primes were isolated words, but not when the same primes appeared in sentence contexts. Identity priming (e.g., faster lexical decisions to visual date after spoken date than after an unrelated prime) appeared, however, both with isolated primes and with primes in prosodically neutral sentences. Associative priming in sentence contexts only emerged when sentence prosody involved contrastive accents, or when sentences were terminated immediately after the prime. Associative priming is therefore not an automatic consequence of speech processing. In no experiment was there associative priming from embedded words (e.g., sedate-time), but there was inhibitory identity priming (e.g., sedate-date) from embedded primes in sentence contexts. Speech comprehension therefore appears to involve separate distinct activation both of token phonological word representations and of conceptual word representations. Furthermore, both of these types of representation are distinct from the long-term memory representations of word form and meaning.

Category specificity in the processing of color-related and form-related words: An ERP study

In this study, we investigated the spatio-temporal patterns of category-specific cortical activation elicited by the visual presentation of words whose meaning relates to a color or to a visual form or shape. We recorded the event-related potentials (ERPs) of ten healthy, right-handed volunteers while they passively read words presented tachistoscopically. As early as 150 ms after stimulus onset, the ERPs revealed significant neurophysiological differences between words and strings of hash marks. Around 200 ms after stimulus onset, we found significant differences in the ERPs elicited by color- and form-related words. We used minimum norm current estimates to investigate the spatial location of these differences. This revealed that, at the 150 ms peak, the activation advantage of words over sequences of hash marks was located in a left posterior area, proximal to what has previously been called the visual word form area. At the 200 ms peak, the advantage of words related to colors over words related to forms seemed to reside in temporal cortical areas, whereas the form-related words elicited greater activation in frontal areas than color-related words. These results provide evidence for early access to detailed category-specific representations of word meaning, with subtle differences in meaning being reflected in the activation of different cortical areas, as early as 200 ms after stimulus presentation. In line with previous studies, these differences can be related to the areas involved in the conceptual processing of sensory (visual) and action-related information.

Partial knowledge of word meanings: thematic and taxonomic representations.

The type of information (taxonomic or thematic) available at different levels of knowledge was investigated. Following extensive norming to identify taxonomic and thematic associates of low-frequency nouns, participants determined if taxonomic or thematic associates were meaningfully related to target words at three levels of knowledge: target words they correctly defined (known), recognized as familiar (frontier), or mistakenly denied as part of the language (unknown). In another experiment, participants reported which type of relationship (taxonomic or thematic) was preferred. Results indicated that both types of information were available at all levels of knowledge. However, accuracy and preference were greater for taxonomic associates across word levels. A differential increase in available thematic information relative to taxonomic information was found. Implications for the acquisition and representation of word meanings are discussed.

Modelling the effects of semantic ambiguity in word recognition

Most words in English are ambiguous between different interpretations; words can mean different things in different contexts. We investigate the implications of different types of semantic ambiguity for connectionist models of word recognition. We present a model in which there is competition to activate distributed semantic representations. The model performs well on the task of retrieving the different meanings of ambiguous words, and is able to simulate data reported by Rodd, Gaskell, and Marslen-Wilson [J. Mem. Lang. 46 (2002) 245] on how semantic ambiguity affects lexical decision performance. In particular, the network shows a disadvantage for words with multiple unrelated meanings (e.g., bark) that coexists with a benefit for words with multiple related word senses (e.g., twist). The ambiguity disadvantage arises because of interference between the different meanings, while the sense benefit arises because of differences in the structure of the attractor basins formed during learning. Words with few senses develop deep, narrow attractor basins, while words with many senses develop shallow, broad basins. We conclude that the mental representations of word meanings can be modelled as stable states within a high-dimensional semantic space, and that variations in the meanings of words shape the landscape of this space.

Modelling the effects of semantic ambiguity in word recognition

AbstractMost words in English are ambiguous between different interpretations; words can mean different things in different contexts. We investigate the implications of different types of semantic ambiguity for connectionist models of word recognition. We present a model in which there is competition to activate distributed semantic representations. The model performs well on the task of retrieving the different meanings of ambiguous words, and is able to simulate data reported by Rodd, Gaskell, and Marslen‐Wilson [J. Mem. Lang. 46 (2002) 245] on how semantic ambiguity affects lexical decision performance. In particular, the network shows a disadvantage forwords with multiple unrelated meanings (e.g., bark) that coexists with a benefit for words with multiple related word senses (e.g., twist). The ambiguity disadvantage arises because of interference between the different meanings, while the sense benefit arises because of differences in the structure of the attractor basins formed during learning. Words with few senses develop deep, narrow attractor basins, while words with many senses develop shallow, broad basins. We conclude that the mental representations of word meanings can be modelled as stable states within a high‐dimensional semantic space, and that variations in the meanings of words shape the landscape of this space.

Number-of-features effects and semantic processing.

Participants list many semantic features for some concrete nouns (e.g., lion) and fewer for others (e.g., lime; McRae, de Sa, & Seidenberg, 1997). Pexman, Lupker, and Hino (2002) reported faster lexical decision and naming responses for high number of features (NOF) words than for low-NOF words. In the present research, we investigated the impact of NOF on semantic processing. We observed NOF effects in a self-paced reading task when prior context was not congruent with the target word (Experiment 1) and in a semantic categorization task (concrete vs. abstract; Experiment 2A). When we narrowed our stimuli to include high- and low-NOF words from a single category (birds), we found substantial NOF effects that were modulated by the specificity of the categorization task (Experiments 3A, 3B, and 3C). We argue that these results provide support for distributed representation of word meaning.

Semantic Representations of Word Meanings by the Cerebral Hemispheres

Two priming experiments investigated kind and strength of semantic knowledge underlying known, frontier, and unknown low frequency words. Results from Experiment 1 suggest that known words reflect categorical knowledge, but frontier and unknown words reflect thematic knowledge. Thematic knowledge for frontier words appears to be stronger than that for unknown words. Experiment 2 entailed visual half-field presentation of targets. All facilitory effects were restricted to the lvf/RH, and inhibitory effects to the rvf/LH. Experiment 1 findings were mirrored by the RH. Thematic knowledge appears to precede categorical knowledge for the RH, but the opposite may be true of the LH . Results are also discussed in terms of the RH role in meaning acquisition and metacontrol.

Noun imageability and the temporal lobes

We used positron emission tomography to investigate brain activity in response to hearing or reading nouns of varying imageability. Three experiments were performed. Activity increased with noun imageability in the left mid-fusiform gyrus, the lateral parahippocampal area in humans, and in the rostral medial temporal lobes close to or within perirhinal cortex. The left mid-fusiform activation has been observed in previous imaging studies of single word processing. Its functional significance was variously attributed to semantic processing, visual imagery, encoding episodic memories, or the integration of lexical inputs from different sensory modalities. These hypotheses are not mutually exclusive. The more rostral medial lobe response to noun imageability has not been observed previously. However, lesions in perirhinal cortex impair knowledge about objects in non-human primates, and bilateral rostral ventromedial temporal lobe potentials in response to object nouns were observed with human intracranial recordings. Imageable (object) nouns are learnt with reference to sensory experiences of living and non-living objects, whereas acquisition of the meaning of low imageable (abstract) nouns is more dependent on their context within sentences. Parahippocampal and perirhinal cortices are reciprocally connected with, respectively, second and third order sensory association cortices. We conclude that access to the representations of word meaning is dependent on heteromodal temporal lobe cortex, and that during the acquisition of object nouns one route is established through ventromedial temporal cortical regions that have reciprocal connections with all sensory association cortices.

An Attractor Model of Lexical Conceptual Processing: Simulating Semantic Priming

An attractor network was trained to compute from word form to semantic representations that were based on subject‐generated features. The model was driven largely by higher‐order semantic structure. The network simulated two recent experiments that employed items included in its training set (McRae and Boisvert, 1998). In Simulation 1, short stimulus onset asynchrony priming was demonstrated for semantically similar items. Simulation 2 reproduced subtle effects obtained by varying degree of similarity. Two predictions from the model were then tested on human subjects. In Simulation 3 and Experiment 1, the items from Simulation 1 were reversed, and both the network and subjects showed minimally different priming effects in the two directions. In Experiment 2, consistent with attractor networks but contrary to a key aspect of hierarchical spreading activation accounts priming was determined by featural similarity rather than shared superordinate category. It is concluded that semantic‐similarity priming is due to featural overlap that is a natural consequence of distributed representations of word meaning.

An attractor model of lexical conceptual processing: simulating semantic priming

An attractor network was trained to compute from word form to semantic representations that were based on subject-generated features. The model was driven largely by higher-order semantic structure. The network simulated two recent experiments that employed items included in its training set (McRae and Boisvert, 1998). In Simulation 1, short stimulus onset asynchrony priming was demonstrated for semantically similar items. Simulation 2 reproduced subtle effects obtained by varying degree of similarity. Two predictions from the model were then tested on human subjects. In Simulation 3 and Experiment 1, the items from Simulation 1 were reversed, and both the network and subjects showed minimally different priming effects in the two directions. In Experiment 2, consistent with attractor networks but contrary to a key aspect of hierarchical spreading activation accounts priming was determined by featural similarity rather than shared superordinate category. It is concluded that semantic-similarity priming is due to featural overlap that is a natural consequence of distributed representations of word meaning.

Tutorials in bilingualism: Psycholinguistic perspectives Ed. by Annette M.B. de Groot and Judith F. Kroll (review)

BOOK NOTICES 199 morphology (reminiscent ofe.g. Tagalog) as a mechanism serving to identify a subject as having reached SpecIP/SpecAgrP as a result of diathetic change. In other words, Austronesian focus morphology is a type of agreement morphology. If the traditional view that voice in IE languages is similar to Austronesian focus is correct, H's analysis of Seediq focus may have relevance for the analysis of IE languages as well. H's guiding pnnciple is to test generative theory on its explanatory power and its capacity to describe Seediq simply and economically. If it fails the test, it is rejected: In Ch. 5, H argues that an antisymmetric minimalist analysis of Seediq syntax is 'at best unnecessarily complex, and at worst misleading' (106). Instead, Seediq syntax is described with a list ofwellmotivated principles and parameters, but against traditional PP theory, H argues that Case-marking within the VP is language-specific; that subject movement is not conditioned by Case-requirements but rather by the principle that each clause must have a subject, which in turn implies that there is movement from one Case-position to another. In Ch. 6 H proposes a morphological model in which the itemand -arrangement model is adapted and combined with a theory of markedness. This system accounts for the mixture of simple and portmanteau affixes in Seediq verbal morphology and explains its irregularities Seediq (morpho-) phonology is analyzed in Ch 7 using the insights of prosodie morphology and autosegmental phonology. As its title indicates, this book is not a reference grammar. For one thing, the Seediq material that is presented is not very rich: it is always part of the analytical argument so illustrations are only given when necessary, and they are often minimally different . However, this should not be taken to mean that the book is too theory-specific to be of interest to a general public of linguists, because it really does inform us about the unique properties of Seediq. Moreover , H's crisp style and transparent exposition make the book read like a novel. [Marian Klamer, Vrije Universiteit Amsterdam.] Tutorials in bilingualism: Psycholinguistic perspectives. Ed. by Annette M.B. de Groot and Judith F. Kroll. Mahwah, NJ: Lawrence Erlbaum, 1997. Pp. viii, 372. This book offers twelve tutorial reviews on topics in the study of bilingualism from the psychological perspective. The first four chapters (19-142) are grouped under the heading 'second language acquisition ' . Birgit Harley and Wenxia Wang analyze the critical period hypothesis and review the evidence and explanations of age-related effects on first and second language acquisition. Nick C. Ellis and Nadine Laporte concern themselves with questions about the distinction between implicit and explicit learning and teaching of second languages; for each question, they review the relevant theories and evidence from field and laboratory studies. Norman Segalowitz draws together theories and evidence from applied linguistics, cognitive psychology, and neuropsychology in his quest for an account of individual differences in ultimate attainment among second-language learners. Brian MacWhinney expounds on his empincist view on language acquisition and how his computationally-implementable competition model explains language transfer phenomena . The competition model is often hailed as a framework that allows a unified treatment of acquisition and processing issues, so this chapter serves as a bridge between the above chapters on acquisition and the following group of five chapters (145-276) on bilingual language processing, the editors' own area of specialization. Marii yn Chapnik Smith tackles the one-lexiconor -two question about the storage of word forms in bilinguals; she also reviews the evidence for separate representations of word form and meaning in monolinguals and for the existence of an orthographic lexicon in readers of shallow orthographies. The editors co-author a chapter where they first summarize the evidence for, and the challenges to, the 'revised hierarchical model' of bilingual memory and then sketch a new model which posits an additional intermediate lemma level and admits distributed representations at both the meaning and word form levels. Nanda Poulisse compares how various proposed models of bilingual language production account for the characteristic behavioral differences between first- and second-language production François Grosjean writes about the psycholinguistics of language mixing ; he discusses...

The Time Course of Activation of Semantic Information during Spoken Word Recognition

We investigated the time course of activation of the mental representations of word meanings in a series of three cross-modal priming experiments. In Experiment 1, we showed a significant priming effect for semantically related targets presented at the “isolation point” of the prime word, confirming earlier evidence for the activation of multiple word meanings before the point at which a word can be recognised. The use of non-associated prime-target materials ruled out the possibility that this could be an artifact of form-based associative priming. Experiment 2 demonstrated that certain semantic properties are made available more rapidly than others in the duration of a spoken word and, specifically, that for words referring to man-made objects, information about their function and design is activated more quickly than information about their physical form. However, this experiment did not reveal any limit on the activation of a word's meaning as a function of the number of simultaneously activated competitor candidates. Finally, Experiment 3 showed that the results of the first two experiments could not be explained in terms of backwards priming from target to prime. We interpret the data with respect to both localist and distributed implementations of the cohort model.

On the nature and scope of featural representations of word meaning.

On the nature and scope of featural representations of word meaning.

On the nature and scope of featural representations of word meaning.

Behavioral experiments and a connectionist model were used to explore the use of featural representations in the computation of word meaning. The research focused on the role of correlations among features, and differences between speeded and untimed tasks with respect to the use of featural information. The results indicate that featural representations are used in the initial computation of word meaning (as in an attractor network), patterns of feature correlations differ between artifacts and living things, and the degree to which features are intercorrelated plays an important role in the organization of semantic memory. The studies also suggest that it may be possible to predict semantic priming effects from independently motivated featural theories of semantic relatedness. Implications for related behavioral phenomena such as the semantic impairments associated with Alzheimer's disease (AD) are discussed.

Possible names: The role of syntax-semantics mappings in the acquisition of nominals

Many scholars have posited constraints on how children construe the meaning of new words. These include the restriction that new words refer to kinds of whole objects (Markman and Hutchinson 1984), that words describing solid objects refer to individual objects while words describing non-solid substances refer to portions of substance (Soja et al. 1991), and that count nouns that name objects are generalized on the basis of shape (Landau et al. 1988). There are theoretical and empirical problems with these proposals, however. Most importantly, they fail to explain the fact that children rapidly acquire words that violate these contraints, such as pronouns and proper names, names for substances, and names for non-material entities. The theory defended here is that children and adults possess mappings from grammatical categories (‘count noun’, ‘mass noun’, and ‘noun phrase’) to abstract semantic categories; these mappings serve to constrain inferences about word meaning. Evidence from developmental psychology and linguistic theory is presented that suggests that even very young children possess such mappings and use them in the course of lexical development. Further issues — such as the possibility of developmental change, the precise nature of these semantic categories, and how children learn words prior to the acquisition of syntax — are also discussed. It is concluded that although these syntax-semantics mappings are not by themselves sufficient to explain children's success at word learning, they play a crucial role in lexical development. As such, only a theory that posits a deep relationship between syntax and semantics can explain the acquisition and representation of word meanings.

Developmental changes in the representation of word meaning: Cross‐cultural findings

This study examined semantic and conceptual development among three socio‐economic groups in western Nigeria: rural, urban and ilite. The sociocultural and material conditions typifying each group were hypothesized to be associated with different patterns of conceptual change. All three groups demonstrated a developmental shift in the representation of word meaning, from representations based more on characteristic features, to those based more on defining features. However, the patterns of development differed across groups. The rural group had the most marked shift and the urban group the least. The differences in developmental patterns were interpreted as reflecting specific aspects of each group's sociocultural milieu.

Lexicographical Metaphor

LEXICOGRAPHICAL METAPHOR VINCENT DAVID REGAN Modern lexicographical practice works to describe semantically , syntactically, and succinctly a native understanding of individual words and multi-word lexical units. Dictionary definitions follow any of several methods of treatment: analytic , synthetic, functional, or synonymous. Whichever treatment or combination of treatments is brought to articulate a word's definition, the guiding principle is objectively and descriptively bound, as opposed to being subjectively and prescriptively founded. Effectively, such a logical, objective system attempts to filter out as much human interference as possible by regarding the world from an impartial or "God's eye" perspective. This insures a fair representation, nondiscriminatory and unbiased, of lexical reality. In an unreal, totally abstract world, perhaps. But we must in common sense acknowledge the human factor with experientially based explications . It would seem that, if there were a philosophical paradox in the make-up of dictionary definitions, the path to its resolution would not involve metaphorical language usage. After all, metaphor has long been ignored in both linguistic and lexicographical theory and only superficially appreciated in literary theory. It has generally been regarded as a nonliteral use of language, i.e., figurative or poetic language. LakofF and Johnson introduced their penetrating study of metaphor by noting that it traditionally was understood as a "rhetorical flourish," constituting "extraordinary rather than ordinary language" (3). And this orientation seems doomed to 2 Vincent David Regan contrived manifestations on the dictionary page. It would be hardly conducive to objective lexicographical analyses. Metaphoric representations of word meaning would be all too susceptible to inexact, variable, and emotional findings. At issue here first is the overriding and all-pervasive scientistic infatuation with objective notions and, concomitantly, the abhorrence and avoidance of unempirical subjective conclusions . Such a theoretical dichotomy presented to the writer of dictionary definitions is simplistic at best and, at worst, unrealistic and fallacious. Missing from this philosophical framework is the role of a third possibility, which transcends the false duality of "either/or" constructs—the very human experiential notions initially mentioned at the end of the first paragraph. This article will be promoting just this experiential tack to the composition and understanding of lexicographical definitions , though ironically such an approach is presently extant in all dictionaries and has ever been so. Whereas the thrust herein will advance the conscious manipulation of metaphor for lexical interpretation, in fact the very nature of language is such that unconsciously language users, including lexicographers, have always worked metaphorically to explain the world. The conceptual system that underlies a language effectively controls the substance and scope of that language's constituent parts. This system is largely imperceptible because the medium for its explanation is that which in itself entails the problem. In effect, language cannot serve to explicate language because language use is problematic by the nature of the very vehicle that disseminates itself. Simply put, the way we conceptualize the world works mentally outside the domain of language and within that of experiential, sociocultural activity. One's conceptual system plays a cen- Lexicographical Metaphor3 tral role in defining everyday reality, and it usually is not something conscious, but rather automatic. Our most reliable evidence for the system's existence is, oddly enough, linguistic and lexical despite the fact that language is the only amenable medium to be used in contriving an understanding of both the medium and its contents, language . Insofar as language is controlled by its users, who are unaware of how it works (people take language for granted), and inasmuch as metaphor is omnipresent in language (literally , not figuratively), our language is structured in large part metaphorically. At a deeper level, as the language is, so also our thoughts and actions are structured. While this presupposes an alinguistic source for our thinking ability, it renders by and large our thinking a relatively automatic phenomenon. Unconsciously it proceeds, instigating metaphorical reflexes to our understanding of reality. "The essence of metaphor is understanding and experiencing one kind of thing in terms of another" (Lakoff and Johnson 5). Structurally complex or superficial, metaphorical concepts are systematic and prioritized to the mainstream culture of the speaker's language. They derive orientationally or ontologically from primal human body functioning in the...

The conceptual basis for referential word meaning in children with autism.

The purpose of this study was to examine the nature of the representation of substantive word meanings in children with autism. The subjects included 3 groups of autistic, mentally retarded, and normal children, who were matched on verbal mental age. The subjects participated in 2 experiments investigating their comprehension of words for basic level and superordinate level categories. The 3 groups were equivalent in their performance in both experiments. They also showed the same patterns of overextension and underextension errors that were related to a prototype representation of the underlying concepts. These findings suggest that semantic knowledge for concrete objects is represented and organized in similar ways in autistic, retarded, and normal children and that previous findings on cognitive deficits in autistic children are more likely related to their inability to use cognitive representations in an appropriate and flexible manner.

Mental models of word meaning

Four experiments compared five alternative mental models of word meaning: a defining-attributes model, two characteristic-attribute models, and two mixed models. The two characteristic-attribute models (and the two mixed models) differed from each other in terms of whether weights of attributes were summed or averaged. In Experiment 1, 11 subjects provided lists of attributes for 24 different nouns. Subjects also rated the necessity, sufficiency, and importance of each attribute to a given word's definition. Results showed that both defining (necessary and sufficient) and characteristic attributes could be identified from subjects' ratings for most nouns, but that the role of defining attributes was especially pronounced for proper names. In Experiment 2, the same subjects later rated the extent to which given lists of attributes successfully described referents of each given word. Mathematical modeling of results supported a mixed model of reference based on defining attributes plus the weighted sum of all attributes (defining and characteristic). Experiment 3 replicated the results of Experiment 1 with 25 new subjects and slightly modified procedures. In Experiment 4, 32 subjects were presented with two alternative attribute lists for each given word, and were to select the better referent of the word as quickly as possible. The preferred mixed model from Experiment 2 was shown best to account for both the mental representation and real-time processing of word meanings.