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M S Seidenberg

Publications and source records attributed to M S Seidenberg.

At least 19 recordsLinked to original sources

How psychological science informs the teaching of reading.

This monograph discusses research, theory, and practice relevant to how children learn to read English. After an initial overview of writing systems, the discussion summarizes research from developmental psychology on children's language competency when they enter school and on the nature of early reading development. Subsequent sections review theories of learning to read, the characteristics of children who do not learn to read (i.e., who have developmental dyslexia), research from cognitive psychology and cognitive neuroscience on skilled reading, and connectionist models of learning to read. The implications of the research findings for learning to read and teaching reading are discussed. Next, the primary methods used to teach reading (phonics and whole language) are summarized. The final section reviews laboratory and classroom studies on teaching reading. From these different sources of evidence, two inescapable conclusions emerge: (a) Mastering the alphabetic principle (that written symbols are associated with phonemes) is essential to becoming proficient in the skill of reading, and (b) methods that teach this principle directly are more effective than those that do not (especially for children who are at risk in some way for having difficulty learning to read). Using whole-language activities to supplement phonics instruction does help make reading fun and meaningful for children, but ultimately, phonics instruction is critically important because it helps beginning readers understand the alphabetic principle and learn new words. Thus, elementary-school teachers who make the alphabetic principle explicit are most effective in helping their students become skilled, independent readers.

Cerebral Cortex↗

Language deficits in dyslexic children: speech perception, phonology, and morphology.

We investigated the relationship between dyslexia and three aspects of language: speech perception, phonology, and morphology. Reading and language tasks were administered to dyslexics aged 8-9 years and to two normal reader groups (age-matched and reading-level matched). Three dyslexic groups were identified: phonological dyslexics (PD), developmentally language impaired (LI), and globally delayed (delay-type dyslexics). The LI and PD groups exhibited similar patterns of reading impairment, attributed to low phonological skills. However, only the LI group showed clear speech perception deficits, suggesting that such deficits affect only a subset of dyslexics. Results also indicated phonological impairments in children whose speech perception was normal. Both the LI and the PD groups showed inflectional morphology difficulties, with the impairment being more severe in the LI group. The delay group's reading and language skills closely matched those of younger normal readers, suggesting these children had a general delay in reading and language skills, rather than a specific phonological impairment. The results are discussed in terms of models of word recognition and dyslexia.

Awareness↗

Impairments in verb morphology after brain injury: a connectionist model.

The formation of the past tense of verbs in English has been the focus of the debate concerning connectionist vs. symbolic accounts of language. Brain-injured patients differ with respect to whether they are more impaired in generating irregular past tenses (TAKE-TOOK) or past tenses for nonce verbs (WUG-WUGGED). Such dissociations have been taken as evidence for distinct "rule" and "associative" memory systems in morphology and against the connectionist approach in which a single system is used for all forms. We describe a simulation model in which these impairments arise from damage to phonological or semantic information, which have different effects on generalization and irregular forms, respectively. The results provide an account of the bases of impairments in verb morphology and show that these impairments can be explained within connectionist models that do not use rules or a separate mechanism for exceptions.

Brain Injuries↗

Phonology, reading acquisition, and dyslexia: insights from connectionist models.

The development of reading skill and bases of developmental dyslexia were explored using connectionist models. Four issues were examined: the acquisition of phonological knowledge prior to reading, how this knowledge facilitates learning to read, phonological and nonphonological bases of dyslexia, and effects of literacy on phonological representation. Compared with simple feedforward networks, representing phonological knowledge in an attractor network yielded improved learning and generalization. Phonological and surface forms of developmental dyslexia, which are usually attributed to impairments in distinct lexical and nonlexical processing "routes," were derived from different types of damage to the network. The results provide a computationally explicit account of many aspects of reading acquisition using connectionist principles.

Child↗

Category-specific semantic deficits in focal and widespread brain damage: a computational account.

Category-specific semantic impairments have been explained in terms of preferential damage to different types of features (e.g., perceptual vs. functional). This account is compatible with cases in which the impairments were the result of relatively focal lesions, as in herpes encephalitis. Recently, however, there have been reports of category-specific impairments associated with Alzheimer's disease, in which there is more widespread, patchy damage. We present experiments with a connectionist model that show how "category-specific" impairments can arise in cases of both localized and widespread damage; in this model, types of features are topographically organized, but specific categories are not. These effects mainly depend on differences between categories in the distribution of correlated features. The model's predictions about degree of impairment on natural kinds and artifacts over the course of semantic deterioration are shown to be consistent with existing patient data. The model shows how the probabilistic nature of damage in Alzheimer's disease interacts with the structure of semantic memory to yield different patterns of impairment between patients and categories over time.

Alzheimer Disease↗

Language acquisition and use: learning and applying probabilistic constraints.

What kinds of knowledge underlie the use of language and how is this knowledge acquired? Linguists equate knowing a language with knowing a grammar. Classic "poverty of the stimulus" arguments suggest that grammar identification is an intractable inductive problem and that acquisition is possible only because children possess innate knowledge of grammatical structure. An alternative view is emerging from studies of statistical and probabilistic aspects of language, connectionist models, and the learning capacities of infants. This approach emphasizes continuity between how language is acquired and how it is used. It retains the idea that innate capacities constrain language learning, but calls into question whether they include knowledge of grammatical structure.

Adult↗

Double dissociation of semantic categories in Alzheimer's disease.

Data that demonstrate distinct patterns of semantic impairment in Alzheimer's disease (AD) are presented. Findings suggest that while groups of mild-moderate patients may not display category specific impairments, some individual patients do show selective impairment of either natural kinds or artifacts. We present a model of semantic organization in which category specific impairments arise from damage to distributed features underlying different types of categories. We incorporate the crucial notions of intercorrelations and distinguishing features, allowing us to demonstrate (1) how category specific impairments can result from widespread damage and (2) how selective deficits in AD reflect different points in the progression of impairment. The different patterns of impairment arise from an interaction between the nature of the semantic categories and the progression of damage.

Aged↗

Are speech perception deficits associated with developmental dyslexia?

Phonological awareness and phoneme identification tasks were administered to dyslexic children and both chronological age (CA) and reading-level (RL) comparison groups. Dyslexic children showed less sharply defined categorical perception of a bath-path continuum varying voice onset time when compared to the CA but not the RL group. The dyslexic children were divided into two subgroups based on phoneme awareness. Dyslexics with low phonemic awareness made poorer /b/-/p/ distinctions than both CA and RL groups, but dyslexics with normal phonemic awareness did not. Examination of individual profiles revealed that the majority of subjects in each group exhibited normal categorical perception. However, 7 of 25 dyslexics had abnormal identification functions, compared to 1 subject in the CA group and 3 in the RL group. The results suggest that some dyslexic children have a perceptual deficit that may interfere with processing of phonological information. Speech perception difficulties may also be partially related to reading experience.

Child↗

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.

Adult↗

On the bases of two subtypes of developmental [corrected] dyslexia.

This study examined whether there are different subtypes of developmental dyslexia. The subjects were 51 dyslexic children (reading below the 30th percentile in isolated word recognition), 51 age-matched normal readers, and 27 younger normal readers who scored in the same range as the dyslexics on word recognition. Using methods developed by Castles and Coltheart (1993), we identified two subgroups who fit the profiles commonly termed "surface" and "phonological" dyslexia. Surface subjects were relatively poorer in reading exception words compared to nonwords; phonological dyslexics showed the opposite pattern. However, most dyslexics were impaired on reading both exception words and nonwords compared to same-aged normal readers. Whereas the surface dyslexics' performance was very similar to that of younger normal readers, the phonological dyslexics' was not. The two dyslexic groups also exhibited a double dissociation on two validation tasks: surface subjects were impaired on a task involving orthographic knowledge but not one involving phonology; phonological dyslexics showed the opposite pattern. The data support the conclusion that there are at least two subtypes of developmental dyslexia. Although these patterns have been taken as evidence for the dual-route model, we provide an alternative account of them within the Seidenberg and McClelland (1989) connectionist model. The connectionist model accounts for why dyslexics tend to be impaired on both exception words and nonwords; it also suggests that the subtypes may arise from multiple underlying deficits. We conclude that performance on exception words and nonwords is not sufficient to identify the basis of dyslexic behavior; rather, information about children's performance on other tasks, their remediation experiences, and the computational mechanisms that give rise to impairments must be taken into account as well.

Child↗

Pseudohomophone effects and models of word recognition.

Two experiments examined factors that influence the processing of pseudohomophones (nonwords such as brone or joap, which sound like words) and nonpseudohomophones (such as brone and joap, which do not sound like words). In Experiment 1, pseudohomophones yielded faster naming latencies and slower lexical-decision latencies than did nonpseudohomophones, replicating results of R. S. McCann and D. Besner (1987) and R. S. McCann, D. Besner, and E. Davelaar (1988). The magnitude of the effect was related to subjects' speed in lexical decision but not naming. In Experiment 2, both immediate and delayed naming conditions were used. There was again a significant pseudohomophone effect that did not change in magnitude across conditions. These results indicate that pseudohomophone effects in the lexical-decision and naming tasks have different bases. In lexical decision, they reflect the pseudohomophone's activation of phonological and semantic information associated with words. In naming, they reflect differences in ease of articulating familiar versus unfamiliar pronunciations. Implications of these results concerning models of word recognition are discussed, focusing on how pseudohomophone effects can arise within models that do not incorporate word-specific representations, such as the M. S. Seidenberg and J. L. McClelland (1989) model.

Humans↗

Understanding normal and impaired word reading: computational principles in quasi-regular domains.

A connectionist approach to processing in quasi-regular domains, as exemplified by English word reading, is developed. Networks using appropriately structured orthographic and phonological representations were trained to read both regular and exception words, and yet were also able to read pronounceable nonwords as well as skilled readers. A mathematical analysis of a simplified system clarifies the close relationship of word frequency and spelling-sound consistency in influencing naming latencies. These insights were verified in subsequent simulations, including an attractor network that accounted for latency data directly in its time to settle on a response. Further analyses of the ability of networks to reproduce data on acquired surface dyslexia support a view of the reading system that incorporates a graded division of labor between semantic and phonological processes, and contrasts in important ways with the standard dual-route account.

Dyslexia↗

Semantic effects in single-word naming.

Three experiments demonstrated that, for lower frequency words, reading aloud is affected not only by spelling-sound typicality but also by a semantic variable, imageability. Participants were slower and more error prone when naming exception words with abstract meanings (e.g., scarce) than when naming either abstract regular words (e.g., scribe) or imageable exception words (e.g., soot). It is proposed that semantic representations of words have the largest impact on translating orthography to phonology when this translation process is slow or noisy (i.e., for low-frequency exceptions) and that words with rich semantic representations (i.e., high-imageability words) are most likely to benefit from this interaction.

Adult↗

Nonword pronunciation and models of word recognition.

Nonword pronunciation is a form of generalization behavior that has been at the center of debates about models of word recognition, the role of rules in explaining behavior, and the adequacy of the parallel distributed processing approach. An experiment yielded data concerning the pronunciation of a large corpus of nonwords. The data were then used to assess 2 models of naming: a model developed by D. C. Plaut and J. L. McClelland (1993), which is similar to the one described by M. S. Seidenberg and J. L. McClelland (1989) but uses improved orthographic and phonological representations, and the grapheme-phoneme correspondence rules of M. Coltheart, B. Curtis, P. Atkins, and M. Haller's (1993) dual-route model. Both models generate plausible nonword pronunciations and match subjects' responses accurately. The dual-route model does so by using rules that generate correct output for most words but mispronounce a significant number of exceptions. The parallel distributed processing model does so by finding a set of weights that allow it to generate correct output for both "rule-governed" items and exceptions. Some ways in which the two approaches differ and other issues facing them are also discussed.

Humans↗

The lexical nature of syntactic ambiguity resolution [corrected].

Ambiguity resolution is a central problem in language comprehension. Lexical and syntactic ambiguities are standardly assumed to involve different types of knowledge representations and be resolved by different mechanisms. An alternative account is provided in which both types of ambiguity derive from aspects of lexical representation and are resolved by the same processing mechanisms. Reinterpreting syntactic ambiguity resolution as a form of lexical ambiguity resolution obviates the need for special parsing principles to account for syntactic interpretation preferences, reconciles a number of apparently conflicting results concerning the roles of lexical and contextual information in sentence processing, explains differences among ambiguities in terms of ease of resolution, and provides a more unified account of language comprehension than was previously available.

Cognition↗

Naming multisyllabic words.

The process of reading multisyllabic words aloud from print was examined in 4 experiments. Experiment 1 used multisyllabic words that vary in terms of the consistency of component spelling-sound correspondences. The stimuli were regular, regular inconsistent, and exception words analogous to the monosyllabic items used in previous studies. Both regular inconsistent and exception words produced longer naming latencies than regular words. In Experiment 2 these differences between word types were found to be limited to lower frequency items. Experiment 3 showed that effects of number of syllables on naming latency are also limited to lower frequency words when the stimulus display forced subjects to use syllabic units. Thus, frequency modulates the effects of two aspects of lexical structure-consistency of spelling-sound correspondences and number of syllables. The results suggest that the naming of multisyllabic words draws on some of the same knowledge representations and processes as monosyllabic words; however, naming does not require syllabic decomposition. The results are discussed in the context of current models of naming.

Adult↗

Context and lexical access: implications of nonword interference for lexical ambiguity resolution.

To eliminate potential "backward" priming effects, Glucksberg, Kreuz, and Rho (1986) introduced a variant of the cross-modal lexical priming task in which subjects made lexical decisions to nonword targets that were modeled on a word related to either the contextually biased or unbiased sense of an ambiguous word. Lexical decisions to nonwords were longer than controls only when the nonword was related to the contextually biased sense of the ambiguous word, leading Glucksberg et al. to conclude that context does constrain lexical access and that the multiple access pattern observed in previous studies was probably an artifact of backward priming. We did not find nonword interference when the nonword targets used by Glucksberg et al. were preceded by semantically related ambiguous or unambiguous word primes. However, we did replicate their sentence context results when the ambiguous words were removed from the sentences. We conclude that the interference obtained by Glucksberg et al. is due to postlexical judgements of the congruence of the sentence context and the target, not to context constraining lexical access.

Adult↗