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 non phonological 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.

the properties of distributed network models, and support this account by demonstrating that an implemented simulation closely approximates the empirical findings despite the absence of expectancy-based processes and postlexical semantic matching. The results suggest that distributed network models can provide a viable single-mechanism account of lexical processing. Introduction It is well-established that people are faster and more accurate to read a word (e.g., BUTTER) when it is preceded by a related word (e.g., BREAD) compared with when it is preceded by an unrelated word (e.g., DOCTOR; The research was supported by an NIMH FIRST award (MH55628) to the first author and by NIMH Training Grant 5T32MH19102 and NICHD Grant 80258. The computational simulation was run using customized software written within the Xerion simulator (version 3.1) developed by Drew van Camp, Tony Plate, and Geoff Hinton at the Univers

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.

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We present a new model for lexical decision, REM-LD, that is based on REM theory (e.g., Shiffrin & Steyvers, 1997). REM-LD uses a principled (i.e., Bayes' rule) decision process that simultaneously considers the diagnosticity of the evidence for the #WORD# response and the #NONWORD# response. The model calculates the odds ratio that the presented stimulus is a word or a nonword by averaging likelihood ratios for lexical entries from a small neighborhood of similar words. We report two experiments that used a signal-to-respond paradigm to obtain information about the time course of lexical processing. Experiment 1 verified the prediction of the model that the frequency of the word stimuli affects performance for nonword

Four experiments investigated potential influences of spelling on single word speech production. A form-preparation paradigm that showed priming effects for words with initial form overlap was used to investigate whether words with form overlap, but different spelling (e.g., "camel"-"kidney") also show priming. Experiment 1 demonstrated that such words did not benefit from the form overlap, suggesting that the incongruent spelling disrupted the form-preparation effect. Experiment 2 replicated the first experiment with an independent set of items and an improved design, and once again showed a disruptive effect of spelling. To divert participants' attention from the spelling of the targets, Experiment 3 was conducted entirely in the auditory domain, but yielded the same outcome as before. Experiment 4 showed that matching initial letters alone, in the absence of matching sounds (e.g., "cycle"-"cobra"), did not produce priming. These findings raise the possibility that orthographic codes are mandatorily activated in speech production by literate speakers.

A property of distributed representations is that related information is coded as overlapping patterns of activation over the same set of units and learning associated with one item extends to related items. Accordingly, the null (or near null) long-term priming observed between form-related words seems to pose a challenge to connectionist theories of reading that include distributed codes. In the present report, priming was assessed in a behavioral study and a computer simulation using Seidenberg and McClelland’s (1989) distributed model of word identification. Contrary to our expectation, both the behavioral and simulation studies obtained robust repetition and little form priming. Furthermore, analysis of the model’s performance revealed that the lack of form priming was the product of collapsing facilitatory effects between rhymes (mint–hint) and inhibitory effects between nonrhymes (pint–hint). A second behavioral experiment confirmed this prediction. A number of additional long-term priming results were also successfully modeled.

The contribution of assembled phonology in reading English was examined in the lexical decision task by comparing two markers: regularity effects and phonological priming. Strategic control was assessed by manipulating the phonological lexicality of the foils: Experiment 1 used legal nonwords, whereas Experiment 2 used pseudohomophones. Replicating existing findings, null regularity effects were obtained in the presence of legal nonwords. Modest regularity effects, in accuracy only, were observed with pseudohomophone foils. In contrast, phonological priming effects emerged in each of the experiments, regardless of the presence of regularity effects. Assembled phonology thus constrains reading under conditions that strongly discourage its use. However, regularity effects are not necessary evidence for its presence. The dissociation of regularity and phonological priming effects is discussed in terms of the two-cycles model. Dual-route models of visual word recognition (e.g., Baron

this paper cast doubts on the existence of reciprocal constraints between orthography and phonology at prelexical stages of processing. Although the absence of a clear FB consistency effect in French might be explained by crosslinguistic differences and task specific decision strategies, additional studies are needed to ascertain the validity and generality of the phenomenon

Does phonology play a role in silent reading? This issue was addressed in Chinese. Phonology effects are less expected in Chinese than in alphabetical languages like English because the basic units of written Chinese (the characters) map directly into units of meaning (morphemes). This linguistic property gave rise to the view that phonology could be bypassed altogether in Chinese. The present study, however, shows that this is not the case. We report two experiments that demonstrate pure phonological frequency effects in processing written Chinese. Characters with a high phonological frequency were processed faster than characters with a low phonological frequency, despite the fact that the characters were matched on orthographic (printed) frequency. The present research points to a universal phonological principle according to which phonological information is routinely activated as a part of word identification. The research further suggests that part of the classic word-frequency effect may be phonological.