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.

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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.

The development of reading depends on phonological awareness across all languages so far studied. Languages vary in the consistency with which phonology is represented in orthography. This results in developmental differences in the grain size of lexical representations and accompanying differences in developmental reading strategies and the manifestation of dyslexia across orthographies. Differences in lexical representations and reading across languages leave developmental “footprints ” in the adult lexicon. The lexical organization and processing strategies that are characteristic of skilled reading in different orthographies are affected by different developmental constraints in different writing systems. The authors develop a novel theoretical framework to explain these cross-language data, which they label a psycholinguistic grain size theory of reading and its development. Reading is the process of understanding speech written down. The goal is to gain access to meaning. To acquire reading, children must learn the code used by their culture for representing speech as a series of visual symbols. Learning to read is thus fundamentally a process of matching distinctive visual symbols to units of sound (phonology). In most languages, the relationship between symbol

A connectionist model of reading development previously used to simulate detailed aspects of developmental dyslexia (Harm & Seidenberg, 1999) was used to explore why certain classes of interventions designed to overcome reading impairments are more effective than others. Previous research has shown that interventions targeting the development of spelling–sound correspondences are more effective at promoting generalization skills than ones designed solely to increase phonological awareness. The simulations broadly replicate the patterns of success and failure found in the developmental literature and provide explicit computational insights into exactly why the interventions that include training on spelling–sound regularities are more effective than those targeting phonological development alone. The number of studies of interventions targeting developmental reading impairments is growing at a rapid rate (see Bus & Ijzendoorn, 1999, for a recent review). Such studies typically involve testing one or more interventions with children; outcome measures indicate the relative strengths and weaknesses of the different interventions being considered. The benefits of such work are obvious: They give direct evidence for which of the tested interventions provide a more effective use of time and resources for the particular population of children studied. The difficulty is that

This thesis describes HABLAR, a computational model of the sensorimotor foundations of early childhood phonological development. HABLAR (an acronym for "Hierarchical Articulatory Based Language Acquisition by Reinforcement learning" and Spanish for "to speak") is intended to replicate the major milestones of emerging speech and demonstrate key characteristics of normal development, including the phonetic characteristics of babble, systematic and context-sensitive patterns of sound substitutions and deletions, overgeneralization errors, and the emergence of adult phonemic organization. It should also mimic abnormal phonological development under certain conditions of damage or degradation. HABLAR simulates a complete sensorimotor system consisting of an auditory system that detects and categorizes speech sounds using only acoustic cues drawn from its linguistic environment, an articulatory system that generates synthetic speech based on a realistic computer model of the vocal tract, an...

In this paper, we make a fundamental distinction between literacy attainment scores and the actual process of learning to read, and examine these two aspects of reading in atypical development. Reading skills in a group of children and adults with the genetic disorder Williams syndrome (WS) were compared to a group of typically developing children matched for reading age and receptive vocabulary scores. Study 1 focused on the product of reading and explored the relationship between reading, general cognition, and phonological skills. Phonological skills were shown to be related to individual differences in reading attainment in both groups, although more weakly in the WS group. Experiment 2 examined the process of learning to read. The two groups were taught to associate abbreviated spellings (cues) with spoken words. The cues differed in their phonetic closeness to the target words, whereas the target words differed on the semantic variable of imageability. Compared to controls, the WS group showed slower learning, less sensitivity to the phonetic quality of the cue, and reduced influence from the imageability of words. The results support the hypothesis that although reading levels in WS depend on phonological skills, the full development of their reading is compromised by weak semantics. The studies highlight the importance in atypical populations of examining both reading levels and the actual process of learning to read.

Word recognition develops with such remarkable speed that, by the end of eighth grade, we expect children learning to read English to know and recognize over 80,000 words (Adams, 1990). At a basic level, beginning readers must establish a system of mappings or correspondences between the letters or graphemes of written words and the phonemes of spoken words (Ehri, 1992), and it is generally thought that this alphabetic decoding system is underpinned by phonological skills (Brady & Shankweiler, 1991; Byrne, 1998; Goswami & Bryant, 1990). To become an accurate and efficient reader of the English language, however, children need to do more than assemble or decode pronunciations on the basis of spelling-sound mappings. They need to acquire a rapid and flexible word-recognition system that embodies knowledge of both the regularities and the irregularities of the English orthography. While it is clear that the development of skilled word recognition requires more than the mastery of alphabetic decoding, we know very little about

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This article proposes that visual encoding learning improves reading fluency by widening the span over which letters are recognized from a fixated text image so that fewer fixations are needed to cover a text line. Encoder is a connectionist model that learns to convert images like the fixated text images human readers encode into the corresponding letter sequences. The computational theory of classification learning predicts that fixated text-image size makes this learning difficult but that reducing image variability and biasing learning should help. Encoder confirms these predictions. It fails to learn as image size increases but achieves humanlike visual encoding accuracy when image variability is reduced by regularities in fixation positions and letter sequences and when learning is biased to discover mapping functions based on the sequential, componential structure of text. After training, Encoder exhibits many humanlike text familiarity effects