Learning with sublexical information from emerging reading vocabularies in exceptionally early and normal reading development.

Predictions from theories of the processes of word reading acquisition have rarely been tested against evidence from exceptionally early readers. The theories of Ehri, Share, and Byrne, and an alternative, Knowledge Sources theory, were so tested. The former three theories postulate that full development of context-free letter sounds and awareness of phonemes are required for normal acquisition, while the claim of the alternative is that with or without such, children can use sublexical information from their emerging reading vocabularies to acquire word reading. Results from two independent samples of children aged 3-5, and 5 years, with mean word reading levels of 7 and 9 years respectively, showed underdevelopment of their context-free letter sounds and phoneme awareness, relative to their word reading levels and normal comparison samples. Despite such underdevelopment, these exceptional readers engaged in a form of phonological recoding that enabled pseudoword reading, at the level of older-age normal controls matched on word reading level. Moreover, in the 5-year-old sample further experiments showed that, relative to normal controls, they had a bias toward use of sublexical information from their reading vocabularies for phonological recoding of heterophonic pseudowords with irregular consistent spelling, and were superior in accessing word meanings independently of phonology, although only if the readers were without exposure to explicit phonics. The three theories were less satisfactory than the alternative theory in accounting for the learning of the exceptionally early readers.

The nature of skilled adult reading varies with type of instruction in childhood.

Does the type of reading instruction experienced during the initial years at school have any continuing effect on the ways in which adults read words? The question has arisen in current discussions about computational models of mature word-reading processes. We tested predicted continuing effects by comparing matched samples of skilled adult readers of English who had received explicit phonics instruction in childhood and those who had not. In responding to nonwords that can receive alternative legitimate pronunciations, those adults having childhood phonics instruction used more regular grapheme-phoneme correspondences that were context free and used fewer vocabulary-based contextually dependent correspondences than did adults who had no phonics instruction. These differences in regularization of naming responses also extended to some low-frequency words. This apparent cognitive footprint of childhood phonics instruction is a phenomenon requiring consideration when researchers attempt to model adult word reading and when they select participants to test the models.

The long learning route to abstract letter units.

This is a review of theory and evidence on how abstract letter units (ALUs) are initially learnt by the developing individual. Despite the predominance of the lower-case form of letters in the print environment, naming identification of upper case has precedence over lower case among preschool children. Such children showed a significant lag in extending their categories of upper-case variants to include the corresponding lower-case forms that are visually dissimilar. As late as 11 years of age children gave longer naming latencies for the lower-case than the upper-case forms. Initial learning of ALUs proceeded slowly over many months, consistent with the "common contexts" hypothesis but not consistent with the early acquisition predicted by the "common letter name" hypothesis. Evidence from cross-case transfer in a training experiment indicated that prior to acquiring full use of ALUs the children had formed representations of words that were letter based but specific to lower-case forms.

Dissociation between deficits in explicit procedures and implicit processes in the visual-spatial and the phonological systems during reading acquisition.

Two clinical studies are reported of children with proficient word-reading skill despite severe performance deficits of explicit visual recognition of the lateral ("mirror image") orientation of letters. In dissociation from their deficit in such an explicit procedure, the children had proficient implicit processing of letters that change identity with lateral reversal, as shown in nonword reading, and in letter-naming accuracy and reaction times relative to a normal comparison sample of children. In one child, another dissociation was also apparent in the phonological system. He had a severe performance deficit in explicit processing of phonemes (phonemic awareness) but was proficient in grapheme-phoneme recoding for reading. The findings indicate that it is possible for both the visual-spatial coding and the phonological systems to function in reading acquisition with impaired performance of explicit procedures in each system while maintaining proficient development of reading skill.

A mechanism of implicit lexicalized phonological recoding used concurrently with underdeveloped explicit letter-sound skills in both precocious and normal reading development.

These are findings of theoretical interest from: (i) follow-up of a case study of a precocious reader; and (ii) normally developing readers who served as comparison groups. The precocious reader was first reported when 2-3 years of age (Cognition 74 (2000) 177). From 3 to 7 years of age her precocious reading development continued, her word reading accuracy increasing from the 8- to the 16-year-level, although her phonemic awareness skills remained underdeveloped relative to word reading. Nonword reading continued to develop rapidly. Her word reading, however, was more than phonological recoding. At 5 years of age, in comparison with reading-level matched normal 11-year-olds she exhibited strong effects of semantic characteristics of words and evidence of well-specified lexical orthographic representations. In common with normal comparison 11-year-olds, who had not received instruction in explicit phonics, her explicit letter-sound skills were underdeveloped but she possessed high speed and accuracy in nonword reading, a result most theories of the acquisition of reading fail to explain. Her responses to irregularly spelt nonwords indicated higher proficiency than the 11-year-olds in acquiring lexical orthographic representations not predictable from prior phonological recoding knowledge. It is considered that this proficiency contributes to an explanation of her precocious reading development. A mechanism of implicit lexicalized phonological recoding is involved which explains the dissociation of skills in both the precocious reader and normally developing readers.