The relationship between auditory temporal processing,phonemic awareness,and reading disability

Recent research suggests an auditory temporal deficit as a possible contributing factor to poor phonemic awareness skills. This study investigated the relationship between auditory temporal processing of nonspeech sounds and phonological awareness ability in children with a reading disability, aged 8-12 years, using Tallal's tone-order judgement task. Normal performance on the tone-order task was established for 36 normal readers. Forty-two children with developmental reading disability were then subdivided by their performance on the tone-order task. Average and poor tone-order subgroups were then compared on their ability to process speech sounds and visual symbols, and on phonological awareness and reading. The presence of a tone-order deficit did not relate to performance on the order processing of speech sounds, to poorer phonological awareness or to more severe reading difficulties. In particular, there was no evidence of a group by interstimulus interval interaction, as previously described in the literature, and thus little support for a general auditory temporal processing difficulty as an underlying problem in poor readers. In this study, deficient order judgement on a nonverbal auditory temporal order task (tone task) did not underlie phonological awareness or reading difficulties.     

Genetic and environmental influences on individual differences in printed word recognition

The genetic and environmental etiologies of individual differences in printed word recognition and related skills were explored in 440 identical and fraternal twin pairs between 8 and 18 years of age. A theoretically driven measurement model identified five latent variables: IQ, phoneme awareness, word recognition, phonological decoding, and orthographic coding. Cholesky decomposition models on these five latent constructs revealed the existence of both common and independent genetic effects, as well as non-shared environmental influences. There was evidence for moderate genetic influences common between IQ, phoneme awareness, and word-reading skills, and for stronger IQ-independent genetic influences that were common between phoneme awareness and word-reading skills, particularly phonological decoding. Phonological and orthographic coding skills in word recognition had both significant common and significant independent genetic influences, with implications for "dual-route" and "connectionist" reading models, subtypes of reading disabilities, and the remediation of reading disabilities.     

Is there a causal link from phonological awareness to success in learning to read?

In this review, we re-assess the evidence that phonological awareness represents a skill specific to spoken language that precedes and directly influences the process of reading acquisition. Longitudinal and experimental training studies are examined in detail, as these are considered most appropriate for exploring a causal hypothesis of this nature. A particular focus of our analysis is the degree to which studies to date have controlled for existing literacy skills in their participants and the influence that these skills might have on performance on phonological awareness tasks. We conclude that no study has provided unequivocal evidence that there is a causal link from competence in phonological awareness to success in reading and spelling acquisition. However, we believe that such a study is possible and outline some ideas for its design and implementation.     

Is Phonological Encoding in Naming Influenced by Literacy?

We examined phonological priming in illiterate adults, using a cross-modal picture-word interference task. Participants named pictures while hearing distractor words at different Stimulus Onset Asynchronies (SOAs). Ex-illiterates and university students were also tested. We specifically assessed the ability of the three populations to use fine-grained, phonemic units in phonological encoding of spoken words. In the phoneme-related condition, auditory words shared only the first phoneme with the target name. All participants named pictures faster with phoneme-related word distractors than with unrelated word distractors. The results thus show that phonemic representations intervene in phonological output processes independently of literacy. However, the phonemic priming effect was observed at a later SOA in illiterates compared to both ex-illiterates and university students. This may be attributed to differences in speed of picture identification.     

The development of the orthographic consistency effect in speech recognition: from sublexical to lexical involvement

The influence of orthography on children's on-line auditory word recognition was studied from the end of Grade 2 to the end of Grade 4, by examining the orthographic consistency effect [Ziegler, J. C., & Ferrand, L. (1998). Orthography shapes the perception of speech: The consistency effect in auditory recognition. Psychonomic Bulletin &Review, 5, 683-689.] in auditory lexical decision and shadowing tasks. Words with rhymes that can be spelled in two different ways (inconsistent) produced longer auditory lexical decision and shadowing times and more errors than did consistent words. A similar consistency effect was also observed on pseudowords. The observation of a general consistency effect, both for words and pseudowords, in lexical decision and in shadowing suggests a widespread influence of orthography in the children's spoken word recognition system. On exactly the same material, with adult listeners we replicated the usual pattern of an orthographic consistency effect restricted to words in lexical decision [Ventura, P., Morais, J., Pattamadilok, C., & Kolinsky, R. (2004). The locus of the orthographic consistency effect in auditory word recognition. Language and Cognitive Processes, 19, 57-95; Ziegler, J. C., & Ferrand, L. (1998). Orthography shapes the perception of speech: The consistency effect in auditory recognition. Psychonomic Bulletin &Review, 5, 683-689]. A reanalysis of the lexical decision and shadowing results of Ventura et al. [Ventura, P., Morais, J., Pattamadilok, C., & Kolinsky, R. (2004). The locus of the orthographic consistency effect in auditory word recognition. Language and Cognitive Processes, 19, 57-95.] confirmed the discrepancy between the effects of orthographic consistency in child readers and adults. A further control experiment showed that orthographic consistency effects were not present in pre-readers. Results are interpreted considering the coexistence in children's reading of a mechanism of automatic access to well-specified orthographic representations of words and the persistence of grapho-phonological decoding procedures.     

Phonological awareness and the use of phonological similarity in letter-sound learning

The effects of the phonological similarity between a letter sound and the sound in a spoken word, and phonological awareness on letter-sound learning were examined. Two groups of 41 kindergartners were taught four letter sounds. First, both groups had to learn the associations between four symbols and four familiar words. Next, both groups were taught the letter sounds that were paired to these same symbols. Each letter sound corresponded to the first sound of the word that was previously associated with that symbol in the phonological similarity group, whereas such a relation was absent in the other group. In addition, measures of vocabulary, letter knowledge, and phonological awareness were administered. Phonological similarity facilitated letter-sound learning. Individual differences in phonological awareness had a strong effect on letter-sound learning even after current letter knowledge was controlled. Unexpectedly, the effects of phonological awareness and the ability to use phonological similarity on letter-sound learning were found to be independent.     

The influence of working memory on reading growth in subgroups of children with reading disabilities

This 3-year longitudinal study determined whether (a) subgroups of children with reading disabilities (RD) (children with RD only, children with both reading and arithmetic deficits, and low verbal IQ readers) and skilled readers varied in working memory (WM) and short-term memory (STM) growth and (b) whether growth in an executive system and/or a phonological storage system mediated growth in reading performance. A battery of memory and reading measures was administered to 84 children (11-17 years of age) across three testing waves spaced 1 year apart. The results showed that skilled readers yielded higher WM growth estimates than did the RD groups. No significant differentiation among subgroups of children with RD on growth measures emerged. Hierarchical linear modeling showed that WM (controlled attention), rather than STM (phonological loop), was related to growth in reading comprehension and reading fluency. The results support the notion that deficient growth in the executive component of WM underlies RD.     

Does phonological recoding occur during silent reading, and is it necessary for orthographic learning?

Two studies were conducted to test the central claim of the self-teaching hypothesis (i.e., phonological recoding is necessary for orthographic learning) in silent reading. The first study aimed to demonstrate the use of phonological recoding during silent reading. Texts containing pseudowords were read silently or aloud. Two days later, target spellings were recognized more often than their homophone spellings. In both reading conditions, homophone alternatives were named faster than nonexposed pseudowords, suggesting that phonological recoding had occurred. The second study aimed to suppress phonological recoding to demonstrate its necessity for orthographic learning. Lexical decisions were performed in a standard condition, with concurrent articulation, or with tapping. One day later, target spellings were recognized less often after lexical decisions with concurrent articulation. Target and homophone naming speed was not affected by lexical decision condition. The results support the use of phonological recoding during silent reading and specify its role in orthographic learning.     

Vocabulary learning in primary school children: Working memory and long-term memory components

The goal of this study was to investigate which working memory and long-term memory components predict vocabulary learning. We used a nonword learning paradigm in which 8- to 10-year-olds learned picture-nonword pairs. The nonwords varied in length (two vs. four syllables) and phonology (native sounding vs. including one Russian phoneme). Short, phonologically native nonwords were learned best, whereas learning long nonwords leveled off after a few presentation cycles. Linear structural equation analyses showed an influence of three constructs—phonological sensitivity, vocabulary knowledge, and central attentional resources (M capacity)—on nonword learning, but the extent of their contributions depended on specific characteristics of the nonwords to be learned. Phonological sensitivity predicted learning of all nonword types except short native nonwords, vocabulary predicted learning of only short native nonwords, and M capacity predicted learning of short nonwords but not long nonwords. The discussion considers three learning processes—effortful activation of phonological representations, lexical mediation, and passive associative learning—that use different cognitive resources and could be involved in learning different nonword types.     

Lifespan changes in working memory in fragile X premutation males

Fragile X syndrome is the world’s most common hereditary cause of developmental delay in males and is now well characterized at the biological, brain and cognitive levels. The disorder is caused by the silencing of a single gene on the X chromosome, the FMR1 gene. The premutation (carrier) status, however, is less well documented but has an emerging literature that highlights a more subtle profile of executive cognitive deficiencies that mirror those reported in fully affected males. Rarely, however, has the issue of age-related declines in cognitive performance in premutation males been addressed. In the present study, we focus specifically on the cognitive domain of working memory and its subcomponents (verbal, spatial and central executive memory) and explore performance across a broad sample of premutation males aged 18–69 years matched on age and IQ to unaffected comparison males. We further tease apart the premutation status into those males with symptoms of the newly identified neurodegenerative disorder, the fragile X-associated tremor/ataxia syndrome (FXTAS) and those males currently symptom-free. Our findings indicate a specific vulnerability in premutation males on tasks that require simultaneous manipulation and storage of new information, so-called executive control of memory. Furthermore, this vulnerability appears to exist regardless of the presence of FXTAS symptoms. Males with FXTAS symptoms demonstrated a more general impairment encompassing phonological working memory in addition to central executive working memory. Among asymptomatic premutation males, we observed the novel finding of a relationship between increased CGG repeat size and impairment to central executive working memory.