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1.
The double-deficit hypothesis (Wolf, 1997; Wolf & Bowers, 1999, this issue) contends that deficits in phonological awareness and deficits in visual naming speed represent two independent causal impediments to reading acquisition for children with developmental reading disabilities (RD). One hundred and sixty-six children with severe RD from 7 to 13 years of age were classified into three deficit subgroups according to a double-deficit framework. A total of 140 children with RD, 84% of the sample, were classified; 54% demonstrated a double deficit (DD), 22% a phonological deficit only (PHON), and 24% a visual-naming speed deficit only (VNS). Diagnostic test profiles highlighted the joint contributions of the two core deficits in depressing written language acquisition. The children in the DD group were more globally impaired than those in the other subgroups, and the VNS group children were the highest achieving and most selectively impaired readers. Following 35 hours of word identification training, sizable gains and significant generalization of training effects were achieved by all subgroups. A metacognitive phonics program resulted in greater generalized effects across the domain of real English words, and a phonological training program produced superior outcomes within the phonological processing domain. The greatest non-word reading gains were achieved by children with only phonological deficits. 相似文献
2.
The double-deficit hypothesis of developmental dyslexia proposes that deficits in phonological processing and naming speed represent independent sources of dysfunction in dyslexia. The present article is a review of the evidence for the double-deficit hypothesis, including a discussion of recent findings related to the hypothesis. Studies in this area have been characterized by variability in methodology--how dyslexia is defined and identified, and how dyslexia subtypes are classified. Such variability sets limitations on the extent to which conclusions may be drawn with respect to the double-deficit hypothesis. Furthermore, the literature is complicated by the persistent finding that measures of phonological processing and naming speed are significantly correlated, resulting in a statistical artifact that makes it difficult to disentangle the influence of naming speed from that of phonological processing. Longitudinal and intervention studies of the double-deficit hypothesis are needed to accumulate evidence that investigates a naming speed deficit that is independent of a phonological deficit for readers with dyslexia. The existing evidence does not support a persistent core deficit in naming speed for readers with dyslexia. 相似文献
3.
Miller CJ Miller SR Bloom JS Jones L Lindstrom W Craggs J Garcia-Barrera M Semrud-Clikeman M Gilger JW Hynd GW 《Annals of dyslexia》2006,56(1):83-102
The double-deficit hypothesis of dyslexia posits that reading deficits are more severe in individuals with weaknesses in phonological awareness and rapid naming than in individuals with deficits in only one of these reading composite skills. In this study, the hypothesis was tested in an adult sample as a model of reading achievement. Participants were parents of children referred for evaluation of reading difficulties. Approximately half of all participants reported difficulty learning to read in childhood and a small subset demonstrated ongoing weaknesses in reading. Structural equation modeling results suggest that the double-deficit hypothesis is an accurate model for understanding adult reading achievement. Better reading achievement was associated with better phonological awareness and faster rapid automatized naming in adults. Posthoc analyses indicated that individuals with double deficits had significantly lower reading achievement than individuals with single deficits or no deficits. 相似文献
4.
The present study explored the double-deficit hypothesis (DDH) in a sample of 146 college students with and without reading disabilities (RD). The results indicated that although both phonological awareness (PA) and visual naming speed (VNS) contributed to performance on measures of decoding and comprehension, their relative contribution was influenced both by the nature of the stimulus (word vs. nonword vs. text) and by the conditions of the task (timed vs. untimed). Similar results were obtained using an individual differences approach, or when between-group comparisons were made of individuals with deficits in PA or VNS. The relative representation of DDH subgroups in groups of adults with RD varied based on the classification criteria used to define RD. These results support the DDH, extend its applicability to adults, and have implications for diagnostic decision making. 相似文献
5.
Escribano CL 《Journal of learning disabilities》2007,40(4):319-330
The double-deficit hypothesis acknowledges both phonological processing deficits and serial naming speed deficits as two dimensions associated with reading disabilities. The purpose of this study was to examine these two dimensions of reading as they were related to the reading skills of 29 Spanish average readers and poor readers (mean age 9 years 7 months) who met the criteria for either single phonological deficit (PD), double deficit (DD), or no deficit. DD children were the slowest readers and had the weakest orthography processing skills. No significant differences were found between PD and DD groups on word and pseudoword reading. Word reading and reading comprehension skills were average or above average in the three studied groups. As in previous studies in transparent orthographies, word reading was not a salient problem for Spanish poor readers, whereas for the DD group, reading speed and orthographic recognition skills were significantly affected. 相似文献
6.
Peggy T. Ackerman Carol A. Holloway Patricia L. Youngdahl Roscoe A. Dykman 《Learning disabilities research & practice》2001,16(3):152-160
The double-deficit theory of reading disability (Wolf & Bowers, 1999) was examined in a sample of 56 reading-disabled and 45 normal-reading elementary school children (aged 8 to 11). As hypothesized, the two groups differed markedly on all phonological analysis tasks and on rapid continuous naming of digits and letters (the double deficits), but they differed as well on orthographic tasks, attention ratings, arithmetic achievement, and all WISC-III factors except perceptual organization. Within the reading-disabled (RD) sample, children in the double-deficit subgroup were no more impaired in reading and spelling than those with a single deficit in phonological analysis, and those with a single deficit in rapid naming were no more impaired than those with neither deficit. Multiple regression analyses suggest that a multiple causality theory of RD is more plausible than a double-deficit theory. 相似文献
7.
Concurrent relationships among measures of naming speed, phonological awareness, orthographic skill, and other reading subskills were explored in a representative sample of second graders. Hierarchical regression analyses revealed that naming speed, as measured by the the rapid automatized naming (RAN) task, accounted for a sizable amount of unique variance in reading with vocabulary and phonemic awareness partialled out. The unique contribution of naming speed to reading was relatively stronger for orthographic skills, whereas the contribution of phonemic skills was stronger for nonword decoding. In further analyses, marked difficulties on a range of reading tasks, including orthographic processing, were seen in a subgroup with a double deficit (slow naming speed and low phonemic awareness) but not in groups with only a single deficit. These findings are broadly consistent with Bowers and Wolf's (1993a, 1993b; Wolf & Bowers, 1999) double-deficit hypothesis of reading disability. 相似文献
8.
Swanson HL 《Journal of learning disabilities》2012,45(1):17-30
This article reviews the results of a meta-analysis of the experimental published literature that compares the academic, cognitive, and behavioral performance of adults with reading disabilities (RD) with average achieving adult readers. The meta-analysis shows that deficits independent of the classification measures emerged for adults with RD on measures of vocabulary, math, spelling, and specific cognitive process related to naming speed, phonological processing, and verbal memory. The results also showed that adults with high verbal IQs (scores > 100) but low word recognition standard scores (< 90) yielded greater deficits related to their average reading counterparts when compared to studies that included adults with RD with verbal IQ and reading scores in the same low range. Implications of the findings related to assessment and intervention are discussed. 相似文献
9.
The present study aimed to investigate the double-deficit hypothesis (DDH) in an orthography of intermediate depth. Eighty-five European Portuguese-speaking children with developmental dyslexia, aged 7 to 12, were tested on measures of phonological awareness (PA), naming speed (NS), reading, and spelling. The results indicated that PA and NS were not significantly correlated, and that NS predicts reading fluency (but not reading accuracy and spelling) beyond what is accounted for by PA. Although the majority of the children with developmental dyslexia have double deficit (62.4%), some children have a single phonological deficit (24.7%) or a single NS deficit (8.2%). Children with a double deficit were not more impaired in reading fluency, reading accuracy, and spelling than both single-deficit subtypes. In conclusion, the findings of the present study are partially consistent with the DDH and provide evidence for the multifactorial model of developmental dyslexia. Implications of the DDH for an orthography of intermediate depth are emphasized.
相似文献10.
First-grade students (N = 221) were individually tested on a battery of cognitive and achievement measures of verbal fluency, visual attention, phonological awareness, orthographic recognition, rapid automatized naming (RAN) of letters and objects, and reading. All tests were subjected to postacquisition scoring, and all RAN measures were segregated into measures of articulation time, pause time, and consistency of the pause time. Structural equation modeling demonstrated that word reading was directly and significantly predicted by RAN letter naming and general RAN cognitive processing time of objects. Moreover, RAN letter reading constructs were significantly and directly predicted by the latent variables of phonological awareness, orthographic recognition, and general RAN object articulation and cognitive processing times. RAN letter naming constructs were also significantly and indirectly predicted by visual attention. The reading model was found to be consistent with a total mediation of the relation of phonological awareness and reading through RAN letter naming and supported the validity of the RAN letter naming subtest as a basic letter reading test. These findings supported the double-deficit hypothesis for letter reading. We suggest that phonological memory is a basic factor underlying general RAN cognitive processing time of objects and domain-specific information associated with phonemes and their graphic representations. 相似文献
11.
Cognitive profiling in Chinese developmental dyslexia with attention-deficit/hyperactivity disorders
Won Shing Raymond Chan Se Fong Hung Suet Nga Liu Cheuk Kiu Kathy Lee 《Reading and writing》2008,21(6):661-674
The cognitive profiles of children with Developmental Reading Disorder (RD) and Attention-Deficit/Hyperactivity Disorders
(ADHD) have been extensively studied in alphabetic language communities. Deficits in phonological processing and rapid naming
have been implicated as core features of RD although whether the latter is a deficit specific to RD remains controversial.
Similar research aiming to explore the cognitive profiles of children with both RD and ADHD in non-alphabetic language communities
is limited. The specificity of rapid naming deficit to RD among Chinese has yet to be studied. In the first study, 43 Chinese
children with confirmed diagnoses of RD + ADHD were assessed on their cognitive abilities in relating to reading. In the second
study, the specificity deficit hypothesis of rapid naming to RD but not ADHD was examined. A digit naming test was administered
to the RD + ADHD group (43 subjects) and an ADHD only group (49 subjects). In regard to cognitive profiling, rapid naming
and orthographic knowledge were found to be the most common deficits among the Chinese RD + ADHD group. This co-morbid group
was also found to have a significant deficit performance on the rapid naming task than the ADHD only group. The present findings
support the double dissociation hypothesis in cognitive deficit between RD and ADHD. The results of both studies are discussed
with reference to the findings of the Western counterparts. 相似文献
12.
Tractenberg RE 《Journal of learning disabilities》2002,35(5):407-424
Reading-related skills were tested in adults with and without reading disabilities (RD) and adults with profound hearing impairment (PHI) who did not differ on average Performance IQ. The RD group and the PHI group both demonstrated levels of phonological awareness lower than the control group's, but only the RD group also exhibited deficits in other skills, including verbal short-term memory, morphological awareness, speeded written naming, and reading comprehension. The average reading level of the PHI group was significantly higher than that of the RD group. Three control group members also demonstrated limited phonological awareness without other deficits in a pilot study, performing similarly to the PHI group. The results support other studies suggesting that processes dependent on memory, not solely phonological awareness, may contribute to determining reading achievement. 相似文献
13.
Some previous research has shown strong associations between spelling ability and rapid automatic naming (RAN) after controls for phonological processing and nonsense-word reading ability, consistent with the double-deficit hypothesis in reading and spelling. Previous studies did not, however, control for nonsense-word spelling ability before assessing RAN--spelling associations. In this study, 65 children with poor spelling skills but average reasoning ability completed RAN tasks and spelling, reading, and reasoning tasks. Hierarchical regression analyses revealed that, after controls for chronological age, reasoning ability, and spelling of nonsense words, alphanumeric RAN, but not nonalphanumeric RAN, was still a strong predictor of spelling acquisition. Findings are discussed in terms of single- and double-deficit models of spelling and implications for effective teaching. 相似文献
14.
This article integrates the findings in the special issue with a comprehensive review of the evidence for seven central questions about the role of naming-speed deficits in developmental reading disabilities. Cross-sectional, longitudinal, and cross-linguistic research on naming-speed processes, timing processes, and reading is presented. An evolving model of visual naming illustrates areas of difference and areas of overlap between naming speed and phonology in their underlying requirements. Work in the cognitive neurosciences is used to explore two nonexclusive hypotheses about the putative links between naming speed and reading processes and about the sources of disruption that may cause subtypes of reading disabilities predicted by the double-deficit hypothesis. Finally, the implications of the work in this special issue for diagnosis and intervention are elaborated. 相似文献
15.
Maryanne Wolf 《Annals of dyslexia》1999,49(1):1-28
This paper is a written version of the Norman Geschwind Lecture delivered to the International Dyslexia Association on November
13, 1998. The first purpose is a theoretical one: to describe a new conceptualization of reading disabilities, the double-deficit
hypothesis, that depicts and integrates work on two core deficits in the phonological system and in processes underlying naming
speed. Implications for subtyping, diagnosis, and, in particular, intervention are described. The second purpose is to thank
the women and men whose commitment to children with reading disabilities has transformed our field over the last century.
Within that double set of purposes, I wish to dedicate this paper to five research teachers whose insights have been the foundation
for my work and the efforts of many of us in the field of reading disabilities research: Jeanne Chall, Carol Chomsky, Martha
Bridge Denckla, Helen Popp, and especially, Norman Geschwind. 相似文献
16.
The purpose of this study was to determine the components of working memory (WM) that underlie less skilled readers' comprehension and word recognition difficulties. Performance of 3 less skilled reading subgroups---children with reading disabilities (RD) in both word recognition and comprehension; children with comprehension deficits only; and children with low verbal IQ, word recognition, and comprehension (poor readers)--was compared to that of skilled readers on WM, short-term memory (STM), processing speed, executive, and phonological processing measures. Ability group comparisons showed that (a) skilled readers outperformed all less skilled readers on measures of WM, updating, and processing speed; (b) children with comprehension deficits only outperformed children with RD on measures of WM, STM, phonological processing, and processing speed; and (c) children with RD outperformed poor readers on WM and phonological processing measures. A hierarchical regression analysis showed that (a) subgroup differences on WM tasks among less skilled readers were moderated by a storage system not specific to phonological skills, and (b) STM and updating contributed significant variance to WM beyond what was contributed by reading group classification. The latter finding suggested that some differences in storage and executive processing emerged between skilled and less skilled readers that were not specific to reading. 相似文献
17.
In this study, a reading-level-match design was used to test the hypothesis that children with reading disability (RD) are characterized by poor phonological skills, and that a developmental lag, as opposed to a specific deficit, will be found in transparent orthographies. Spanish has a transparent orthography and thus children with RD should not show severe difficulties in the use of the phonological route, as in the English language. A sample of 118 participants was selected and organized into three different groups: 40 with RD, 38 normal readers matched in age with the former, and 40 younger normal readers at the same reading level as those with RD. Two experiments were conducted to investigate the effects of lexicality, word frequency, word length, and positional frequency of syllables on lexical decision making and word-naming performance. While the participants were performing the naming task, we recorded what they read to subsequently analyze the form as well as the frequency of naming errors. The present study provides evidence for a deficit in phonological processing in a transparent orthography, particularly in nonword reading, because there were differences between the reading-level-matched groups. 相似文献
18.
Judith A. Bowey Michaela McGuigan Annette Ruschena 《Journal of Research in Reading》2005,28(4):400-422
The current study examined several alternative explanations of the association between serial naming speed within fourth‐grade children by determining the extent to which the association between word reading and naming speed for letters and numbers is mediated by global processing speed, alphanumeric symbol processing efficiency and phonological processing ability. Children were given multiple measures of key constructs, i.e. word‐level reading, serial naming of both alphanumeric and non‐alphanumeric items, phonological processing ability, articulation rate and global processing speed. The robust association between alphanumeric naming speed and reading within fourth‐grade children was largely mediated by phonological processing ability. Markedly different patterns of results were observed for naming speed for letters and digits and naming speed for colours and pictures in children of this age. Relative to the latter, alphanumeric naming speed better assesses an underlying phonological processing ability that is common to word‐reading ability. We argue that item identification processes contribute little to individual differences in alphanumeric naming speed within relatively proficient readers and that the extent to which alphanumeric naming speed primarily reflects phonological processing is likely to vary with the level of overlearning of letters and numbers and their names. 相似文献
19.
There is evidence that phonological awareness skills secure decoding ability and that phonological deficits underlie failure to acquire adequate word recognition. Slow word‐reading rate may be an additional defining characteristic of reading disability. The present study aimed to investigate whether: (1) reading disabled (RD) Greek‐speaking children showed reading accuracy and reading speed deficits relative to chronological age‐matched controls (CAC) and reading age‐matched controls (RAC); (2) they showed phonological deficits relative to the two control groups who do not present reading difficulties; and (3) they showed reading comprehension deficits over and above any word reading deficits.
Results suggested that the reading accuracy of the RD group was predictably weaker than that of the CAC group but equivalent to that of the RAC group. However, the reading speed of the RD group was significantly slower than the RAC group, who showed the same single word reading speed as the CAC group.
Slow and laboured decoding was found to compromise the reading comprehension of the RD group, whose listening comprehension performance was as good as the two other groups. The RD children performed poorly on phonological awareness tasks and naming speed. Naming speed was not an independent core feature of reading difficulties in the Greek language but was associated with a general phonological deficit.
It is recommended that diagnostic assessments for children with reading difficulties in Greek should include phonological awareness, single word reading and pseudoword reading tasks that measure both accuracy and speed. 相似文献
20.
Schatschneider C Carlson CD Francis DJ Foorman BR Fletcher JM 《Journal of learning disabilities》2002,35(3):245-256
It is widely accepted that deficits in phonological awareness skills are related to reading difficulties. Recently, another source of reading difficulty has been identified that involves naming speed, and combined impairments in phonological skills and naming speed will produce more severe reading deficits than single deficits in either of these cognitive skills. The purpose of this study was to investigate the consequences of grouping children based on the presence or absence of deficits in these skills. We demonstrate that the greater severity of reading impairment found in children with a double deficit could be due in part to a statistical artifact caused by grouping children based on their performance on two correlated continuous variables. This artifact also makes it difficult to establish the relative impact of deficits in naming speed on reading ability independent of deficits in phonological awareness. 相似文献