首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 375 毫秒
1.
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   

2.
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   

3.
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   

4.
The present study investigated the persistent nature of naming speed deficits within the context of the double-deficit hypothesis in a university sample of adults with reading disabilities (RD). Twenty-five university students with RD were compared to 28 typically achieving readers on measures of reading skill, phonological processing, and naming speed. The results indicated that both naming speed and phonological processing deficits characterized the RD group. In a regression analysis, neither naming speed nor phonological processing were important variables in explaining comprehension when reading rate was in the model. The results of the present study are mixed at best and are consistent with earlier conclusions that support for the double-deficit hypothesis of dyslexia remains limited.  相似文献   

5.
The double-deficit hypothesis suggests that deficient skills on two dimensions, rapid naming and phonemic awareness, are associated with poor reading. We studied the reading, spelling, and orthographic skills of Grade 3 children who met our criteria for double asset (DA), single phonological deficit (PD), single naming speed deficit (NSD), and double deficit (DD) groups. Analyses of variance revealed main effects of each factor, oftentimes modified by significant interactions, on the varied achievement measures. All deficit groups performed below the DA children. Compared to children with NSD, children with PD (a) were less accurate decoders, (b) were faster readers, (c) had weaker spelling dictation, and (d) had comparably poor spelling recognition scores. Children with DD showed a mixed pattern of stronger, equal, or weaker skills compared to younger reading level controls.  相似文献   

6.
Phonological coding, measured by the oral reading of nonwords, and orthographic coding, measured by the discrimination of words from homophonic nonwords (e.g., rane, rain), were compared for pairs of older children with reading disabilities (RD) and younger nondisabled readers matched on word recognition. Phonological coding was substantially lower for most children with RD, indicating a unique developmental deficit in phonological coding rather than an equal developmental lag across all component reading skills. Data from identical and fraternal twins indicated that the phonological coding deficit of the children with RD was highly heritable and accounted for most of the heritable variance in their word recognition deficits. The deficits of the twins with RD in segmental language skills (rhyming and phoneme segmentation) were related to the heritable variance in their phonological coding deficits. Orthographic coding was not significantly heritable, and it accounted for much of the environmental variance in word recognition deficits. Implications of the results for the remediation of reading disability are discussed.  相似文献   

7.
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   

8.

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   

9.
Dyslexia and the double deficit hypothesis   总被引:1,自引:4,他引:1  
The double deficit hypothesis (Bowers and Wolf 1993) maintains that children with both phonological and naming-speed deficits will be poorer readers than children with just one or neither of these deficits. In the present study, we drew on this hypothesis to help understand why some children have a serious reading impairment. In addition, by adding an orthographic factor, we extended it to a triple deficit hypothesis. Participants were 90 children aged 6 to 10 years. Dyslexic children, whose reading was low for age and for expected level, garden-variety poor readers, reading-level matched younger children, and low verbal IQ good readers, were compared. The dyslexic group was significantly lower then the garden-variety poor readers and the low verbal IQ good readers on most measures, and lower than the younger group on phonological measures. Findings support the double deficit hypothesis of Bowers and Wolf, and also the triple deficit hypothesis. Most of the poorest readers, nearly all of whom qualified as dyslexic, had a double or triple deficit in phonological, naming-speed, and orthographic skills. Conclusions were that dyslexia results from an overload of deficits in skills related to reading, for which the child cannot easily compensate.  相似文献   

10.
It has been proposed that the phonological coredeficit that is linked to reading failure hasas its underlying cause a deficit in temporalprocessing. In a multivariate investigationdesigned to examine the temporal processingdeficit hypothesis, thirty reading-disabled(RD) adults, thirty-two normally achievingadults and thirty-one normally achievingchildren (reading-level controls) wereadministered a comprehensive battery thatincluded a wide range of timing tasks, inaddition to reading and phonological measures. Although adults with RD displayed overallperformance that was below that of normallyachieving adults on most of the timing tasks,their performance was not differentiallyinfluenced by rate of stimulus presentation. Although the RD adults displayed the typicalpattern of impaired phonological awareness andpseudoword reading relative to reading-levelmatched children, the reading-disabled adultsoutperformed the children on the timing tasks. Finally, with the exception of continuousnaming, the timing tasks shared little variancewith phonological sensitivity and contributedlittle unique variance to word reading. Although these findings undermine the timingdeficit hypothesis, they do provide evidencefor the involvement of naming deficits inreading disability.  相似文献   

11.
The current meta-analysis synthesized findings from profiling research on Chinese children with reading difficulties (RD). We reviewed a total of 81 studies published between 1964 and May 2015, representing a total of 9735 Chinese children. There are 982 effect sizes for the comparison between children with RD and age-matched typically developing (A-TD) children and 152 effect sizes for the comparison between children with RD and reading-level-matched typically developing (R-TD) children on multiple linguistic and cognitive skills. Results showed that compared to A-TD children, children with RD have severe deficits in morphological awareness, orthographic knowledge, phonological awareness, rapid naming, working memory, and visual skills and moderate deficits in short-term memory and motor skills. Compared to R-TD children, children with RD only have moderate deficits in rapid naming and mild deficits in orthographic knowledge. Moderation analyses for the comparison between RD and A-TD children revealed that children with more severe RD show more severe deficits in morphological awareness, phonological awareness, rapid naming, and visual skills. However, neither location (Mainland vs. Hong Kong) nor type of reading screening (character recognition vs. character recognition combined with reading comprehension) emerged as a moderator of the deficit profiles. These findings indicate that Chinese children with RD have deficits on a wide range of cognitive and linguistic skills. Deficits in rapid naming and orthographic knowledge may be potential causal factors for RD in Chinese based on existing evidence. Implications for the diagnosis and instructions of Chinese children with RD were discussed.  相似文献   

12.
To examine whether there are common or specific deficits of reading disability (RD) in first (L1) and second languages (L2), Chinese children (9–11 years, N = 76) with or without RD who learn English as an L2 were studied during a visual word rhyming judgment task. Evidence was found for common deficits in L1 and L2 in visuo-orthographic processes in left inferior temporal gyrus and left precuneus, as well as in phonological processes in left dorsal inferior frontal gyrus as children with RD showed less activation than controls in both languages. Furthermore, the visuo-orthographic deficit appears to be a RD effect, whereas the phonological deficit appears to be a reading/performance effect. Some weak evidence for language specific effects was also found.  相似文献   

13.
Children with developmental reading disabilities (RD) frequently display impaired working memory functioning. However, research has been divergent regarding the characteristics of the deficit. Our investigation addressed this controversy by assessing Baddeley's working memory model as a whole rather than focusing on particular aspects of it, as has been done by much of the research to date. Participants included 20 children with RD and 20 typical readers between the ages of 9 and 13. The phonological loop, visual-spatial sketchpad, and central executive were assessed according to Baddeley's model. The results demonstrated that children with RD have an impaired phonological loop but intact visual-spatial sketchpad and central executive functioning as compared to controls. In terms of the phonological loop, the deficit appears to be specific to the phonological store. Furthermore, our research supports a relationship between phonological processing and phonological loop functioning.  相似文献   

14.
The double-deficit hypothesis: a comprehensive analysis of the evidence   总被引:5,自引:0,他引:5  
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   

15.
The current intervention study investigated the sustained effectiveness of phonological awareness training on the reading development of 16 children in French immersion who were identified as at-risk readers based on grade 1 English measures. The intervention program provided children from three cohorts with supplemental reading in small groups on a withdrawal basis. Children in the experimental group (n = 5) received English phonological awareness training in combination with letter-sound correspondence instruction twice per week for 18 consecutive weeks, while those in the control condition (n = 7) engaged in English vocabulary-building activities. Significant gains were made after the training and maintained for 2 years on both French phonological awareness and French word reading skills for the experimental group. Results suggest that a phonologically based intervention in English can effectively address phonological awareness deficits and facilitate reading acquisition for French immersion children who may be at-risk for later reading difficulties.  相似文献   

16.
The present investigation examined thehypothesis that early auditory temporalprocessing deficits cause later specificreading disability by impairing phonologicalprocessing (Farmer & Klein 1995; Tallal1980, 1984). Temporal processing ability atschool entry was examined using Tallal'sRepetition Test in a large unselected sample ofover 500 children followed over subsequentyears. Although our data confirmed the presenceof certain non-speech auditory processingdeficits in children later classified asspecific reading-disabled, many findings wereclearly at odds with a causal interpretation ofthis relationship. (1) Reading-disabled (RD)children were impaired at school entry on thesubtest with long interstimulus intervals(ISIs) but not the critical short-ISIsubtest. (2) RD children were not inferior toreading-age (RA) controls. (3) A subgroup of RDchildren with evidence of temporal deficitswere no less proficient on later phonologicalor reading measures than RD children with noevidence of early temporal impairment. (4)Although there was a reliable concurrentcorrelation between temporal deficits andphonological awareness at school entry(suggesting a possible common causeexplanation), early temporal deficits did notpredict later phonological impairment,pseudoword processing difficulties, or specificreading disability. On the other hand, earlytemporal deficits did predict later oralreceptive vocabulary and reading comprehensionweaknesses. These findings suggest thatauditory temporal deficits in dyslexics may beassociated with the same dysphasic-typesymptoms observed by Tallal and her colleaguesin specific language-impaired populations, butdo not cause the core phonological deficitsthat characterize dyslexic groups.  相似文献   

17.
The goal of the present study was to ascertain whether developmental dyslexics and their affected parents evinced similar patterns of deficits in word recognition skills. Forty dyslexic children and both their biological parents were administered a battery of experimental measures of phonological and orthographic processing. Deficits in component skills were defined in terms of deviations from the performance of normal readers matched on reading achievement level. Four distinct patterns of deficits were found among both the dyslexics and their parents: a subgroup with a specific deficit in processing phonological codes; a subgroup with a specific deficit in processing orthographic codes; a subgroup with deficits in processing both phonological and orthographic codes; and a subgroup of individuals who did not significantly differ from normal readers at the same reading level in either processing domain. Although limited evidence for familial subgroup concordance was obtained in both the phonological and combined phonological subgroups, no concordance was observed among families classified into the orthographic or reading-achievement equivalent subgroups. It was concluded that all affected family members shared a propensity for a phonological deficit, and that some family members share a fundamental problem in processing orthographic information as well. This research was supported by a Biomedical Research Support Grant from the University of Southern California. The research reported in this paper was based on a Ph.D. thesis conducted by the first author at the University of Southern California.  相似文献   

18.
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   

19.
To evaluate the orthographic and phonological processing skills of developmental dyslexics, we (a) examined their abilities to exploit properties of orthographic redundancy and (b) tested whether their phonological deficit extends to spelling-to-sound connections for large-grain size units such as syllables. To assess the processing skills in dyslexics, we utilized the illusory conjunction paradigm to investigate the nature of reading units in French dyslexic and control children matched in reading age. In control children, reading units were defined by both orthographic redundancy and phonological syllable information. In dyslexics, however, reading units were defined only by orthographic redundancy. Therefore, despite their impairment in reading acquisition, developmental dyslexics have the ability to encode and exploit letter frequency co-occurrences. In contrast, their access to phonological syllables from letters was impaired, suggesting that their phonological deficit extends to large grain-size phonological units.  相似文献   

20.
This study examined whether the characteristic reading speed impairment of German dyslexic children results from a general skill-automatization deficit sensu Nicolson and Fawcett (1990) or from more specific deficits in visual naming speed and phonological skills. The hypothesized skill-automatization deficit was assessed by balancing, peg moving, and visual search. Rapid "automatized" naming tasks served as measures of impaired visual naming speed, and the phonological deficit was assessed by speech perception, phonological sensitivity, and phonological memory tasks. Dyslexic German children and age-matched control children (all boys) were tested at the end of Grade 2 and as participants of a longitudinal study also at the beginning of Grade 1. No evidence for a skill-automatization deficit was found, as the dyslexic children did not differ at all on the balancing tasks and little on the other nonverbal skill tasks. However, the dyslexic children showed impaired visual naming speed and impaired phonological memory performance that were observed not only in Grade 2 but also before learning to read. Overall, the findings support the conclusion that, even in regular orthographies, difficulties in learning to read are due to a phonological deficit and not to a general skill-automatization deficit.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号