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1.
Graph complexity as measured by topological entropy has been previously shown to affect performance on artificial grammar learning tasks among typically developing children. The aim of this study was to examine the effect of graph complexity on implicit sequential learning among children with developmental dyslexia. Our goal was to determine whether children’s performance depends on the complexity level of the grammar system learned. We conducted two artificial grammar learning experiments that compared performance of children with developmental dyslexia with that of age- and reading level-matched controls. Experiment 1 was a high topological entropy artificial grammar learning task that aimed to establish implicit learning phenomena in children with developmental dyslexia using previously published experimental conditions. Experiment 2 is a lower topological entropy variant of that task. Results indicated that given a high topological entropy grammar system, children with developmental dyslexia who were similar to the reading age-matched control group had substantial difficulty in performing the task as compared to typically developing children, who exhibited intact implicit learning of the grammar. On the other hand, when tested on a lower topological entropy grammar system, all groups performed above chance level, indicating that children with developmental dyslexia were able to identify rules from a given grammar system. The results reinforced the significance of graph complexity when experimenting with artificial grammar learning tasks, particularly with dyslexic participants.  相似文献   

2.
There’s a long held view that chunks play a crucial role in artificial grammar learning performance. We compared chunk strength influences on performance, in high and low topological entropy (a measure of complexity) grammar systems, with dyslexic children, age-matched and reading-level-matched control participants. Findings show that age-matched control participants’ performance reflected equivalent influence of chunk strength in the two topological entropy conditions, as typically found in artificial grammar learning experiments. By contrast, dyslexic children and reading-level-matched controls’ performance reflected knowledge of chunk strength only under the low topological entropy condition. In the low topological entropy grammar system, they appeared completely unable to utilize chunk strength to make appropriate test item selections. In line with previous research, this study suggests that for typically developing children, it is the chunks that are attended during artificial grammar learning and create a foundation on which implicit associative learning mechanisms operate, and these chunks are unitized to different strengths. However, for children with dyslexia, it is complexity that may influence the subsequent memorability of chunks, independently of their strength.  相似文献   

3.
It is commonly assumed that children with dyslexia are slower at handwriting than other children. However, evidence of slow handwriting in children with dyslexia is very mixed. Thirty-one children with dyslexia, aged 9 years, were compared to both age-matched children and younger spelling-ability matched children. Participants completed an alphabet-writing task and a composition task on the surface of a digital writing tablet. Children with dyslexia wrote the same amount of letters per minute in the alphabet task but wrote fewer words per minute when composing their texts than children of the same age. Crucially, no differences were found between children with dyslexia and their same age peers for speed of handwriting execution, measured by the tablet, when writing the alphabet or composing their texts. However, children with dyslexia were found to pause within their compositions as often as the spelling ability matched group. Thus handwriting execution is not impaired in children with dyslexia. The slow writing that is typical of children with dyslexia is due to pausing more often when composing and is related to spelling ability. This may reflect processing problems in response to high cognitive load through having to contend with spelling and composing concurrently.  相似文献   

4.
The aim of this study was to investigate the theory that visual magnocellular deficits seen in groups with dyslexia are linked to reading via the mechanisms of visual attention. Visual attention was measured with a serial search task and magnocellular function with a coherent motion task. A large group of children with dyslexia (n = 70) had slower serial search times than a control group of typical readers. However, the effect size was small (η p2 = 0.05) indicating considerable overlap between the groups. When the dyslexia sample was split into those with or without a magnocellular deficit, there was no difference in visual search reaction time between either group and controls. The data suggest that magnocellular sensitivity and visual spatial attention weaknesses are independent of one another. They also provide more evidence of heterogeneity in response to psychophysical tasks in groups with dyslexia. Alternative explanations for poor performance on visual attention tasks are proposed along with avenues for future research.  相似文献   

5.
Cross-linguistic studies suggest that the orthographic system determines the reading performance of dyslexic children. In opaque orthographies, the fundamental feature of developmental dyslexia is difficulty in reading accuracy, whereas slower reading speed is more common in transparent orthographies. The aim of the current study was to examine the extent to which different variables of words affect reaction times and articulation times in developmental dyslexics. A group of 19 developmental dyslexics of different ages and an age-matched group of 19 children without reading disabilities completed a word naming task. The children were asked to read 100 nouns that differed in length, frequency, age of acquisition, imageability, and orthographic neighborhood. The stimuli were presented on a laptop computer, and the responses were recorded using DMDX software. We conducted analyses of mixed-effects models to determine which variables influenced reading times in dyslexic children. We found that word naming skills in dyslexic children are affected predominantly by length, while in non-dyslexics children the principal variable is the age of acquisition, a lexical variable. These findings suggest that Spanish-speaking developmental dyslexics use a sublexical procedure for reading words, which is reflected in slower speed when reading long words. In contrast, normal children use a lexical strategy, which is frequently observed in readers of opaque languages.  相似文献   

6.
Impaired visual attention in children with dyslexia   总被引:2,自引:0,他引:2  
Reading involves the correct and rapid identification of visual stimuli with letters and words. The processing of visual stimuli depends not only on the integrity of the peripheral and central visual system but also on the attentional systems involved. In the present study, a cue-target visual attention task was administered to a population-based sample of 25 children with dyslexia from 10 to 12 years of age. A control group matched for group size, age, and gender was obtained from the same general population. A two-stage screening process involved a spelling task of regular words followed by a battery of five single-word reading tasks. The cue-target task involved both a computer-controlled stimulus presentation and a computer-controlled measurement of reaction time. The data were analyzed by visual field, cue condition (valid, invalid, and no cue), and cue-target interval (CTI). The results showed a general pattern of slower responses in the dyslexia group compared to the control group. The dyslexia group also had longer reaction times in the short CTI condition (covert shift of attention) and in the long CTI condition (overt shift of attention). The findings may reflect a general attentional deficit to visual stimuli in dyslexia, possibly related to problems with the recruitment of necessary cognitive resources for the performance of complex reaction time tasks and for fluent reading.  相似文献   

7.
The present study explores the relationship between basic auditory processing of sound rise time, frequency, duration and intensity, phonological skills (onset-rime and tone awareness, sound blending, RAN, and phonological memory) and reading disability in Chinese. A series of psychometric, literacy, phonological, auditory, and character processing tasks were given to 73 native speakers of Mandarin with an average age of 9.7 years. Twenty-six children had developmental dyslexia, 29 were chronological age-matched controls (CA controls) and 18 were reading-matched controls (RL controls). Chinese children with dyslexia were significantly poorer than CA controls in almost all phonological tasks, in semantic radical search, and in phonological recoding proficiency. Chinese children with dyslexia also showed significant impairments in most of the basic auditory processing tasks. Regression analyses demonstrated that different auditory measures of rise time discrimination were the strongest predictors of individual differences in Chinese character reading (1 Rise task) and phonological recoding (2 Rise task) respectively, with frequency discrimination also important for nonsense syllable decoding. Our results support the hypothesis that accurate perception of the amplitude envelope of speech is critical for phonological development and consequently reading acquisition across languages.  相似文献   

8.
This paper describes two studies that examined the lexical tone awareness of Chinese children both with and without dyslexia at different primary school ages.Study 1 examined the contributions of lexical tone awareness to distinguish children with and without dyslexia with respect to their Chinese character reading skills. Two hundred and seventy Chinese children participated in Study 1. Ninety of these were children with dyslexia (equally recruited from second, fourth, and sixth grades). Moreover, ninety children functioned as a chronological-age control group, and an additional ninety children functioned as a reading-level control group. The participants were tested for nonverbal intelligence, Chinese character reading, and cognitive-linguistic skills and lexical tone awareness. Our results revealed a later developmental ceiling in Chinese children with dyslexia than in those without dyslexia. Furthermore, children’s lexical tone awareness could serve to distinguish children with dyslexia from typically developing children in all primary school years.Study 2 compared the lexical tone awareness and Chinese character reading skills of Chinese children with dyslexia both before and after introducing the Perceptual Training Method. The participants in this study consisted of all the participants with dyslexia from Study 1, and the measurements were the Chinese character reading test and the lexical tone awareness task from Study 1. Our results revealed that only second-grade children with dyslexia gained substantially from the training on both lexical tone awareness and character naming, whereas those in the fourth grade obtained a significant improvement only on lexical tone awareness.  相似文献   

9.
Children (n = 122) and adults (n = 200) with dyslexia completed rapid automatic naming (RAN) letters, rapid automatic switching (RAS) letters and numbers, executive function (inhibition, verbal fluency), and phonological working memory tasks. Typically developing 3rd (n = 117) and 5th (n = 103) graders completed the RAS task. Instead of analyzing RAN/RAS results the usual way (total time), growth mixture modeling assessed trajectories of successive times for naming 10 symbols in each of five rows. For all three samples and both RAN and RAS, two latent classes were identified. The “faster” class performed slowly on the first row and increased time by small increments on subsequent rows. The “slower” latent class performed more slowly on the first row, and children, but not adults, increased time by larger increments on subsequent rows. For children, both the initial row (automaticity index) and slope (sustained controlled processing index) of the trajectory differentiated the classes. For adults, only the initial row separated the classes. The longest time was on row 3 for RAN and row 4 for RAS. For the typically developing 5th graders, close in age to the children with dyslexia, the trajectories were flatter than for children with dyslexia and only the slower class (4%) showed the peak on row 4. For children with dyslexia, inhibition predicted RAN slope within the slower latent class and phonological working memory predicted RAS slope for both latent classes. For adults with dyslexia, inhibition and phonological working memory differentiated both latent classes on RAN intercept and RAS slope. Taken together, RAN, which may assess the phonological loop of working memory, and RAS, which may assess the central executive in working memory, may explain the timing deficit in dyslexia in sustaining coordinated orthographic-phonological processing over time. This research was supported by Grant Ns. P50 33812 and R01 HD25858 from the National Institute of Child Health and Human Development, Virginia W. Berninger, PI.  相似文献   

10.
There is a growing body of evidence that children with dyslexia have problems not just in reading but in a range of skills including several unrelated to reading. In an attempt to compare the severity and incidence of deficits across these varied domains, children with dyslexia (mean ages 8, 12, and 16 years), and control groups of normally achieving children matched for IQ and for age or reading age, were tested on a range of primitive (basic) skills. The children with dyslexia performed significantly worse than the same-age controls on most tasks, and significantly worse even than the reading-age controls on phoneme segmentation, picture naming speed, word tachistoscopic word recognition, speeded bead threading and some balance tasks. The overall performance of the children with dyslexia is interpreted as showing less complete automatization than normal.  相似文献   

11.
The purpose of this study was to investigate whether the use of simultaneous multisensory structured language instruction promoted better letter name and sound production, word reading, and word spelling for second grade children with typical development (N = 6) or with dyslexia (N = 5) than structured language instruction alone. The use of non-English graphemes (letters) to represent two pretend languages was used to control for children’s lexical knowledge. A multiple baseline, multiple probe across subjects single-case design, with an embedded alternating treatments design, was used to compare the efficacy of multisensory and structured language interventions. Both interventions provided explicit systematic phonics instruction; however, the multisensory intervention also utilized simultaneous engagement of at least two sensory modalities (visual, auditory, and kinesthetic/tactile). Participant’s graphed data was visually analyzed, and individual Tau-U and weighted Tau-U effect sizes were calculated for the outcome variables of letter name production, letter sound production, word reading, and word spelling. The multisensory intervention did not provide an advantage over the structured intervention for participants with typical development or dyslexia. However, both interventions had an overall treatment effect for participants with typical development and dyslexia, although intervention effects varied by outcome variable.  相似文献   

12.
A comprehensive test battery, including phonological, speed, motor and cerebellar tasks, was administered to the entire cohort of two schools for children with learning disabilities. Testing was undertaken blind without accessing the psychometric data on the children. Children were then allocated to a discrepancy group on the basis of their IQ, with the majority (n = 29) classified as nondiscrepant (IQ < 90) and a smaller set (n = 7), with IQ of at least 90, classified as discrepant (with dyslexia). Both groups showed significant deficits relative to age-matched controls on almost all the tests. On phonological, speed, and motor tasks, the nondiscrepant group were at least as severely impaired as the discrepant group. By contrast, on the cerebellar tests of postural stability and muscle tone, the nondiscrepant group performed significantly better than the children with dyslexia and close to the level of the controls. The findings indicate that cerebellar tests may prove a valuable method of differentiating between poor readers with and without IQ discrepancy. The findings are interpreted in terms of the cerebellar deficit hypothesis for dyslexia.  相似文献   

13.
The present study evaluated the idea that the hemisphere-specific cognitive demands of reading and writing may induce task-specific maladaptive patterns of language lateralization in children with dyslexia. Situation-specific lateralization was examined in a repeated measures design under three dichotic listening conditions: baseline, concurrent reading, and concurrent writing. Twelve males with phonological dyslexia, 8 to 12 years old, were compared to 12 age-matched and 12 younger reading-matched good readers. Lateralization patterns were examined for condition-specific relationships to pseudoword decoding, word recognition, reading comprehension, spelling, and arithmetic. The results show that dyslexia is not related to incomplete lateralization or to a failure to inhibit verbal processing in the right hemisphere during reading and writing. Reading increased the lateralization of the children with dyslexia, which had a negative relation to arithmetic; writing caused a decrease in lateralization, which was linked specifically to deficits in phonological decoding and visual word recognition. The results suggest that children with dyslexia suffer from a selective linguistic vulnerability to left-hemisphere interference from the idiosyncratic attentional and processing demands of particular school tasks. Dyslexia is a much more dynamic and environmentally sensitive disorder than previously thought.  相似文献   

14.
This article describes a small‐scale study exploring the perspectives of five undergraduate students with dyslexia. Semi‐structured interviews were conducted in two universities in the UK. The interviews explored participants’ perceptions of their dyslexia label and how it had affected their academic success. The aim of the research was to identify facilitating factors that supported participants with dyslexia during their education. The following themes were identified: age of dyslexia identification, family support, dyslexic identity, self‐advocacy skills and learning resources. The study makes a case for an intervention for children and young people (CYP) with dyslexia that, in addition to remedial literacy support, explores self‐advocacy, thinking and study skills and facilitates positive academic self‐concepts. Future research could evaluate such an intervention for its effectiveness on CYP's social emotional well‐being and literacy skills.  相似文献   

15.
Reading disability in children with dyslexia has been proposed to reflect impairment in auditory timing perception. We investigated one aspect of timing perception—temporal grouping—as present in prosodic phrase boundaries of natural speech, in age-matched groups of children, ages 6–8 years, with and without dyslexia. Prosodic phrase boundaries are characterized by temporal grouping of functionally related speech elements and can facilitate syntactic processing of speech. For example, temporary syntactic ambiguities, such as early-closure structures, are processed faster when prosodic phrase boundaries are present. We examined children’s prosodic facilitation by measuring their efficiency of sentence processing for temporary syntactic ambiguities spoken with (facilitating) versus without (neutral) prosodic phrase boundaries. Both groups of children benefited similarly from prosodic facilitation, displaying faster reaction times in facilitating compared to neutral prosody. These findings indicate that the use of prosodic phrase boundaries for speech processing is not impaired in children with dyslexia.  相似文献   

16.
Valdois  Sylviane  Bosse  Marie-Line  Ans  B.  Carbonnel  S.  Zorman  Michel  David  D.  Pellat  Jacques 《Reading and writing》2003,16(6):541-572
The present study describes two Frenchteenagers with developmental reading andwriting impairments whose performance wascompared to that of chronological age andreading age matched non-dyslexic participants.Laurent conforms to the pattern of phonologicaldyslexia: he exhibits a poor performance inpseudo-word reading and spelling, producesphonologically inaccurate misspellings butreads most exception words accurately. Nicolas,in contrast, is poor in reading and spelling ofexception words but is quite good atpseudo-word spelling, suggesting that hesuffers from surface dyslexia and dysgraphia.The two participants were submitted to anextensive battery of metaphonological tasks andto two visual attentional tasks. Laurentdemonstrated poor phonemic awareness skills butgood visual processing abilities, while Nicolasshowed the reverse pattern with severedifficulties in the visual attentional tasksbut good phonemic awareness. The presentresults suggest that a visual attentionaldisorder might be found to be associated withthe pattern of developmental surface dyslexia.The present findings further show thatphonological and visual processing deficits candissociate in developmental dyslexia.  相似文献   

17.
Lexical-decision studies with experienced English and French readers have shown that visual-word identification is not only affected by pronunciation inconsistency of a word (i.e., multiple ways to pronounce a spelling body), but also by spelling inconsistency (i.e., multiple ways to spell a pronunciation rime). The aim of this study was to compare the reading behavior of young Dutch readers with dyslexia to the behavior of readers without dyslexia. All students participated in a lexical-decision task in which we presented pronunciation-consistent words and pseudowords. Half of the pronunciation-consistent stimuli were spelling consistent and the other half were spelling inconsistent. All three reader groups, that is, students with dyslexia, age-match students, and reading-match students, read spelling-consistent words faster than spelling-inconsistent words. Overall reading speed of students with dyslexia was similar to that of reading-match students, and was substantially slower than that of age-match students. The results suggest that reading in students with or without dyslexia is similarly affected by spelling inconsistency. Subtle qualitative differences emerged, however, with respect to pseudoword identification. The conclusion was that the findings were best interpreted in terms of a recurrent-feedback model.  相似文献   

18.
The purpose of this study was to examine different hypotheses in relation to RAN deficits in dyslexia. Thirty university students with dyslexia and 32 chronological-age controls were assessed on RAN Digits and Colors as well as on two versions of RAN Letters and Objects (one with five items repeated 16 times and one with 20 items repeated four times). In addition, participants were tested on discrete letter and object naming, phonological awareness, orthographic knowledge, and speed of processing, and the RAN Letters and Objects total times were partitioned into pause times and articulation times. Results showed first that the dyslexia group was slower than the control group on all RAN tasks and the differences remained significant after controlling for discrete naming time. Second, both groups were slower in the large item set condition (20 ×?4) than in the small set condition (5 ×?16). Third, the dyslexia group was slower than the control group in both the pause and the articulation times. Although none of the processing skills was sufficient on its own to eliminate group differences in RAN Letters components, phonological awareness, and orthographic processing were sufficient on their own to eliminate group differences in the RAN Objects pause time. Taken together, our findings suggest that the deficits in RAN are not due to impaired anchoring, but rather due to subtle impairments in lexical access (specific to alphanumeric RAN), serial processing, and articulation.  相似文献   

19.
Executive functions, including inhibition, have been implicated in children’s reading ability. This study investigates whether children’s performance on an inhibition task is more indicative of reading ability than a measure of another executive function, that is, planning. Fifty‐three male participants were administered a reading test and tests of inhibition and planning not requiring a verbal response. Regression analyses revealed that only inhibition significantly predicted reading. Previous inconsistencies may reflect the modality of the tasks used to measure inhibition. Therefore non‐verbal measures may have highest utility for educational psychologists.  相似文献   

20.
Nicolson and Fawcett (1990) demonstrated specifically impaired balancing performance of children with dyslexia when balancing had to be done simultaneously with a secondary task. This finding was taken as evidence for a general automatization deficit of children with dyslexia. We attempted to replicate this finding with German children with dyslexia, whose characteristic reading difficulty is a fluency problem quite in correspondence with the automatization deficit explanation. Because we were concerned about a potential confound between dyslexia and attention-deficit/hyperactivity disorder (ADHD), we also collected teacher ratings on ADHD symptoms. We found that poor dual-task balancing was limited to children with higher ADHD ratings and that children with dyslexia without higher ADHD ratings performed as well on dual-task balancing as age-matched control children. This finding supports the aforementioned confound. Together with other findings from our research group, it supports the position that, even in consistent orthographies, difficulties in learning to read are caused by a specific phonological deficit.  相似文献   

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