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1.
Zvia Breznitz 《Reading and writing》2002,15(1-2):15-42
This study investigated whether asynchrony ofspeed of processing (SOP) betweenvisual-orthographic and auditory-phonologicalmodalities can account for word recognitiondeficits among dyslexic readers. SOP amongelementary school dyslexic readers was comparedto that of chronologically age-matched normalreaders. SOP was assessed using nonlinguisticand linguistic auditory and visual low-leveltasks and higher-level orthographic andphonological tasks. Behavioral andelectrophysiological (ERP) measures of SOP wereobtained. Data indicated that dyslexic readerswere significantly slower than control readersin most of the experimental tasks. Moreover,dyslexics revealed a systematic SOP gap betweenthe auditory-phonological and thevisual-orthographic modalities. This gap wasfound in both P200 and P300 latencies, andexplained most of the variance in wordrecognition. A theory is proposed suggestingthat asynchrony between the processing rates ofthe visual and the auditory modalities may bean underlying cause of dyslexia. 相似文献
2.
The quality of implicit morphological knowledge in adult Hebrew readers with developmental dyslexia was investigated. The priming paradigm was used to examine whether these adults extract and represent morphemic units similarly to normal readers during online word recognition. The group with dyslexia as a whole did not exhibit priming with visual presentation as opposed to both age- and reading-level controls. Priming was absent when the prime and target words shared a morpheme and even when the prime and the target were identical. Only the students with phonological dyslexia, who exhibited relatively good performance in the orthographic judgment task, exhibited repetition priming but not morphological priming. Strong repetition and morphological priming effects were found for participants with dyslexia when the stimuli were auditory. The implications of the dissociation between visual and auditory priming for the locus of the deficit in morphological processing during word recognition are discussed. 相似文献
3.
An investigation was conducted into the visual and auditory temporal processing profiles of two groups of 4‐ to 6‐year‐old children: pre‐alphabetic children, who showed no alphabetic ability (failing to read any non‐words in a test), and those who demonstrated some alphabetic ability. This alphabetic group showed higher scores in reading and spelling attainment than the pre‐alphabetic group. They were also faster than the pre‐alphabetic group in reacting to the onset and offset of auditory and visual stimuli. However, when age was used as a covariate, only reaction times (RTs) to the offsets of visual stimuli were found to be faster in the alphabetic than the pre‐alphabetic group. This suggests that responses to the offset of visual stimuli are becoming more rapid during the same developmental period when alphabetic ability is beginning to be acquired. Within the alphabetic group, after accounting for age, visual and auditory onset RTs were strongly correlated, whereas within the pre‐alphabetic group there were high correlations between visual and auditory offset RTs. It is therefore suggested that a strong association between RTs to visual and auditory onsets may be beneficial during early alphabetic acquisition, when phoneme–grapheme associations are established. Multiple regression analyses showed visual offset RT as the only variable to account for a significant amount of variance in spelling attainment after age was taken into account, which may relate to Frith's (1985) contention that spelling is important in driving early alphabetic ability. 相似文献
4.
Young children often have a preference for auditory input, with auditory input often overshadowing visual input. The current research investigated the developmental trajectory and factors underlying these effects with 137 infants, 132 four-year-olds, and 89 adults. Auditory preference reverses with age: Infants demonstrated an auditory preference, 4-year-olds switched between auditory and visual preference, and adults demonstrated a visual preference. Furthermore, younger participants were likely to process stimuli only in the preferred modality, thus exhibiting modality dominance, whereas adults processed stimuli in both modalities. Finally, younger participants ably processed stimuli presented to the nonpreferred modality when presented in isolation, indicating that auditory and visual stimuli may be competing for attention early in development. Underlying factors and broader implications of these findings are discussed. 相似文献
5.
John M. Reddington Kel D. Cameron 《International Journal of Disability, Development & Education》1991,38(2):171-203
THIS DOUBLE‐BLIND experiment investigated various aspects of visual and auditory problems related to dyslexia. Seventeen children with dyslexia aged 7.25 to 10.25 years were compared with 17 normal readers matched for CA and intellectual ability. A speech perception task which measured the subjects’ auditory threshold level significantly separated the two groups. No difference was found when this task was performed at 35 dB above individual threshold levels. A significant difference between groups was found for the Form Constancy Subtest of the Frostig Developmental Test of Visual Perception (DTVP) (1966). A significant negative correlation found between these measures for the dyslexics, but not for the normal readers, supports previous evidence for auditory and visual subtypes in dyslexia. Various optometric measures were also examined. Four dyslexics, but no normal readers, suffered fixation disparity. This difference was significant. Six representative subjects of each group were compared for eye tracking in reading. The word span of the dyslexics was significantly smaller than that of the normal readers. A multiple discriminant analysis incorporating the auditory threshold task, form constancy, fusional reserves (distance, negative), accommodation right eye and heterophoria significantly discriminated the two reading groups. The perceptual variables were more heavily weighted than the optometric measures. It was concluded that while eye tracking and binocular fusion problems should always be considered in the assessment of dyslexics, factors involved in information processing in auditory and visual perception appear to be those which are more highly implicated. 相似文献
6.
In addition to an intrinsic difficulty in reading and spelling, one of the defining characteristics of dyslexia is an enduring and pervasive difficulty in phonological coding, such that dyslexic readers find it particularly challenging to process and manipulate the constituent sounds of a language. Coexistent with this finding is the evidence that some dyslexic readers also demonstrate subtle sensory coding problems in the visual and auditory domains. Few theories have been proposed to unite these different findings within a coherent model of reading. Here the evidence for visual, auditory and phonological coding problems in dyslexia is briefly reviewed, and a hypothesis is proposed for how adequate early sensory coding may be intrinsic to phonological awareness and subsequent reading ability. In this hypothesis, a cortical network is assumed that incorporates the visual, auditory and phonological skills of reading. The visual sub‐component of the network is mediated by the dorsal visual pathway, which is responsible for the accurate spatial encoding of letters, words and text. The auditory component of the network in pre‐readers is intrinsic to the development of phonological sensitivity, and then grapheme‐phoneme assimilation as reading skills develop. In this hypothesis, some of the symptoms of dyslexia may result from subtle problems in the encoding of both visual and auditory information and their role in maintaining the synchronicity of the reading network. 相似文献
7.
The purpose of this study was to validate Bakker's (1990, 1992) clinical neuropsychological balance model of dyslexia when implemented in a traditional general education classroom environment. The sample included 45 middle school, right-handed boys and girls (mean age = 12.78) with L-type dyslexia (excessively fast readers who make substantive reading errors), P-type dyslexia (displaying accurate but slow and laborious reading), and M-type dyslexia (readers who commit a combination of L-type and P-type dyslexia errors). The experimental groups (L and P type dyslexia) were presented with hemisphere specific stimulation (HSS) and hemispheric alluding stimuli (HAS). HSS involves the presentation of words into the right visual field (RVF) or the left visual field (LVF) or through tactile exercises with the right or left hand. HAS is achieved by constructing semantically and phonetically challenging letters and words. The children with M-type dyslexia served as a control group and received traditional decoding and comprehension exercises. The readers were exposed to a specific treatment model for 16 weeks, depending on their reading accuracy and comprehension. Statistical analyses indicated that, although there were no significant changes in word recognition for the dyslexia subtypes, the readers with L-type, P-type, and M-type dyslexia exhibited significant improvement in reading accuracy and comprehension as assessed by results from pretest to posttest. These results suggest that Bakker's clinical neuropsychological intervention can be effectively applied to the general education setting as well. 相似文献
8.
W E Pelham 《Child development》1979,50(4):1050-1061
Poor readers (PRs) and controls (i.e., normal readers) from the second, fourth, and sixth grades were compared on four tasks chosen to measure the development of selective attention. The PRs performed more poorly than controls on the central but not on the incidental portion of an auditory memory task. The differences on the central task were interpreted as a function of group differences in mnemonic skills rather than selective attention. There were no group differences on either central or incidental portions of a visual memory task. In a speeded classification task, PRs exhibited a slower rate of information processing, measured in bits of information transmitted per second, than controls, but this difference in rate was not affected by distraction. On a dichotic listening task, PRs performed more poorly than controls under a variety of conditions in which the presence of distraction, the rate of information presentation, and attended ear were manipulated; the pattern of differences obtained, however, was not readily interpretable as a function of greater distractibility on the part of PRs than controls. As a whole, the results did not support the hypothesis that PRs show deficits in selective attention relative to age-matched normal readers. In addition, correlations computed among indices of selectivity (residualized gain scores) derived from the four tasks were uniformly low, suggesting that the four tasks did not measure the same cognitive construct. The implications for the study of reading disabilities and for the construct of selective attention in developmental studies are discussed. 相似文献
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The purpose of this study was to compare the efficacy of two auditory processing interventions for developmental dyslexia, one based on rhythm and one based on phonetic training. Thirty-three children with dyslexia participated and were assigned to one of three groups (a) a novel rhythmic processing intervention designed to highlight auditory rhythmic information in non-speech and speech stimuli; (b) a commercially-available phoneme discrimination intervention; and (c) a no-intervention control. The intervention lasted for 6 weeks. Both interventions yielded equivalent and significant gains on measures of phonological awareness (at both rhyme and phoneme levels), with large effect sizes at the phoneme level. Both programs had medium effect sizes on literacy outcome measures, although gains were non-significant when compared to the controls. The data suggest that rhythmic training has an important role to play in developing the phonological skills that are critical for efficient literacy acquisition. It is suggested that combining both prosodic/rhythmic and phonemic cues in auditory training programs may offer advantages for children with developmental dyslexia. This may be especially true for those who appear resistant to conventional phonics training methods. 相似文献
12.
Matthew H. Schneps Chen Chen Marc Pomplun Jiahui Wang Anne D. Crosby Kevin Kent 《Mind, Brain, and Education》2019,13(1):14-29
People who are practiced in using text‐to‐speech can drive listening speeds to surprisingly high limits. Here, we investigate the extent to which people who are otherwise untrained, with and without dyslexia, can increase their reading speed when forcibly accelerated visual or auditory presentations are used in isolation or in tandem. The experiment examined the reading speed and comprehension of 43 college students using three methods enabled by software on a handheld device: forcibly accelerated visual augmentation, auditory text‐to‐speech, and a combination of the two. We found that both typical and impaired readers attained the highest reading speed using the combined method, controlling for comprehension. Importantly, those with dyslexia using the combined methods reached the equivalent reading speed of typical readers using paper, visual, or auditory methods, with no loss in comprehension. Findings here suggest that in future evolutions—using technologies available today—parallel neurological pathways for language processing can be exploited to optimize reading for those impaired. 相似文献
13.
This study examines reading difficulty characteristics in Hebrew in three reading-impaired populations. Two are groups of dyslexics: 100 readers with impaired auditory perception and 100 readers with impaired visual perception. The third group comprises 61 readers with deep/severe hearing impairment. All were elementary schools students in the second to sixth grades. The subjects were tested with a conventional Hebrew reading test. It examined types of reading errors (e.g. changes of phonetic structure or word content), self-correction in reading, reading speed, sequential/holistic reading, the effect of reading texts with and without the Hebrew diacritical vowel signs ('punctuation'), and the effect of meaningful or meaningless text material on the amount of reading errors. The literature describes distinctions between various kinds of reading disability related to auditory impairment and visual perception, and the definition of dyslexia as being one category or including sub-groups. Our research hypothesis was that similar characteristics of reading difficulties would be found amongst auditory perception-impaired students and hearing-impaired students, and that they would differ from those of students with impaired visual perception. Our findings support this hypothesis. Many of the sub-tests revealed similarity in the reading difficulties between the hearing impaired students and those with impaired auditory perception versus the visually impaired. An unexpected finding revealed that fourth grade students in all the groups were a special sub-group in each group. These findings suggest, in accordance with a major research approach, that dyslexia should be defined in terms of dyslexia sub-groups rather than as a single category. 相似文献
14.
The visual deficit hypothesis of development dyslexia has largely been abandoned because many of the phenomena that initially motivated it could not be replicated under controlled experimental conditions, while phonological processing deficits were found to provide a better explanation for the replicable phenomena. Nevertheless, many teachers and special educators continue to subscribe to the hypothesis that deficits of visual perception are a major cause of reading failure in dyslexia. As part of a larger family study, we reexamined the questions (1) whether probands and affected relatives in dyslexia families reverse easily confused letters more frequently under experimental conditions than normal readers from the same families, and (2) whether they show unusual facility in reading geometrically transformed text. The findings indicated that young dyslexia students reverse easily confused letters more often than normal readers. Reading group differences of letter reversal were significant in children from 7–10 years but not thereafter; and virtually no subject reversed letters when spelling whole words. Furthermore, dyslexic persons in every age group from 7–60 years actually took longer than normal readers to decode geometrically transformed text; and the time to decode transformed texts increased progressively with age after adolescence in both dyslexic persons and normal readers. Thus, reading group differences in decoding easily confused letters and reading geometrically transformed text do not support the visual deficit hypothesis and probably do not help to clarify the etiology of developmental dyslexia. 相似文献
15.
The simultaneous auditory processing skills of 17 dyslexic children and 17 skilled readers were measured using a dichotic listening task. Results showed that the dyslexic children exhibited difficulties reporting syllabic material when presented simultaneously. As a measure of simultaneous visual processing, visual attention span skills were assessed in the dyslexic children. We presented the dyslexic children with a phonological short-term memory task and a phonemic awareness task to quantify their phonological skills. Visual attention spans correlated positively with individual scores obtained on the dichotic listening task while phonological skills did not correlate with either dichotic scores or visual attention span measures. Moreover, all the dyslexic children with a dichotic listening deficit showed a simultaneous visual processing deficit, and a substantial number of dyslexic children exhibited phonological processing deficits whether or not they exhibited low dichotic listening scores. These findings suggest that processing simultaneous auditory stimuli may be impaired in dyslexic children regardless of phonological processing difficulties and be linked to similar problems in the visual modality. 相似文献
16.
Orton (1936) observed that dyslexic readers display not only obvious linguistic processing errors, but also diminished lateralized
specialization of other cerebral hemispheric functions. To explore his “intergrading” hypothesis, six developmental dyslexics
(DDs) and a group of good readers (GRs) were tested on measures of interhemispheric coordination. All subjects (ages 16 to
47) demonstrated normal oculomotor control and visual acuity prior to testing. Subjects were instructed to track three different
point-light source patterns, (single stimulus in one hemifield, dual stimuli in one hemifield and a pair of simultaneous,
symmetric, bihemifield stimuli [SSBS]), presented in random sequence and arrayed horizontally at ±5, ±10, and ±15 degrees
eccentricity. Tested with unihemifield stimuli, all subjects showed normal saccadic latencies and trajectories. In response
to SSBS, all GRs showed pronounced directional preference, choosing largely to track one side over the other. DDs showed reduced
laterality bias (p<.025). DDs showed significantly longer response latencies to SSBS than to unihemifield stimulation (p<.01)
and differed significantly from GRs (p<.05). 相似文献
17.
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
18.
Nathlie A. Badian 《Reading and writing》1994,6(1):45-63
The rationale for the study was that if dyslexic and garden-variety poor readers differ in reading-related cognitive skills, there is justification for believing dyslexia to be a distinct entity. Subjects were 110 children aged 6 to 10 years, divided into groups of dyslexic poor readers varying in verbal IQ, garden-variety poor readers, and good readers. Findings suggest that there are valid grounds for believing that dyslexia is a separate entity from garden-variety poor reading, and that it is found among children at all verbal IQ levels. Poor phonological awareness and nonword reading, in relation to normal readers, were shared by dyslexic and garden-variety poor readers. Deficits unique to dyslexic poor readers were problems in both automatic visual recognition and phonological recoding of graphic stimuli. The study supports the phonological-core variable-difference model of Stanovich (1988) in that both dyslexic and garden-variety poor readers showed phonological processing deficits, but they were more extensive in dyslexics. 相似文献
19.
Clock drawing in developmental dyslexia 总被引：2，自引：0，他引：2
Although developmental dyslexia is often defined as a language-based reading impairment not attributable to low intelligence or educational or socioeconomic limitations, the behavioral manifestations of dyslexia are not restricted to the realm of language. Functional brain imaging studies have shed light on physiological differences associated with poor reading both inside and outside the classical language areas of the brain. Concurrently, clinically useful tests that elicit these nonlinguistic deficits are few. Specifically, the integrity of the dorsal visual pathway, which predominantly projects to the parietal cortex, remains underinvestigated, lacking easily administered tests. Here we present the Clock Drawing Test (CDT), used to test the visuoconstructive ability of children with and without dyslexia and garden-variety poor readers. Compared to typically reading children, many children with dyslexia and some garden-variety poor readers showed significant left neglect, as measured by the distribution of figures drawn on the left clock face. In the poor readers with dyslexia, we observed spatial construction deficits like those of patients with acquired right-hemisphere lesions. The results suggest that in some children with dyslexia, right-hemisphere dysfunction may compound the phonological processing deficits attributed to the left hemisphere. The CDT provides an easy opportunity to assess skills known to be associated with right-hemisphere parietal function. This test can be easily administered to children for both clinical and research purposes. 相似文献
20.
Marja Laasonen Veijo Virsu Suvi Oinonen Mirja Sandbacka Anita Salakari Elisabet Service 《Reading and writing》2012,25(9):2247-2273
We investigated whether poor short-term memory (STM) in developmental dyslexia affects the processing of sensory stimulus sequences in addition to phonological material. STM for brief binary non-verbal stimuli (light flashes, tone bursts, finger touches, and their crossmodal combinations) was studied in 20 Finnish adults with dyslexia and 24 healthy controls. To determine sensory Item STM, participants were asked to match pairs of sequences of increasing length. In Time STM, participants matched pairs of five-stimulus-sequences of increasing stimulus onset asynchrony between the stimuli. Phonological STM was studied with digit span forwards and backwards, pseudoword span, pseudoword matching span, and pseudoword repetition. Earlier results associating phonological STM impairment with dyslexia were replicated. Dyslexic participants also performed more poorly than controls in sensory STM, suggesting that they have general difficulties in representing temporal sequences in STM. Further, sensory STM, phonological STM, temporal acuity, and reading ability were correlated, pointing to shared processes. 相似文献