Are Specific Language Impairment and Dyslexia Distinct Disorders?

PubMed Central

Catts, Hugh W.; Adlof, Suzanne M.; Hogan, Tiffany; Weismer, Susan Ellis

2010-01-01

Purpose The purpose of this study was to determine whether specific language impairment (SLI) and dyslexia are distinct developmental disorders. Method Study 1 investigated the overlap between SLI identified in kindergarten and dyslexia identified in 2nd, 4th, or 8th grades in a representative sample of 527 children. Study 2 examined phonological processing in a subsample of participants, including 21 children with dyslexia only, 43 children with SLI only, 18 children with SLI and dyslexia, and 165 children with typical language/reading development. Measures of phonological awareness and nonword repetition were considered. Results Study 1 showed limited but statistically significant overlap between SLI and dyslexia. Study 2 found that children with dyslexia or a combination of dyslexia and SLI performed significantly less well on measures of phonological processing than did children with SLI only and those with typical development. Children with SLI only showed only mild deficits in phonological processing compared with typical children. Conclusions These results support the view that SLI and dyslexia are distinct but potentially comorbid developmental language disorders. A deficit in phonological processing is closely associated with dyslexia but not with SLI when it occurs in the absence of dyslexia. PMID:16478378

Effective Learning and Retention of Braille Letter Tactile Discrimination Skills in Children with Developmental Dyslexia

ERIC Educational Resources Information Center

Hayek, Maisam; Dorfberger, Shoshi; Karni, Avi

2016-01-01

Children with developmental dyslexia (DD) may differ from typical readers in aspects other than reading. The notion of a general deficit in the ability to acquire and retain procedural ("how to") knowledge as long-term procedural memory has been proposed. Here, we compared the ability of elementary school children, with and without…

Lexical Tone Awareness among Chinese Children with Developmental Dyslexia

ERIC Educational Resources Information Center

Li, Wing-Sze; Ho, Connie Suk-Han

2011-01-01

This study examined the extent and nature of lexical tone deficit in Chinese developmental dyslexia. Twenty Cantonese-speaking Chinese dyslexic children (mean age 8 ; 11) were compared to twenty average readers of the same age (CA control group, mean age 8 ; 11), and another twenty younger average readers of the same word reading level (RL control…

Visual Perception and Reading: New Clues to Patterns of Dysfunction Across Multiple Visual Channels in Developmental Dyslexia.

PubMed

Pina Rodrigues, Ana; Rebola, José; Jorge, Helena; Ribeiro, Maria José; Pereira, Marcelino; van Asselen, Marieke; Castelo-Branco, Miguel

2017-01-01

The specificity of visual channel impairment in dyslexia has been the subject of much controversy. The purpose of this study was to determine if a differential pattern of impairment can be verified between visual channels in children with developmental dyslexia, and in particular, if the pattern of deficits is more conspicuous in tasks where the magnocellular-dorsal system recruitment prevails. Additionally, we also aimed at investigating the association between visual perception thresholds and reading. In the present case-control study, we compared perception thresholds of 33 children diagnosed with developmental dyslexia and 34 controls in a speed discrimination task, an achromatic contrast sensitivity task, and a chromatic contrast sensitivity task. Moreover, we addressed the correlation between the different perception thresholds and reading performance, as assessed by means of a standardized reading test (accuracy and fluency). Group comparisons were performed by the Mann-Whitney U test, and Spearman's rho was used as a measure of correlation. Results showed that, when compared to controls, children with dyslexia were more impaired in the speed discrimination task, followed by the achromatic contrast sensitivity task, with no impairment in the chromatic contrast sensitivity task. These results are also consistent with the magnocellular theory since the impairment profile of children with dyslexia in the visual threshold tasks reflected the amount of magnocellular-dorsal stream involvement. Moreover, both speed and achromatic thresholds were significantly correlated with reading performance, in terms of accuracy and fluency. Notably, chromatic contrast sensitivity thresholds did not correlate with any of the reading measures. Our evidence stands in favor of a differential visual channel deficit in children with developmental dyslexia and contributes to the debate on the pathophysiology of reading impairments.

Developmental Dyslexia: An Evaluation of a Theory.

ERIC Educational Resources Information Center

Satz, Paul; Van Nostrand, Gary K.

The paper reviews a theory advanced by Satz and Sparrow (1970) which purports to explain the nature and cause of specific developmental dyslexia, and evaluates several developmental hypotheses which are generated bythe theory. The theory postulates that developmental dyslexia is not a unitary syndrome but rather reflects a lag in the maturation of…

Surface developmental dyslexia is as prevalent as phonological dyslexia when appropriate control groups are employed.

PubMed

Wybrow, Dean P; Hanley, J Richard

2015-01-01

Previous investigations of the incidence of developmental surface and phonological dyslexia using reading-age-matched control groups have identified many more phonological dyslexics (poor nonword reading relative to irregular-word reading) than surface dyslexics (poor irregular-word reading relative to nonword reading). However, because the measures that have been used to estimate reading age include irregular-word reading ability, they appear inappropriate for assessing the incidence of surface dyslexia. The current study used a novel method for generating control groups whose reading ability was matched to that of the dyslexic sample. The incidence of surface dyslexia was assessed by comparing dyslexic performance with that of a control group who were matched with the dyslexics on a test of nonword reading. The incidence of phonological dyslexia was assessed with reference to a control group who were matched with the dyslexics at irregular-word reading. These control groups led to the identification of an approximately equal number of children with surface and phonological dyslexia. It appeared that selecting control participants who were matched with dyslexics for reading age led to the recruitment of individuals with relatively high nonword reading scores relative to their irregular-word reading scores compared with other types of control group. The theoretical implications of these findings are discussed.

DYSLEXIA--IS THERE SUCH A THING.

ERIC Educational Resources Information Center

BOTEL, MORTON

THE THEORY OF DEVELOPMENTAL DYSLEXIA IS CONTRASTED WITH THE THEORY OF DEVELOPMENTAL IMMATURITY TO EXPLAIN EXTREME READING RETARDATION. DYSLEXIA IS DEFINED AS AN ORGANICALLY BASED READING DISABILITY WHICH IS DETERMINED INDIRECTLY SINCE NO ANATOMIC LESION, CHROMOSOME, OR GENE HAS YET BEEN FOUND RESPONSIBLE. DYSLEXIA IS USUALLY DEDUCED FROM (1)…

Developmental Dyslexia as Developmental and Linguistic Variation: Editor's Commentary.

ERIC Educational Resources Information Center

Leong, Che Kan

2002-01-01

This commentary reviews forthcoming articles on the scientific study of dyslexia, genetic and neurophysiological aspects of dyslexia, cross-linguistic aspects of literacy development and dyslexia, and theory-based practice. It concludes that educators should continue to strive to promote theory-based research and evidence-based practice to achieve…

Rise Time Perception and Detection of Syllable Stress in Adults with Developmental Dyslexia

ERIC Educational Resources Information Center

Leong, Victoria; Hamalainen, Jarmo; Soltesz, Fruzsina; Goswami, Usha

2011-01-01

Introduction: The perception of syllable stress has not been widely studied in developmental dyslexia, despite strong evidence for auditory rhythmic perceptual difficulties. Here we investigate the hypothesis that perception of sound rise time is related to the perception of syllable stress in adults with developmental dyslexia. Methods: A…

Developmental Dyslexia and Widespread Activation across the Cerebellar Hemispheres

ERIC Educational Resources Information Center

Baillieux, Hanne; Vandervliet, Everhard J. M.; Manto, Mario; Parizel, Paul M.; De Deyn, Peter P.; Marien, Peter

2009-01-01

Developmental dyslexia is the most common learning disability in school-aged children with an estimated incidence of five to ten percent. The cause and pathophysiological substrate of this developmental disorder is unclear. Recently, a possible involvement of the cerebellum in the pathogenesis of dyslexia has been postulated. In this study, 15…

Procedural learning in Parkinson's disease, specific language impairment, dyslexia, schizophrenia, developmental coordination disorder, and autism spectrum disorders: A second-order meta-analysis.

PubMed

Clark, Gillian M; Lum, Jarrad A G

2017-10-01

The serial reaction time task (SRTT) has been used to study procedural learning in clinical populations. In this report, second-order meta-analysis was used to investigate whether disorder type moderates performance on the SRTT. Using this approach to quantitatively summarise past research, it was tested whether autism spectrum disorder, developmental coordination disorder, dyslexia, Parkinson's disease, schizophrenia, and specific language impairment differentially affect procedural learning on the SRTT. The main analysis revealed disorder type moderated SRTT performance (p=0.010). This report demonstrates comparable levels of procedural learning impairment in developmental coordination disorder, dyslexia, Parkinson's disease, schizophrenia, and specific language impairment. However, in autism, procedural learning is spared. Copyright © 2017 Elsevier Inc. All rights reserved.

Inhibition and Updating, but Not Switching, Predict Developmental Dyslexia and Individual Variation in Reading Ability

PubMed Central

Doyle, Caoilainn; Smeaton, Alan F.; Roche, Richard A. P.; Boran, Lorraine

2018-01-01

To elucidate the core executive function profile (strengths and weaknesses in inhibition, updating, and switching) associated with dyslexia, this study explored executive function in 27 children with dyslexia and 29 age matched controls using sensitive z-mean measures of each ability and controlled for individual differences in processing speed. This study found that developmental dyslexia is associated with inhibition and updating, but not switching impairments, at the error z-mean composite level, whilst controlling for processing speed. Inhibition and updating (but not switching) error composites predicted both dyslexia likelihood and reading ability across the full range of variation from typical to atypical. The predictive relationships were such that those with poorer performance on inhibition and updating measures were significantly more likely to have a diagnosis of developmental dyslexia and also demonstrate poorer reading ability. These findings suggest that inhibition and updating abilities are associated with developmental dyslexia and predict reading ability. Future studies should explore executive function training as an intervention for children with dyslexia as core executive functions appear to be modifiable with training and may transfer to improved reading ability. PMID:29892245

Dissociations between developmental dyslexias and attention deficits

PubMed Central

Lukov, Limor; Friedmann, Naama; Shalev, Lilach; Khentov-Kraus, Lilach; Shalev, Nir; Lorber, Rakefet; Guggenheim, Revital

2014-01-01

We examine whether attention deficits underlie developmental dyslexia, or certain types of dyslexia, by presenting double dissociations between the two. We took into account the existence of distinct types of dyslexia and of attention deficits, and focused on dyslexias that may be thought to have an attentional basis: letter position dyslexia (LPD), in which letters migrate within words, attentional dyslexia (AD), in which letters migrate between words, neglect dyslexia, in which letters on one side of the word are omitted or substituted, and surface dyslexia, in which words are read via the sublexical route. We tested 110 children and adults with developmental dyslexia and/or attention deficits, using extensive batteries of reading and attention. For each participant, the existence of dyslexia and the dyslexia type were tested using reading tests that included stimuli sensitive to the various dyslexia types. Attention deficit and its type was established through attention tasks assessing sustained, selective, orienting, and executive attention functioning. Using this procedure, we identified 55 participants who showed a double dissociation between reading and attention: 28 had dyslexia with normal attention and 27 had attention deficits with normal reading. Importantly, each dyslexia with suspected attentional basis dissociated from attention: we found 21 individuals with LPD, 13 AD, 2 neglect dyslexia, and 12 surface dyslexia without attention deficits. Other dyslexia types (vowel dyslexia, phonological dyslexia, visual dyslexia) also dissociated from attention deficits. Examination of 55 additional individuals with both a specific dyslexia and a certain attention deficit found no attention function that was consistently linked with any dyslexia type. Specifically, LPD and AD dissociated from selective attention, neglect dyslexia dissociated from orienting, and surface dyslexia dissociated from sustained and executive attention. These results indicate that visuospatial attention deficits do not underlie these dyslexias. PMID:25628578

Dissociations between developmental dyslexias and attention deficits.

PubMed

Lukov, Limor; Friedmann, Naama; Shalev, Lilach; Khentov-Kraus, Lilach; Shalev, Nir; Lorber, Rakefet; Guggenheim, Revital

2014-01-01

We examine whether attention deficits underlie developmental dyslexia, or certain types of dyslexia, by presenting double dissociations between the two. We took into account the existence of distinct types of dyslexia and of attention deficits, and focused on dyslexias that may be thought to have an attentional basis: letter position dyslexia (LPD), in which letters migrate within words, attentional dyslexia (AD), in which letters migrate between words, neglect dyslexia, in which letters on one side of the word are omitted or substituted, and surface dyslexia, in which words are read via the sublexical route. We tested 110 children and adults with developmental dyslexia and/or attention deficits, using extensive batteries of reading and attention. For each participant, the existence of dyslexia and the dyslexia type were tested using reading tests that included stimuli sensitive to the various dyslexia types. Attention deficit and its type was established through attention tasks assessing sustained, selective, orienting, and executive attention functioning. Using this procedure, we identified 55 participants who showed a double dissociation between reading and attention: 28 had dyslexia with normal attention and 27 had attention deficits with normal reading. Importantly, each dyslexia with suspected attentional basis dissociated from attention: we found 21 individuals with LPD, 13 AD, 2 neglect dyslexia, and 12 surface dyslexia without attention deficits. Other dyslexia types (vowel dyslexia, phonological dyslexia, visual dyslexia) also dissociated from attention deficits. Examination of 55 additional individuals with both a specific dyslexia and a certain attention deficit found no attention function that was consistently linked with any dyslexia type. Specifically, LPD and AD dissociated from selective attention, neglect dyslexia dissociated from orienting, and surface dyslexia dissociated from sustained and executive attention. These results indicate that visuospatial attention deficits do not underlie these dyslexias.

Subtypes of developmental dyslexia: testing the predictions of the dual-route and connectionist frameworks.

PubMed

Peterson, Robin L; Pennington, Bruce F; Olson, Richard K

2013-01-01

We investigated the phonological and surface subtypes of developmental dyslexia in light of competing predictions made by two computational models of single word reading, the Dual-Route Cascaded Model (DRC; Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001) and Harm and Seidenberg's connectionist model (HS model; Harm & Seidenberg, 1999). The regression-outlier procedure was applied to a large sample to identify children with disproportionately poor phonological coding skills (phonological dyslexia) or disproportionately poor orthographic coding skills (surface dyslexia). Consistent with the predictions of the HS model, children with "pure" phonological dyslexia, who did not have orthographic deficits, had milder phonological impairments than children with "relative" phonological dyslexia, who did have secondary orthographic deficits. In addition, pure cases of dyslexia were more common among older children. Consistent with the predictions of the DRC model, surface dyslexia was not well conceptualized as a reading delay; both phonological and surface dyslexia were associated with patterns of developmental deviance. In addition, some results were problematic for both models. We identified a small number of individuals with severe phonological dyslexia, relatively intact orthographic coding skills, and very poor real word reading. Further, a subset of controls could read normally despite impaired orthographic coding. The findings are discussed in terms of improvements to both models that might help better account for all cases of developmental dyslexia. Copyright © 2012 Elsevier B.V. All rights reserved.

Subtypes of developmental dyslexia: Testing the predictions of the dual-route and connectionist frameworks

PubMed Central

Peterson, Robin L.; Pennington, Bruce F.; Olson, Richard K.

2012-01-01

We investigated the phonological and surface subtypes of developmental dyslexia in light of competing predictions made by two computational models of single word reading, the dual-route cascaded model (DRC; Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001) and Harm and Seidenberg’s connectionist model (HS model; Harm & Seidenberg, 1999). The regression-outlier procedure was applied to a large sample to identify children with disproportionately poor phonological coding skills (phonological dyslexia) or disproportionately poor orthographic coding skills (surface dyslexia). Consistent with the predictions of the HS model, children with “pure” phonological dyslexia, who did not have orthographic deficits, had milder phonological impairments than children with “relative” phonological dyslexia, who did have secondary orthographic deficits. In addition, pure cases of dyslexia were more common among older children. Consistent with the predictions of the DRC model, surface dyslexia was not well conceptualized as a reading delay; both phonological and surface dyslexia were associated with patterns of developmental deviance. In addition, some results were problematic for both models. We identified a small number of individuals with severe phonological dyslexia, relatively intact orthographic coding skills, and very poor real word reading. Further, a subset of controls could read normally despite impaired orthographic coding. The findings are discussed in terms of improvements to both models that might help better account for all cases of developmental dyslexia. PMID:23010562

Examining the relationship between home literacy environment and neural correlates of phonological processing in beginning readers with and without a familial risk for dyslexia: an fMRI study

PubMed Central

Powers, Sara J.; Wang, Yingying; Beach, Sara D.; Sideridis, Georgios D.; Gaab, Nadine

2016-01-01

Developmental dyslexia is a language-based learning disability characterized by persistent difficulty in learning to read. While an understanding of genetic contributions is emerging, the ways the environment affects brain functioning in children with developmental dyslexia are poorly understood. A relationship between the home literacy environment (HLE) and neural correlates of reading has been identified in typically developing children, yet it remains unclear whether similar effects are observable in children with a genetic predisposition for dyslexia. Understanding environmental contributions is important given that we do not understand why some genetically at-risk children do not develop dyslexia. Here we investigate for the first time the relationship between HLE and the neural correlates of phonological processing in beginning readers with (FHD+, n=29) and without (FHD−, n=21) a family history of developmental dyslexia. We controlled for socio-economic status to isolate the neurobiological mechanism by which HLE affects reading development. Group differences revealed stronger correlation of HLE with brain activation in the left inferior/middle frontal and right fusiform gyri in FHD− compared to FHD+ children, suggesting greater impact of HLE on manipulation of phonological codes and recruitment of orthographic representations in typically developing children. In contrast, activation in the right precentral gyrus showed a significantly stronger correlation with HLE in FHD+ compared to FHD− children, suggesting emerging compensatory networks in genetically at-risk children. Overall, our results suggest that genetic predisposition for dyslexia alters contributions of HLE to early reading skills before formal reading instruction, which has important implications for educational practice and intervention models. PMID:27550556

Examining the relationship between home literacy environment and neural correlates of phonological processing in beginning readers with and without a familial risk for dyslexia: an fMRI study.

PubMed

Powers, Sara J; Wang, Yingying; Beach, Sara D; Sideridis, Georgios D; Gaab, Nadine

2016-10-01

Developmental dyslexia is a language-based learning disability characterized by persistent difficulty in learning to read. While an understanding of genetic contributions is emerging, the ways the environment affects brain functioning in children with developmental dyslexia are poorly understood. A relationship between the home literacy environment (HLE) and neural correlates of reading has been identified in typically developing children, yet it remains unclear whether similar effects are observable in children with a genetic predisposition for dyslexia. Understanding environmental contributions is important given that we do not understand why some genetically at-risk children do not develop dyslexia. Here, we investigate for the first time the relationship between HLE and the neural correlates of phonological processing in beginning readers with (FHD+, n = 29) and without (FHD-, n = 21) a family history of developmental dyslexia. We further controlled for socioeconomic status to isolate the neurobiological mechanism by which HLE affects reading development. Group differences revealed stronger correlation of HLE with brain activation in the left inferior/middle frontal and right fusiform gyri in FHD- compared to FHD+ children, suggesting greater impact of HLE on manipulation of phonological codes and recruitment of orthographic representations in typically developing children. In contrast, activation in the right precentral gyrus showed a significantly stronger correlation with HLE in FHD+ compared to FHD- children, suggesting emerging compensatory networks in genetically at-risk children. Overall, our results suggest that genetic predisposition for dyslexia alters contributions of HLE to early reading skills before formal reading instruction, which has important implications for educational practice and intervention models.

Increased deficit of visual attention span with development in Chinese children with developmental dyslexia.

PubMed

Zhao, Jing; Liu, Menglian; Liu, Hanlong; Huang, Chen

2018-02-16

It has been suggested that orthographic transparency and age changes may affect the relationship between visual attention span (VAS) deficit and reading difficulty. The present study explored the developmental trend of VAS in children with developmental dyslexia (DD) in Chinese, a logographic language with a deep orthography. Fifty-seven Chinese children with DD and fifty-four age-matched normal readers participated. The visual 1-back task was adopted to examine VAS. Phonological and morphological awareness tests, and reading tests in single-character and sentence levels were used for reading skill measurements. Results showed that only high graders with dyslexia exhibited lower accuracy than the controls in the VAS task, revealing an increased VAS deficit with development in the dyslexics. Moreover, the developmental trajectory analyses demonstrated that the dyslexics seemed to exhibit an atypical but not delayed pattern in their VAS development as compared to the controls. A correlation analysis indicated that VAS was only associated with morphological awareness for dyslexic readers in high grades. Further regression analysis showed that VAS skills and morphological awareness made separate and significant contributions to single-character reading for high grader with dyslexia. These findings suggested a developmental increasing trend in the relationship between VAS skills and reading (dis)ability in Chinese.

Adults with Dyslexia Demonstrate Space-Based and Object-Based Covert Attention Deficits: Shifting Attention to the Periphery and Shifting Attention between Objects in the Left Visual Field

ERIC Educational Resources Information Center

Buchholz, J.; Davies, A.A.

2005-01-01

Performance on a covert visual attention task is compared between a group of adults with developmental dyslexia (specifically phonological difficulties) and a group of age and IQ matched controls. The group with dyslexia were generally slower to detect validly-cued targets. Costs of shifting attention toward the periphery when the target was…

Psychosocial Functioning of Children with and without Dyslexia: A Follow-up Study from Ages Four to Nine.

PubMed

Parhiala, P; Torppa, M; Eklund, K; Aro, T; Poikkeus, A-M; Heikkilä, R; Ahonen, T

2015-08-01

This longitudinal study compares developmental changes in psychosocial functioning during the transition into school of children with and without dyslexia. In addition, it examines the effects of gender and family risk for dyslexia in terms of the associations between dyslexia and psychosocial functioning. Children's psychosocial functioning (social skills, inattention and externalizing and internalizing problems) was evaluated by their parents at ages 4, 6 and 9, and diagnosis for dyslexia was made at age 8 (in grade 2). The findings indicated that children with dyslexia were already rated as having poorer social skills and being more inattentive than were typical readers before their entry into school. Significant interactions of gender and diagnosis of dyslexia emerged for social skills and inattention. The social skills of boys with dyslexia improved after school entry as compared to the level of girls without dyslexia, whereas the social skills of girls with dyslexia did not improve. Boys with dyslexia were rated as showing a high level of inattention both prior to and after school entry, whereas, for girls with dyslexia, inattention ratings increased after school entry, eventually matching the boys' levels. Copyright © 2014 John Wiley & Sons, Ltd.

Developmental dyslexia: the visual attention span deficit hypothesis.

PubMed

Bosse, Marie-Line; Tainturier, Marie Josèphe; Valdois, Sylviane

2007-08-01

The visual attention (VA) span is defined as the amount of distinct visual elements which can be processed in parallel in a multi-element array. Both recent empirical data and theoretical accounts suggest that a VA span deficit might contribute to developmental dyslexia, independently of a phonological disorder. In this study, this hypothesis was assessed in two large samples of French and British dyslexic children whose performance was compared to that of chronological-age matched control children. Results of the French study show that the VA span capacities account for a substantial amount of unique variance in reading, as do phonological skills. The British study replicates this finding and further reveals that the contribution of the VA span to reading performance remains even after controlling IQ, verbal fluency, vocabulary and single letter identification skills, in addition to phoneme awareness. In both studies, most dyslexic children exhibit a selective phonological or VA span disorder. Overall, these findings support a multi-factorial view of developmental dyslexia. In many cases, developmental reading disorders do not seem to be due to phonological disorders. We propose that a VA span deficit is a likely alternative underlying cognitive deficit in dyslexia.

Computer-based multisensory learning in children with developmental dyslexia.

PubMed

Kast, Monika; Meyer, Martin; Vögeli, Christian; Gross, Markus; Jäncke, Lutz

2007-01-01

Several attempts have been made to remediate developmental dyslexia using various training environments. Based on the well-known retrieval structure model, the memory strength of phonemes and graphemes should be strengthened by visual and auditory associations between graphemes and phonemes. Using specifically designed training software, we examined whether establishing a multitude of visuo-auditory associations might help to mitigate writing errors in children with developmental dyslexia. Forty-three children with developmental dyslexia and 37 carefully matched normal reading children performed a computer-based writing training (15-20 minutes 4 days a week) for three months with the aim to recode a sequential textual input string into a multi-sensory representation comprising visual and auditory codes (including musical tones). The study included four matched groups: a group of children with developmental dyslexia (n=20) and a control group (n=18) practiced with the training software in the first period (3 months, 15-20 minutes 4 days a week), while a second group of children with developmental dyslexia (n=23) (waiting group) and a second control group (n=19) received no training during the first period. In the second period the children with developmental dyslexia and controls who did not receive training during the first period now took part in the training. Children with developmental dyslexia who did not perform computer-based training during the first period hardly improved their writing skills (post-pre improvement of 0-9%), the dyslexic children receiving training strongly improved their writing skills (post-pre improvement of 19-35%). The group who did the training during the second period also revealed improvement of writing skills (post-pre improvement of 27-35%). Interestingly, we noticed a strong transfer from trained to non-trained words in that the children who underwent the training were also better able to write words correctly that were not part of the training software. In addition, even non-impaired readers and writers (controls) benefited from this training. Three-month of visual-auditory multimedia training strongly improved writing skills in children with developmental dyslexia and non-dyslexic children. Thus, according to the retrieval structure model, multi-sensory training using visual and auditory cues enhances writing performance in children with developmental dyslexia and non-dyslexic children.

Sound localization and word discrimination in reverberant environment in children with developmental dyslexia.

PubMed

Castro-Camacho, Wendy; Peñaloza-López, Yolanda; Pérez-Ruiz, Santiago J; García-Pedroza, Felipe; Padilla-Ortiz, Ana L; Poblano, Adrián; Villarruel-Rivas, Concepción; Romero-Díaz, Alfredo; Careaga-Olvera, Aidé

2015-04-01

Compare if localization of sounds and words discrimination in reverberant environment is different between children with dyslexia and controls. We studied 30 children with dyslexia and 30 controls. Sound and word localization and discrimination was studied in five angles from left to right auditory fields (-90o, -45o, 0o, +45o, +90o), under reverberant and no-reverberant conditions; correct answers were compared. Spatial location of words in no-reverberant test was deficient in children with dyslexia at 0º and +90o. Spatial location for reverberant test was altered in children with dyslexia at all angles, except –-90o. Word discrimination in no-reverberant test in children with dyslexia had a poor performance at left angles. In reverberant test, children with dyslexia exhibited deficiencies at -45o, -90o, and +45o angles. Children with dyslexia could had problems when have to locate sound, and discriminate words in extreme locations of the horizontal plane in classrooms with reverberation.

A taxometric investigation of developmental dyslexia subtypes.

PubMed

O'Brien, Beth A; Wolf, Maryanne; Lovett, Maureen W

2012-02-01

Long-standing issues with the conceptualization, identification and subtyping of developmental dyslexia persist. This study takes an alternative approach to examine the heterogeneity of developmental dyslexia using taxometric classification techniques. These methods were used with a large sample of 671 children ages 6-8 who were diagnosed with severe reading disorders. Latent characteristics of the sample are assessed in regard to posited subtypes with phonological deficits and naming speed deficits, thus extending prior work by addressing whether these deficits embody separate classes of individuals. Findings support separate taxa of dyslexia with and without phonological deficits. Different latent structure for naming speed deficits was found depending on the definitional criterion used to define dyslexia. Non-phonologically based forms of dyslexia showed particular difficulty with naming speed and reading fluency. Copyright © 2012 John Wiley & Sons, Ltd.

Neural substrates related to auditory working memory comparisons in dyslexia: An fMRI study

PubMed Central

CONWAY, TIM; HEILMAN, KENNETH M.; GOPINATH, KAUNDINYA; PECK, KYUNG; BAUER, RUSSELL; BRIGGS, RICHARD W.; TORGESEN, JOSEPH K.; CROSSON, BRUCE

2010-01-01

Adult readers with developmental phonological dyslexia exhibit significant difficulty comparing pseudowords and pure tones in auditory working memory (AWM). This suggests deficient AWM skills for adults diagnosed with dyslexia. Despite behavioral differences, it is unknown whether neural substrates of AWM differ between adults diagnosed with dyslexia and normal readers. Prior neuroimaging of adults diagnosed with dyslexia and normal readers, and post-mortem findings of neural structural anomalies in adults diagnosed with dyslexia support the hypothesis of atypical neural activity in temporoparietal and inferior frontal regions during AWM tasks in adults diagnosed with dyslexia. We used fMRI during two binaural AWM tasks (pseudowords or pure tones comparisons) in adults diagnosed with dyslexia (n = 11) and normal readers (n = 11). For both AWM tasks, adults diagnosed with dyslexia exhibited greater activity in left posterior superior temporal (BA 22) and inferior parietal regions (BA 40) than normal readers. Comparing neural activity between groups and between stimuli contrasts (pseudowords vs. tones), adults diagnosed with dyslexia showed greater primary auditory cortex activity (BA 42; tones > pseudowords) than normal readers. Thus, greater activity in primary auditory, posterior superior temporal, and inferior parietal cortices during linguistic and non-linguistic AWM tasks for adults diagnosed with dyslexia compared to normal readers indicate differences in neural substrates of AWM comparison tasks. PMID:18577292

Prosodic Similarity Effects in Short-Term Memory in Developmental Dyslexia.

PubMed

Goswami, Usha; Barnes, Lisa; Mead, Natasha; Power, Alan James; Leong, Victoria

2016-11-01

Children with developmental dyslexia are characterized by phonological difficulties across languages. Classically, this 'phonological deficit' in dyslexia has been investigated with tasks using single-syllable words. Recently, however, several studies have demonstrated difficulties in prosodic awareness in dyslexia. Potential prosodic effects in short-term memory have not yet been investigated. Here we create a new instrument based on three-syllable words that vary in stress patterns, to investigate whether prosodic similarity (the same prosodic pattern of stressed and unstressed syllables) exerts systematic effects on short-term memory. We study participants with dyslexia and age-matched and younger reading-level-matched typically developing controls. We find that all participants, including dyslexic participants, show prosodic similarity effects in short-term memory. All participants exhibited better retention of words that differed in prosodic structure, although participants with dyslexia recalled fewer words accurately overall compared to age-matched controls. Individual differences in prosodic memory were predicted by earlier vocabulary abilities, by earlier sensitivity to syllable stress and by earlier phonological awareness. To our knowledge, this is the first demonstration of prosodic similarity effects in short-term memory. The implications of a prosodic similarity effect for theories of lexical representation and of dyslexia are discussed. © 2016 The Authors. Dyslexia published by John Wiley & Sons Ltd. © 2016 The Authors. Dyslexia published by John Wiley & Sons Ltd.

Comorbidities in Preschool Children at Family Risk of Dyslexia

ERIC Educational Resources Information Center

Gooch, Debbie; Hulme, Charles; Nash, Hannah M.; Snowling, Margaret J.

2014-01-01

Background: Comorbidity among developmental disorders such as dyslexia, language impairment, attention deficit/hyperactivity disorder and developmental coordination disorder is common. This study explores comorbid weaknesses in preschool children at family risk of dyslexia with and without language impairment and considers the role that…

Slow perceptual processing at the core of developmental dyslexia: a parameter-based assessment of visual attention.

PubMed

Stenneken, Prisca; Egetemeir, Johanna; Schulte-Körne, Gerd; Müller, Hermann J; Schneider, Werner X; Finke, Kathrin

2011-10-01

The cognitive causes as well as the neurological and genetic basis of developmental dyslexia, a complex disorder of written language acquisition, are intensely discussed with regard to multiple-deficit models. Accumulating evidence has revealed dyslexics' impairments in a variety of tasks requiring visual attention. The heterogeneity of these experimental results, however, points to the need for measures that are sufficiently sensitive to differentiate between impaired and preserved attentional components within a unified framework. This first parameter-based group study of attentional components in developmental dyslexia addresses potentially altered attentional components that have recently been associated with parietal dysfunctions in dyslexia. We aimed to isolate the general attentional resources that might underlie reduced span performance, i.e., either a deficient working memory storage capacity, or a slowing in visual perceptual processing speed, or both. Furthermore, by analysing attentional selectivity in dyslexia, we addressed a potential lateralized abnormality of visual attention, i.e., a previously suggested rightward spatial deviation compared to normal readers. We investigated a group of high-achieving young adults with persisting dyslexia and matched normal readers in an experimental whole report and a partial report of briefly presented letter arrays. Possible deviations in the parametric values of the dyslexic compared to the control group were taken as markers for the underlying deficit. The dyslexic group showed a striking reduction in perceptual processing speed (by 26% compared to controls) while their working memory storage capacity was in the normal range. In addition, a spatial deviation of attentional weighting compared to the control group was confirmed in dyslexic readers, which was larger in participants with a more severe dyslexic disorder. In general, the present study supports the relevance of perceptual processing speed in disorders of written language acquisition and demonstrates that the parametric assessment provides a suitable tool for specifying the underlying deficit within a unitary framework. Copyright © 2011 Elsevier Ltd. All rights reserved.

Language-Universal Sensory Deficits in Developmental Dyslexia: English, Spanish, and Chinese

ERIC Educational Resources Information Center

Goswami, Usha; Wang, H.-L. Sharon; Cruz, Alicia; Fosker, Tim; Mead, Natasha; Huss, Martina

2011-01-01

Studies in sensory neuroscience reveal the critical importance of accurate sensory perception for cognitive development. There is considerable debate concerning the possible sensory correlates of "phonological processing", the primary cognitive risk factor for developmental dyslexia. Across languages, children with dyslexia have a specific…

Planum Temporale Morphology in Children with Developmental Dyslexia

PubMed Central

Bloom, Juliana Sanchez; Garcia-Barrera, Mauricio A.; Miller, Carlin J.; Miller, Scott R.; Hynd, George W.

2013-01-01

The planum temporale is a highly lateralized cortical region, located within Wernicke’s area, which is thought to be involved in auditory processing, phonological processing, and language. Research has linked abnormal morphology of the planum temporale to developmental dyslexia, although results have varied in large part due to methodological inconsistencies in the literature. This study examined the asymmetry of the planum temporale in 29 children who met criteria for dyslexia and 26 children whose reading was unimpaired. Leftward asymmetry of the planum temporale was found in the total sample and this leftward asymmetry was significantly reduced in children with dyslexia. This reduced leftward asymmetry in children with dyslexia was due to a planum temporale that is larger in the right hemisphere. This study lends support to the idea that planum temporale asymmetry is altered in children with developmental dyslexia. PMID:23707683

Accuracy and speed of orthographic processing in persons with developmental dyslexia.

PubMed

King, Wayne M; Lombardino, Linda L; Ahmed, Sarah

2005-08-01

A group of 39 persons (20 male and 19 female, 11.0 to 32.5 yr.) with developmental dyslexia and 42 controls (21 male and 21 female, 11.2 to 32.3 years) were compared on computerized tests of sight word reading, nonword decoding, and spelling recognition. The subjects with developmental dyslexia performed significantly slower and less accurately than controls on all tasks. Further, the effect size of the group differences was larger for the older group. Within-group analyses showed a significant difference by age group on accuracy. Only the control group showed a significant age difference between groups on response time. Mean accuracy and response times for the reading-disabled subjects resembled shifted versions of the control group means. These results agree with previous reports that phonological deficits persist for reading-disabled adults and suggest a test of whether the discrepancy between reading-disabled and typically achieving readers may actually increase across age groups.

Auditory and Motor Rhythm Awareness in Adults with Dyslexia

ERIC Educational Resources Information Center

Thomson, Jennifer M.; Fryer, Ben; Maltby, James; Goswami, Usha

2006-01-01

Children with developmental dyslexia appear to be insensitive to basic auditory cues to speech rhythm and stress. For example, they experience difficulties in processing duration and amplitude envelope onset cues. Here we explored the sensitivity of adults with developmental dyslexia to the same cues. In addition, relations with expressive and…

Phonology, Reading Development, and Dyslexia: A Cross-Linguistic Perspective.

ERIC Educational Resources Information Center

Goswami, Usha

2002-01-01

This article presents a theoretical overview at the cognitive level of the role of phonological awareness in reading development and developmental dyslexia across languages. It is argued that the primary deficit in developmental dyslexia in all languages lies in representing speech sounds: a deficit in phonological representation. (Contains…

Impaired Balance in Developmental Dyslexia? A Meta-Analysis of the Contending Evidence

ERIC Educational Resources Information Center

Rochelle, Kim S. H.; Talcott, Joel B.

2006-01-01

Background: Developmental dyslexia is typically defined by deficits in phonological skills, but it is also associated with anomalous performance on measures of balance. Although balance assessments are included in several screening batteries for dyslexia, the association between impairments in literacy and deficits in postural stability could be…

Probabilistic Category Learning in Developmental Dyslexia: Evidence from Feedback and Paired-Associate Weather Prediction Tasks

PubMed Central

Gabay, Yafit; Vakil, Eli; Schiff, Rachel; Holt, Lori L.

2015-01-01

Objective Developmental dyslexia is presumed to arise from specific phonological impairments. However, an emerging theoretical framework suggests that phonological impairments may be symptoms stemming from an underlying dysfunction of procedural learning. Method We tested procedural learning in adults with dyslexia (n=15) and matched-controls (n=15) using two versions of the Weather Prediction Task: Feedback (FB) and Paired-associate (PA). In the FB-based task, participants learned associations between cues and outcomes initially by guessing and subsequently through feedback indicating the correctness of response. In the PA-based learning task, participants viewed the cue and its associated outcome simultaneously without overt response or feedback. In both versions, participants trained across 150 trials. Learning was assessed in a subsequent test without presentation of the outcome, or corrective feedback. Results The Dyslexia group exhibited impaired learning compared with the Control group on both the FB and PA versions of the weather prediction task. Conclusions The results indicate that the ability to learn by feedback is not selectively impaired in dyslexia. Rather it seems that the probabilistic nature of the task, shared by the FB and PA versions of the weather prediction task, hampers learning in those with dyslexia. Results are discussed in light of procedural learning impairments among participants with dyslexia. PMID:25730732

Phonological deficits in specific language impairment and developmental dyslexia: towards a multidimensional model

PubMed Central

Ramus, Franck; Marshall, Chloe R.; Rosen, Stuart

2013-01-01

An on-going debate surrounds the relationship between specific language impairment and developmental dyslexia, in particular with respect to their phonological abilities. Are these distinct disorders? To what extent do they overlap? Which cognitive and linguistic profiles correspond to specific language impairment, dyslexia and comorbid cases? At least three different models have been proposed: the severity model, the additional deficit model and the component model. We address this issue by comparing children with specific language impairment only, those with dyslexia-only, those with specific language impairment and dyslexia and those with no impairment, using a broad test battery of language skills. We find that specific language impairment and dyslexia do not always co-occur, and that some children with specific language impairment do not have a phonological deficit. Using factor analysis, we find that language abilities across the four groups of children have at least three independent sources of variance: one for non-phonological language skills and two for distinct sets of phonological abilities (which we term phonological skills versus phonological representations). Furthermore, children with specific language impairment and dyslexia show partly distinct profiles of phonological deficit along these two dimensions. We conclude that a multiple-component model of language abilities best explains the relationship between specific language impairment and dyslexia and the different profiles of impairment that are observed. PMID:23413264

Location negative priming effects in children with developmental dyslexia: An event-related potential study.

PubMed

Ma, Yujun; Wang, Enguo; Yuan, Tian; Zhao, Guo Xiang

2016-08-01

As the reading process is inseparable from working memory, inhibition, and other higher cognitive processes, the deep cognitive processing defects that are associated with dyslexia may be due to defective distraction inhibition systems. In this study, we used event-related potential technology to explore the source of negative priming effects in children with developmental dyslexia and in a group of healthy children for comparison. We found that the changes in the average response times in the negative priming and control conditions were consistent across the two groups, while the negative priming effects differed significantly between the groups. The magnitude of the negative priming effect was significantly different between the two groups, with the magnitude being significantly higher in the control group than it was in the developmental dyslexia group. These results indicate that there are deficits in distraction inhibition in children with developmental dyslexia. In terms of the time course of processing, inhibition deficits in the dyslexia group appeared during early-stage cognition selection and lasted through the response selection phase. Regarding the cerebral cortex locations, early-stage cognition selection was mainly located in the parietal region, while late-stage response selection was mainly located in the frontal and central regions. The results of our study may help further our understanding of the intrinsic causes of developmental dyslexia. Copyright © 2016 Elsevier Ltd. All rights reserved.

Process Dissociation of Sight Vocabulary and Phonetic Decoding in Reading: A New Perspective on Surface and Phonological Dyslexias

ERIC Educational Resources Information Center

McDougall, Patricia; Borowsky, Ron; MacKinnon, G. E.; Hymel, Shelley

2005-01-01

Recent research on developmental dyslexia has suggested a phonological core deficit hypothesis (e.g., Manis, Seidenberg, Doi, McBride-Chang, & Peterson, 1996; Stanovich, Siegel, & Gottardo, 1997) whereby pure cases of developmental phonological dyslexia (dysfunctional phonetic decoding processing but normal sight vocabulary processing) can exist,…

Differentiating the Neural Response to Intervention in Children with Developmental Dyslexia

ERIC Educational Resources Information Center

Odegard, Timothy N.; Ring, Jeremiah; Smith, Stephanie; Biggan, John; Black, Jeff

2008-01-01

Developmental dyslexia is associated with functional abnormalities within reading areas of the brain. For some children diagnosed with dyslexia, phonologically based remediation programs appear to rehabilitate brain function in key reading areas (Shaywitz et al., Biological Psychiatry 55: 101-110, 2004; Simos et al., Neuroscience 58: 1203-1213,…

Motor Skills, Automaticity and Developmental Dyslexia: A Review of the Research Literature

ERIC Educational Resources Information Center

Savage, Robert

2004-01-01

This paper reviews a body of prominent theories of automaticity in developmental dyslexia. The first part of the review considers the relationship between dyslexia and rapid automatic naming and fluency. Additional theoretical and empirical advances are suggested to this already strong research base. In particular, there is a need is for…

Developmental Dyslexia in Chinese and English Populations: Dissociating the Effect of Dyslexia from Language Differences

ERIC Educational Resources Information Center

Hu, Wei; Lee, Hwee Ling; Zhang, Qiang; Liu, Tao; Geng, Li Bo; Seghier, Mohamed L.; Shakeshaft, Clare; Twomey, Tae; Green, David W.; Yang, Yi Ming; Price, Cathy J.

2010-01-01

Previous neuroimaging studies have suggested that developmental dyslexia has a different neural basis in Chinese and English populations because of known differences in the processing demands of the Chinese and English writing systems. Here, using functional magnetic resonance imaging, we provide the first direct statistically based investigation…

Neuroanatomical anomalies of dyslexia: Disambiguating the effects of disorder, performance, and maturation.

PubMed

Xia, Zhichao; Hoeft, Fumiko; Zhang, Linjun; Shu, Hua

2016-01-29

An increasing body of studies has revealed neuroanatomical impairments in developmental dyslexia. However, whether these structural anomalies are driven by dyslexia (disorder-specific effects), absolute reading performance (performance-dependent effects), and/or further influenced by age (maturation-sensitive effects) remains elusive. To help disentangle these sources, the current study used a novel disorder (dyslexia vs. control) by maturation (younger vs. older) factorial design in 48 Chinese children who were carefully matched. This design not only allows for direct comparison between dyslexics versus controls matched for chronological age and reading ability, but also enables examination of the influence of maturation and its interaction with dyslexia. Voxel-based morphometry (VBM) showed that dyslexic children had reduced regional gray matter volume in the left temporo-parietal cortex (spanning over Heschl's gyrus, planum temporale and supramarginal gyrus), middle frontal gyrus, superior occipital gyrus, and reduced regional white matter in bilateral parieto-occipital regions (left cuneus and right precuneus) compared with both age-matched and reading-level matched controls. Therefore, maturational stage-invariant neurobiological signatures of dyslexia were found in brain regions that have been associated with impairments in the auditory/phonological and attentional systems. On the other hand, maturational stage-dependent effects on dyslexia were observed in three regions (left ventral occipito-temporal cortex, left dorsal pars opercularis and genu of the corpus callosum), all of which were previously reported to be involved in fluent reading and its development. These striking dissociations collectively suggest potential atypical developmental trajectories of dyslexia, where underlying mechanisms are currently unknown but may be driven by interactions between genetic and/or environmental factors. In summary, this is the first study to disambiguate maturational stage on neuroanatomical anomalies of dyslexia in addition to the effects of disorder, reading performance and maturational stage on neuroanatomical anomalies of dyslexia, despite the limitation of a relatively small sample-size. These results will hopefully encourage future research to place greater emphasis on taking a developmental perspective to dyslexia, which may, in turn, further our understanding of the etiological basis of this neurodevelopmental disorder, and ultimately optimize early identification and remediation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Neuroanatomical Anomalies of Dyslexia: Disambiguating the Effects of Disorder, Performance, and Maturation

PubMed Central

Xia, Zhichao; Hoeft, Fumiko; Zhang, Linjun; Shu, Hua

2016-01-01

An increasing body of studies has revealed neuroanatomical impairments in developmental dyslexia. However, whether these structural anomalies are driven by dyslexia (disorder-specific effects), absolute reading performance (performance-dependent effects), and/or further influenced by age (maturation-sensitive effects) remains elusive. To help disentangle these sources, the current study used a novel disorder (dyslexia vs. control) by maturation (younger vs. older) factorial design in 48 Chinese children who were carefully matched. This design not only allows for direct comparison between dyslexics versus controls matched for chronological age and reading ability, but also enables examination of the influence of maturation and its interaction with dyslexia. Voxel-based morphometry (VBM) showed that dyslexic children had reduced regional gray matter volume in the left temporo-parietal cortex (spanning over Heschl’s gyrus, planum temporale and supramarginal gyrus), middle frontal gyrus, superior occipital gyrus, and reduced regional white matter in bilateral parieto-occipital regions (left cuneus and right precuneus) compared with both age-matched and reading-level matched controls. Therefore, maturational stage-invariant neurobiological signatures of dyslexia were found in brain regions that have been associated with impairments in the auditory/phonological and attentional systems. On the other hand, maturational stage-dependent effects on dyslexia were observed in three regions (left ventral occipito-temporal cortex, left dorsal pars opercularis and genu of the corpus callosum), all of which were previously reported to be involved in fluent reading and its development. These striking dissociations collectively suggest potential atypical developmental trajectories of dyslexia, where underlying mechanisms are currently unknown but may be driven by interactions between genetic and/or environmental factors. In summary, this is the first study to disambiguate maturational stage on neuroanatomical anomalies of dyslexia in addition to the effects of disorder, reading performance and maturational stage on neuroanatomical anomalies of dyslexia, despite the limitation of a relatively small sample-size. These results will hopefully encourage future research to place greater emphasis on taking a developmental perspective to dyslexia, which may, in turn, further our understanding of the etiological basis of this neurodevelopmental disorder, and ultimately optimize early identification and remediation. PMID:26679527

Is Weak Oral Language Associated with Poor Spelling in School-Age Children with Specific Language Impairment, Dyslexia, or Both?

PubMed Central

McCarthy, Jillian H.; Hogan, Tiffany P.; Catts, Hugh W.

2013-01-01

The purpose of this study was to test the hypothesis that word reading accuracy, not oral language, is associated with spelling performance in school-age children. We compared fourth grade spelling accuracy in children with specific language impairment (SLI), dyslexia, or both (SLI/dyslexia) to their typically developing grade-matched peers. Results of the study revealed that children with SLI performed similarly to their typically developing peers on a single word spelling task. Alternatively, those with dyslexia and SLI/dyslexia evidenced poor spelling accuracy. Errors made by both those with dyslexia and SLI/dyslexia were characterized by numerous phonologic, orthographic, and semantic errors. Cumulative results support the hypothesis that word reading accuracy, not oral language, is associated with spelling performance in typically developing school-age children and their peers with SLI and dyslexia. Findings are provided as further support for the notion that SLI and dyslexia are distinct, yet co-morbid, developmental disorders. PMID:22876769

Implicit learning and reading: insights from typical children and children with developmental dyslexia using the artificial grammar learning (AGL) paradigm.

PubMed

Pavlidou, Elpis V; Williams, Joanne M

2014-07-01

We examined implicit learning in school-aged children with and without developmental dyslexia based on the proposal that implicit learning plays a significant role in mastering fluent reading. We ran two experiments with 16 typically developing children (9 to 11-years-old) and 16 age-matched children with developmental dyslexia using the artificial grammar learning (AGL) paradigm. In Experiment 1 (non-transfer task), children were trained on stimuli that followed patterns (rules) unknown to them. Subsequently, they were asked to decide from a novel set which stimuli follow the same rules (grammaticality judgments). In Experiment 2 (transfer task), training and testing stimuli differed in their superficial characteristics but followed the same rules. Again, children were asked to make grammaticality judgments. Our findings expand upon previous research by showing that children with developmental dyslexia show difficulties in implicit learning that are most likely specific to higher-order rule-like learning. These findings are discussed in relation to current theories of developmental dyslexia and of implicit learning. Copyright © 2014 Elsevier Ltd. All rights reserved.

Phonological and Sensory Short-Term Memory Are Correlates and Both Affected in Developmental Dyslexia

ERIC Educational Resources Information Center

Laasonen, Marja; Virsu, Veijo; Oinonen, Suvi; Sandbacka, Mirja; Salakari, Anita; Service, Elisabet

2012-01-01

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…

Dorsal Stream Deficits Suggest Hidden Dyslexia among Deaf Poor Readers: Correlated Evidence from Reduced Perceptual Speed and Elevated Coherent Motion Detection Thresholds

ERIC Educational Resources Information Center

Samar, V.J.; Parasnis, I.

2005-01-01

Prelingual deafness and developmental dyslexia have confounding developmental effects on reading acquisition. Therefore, standard reading assessment methods for diagnosing dyslexia in hearing people are ineffective for use with deaf people. Recently, Samar, Parasnis, and Berent (2002) reported visual evoked potential evidence that deaf poor…

Knowledge and Beliefs about Developmental Dyslexia in Pre-Service and In-Service Spanish-Speaking Teachers

ERIC Educational Resources Information Center

Soriano-Ferrer, Manuel; Echegaray-Bengoa, Joyce; Joshi, R. Malathesa

2016-01-01

The present study investigated knowledge, misconceptions, and lack of information about dyslexia among pre-service (PST) and in-service (IST) Spanish-speaking teachers in Spain and Peru. Two hundred and forty-six pre-service teachers and 267 in-service teachers completed the Knowledge and Beliefs about Developmental Dyslexia Scale (KBDDS).…

The Nature of Developmental Dyslexia in a Transparent Orthography

ERIC Educational Resources Information Center

Verhoeven, Ludo; Keuning, Jos

2018-01-01

The present study aimed to explore the nature of developmental dyslexia in a language considered to have a transparent orthography, namely, Dutch. We assessed the accuracy and efficiency of decoding words and pseudowords with four lengths as well as three types of phonological ability in 2,760 typical children and 397 peers with dyslexia across…

Hemispheric, Attentional, and Processing Speed Factors in the Treatment of Developmental Dyslexia

ERIC Educational Resources Information Center

Lorusso, Maria Luisa; Facoetti, Andrea; Molteni, Massimo

2004-01-01

Aim of the study is to analyze the contributions of hemispheric, attentional, and processing speed factors to the effects of neuropsychological treatment of developmental dyslexia. Four groups of dyslexic children (M-type dyslexia) were treated over a period of four months. A first group (n=9) underwent Bakker's Hemisphere-Specific Stimulation,…

Working Memory Deficits in Children with Specific Learning Disorders

ERIC Educational Resources Information Center

Schuchardt, Kirsten; Maehler, Claudia; Hasselhorn, Marcus

2008-01-01

This article examines working memory functioning in children with specific developmental disorders of scholastic skills as defined by ICD-10. Ninety-seven second to fourth graders with a minimum IQ of 80 are compared using a 2 x 2 factorial (dyscalculia vs. no dyscalculia; dyslexia vs. no dyslexia) design. An extensive test battery assesses the…

The Effects of Audiobooks on the Psychosocial Adjustment of Pre-Adolescents and Adolescents with Dyslexia

ERIC Educational Resources Information Center

Milani, Anna; Lorusso, Maria Luisa; Molteni, Massimo

2010-01-01

The objective of the present research study was to understand what benefits the use of audiobooks (both school-books and books of various genres, recorded on digital media) could bring to preadolescents and adolescents with developmental dyslexia. Two groups, each consisting of 20 adolescents, were compared. The experimental group used the…

Disrupted white matter connectivity underlying developmental dyslexia: A machine learning approach.

PubMed

Cui, Zaixu; Xia, Zhichao; Su, Mengmeng; Shu, Hua; Gong, Gaolang

2016-04-01

Developmental dyslexia has been hypothesized to result from multiple causes and exhibit multiple manifestations, implying a distributed multidimensional effect on human brain. The disruption of specific white-matter (WM) tracts/regions has been observed in dyslexic children. However, it remains unknown if developmental dyslexia affects the human brain WM in a multidimensional manner. Being a natural tool for evaluating this hypothesis, the multivariate machine learning approach was applied in this study to compare 28 school-aged dyslexic children with 33 age-matched controls. Structural magnetic resonance imaging (MRI) and diffusion tensor imaging were acquired to extract five multitype WM features at a regional level: white matter volume, fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity. A linear support vector machine (LSVM) classifier achieved an accuracy of 83.61% using these MRI features to distinguish dyslexic children from controls. Notably, the most discriminative features that contributed to the classification were primarily associated with WM regions within the putative reading network/system (e.g., the superior longitudinal fasciculus, inferior fronto-occipital fasciculus, thalamocortical projections, and corpus callosum), the limbic system (e.g., the cingulum and fornix), and the motor system (e.g., the cerebellar peduncle, corona radiata, and corticospinal tract). These results were well replicated using a logistic regression classifier. These findings provided direct evidence supporting a multidimensional effect of developmental dyslexia on WM connectivity of human brain, and highlighted the involvement of WM tracts/regions beyond the well-recognized reading system in dyslexia. Finally, the discriminating results demonstrated a potential of WM neuroimaging features as imaging markers for identifying dyslexic individuals. © 2016 Wiley Periodicals, Inc.

Orthographic Processing Efficiency in Developmental Dyslexia: An Investigation of Age and Treatment Factors at the Sublexical Level

ERIC Educational Resources Information Center

O'Brien, Beth A.; Wolf, Maryanne; Miller, Lynne T.; Lovett, Maureen W.; Morris, Robin

2011-01-01

Reading fluency beyond decoding is a limitation to many children with developmental reading disorders. In the interest of remediating dysfluency, contributing factors need to be explored and understood in a developmental framework. The focus of this study is orthographic processing in developmental dyslexia, and how it may contribute to reading…

The Contribution of White and Gray Matter Differences to Developmental Dyslexia: Insights from DTI and VBM at 3.0 T

ERIC Educational Resources Information Center

Steinbrink, C.; Vogt, K.; Kastrup, A.; Muller, H. P.; Juengling, F. D.; Kassubek, J.; Riecker, A.

2008-01-01

Developmental dyslexia is one of the most common neuropsychological disorders in children and adults. Only few data are available on the pathomechanisms of this specific dysfunction, assuming--among others--that dyslexia might be a disconnection syndrome of anterior and posterior brain regions involved in phonological and orthographic aspects of…

Auditory temporal processing skills in musicians with dyslexia.

PubMed

Bishop-Liebler, Paula; Welch, Graham; Huss, Martina; Thomson, Jennifer M; Goswami, Usha

2014-08-01

The core cognitive difficulty in developmental dyslexia involves phonological processing, but adults and children with dyslexia also have sensory impairments. Impairments in basic auditory processing show particular links with phonological impairments, and recent studies with dyslexic children across languages reveal a relationship between auditory temporal processing and sensitivity to rhythmic timing and speech rhythm. As rhythm is explicit in music, musical training might have a beneficial effect on the auditory perception of acoustic cues to rhythm in dyslexia. Here we took advantage of the presence of musicians with and without dyslexia in musical conservatoires, comparing their auditory temporal processing abilities with those of dyslexic non-musicians matched for cognitive ability. Musicians with dyslexia showed equivalent auditory sensitivity to musicians without dyslexia and also showed equivalent rhythm perception. The data support the view that extensive rhythmic experience initiated during childhood (here in the form of music training) can affect basic auditory processing skills which are found to be deficient in individuals with dyslexia. Copyright © 2014 John Wiley & Sons, Ltd.

The Double-Deficit Hypothesis in Spanish Developmental Dyslexia

ERIC Educational Resources Information Center

Jimenez, Juan E.; Hernandez-Valle, Isabel; Rodriguez, Cristina; Guzman, Remedios; Diaz, Alicia; Ortiz, Rosario

2008-01-01

The double-deficit hypothesis (DDH) of developmental dyslexia was investigated in seven to twelve year old Spanish children. It was observed that the double deficit (DD) group had the greatest difficulty with reading.

Dyslexic children fail to comply with the rhythmic constraints of handwriting.

PubMed

Pagliarini, Elena; Guasti, Maria Teresa; Toneatto, Carlo; Granocchio, Elisa; Riva, Federica; Sarti, Daniela; Molteni, Bruna; Stucchi, Natale

2015-08-01

In this study, we sought to demonstrate that deficits in a specific motor activity, handwriting, are associated to Developmental Dyslexia. The linguistic and writing performance of children with Developmental Dyslexia, with and without handwriting problems (dysgraphia), were compared to that of children with Typical Development. The quantitative kinematic variables of handwriting were collected by means of a digitizing tablet. The results showed that all children with Developmental Dyslexia wrote more slowly than those with Typical Development. Contrary to typically developing children, they also varied more in the time taken to write the individual letters of a word and failed to comply with the principles of isochrony and homothety. Moreover, a series of correlations was found among reading, language measures and writing measures suggesting that the two abilities may be linked. We propose that the link between handwriting and reading/language deficits is mediated by rhythm, as both reading (which is grounded on language) and handwriting are ruled by principles of rhythmic organization. Copyright © 2015 Elsevier B.V. All rights reserved.

Tackling the ‘dyslexia paradox’: reading brain and behavior for early markers of developmental dyslexia

PubMed Central

Ozernov-Palchik, Ola; Gaab, Nadine

2016-01-01

Developmental dyslexia is an unexplained inability to acquire accurate or fluent reading that affects approximately 5–17% of children. Dyslexia is associated with structural and functional alterations in various brain regions that support reading. Neuroimaging studies in infants and pre-reading children suggest that these alterations predate reading instruction and reading failure, supporting the hypothesis that variant function in dyslexia susceptibility genes lead to atypical neural migration and/or axonal growth during early, most likely in utero, brain development. Yet, dyslexia is typically not diagnosed until a child has failed to learn to read as expected (usually in second grade or later). There is emerging evidence that neuroimaging measures, when combined with key behavioral measures, can enhance the accuracy of identification of dyslexia risk in prereading children but its sensitivity, specificity, and cost-efficiency is still unclear. Early identification of dyslexia risk carries important implications for dyslexia remediation and the amelioration of the psychosocial consequences commonly associated with reading failure. PMID:26836227

Examining the Relationship between Home Literacy Environment and Neural Correlates of Phonological Processing in Beginning Readers with and without a Familial Risk for Dyslexia: An fMRI Study

ERIC Educational Resources Information Center

Powers, Sara J.; Wang, Yingying; Beach, Sara D.; Sideridis, Georgios D.; Gaab, Nadine

2016-01-01

Developmental dyslexia is a language-based learning disability characterized by persistent difficulty in learning to read. While an understanding of genetic contributions is emerging, the ways the environment affects brain functioning in children with developmental dyslexia are poorly understood. A relationship between the home literacy…

Dyslexia Heterogeneity: Cognitive Profiling of Portuguese Children with Dyslexia

ERIC Educational Resources Information Center

Pacheco, Andreia; Reis, Alexandra; Araújo, Susana; Inácio, Filomena; Petersson, Karl Magnus; Faísca, Luís

2014-01-01

Recent studies have emphasized that developmental dyslexia is a multiple-deficit disorder, in contrast to the traditional single-deficit view. In this context, cognitive profiling of children with dyslexia may be a relevant contribution to this unresolved discussion. The aim of this study was to profile 36 Portuguese children with dyslexia from…

Rise time and formant transition duration in the discrimination of speech sounds: the Ba-Wa distinction in developmental dyslexia.

PubMed

Goswami, Usha; Fosker, Tim; Huss, Martina; Mead, Natasha; Szucs, Dénes

2011-01-01

Across languages, children with developmental dyslexia have a specific difficulty with the neural representation of the sound structure (phonological structure) of speech. One likely cause of their difficulties with phonology is a perceptual difficulty in auditory temporal processing (Tallal, 1980). Tallal (1980) proposed that basic auditory processing of brief, rapidly successive acoustic changes is compromised in dyslexia, thereby affecting phonetic discrimination (e.g. discriminating /b/ from /d/) via impaired discrimination of formant transitions (rapid acoustic changes in frequency and intensity). However, an alternative auditory temporal hypothesis is that the basic auditory processing of the slower amplitude modulation cues in speech is compromised (Goswami et al., 2002). Here, we contrast children's perception of a synthetic speech contrast (ba/wa) when it is based on the speed of the rate of change of frequency information (formant transition duration) versus the speed of the rate of change of amplitude modulation (rise time). We show that children with dyslexia have excellent phonetic discrimination based on formant transition duration, but poor phonetic discrimination based on envelope cues. The results explain why phonetic discrimination may be allophonic in developmental dyslexia (Serniclaes et al., 2004), and suggest new avenues for the remediation of developmental dyslexia. © 2010 Blackwell Publishing Ltd.

Adults with dyslexia demonstrate space-based and object-based covert attention deficits: shifting attention to the periphery and shifting attention between objects in the left visual field.

PubMed

Buchholz, Judy; Aimola Davies, Anne

2005-02-01

Performance on a covert visual attention task is compared between a group of adults with developmental dyslexia (specifically phonological difficulties) and a group of age and IQ matched controls. The group with dyslexia were generally slower to detect validly-cued targets. Costs of shifting attention toward the periphery when the target was invalidly cued were significantly higher for the group with dyslexia, while costs associated with shifts toward the fovea tended to be lower. Higher costs were also shown by the group with dyslexia for up-down shifts of attention in the periphery. A visual field processing difference was found, in that the group with dyslexia showed higher costs associated with shifting attention between objects in they LVF. These findings indicate that these adults with dyslexia have difficulty in both the space-based and the object-based components of covert visual attention, and more specifically to stimuli located in the periphery.

Development of reading and phonological skills of children at family risk for dyslexia: a longitudinal analysis from kindergarten to sixth grade.

PubMed

Dandache, Sophie; Wouters, Jan; Ghesquière, Pol

2014-11-01

The main focus of this article is to develop a better understanding of the developmental trajectories of literacy and phonological skills within Dutch-speaking children. Children at high and low risk for dyslexia were followed and compared at four different moments: kindergarten and first, third and sixth grades. Three groups were then compared: (1) dyslexic readers; (2) normal readers at high risk for dyslexia; and (3) normal readers at low risk for dyslexia. Children diagnosed with dyslexia scored lower than high-risk normal readers on phonological awareness (PA), rapid automatized naming (RAN), verbal short-term memory and literacy skills. Normal readers at high risk scored between both groups, confirming that dyslexia is to be considered as a continuum rather than an all-or-none condition. Growth analyses showed that the three groups evolved similarly on all measures except for phoneme deletion and literacy measures. Finally, solely PA and RAN explained a significant amount of variance in the evolution of reading skills. Copyright © 2014 John Wiley & Sons, Ltd.

An oscillopathic approach to developmental dyslexia: From genes to speech processing.

PubMed

Jiménez-Bravo, Miguel; Marrero, Victoria; Benítez-Burraco, Antonio

2017-06-30

Developmental dyslexia is a heterogeneous condition entailing problems with reading and spelling. Several genes have been linked or associated to the disease, many of which contribute to the development and function of brain areas important for auditory and phonological processing. Nonetheless, a clear link between genes, the brain, and the symptoms of dyslexia is still pending. The goal of this paper is contributing to bridge this gap. With this aim, we have focused on how the dyslexic brain fails to process speech sounds and reading cues. We have adopted an oscillatory perspective, according to which dyslexia may result from a deficient integration of different brain rhythms during reading/spellings tasks. Moreover, we show that some candidate genes for this condition are related to brain rhythms. This fresh approach is expected to provide a better understanding of the aetiology and the clinical presentation of developmental dyslexia, but also to achieve an earlier and more accurate diagnosis of the disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Could Specific Braille Reading Difficulties Result from Developmental Dyslexia?

ERIC Educational Resources Information Center

Veispak, Anneli; Ghesquiere, Pol

2010-01-01

A proportion of children with visual impairments have specific reading difficulties that cannot be easily explained. This article reviews the data on problems with braille reading and interprets them from the framework of the temporal-processing deficit theory of developmental dyslexia.

Does viotin activate violin more than viocin? On the use of visual cues during visual-word recognition.

PubMed

Perea, Manuel; Panadero, Victoria

2014-01-01

The vast majority of neural and computational models of visual-word recognition assume that lexical access is achieved via the activation of abstract letter identities. Thus, a word's overall shape should play no role in this process. In the present lexical decision experiment, we compared word-like pseudowords like viotín (same shape as its base word: violín) vs. viocín (different shape) in mature (college-aged skilled readers), immature (normally reading children), and immature/impaired (young readers with developmental dyslexia) word-recognition systems. Results revealed similar response times (and error rates) to consistent-shape and inconsistent-shape pseudowords for both adult skilled readers and normally reading children - this is consistent with current models of visual-word recognition. In contrast, young readers with developmental dyslexia made significantly more errors to viotín-like pseudowords than to viocín-like pseudowords. Thus, unlike normally reading children, young readers with developmental dyslexia are sensitive to a word's visual cues, presumably because of poor letter representations.

Developmental dyslexia in Chinese and English populations: dissociating the effect of dyslexia from language differences

PubMed Central

Hu, Wei; Lee, Hwee Ling; Zhang, Qiang; Liu, Tao; Geng, Li Bo; Seghier, Mohamed L.; Shakeshaft, Clare; Twomey, Tae; Green, David W.; Yang, Yi Ming

2010-01-01

Previous neuroimaging studies have suggested that developmental dyslexia has a different neural basis in Chinese and English populations because of known differences in the processing demands of the Chinese and English writing systems. Here, using functional magnetic resonance imaging, we provide the first direct statistically based investigation into how the effect of dyslexia on brain activation is influenced by the Chinese and English writing systems. Brain activation for semantic decisions on written words was compared in English dyslexics, Chinese dyslexics, English normal readers and Chinese normal readers, while controlling for all other experimental parameters. By investigating the effects of dyslexia and language in one study, we show common activation in Chinese and English dyslexics despite different activation in Chinese versus English normal readers. The effect of dyslexia in both languages was observed as less than normal activation in the left angular gyrus and in left middle frontal, posterior temporal and occipitotemporal regions. Differences in Chinese and English normal reading were observed as increased activation for Chinese relative to English in the left inferior frontal sulcus; and increased activation for English relative to Chinese in the left posterior superior temporal sulcus. These cultural differences were not observed in dyslexics who activated both left inferior frontal sulcus and left posterior superior temporal sulcus, consistent with the use of culturally independent strategies when reading is less efficient. By dissociating the effect of dyslexia from differences in Chinese and English normal reading, our results reconcile brain activation results with a substantial body of behavioural studies showing commonalities in the cognitive manifestation of dyslexia in Chinese and English populations. They also demonstrate the influence of cognitive ability and learning environment on a common neural system for reading. PMID:20488886

Developmental dyslexia in Chinese and English populations: dissociating the effect of dyslexia from language differences.

PubMed

Hu, Wei; Lee, Hwee Ling; Zhang, Qiang; Liu, Tao; Geng, Li Bo; Seghier, Mohamed L; Shakeshaft, Clare; Twomey, Tae; Green, David W; Yang, Yi Ming; Price, Cathy J

2010-06-01

Previous neuroimaging studies have suggested that developmental dyslexia has a different neural basis in Chinese and English populations because of known differences in the processing demands of the Chinese and English writing systems. Here, using functional magnetic resonance imaging, we provide the first direct statistically based investigation into how the effect of dyslexia on brain activation is influenced by the Chinese and English writing systems. Brain activation for semantic decisions on written words was compared in English dyslexics, Chinese dyslexics, English normal readers and Chinese normal readers, while controlling for all other experimental parameters. By investigating the effects of dyslexia and language in one study, we show common activation in Chinese and English dyslexics despite different activation in Chinese versus English normal readers. The effect of dyslexia in both languages was observed as less than normal activation in the left angular gyrus and in left middle frontal, posterior temporal and occipitotemporal regions. Differences in Chinese and English normal reading were observed as increased activation for Chinese relative to English in the left inferior frontal sulcus; and increased activation for English relative to Chinese in the left posterior superior temporal sulcus. These cultural differences were not observed in dyslexics who activated both left inferior frontal sulcus and left posterior superior temporal sulcus, consistent with the use of culturally independent strategies when reading is less efficient. By dissociating the effect of dyslexia from differences in Chinese and English normal reading, our results reconcile brain activation results with a substantial body of behavioural studies showing commonalities in the cognitive manifestation of dyslexia in Chinese and English populations. They also demonstrate the influence of cognitive ability and learning environment on a common neural system for reading.

Impaired Statistical Learning in Developmental Dyslexia

ERIC Educational Resources Information Center

Gabay, Yafit; Thiessen, Erik D.; Holt, Lori L.

2015-01-01

Purpose: Developmental dyslexia (DD) is commonly thought to arise from phonological impairments. However, an emerging perspective is that a more general procedural learning deficit, not specific to phonological processing, may underlie DD. The current study examined if individuals with DD are capable of extracting statistical regularities across…

Developmental Dyslexia: Predicting Individual Risk

ERIC Educational Resources Information Center

Thompson, Paul A.; Hulme, Charles; Nash, Hannah M.; Gooch, Debbie; Hayiou-Thomas, Emma; Snowling, Margaret J.

2015-01-01

Background: Causal theories of dyslexia suggest that it is a heritable disorder, which is the outcome of multiple risk factors. However, whether early screening for dyslexia is viable is not yet known. Methods: The study followed children at high risk of dyslexia from preschool through the early primary years assessing them from age 3 years and 6…

Incidental learning of sound categories is impaired in developmental dyslexia.

PubMed

Gabay, Yafit; Holt, Lori L

2015-12-01

Developmental dyslexia is commonly thought to arise from specific phonological impairments. However, recent evidence is consistent with the possibility that phonological impairments arise as symptoms of an underlying dysfunction of procedural learning. The nature of the link between impaired procedural learning and phonological dysfunction is unresolved. Motivated by the observation that speech processing involves the acquisition of procedural category knowledge, the present study investigates the possibility that procedural learning impairment may affect phonological processing by interfering with the typical course of phonetic category learning. The present study tests this hypothesis while controlling for linguistic experience and possible speech-specific deficits by comparing auditory category learning across artificial, nonlinguistic sounds among dyslexic adults and matched controls in a specialized first-person shooter videogame that has been shown to engage procedural learning. Nonspeech auditory category learning was assessed online via within-game measures and also with a post-training task involving overt categorization of familiar and novel sound exemplars. Each measure reveals that dyslexic participants do not acquire procedural category knowledge as effectively as age- and cognitive-ability matched controls. This difference cannot be explained by differences in perceptual acuity for the sounds. Moreover, poor nonspeech category learning is associated with slower phonological processing. Whereas phonological processing impairments have been emphasized as the cause of dyslexia, the current results suggest that impaired auditory category learning, general in nature and not specific to speech signals, could contribute to phonological deficits in dyslexia with subsequent negative effects on language acquisition and reading. Implications for the neuro-cognitive mechanisms of developmental dyslexia are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Incidental Learning of Sound Categories is Impaired in Developmental Dyslexia

PubMed Central

Gabay, Yafit; Holt, Lori L.

2015-01-01

Developmental dyslexia is commonly thought to arise from specific phonological impairments. However, recent evidence is consistent with the possibility that phonological impairments arise as symptoms of an underlying dysfunction of procedural learning. The nature of the link between impaired procedural learning and phonological dysfunction is unresolved. Motivated by the observation that speech processing involves the acquisition of procedural category knowledge, the present study investigates the possibility that procedural learning impairment may affect phonological processing by interfering with the typical course of phonetic category learning. The present study tests this hypothesis while controlling for linguistic experience and possible speech-specific deficits by comparing auditory category learning across artificial, nonlinguistic sounds among dyslexic adults and matched controls in a specialized first-person shooter videogame that has been shown to engage procedural learning. Nonspeech auditory category learning was assessed online via within-game measures and also with a post-training task involving overt categorization of familiar and novel sound exemplars. Each measure reveals that dyslexic participants do not acquire procedural category knowledge as effectively as age- and cognitive-ability matched controls. This difference cannot be explained by differences in perceptual acuity for the sounds. Moreover, poor nonspeech category learning is associated with slower phonological processing. Whereas phonological processing impairments have been emphasized as the cause of dyslexia, the current results suggest that impaired auditory category learning, general in nature and not specific to speech signals, could contribute to phonological deficits in dyslexia with subsequent negative effects on language acquisition and reading. Implications for the neuro-cognitive mechanisms of developmental dyslexia are discussed. PMID:26409017

The joint effects of risk status, gender, early literacy and cognitive skills on the presence of dyslexia among a group of high-risk Chinese children.

PubMed

Wong, Simpson W L; McBride-Chang, Catherine; Lam, Catherine; Chan, Becky; Lam, Fanny W F; Doo, Sylvia

2012-02-01

This study sought to examine factors that are predictive of future developmental dyslexia among a group of 5-year-old Chinese children at risk for dyslexia, including 62 children with a sibling who had been previously diagnosed with dyslexia and 52 children who manifested clinical at-risk factors in aspects of language according to testing by paediatricians. The age-5 performances on various literacy and cognitive tasks, gender and group status (familial risk or language delayed) were used to predict developmental dyslexia 2 years later using logistic regression analysis. Results showed that greater risk of dyslexia was related to slower rapid automatized naming, lower scores on morphological awareness, Chinese character recognition and English letter naming, and gender (boys had more risk). Three logistic equations were generated for estimating individual risk of dyslexia. The strongest models were those that included all print-related variables (including speeded number naming, character recognition and letter identification) and gender, with about 70% accuracy or above. Early identification of those Chinese children at risk for dyslexia can facilitate better dyslexia risk management. Copyright © 2012 John Wiley & Sons, Ltd.

Hemispheric asymmetries in the orientation and location of the lateral geniculate nucleus in dyslexia.

PubMed

Giraldo-Chica, Mónica; Schneider, Keith A

2018-05-01

Human brain asymmetry reflects normal specialization of functional roles and may derive from evolutionary, hereditary, developmental, experiential, and pathological factors (Toga & Thompson, 2003). Geschwind and Galaburda (1985) suggested that processing difficulties in dyslexia are due to structural differences between hemispheres. Because of its potential significance to the controversial magnocellular theory of dyslexia, we investigated hemispheric differences in the human lateral geniculate nucleus (LGN), the primary visual relay and control nucleus in the thalamus, in subjects with dyslexia compared to normal readers. We acquired and averaged multiple high-resolution proton density (PD) weighted structural magnetic resonance imaging (MRI) volumes to measure in detail the anatomical boundaries of the LGN in each hemisphere. We observed hemispheric asymmetries in the orientation of the nucleus in subjects with dyslexia that were absent in controls. We also found differences in the location of the LGN between hemispheres in controls but not in subjects with dyslexia. Neither the precise anatomical differences in the LGN nor their functional consequences are known, nor is it clear whether the differences might be causes or effects of dyslexia. Copyright © 2018 John Wiley & Sons, Ltd.

The Visual Magnocellular Pathway in Chinese-Speaking Children with Developmental Dyslexia

ERIC Educational Resources Information Center

Wang, Jiu-Ju; Bi, Hong-Yan; Gao, Li-Qun; Wydell, Taeko N.

2010-01-01

Previous research into the cognitive processes involved in reading Chinese and developmental dyslexia in Chinese, revealed that the single most important factor appears to be orthographic processing skills rather than phonological skills. Also some studies have indicated that even in alphabetic languages some dyslexic individuals reveal deficits…

Implicit Learning Deficits among Adults with Developmental Dyslexia

ERIC Educational Resources Information Center

Kahta, Shani; Schiff, Rachel

2016-01-01

The aim of the present study was to investigate implicit learning processes among adults with developmental dyslexia (DD) using a visual linguistic artificial grammar learning (AGL) task. Specifically, it was designed to explore whether the intact learning reported in previous studies would also occur under conditions including minimal training…

Amplitude Envelope Perception, Phonology and Prosodic Sensitivity in Children with Developmental Dyslexia

ERIC Educational Resources Information Center

Goswami, Usha; Gerson, Danielle; Astruc, Luisa

2010-01-01

Here we explore relations between auditory perception of amplitude envelope structure, prosodic sensitivity, and phonological awareness in a sample of 56 typically-developing children and children with developmental dyslexia. We examine whether rise time sensitivity is linked to prosodic sensitivity, and whether prosodic sensitivity is linked to…

Longitudinal Stability of Phonological and Surface Subtypes of Developmental Dyslexia

ERIC Educational Resources Information Center

Peterson, Robin L.; Pennington, Bruce F.; Olson, Richard K.; Wadsworth, Sally J.

2014-01-01

Limited evidence supports the external validity of the distinction between developmental phonological and surface dyslexia. We previously identified children ages 8 to 13 meeting criteria for these subtypes (Peterson, Pennington, & Olson, 2013) and now report on their reading and related skills approximately 5 years later. Longitudinal…

Perception of Filtered Speech by Children with Developmental Dyslexia and Children with Specific Language Impairments

PubMed Central

Goswami, Usha; Cumming, Ruth; Chait, Maria; Huss, Martina; Mead, Natasha; Wilson, Angela M.; Barnes, Lisa; Fosker, Tim

2016-01-01

Here we use two filtered speech tasks to investigate children’s processing of slow (<4 Hz) versus faster (∼33 Hz) temporal modulations in speech. We compare groups of children with either developmental dyslexia (Experiment 1) or speech and language impairments (SLIs, Experiment 2) to groups of typically-developing (TD) children age-matched to each disorder group. Ten nursery rhymes were filtered so that their modulation frequencies were either low-pass filtered (<4 Hz) or band-pass filtered (22 – 40 Hz). Recognition of the filtered nursery rhymes was tested in a picture recognition multiple choice paradigm. Children with dyslexia aged 10 years showed equivalent recognition overall to TD controls for both the low-pass and band-pass filtered stimuli, but showed significantly impaired acoustic learning during the experiment from low-pass filtered targets. Children with oral SLIs aged 9 years showed significantly poorer recognition of band pass filtered targets compared to their TD controls, and showed comparable acoustic learning effects to TD children during the experiment. The SLI samples were also divided into children with and without phonological difficulties. The children with both SLI and phonological difficulties were impaired in recognizing both kinds of filtered speech. These data are suggestive of impaired temporal sampling of the speech signal at different modulation rates by children with different kinds of developmental language disorder. Both SLI and dyslexic samples showed impaired discrimination of amplitude rise times. Implications of these findings for a temporal sampling framework for understanding developmental language disorders are discussed. PMID:27303348

Statistical Learning and Dyslexia: A Systematic Review

ERIC Educational Resources Information Center

Schmalz, Xenia; Altoè, Gianmarco; Mulatti, Claudio

2017-01-01

The existing literature on developmental dyslexia (hereafter: dyslexia) often focuses on isolating cognitive skills which differ across dyslexic and control participants. Among potential correlates, previous research has studied group differences between dyslexic and control participants in performance on statistical learning tasks. A statistical…

Predicting Growth in Word Level Reading Skills in Children With Developmental Dyslexia Using an Object Rhyming Functional Neuroimaging Task.

PubMed

Farris, Emily A; Ring, Jeremiah; Black, Jeffrey; Lyon, G Reid; Odegard, Timothy N

2016-04-01

An object rhyming task that does not require text reading and is suitable for younger children was used to predict gains in word level reading skills following an intensive 2-year reading intervention for children with developmental dyslexia. The task evoked activation in bilateral inferior frontal regions. Growth in untimed pseudoword reading was associated with increased pre-intervention activation of the left inferior frontal gyrus, and growth in timed word reading was associated with pre-intervention activation of the left and right inferior frontal gyri. These analyses help identify pre-intervention factors that facilitate reading skill improvements in children with developmental dyslexia.

Spelling and Morphology in Dyslexia: A Developmental Study Across the School Years.

PubMed

Schiff, Rachel; Levie, Ronit

2017-11-01

The current study examined the effect of morphological knowledge on spelling development in Hebrew-speaking schoolchildren, adolescents and adults with dyslexia, compared with typically developing (TD) peers. Participants were 238 Hebrew-speaking readers of five grade levels of whom 139 were TD and 99 had developmental dyslexia (DD). Participants were tested on a function letter spelling task, a phonological awareness task and a morphological awareness task. The overall picture that emerged from the results is that performance on all measures increased with grade level, with TD participants always scoring higher than peers with DD. Moreover, the higher the morphological complexity in spelling and irregularity in noun inflection, the higher the differences between the DD and TD participants. Finally, performance on the morphological awareness task contributed to spelling morphologically more complex spelling items in the TD, but not in the DD group. From clinical and educational perspectives, these results strongly suggest that rigorous morphological instruction is necessary in teaching children and adolescents with dyslexia to identify and use morphological cues in spoken and written Hebrew. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Screening for Dyslexia in French-Speaking University Students: An Evaluation of the Detection Accuracy of the "Alouette" Test

ERIC Educational Resources Information Center

Cavalli, Eddy; Colé, Pascale; Leloup, Gilles; Poracchia-George, Florence; Sprenger-Charolles, Liliane; El Ahmadi, Abdessadek

2018-01-01

Developmental dyslexia is a lifelong impairment affecting 5% to 10% of the population. In French-speaking countries, although a number of standardized tests for dyslexia in children are available, tools suitable to screen for dyslexia in adults are lacking. In this study, we administered the "Alouette" reading test to a normative sample…

Rate and Timing Precision of Motor Coordination in Developmental Dyslexia.

ERIC Educational Resources Information Center

Wolff, Peter H.; And Others

1990-01-01

Adolescents and young adults with developmental dyslexia and matched normal and disabled controls were asked to tap in time to a metronome at three rates by moving the index fingers of both hands in unison, in rhythmical alternation, or in more complex bimanual patterns. Dyslexic subjects showed significant deficits on asynchronous, but not…

Developmental Dyslexia: The Visual Attention Span Deficit Hypothesis

ERIC Educational Resources Information Center

Bosse, Marie-Line; Tainturier, Marie Josephe; Valdois, Sylviane

2007-01-01

The visual attention (VA) span is defined as the amount of distinct visual elements which can be processed in parallel in a multi-element array. Both recent empirical data and theoretical accounts suggest that a VA span deficit might contribute to developmental dyslexia, independently of a phonological disorder. In this study, this hypothesis was…

Arithmetic Abilities in Children with Developmental Dyslexia: Performance on French ZAREKI-R Test

ERIC Educational Resources Information Center

De Clercq-Quaegebeur, Maryse; Casalis, Séverine; Vilette, Bruno; Lemaitre, Marie-Pierre; Vallée, Louis

2018-01-01

A high comorbidity between reading and arithmetic disabilities has already been reported. The present study aims at identifying more precisely patterns of arithmetic performance in children with developmental dyslexia, defined with severe and specific criteria. By means of a standardized test of achievement in mathematics ("Calculation and…

Multisensory Spatial Attention Deficits Are Predictive of Phonological Decoding Skills in Developmental Dyslexia

ERIC Educational Resources Information Center

Facoetti, Andrea; Trussardi, Anna Noemi; Ruffino, Milena; Lorusso, Maria Luisa; Cattaneo, Carmen; Galli, Raffaella; Molteni, Massimo; Zorzi, Marco

2010-01-01

Although the dominant approach posits that developmental dyslexia arises from deficits in systems that are exclusively linguistic in nature (i.e., phonological deficit theory), dyslexics show a variety of lower level deficits in sensory and attentional processing. Although their link to the reading disorder remains contentious, recent empirical…

Behavioral and ERP Evidence for Amodal Sluggish Attentional Shifting in Developmental Dyslexia

ERIC Educational Resources Information Center

Lallier, Marie; Tainturier, Marie-Josephe; Dering, Benjamin; Donnadieu, Sophie; Valdois, Sylviane; Thierry, Guillaume

2010-01-01

The goal of this study was to examine the claim that amodal deficits in attentional shifting may be the source of reading acquisition disorders in phonological developmental dyslexia (sluggish attentional shifting, SAS, theory, Hari & Renvall, 2001). We investigated automatic attentional shifting in the auditory and visual modalities in 13…

Learning Novel Phonological Representations in Developmental Dyslexia: Associations with Basic Auditory Processing of Rise Time and Phonological Awareness

ERIC Educational Resources Information Center

Thomson, Jennifer M.; Goswami, Usha

2010-01-01

Across languages, children with developmental dyslexia are known to have impaired lexical phonological representations. Here, we explore associations between learning new phonological representations, phonological awareness, and sensitivity to amplitude envelope onsets (rise time). We show that individual differences in learning novel phonological…

Auditory Processing of Amplitude Envelope Rise Time in Adults Diagnosed with Developmental Dyslexia

ERIC Educational Resources Information Center

Pasquini, Elisabeth S.; Corriveau, Kathleen H.; Goswami, Usha

2007-01-01

Studies of basic (nonspeech) auditory processing in adults thought to have developmental dyslexia have yielded a variety of data. Yet there has been little consensus regarding the explanatory value of auditory processing in accounting for reading difficulties. Recently, however, a number of studies of basic auditory processing in children with…

Subtypes of Developmental Dyslexia: Testing the Predictions of the Dual-Route and Connectionist Frameworks

ERIC Educational Resources Information Center

Peterson, Robin L.; Pennington, Bruce F.; Olson, Richard K.

2013-01-01

We investigated the phonological and surface subtypes of developmental dyslexia in light of competing predictions made by two computational models of single word reading, the Dual-Route Cascaded Model (DRC; Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001) and Harm and Seidenberg's connectionist model (HS model; Harm & Seidenberg, 1999). The…

Coherence Motion Perception in Developmental Dyslexia: A Meta-Analysis of Behavioral Studies

ERIC Educational Resources Information Center

Benassi, Mariagrazia; Simonelli, Letizia; Giovagnoli, Sara; Bolzani, Roberto

2010-01-01

The magnitude of the association between developmental dyslexia (DD) and motion sensitivity is evaluated in 35 studies, which investigated coherence motion perception in DD. A first analysis is conducted on the differences between DD groups and age-matched control (C) groups. In a second analysis, the relationship between motion coherence…

M-Stream Deficits and Reading-Related Visual Processes in Developmental Dyslexia

ERIC Educational Resources Information Center

Boden, Catherine; Giaschi, Deborah

2007-01-01

Some visual processing deficits in developmental dyslexia have been attributed to abnormalities in the subcortical M stream and/or the cortical dorsal stream of the visual pathways. The nature of the relationship between these visual deficits and reading is unknown. The purpose of the present article was to characterize reading-related perceptual…

Specifying Theories of Developmental Dyslexia: A Diffusion Model Analysis of Word Recognition

ERIC Educational Resources Information Center

Zeguers, Maaike H. T.; Snellings, Patrick; Tijms, Jurgen; Weeda, Wouter D.; Tamboer, Peter; Bexkens, Anika; Huizenga, Hilde M.

2011-01-01

The nature of word recognition difficulties in developmental dyslexia is still a topic of controversy. We investigated the contribution of phonological processing deficits and uncertainty to the word recognition difficulties of dyslexic children by mathematical diffusion modeling of visual and auditory lexical decision data. The first study showed…

Efficacy of a perceptual and visual-motor skill intervention program for students with dyslexia.

PubMed

Fusco, Natália; Germano, Giseli Donadon; Capellini, Simone Aparecida

2015-01-01

To verify the efficacy of a perceptual and visual-motor skill intervention program for students with dyslexia. The participants were 20 students from third to fifth grade of a public elementary school in Marília, São Paulo, aged from 8 years to 11 years and 11 months, distributed into the following groups: Group I (GI; 10 students with developmental dyslexia) and Group II (GII; 10 students with good academic performance). A perceptual and visual-motor intervention program was applied, which comprised exercises for visual-motor coordination, visual discrimination, visual memory, visual-spatial relationship, shape constancy, sequential memory, visual figure-ground coordination, and visual closure. In pre- and post-testing situations, both groups were submitted to the Test of Visual-Perceptual Skills (TVPS-3), and the quality of handwriting was analyzed using the Dysgraphia Scale. The analyzed statistical results showed that both groups of students had dysgraphia in pretesting situation. In visual perceptual skills, GI presented a lower performance compared to GII, as well as in the quality of writing. After undergoing the intervention program, GI increased the average of correct answers in TVPS-3 and improved the quality of handwriting. The developed intervention program proved appropriate for being applied to students with dyslexia, and showed positive effects because it provided improved visual perception skills and quality of writing for students with developmental dyslexia.

Developmental Trajectories for Children With Dyslexia and Low IQ Poor Readers

PubMed Central

2016-01-01

Reading difficulties are found in children with both high and low IQ and it is now clear that both groups exhibit difficulties in phonological processing. Here, we apply the developmental trajectories approach, a new methodology developed for studying language and cognitive impairments in developmental disorders, to both poor reader groups. The trajectory methodology enables identification of atypical versus delayed development in datasets gathered using group matching designs. Regarding the cognitive predictors of reading, which here are phonological awareness, phonological short-term memory (PSTM) and rapid automatized naming (RAN), the method showed that trajectories for the two groups diverged markedly. Children with dyslexia showed atypical development in phonological awareness, while low IQ poor readers showed developmental delay. Low IQ poor readers showed atypical PSTM and RAN development, but children with dyslexia showed developmental delay. These divergent trajectories may have important ramifications for supporting each type of poor reader, although all poor readers showed weakness in all areas. Regarding auditory processing, the developmental trajectories were very similar for the two poor reader groups. However, children with dyslexia demonstrated developmental delay for auditory discrimination of Duration, while the low IQ children showed atypical development on this measure. The data show that, regardless of IQ, poor readers have developmental trajectories that differ from typically developing children. The trajectories approach enables differences in trajectory classification to be identified across poor reader group, as well as specifying the individual nature of these trajectories. PMID:27110928

Visuospatial Superiority in Developmental Dyslexia: Myth or Reality?

ERIC Educational Resources Information Center

Brunswick, Nicola; Martin, G. Neil; Marzano, Lisa

2010-01-01

Anecdotal evidence indicates that dyslexia is positively associated with superior visuospatial ability but empirical evidence is inconsistent. We explicitly tested the hypothesis that dyslexia is associated with visuospatial advantage in 20 dyslexic and 21 unimpaired adult readers using paper-and-pencil measures and tests of "everyday"…

Reading and Dyslexia in Different Orthographies

ERIC Educational Resources Information Center

Brunswick, Nicola, Ed.; McDougall, Sine, Ed.; de Mornay Davies, Paul, Ed.

2010-01-01

This book provides a unique and accessible account of current research on reading and dyslexia in different orthographies. While most research has been conducted in English, this text presents cross-language comparisons to provide insights into universal aspects of reading development and developmental dyslexia in alphabetic and non-alphabetic…

Delayed Detection of Tonal Targets in Background Noise in Dyslexia

ERIC Educational Resources Information Center

Chait, Maria; Eden, Guinevere; Poeppel, David; Simon, Jonathan Z.; Hill, Deborah F.; Flowers, D. Lynn

2007-01-01

Individuals with developmental dyslexia are often impaired in their ability to process certain linguistic and even basic non-linguistic auditory signals. Recent investigations report conflicting findings regarding impaired low-level binaural detection mechanisms associated with dyslexia. Binaural impairment has been hypothesized to stem from a…

Neural entrainment to rhythmic speech in children with developmental dyslexia

PubMed Central

Power, Alan J.; Mead, Natasha; Barnes, Lisa; Goswami, Usha

2013-01-01

A rhythmic paradigm based on repetition of the syllable “ba” was used to study auditory, visual, and audio-visual oscillatory entrainment to speech in children with and without dyslexia using EEG. Children pressed a button whenever they identified a delay in the isochronous stimulus delivery (500 ms; 2 Hz delta band rate). Response power, strength of entrainment and preferred phase of entrainment in the delta and theta frequency bands were compared between groups. The quality of stimulus representation was also measured using cross-correlation of the stimulus envelope with the neural response. The data showed a significant group difference in the preferred phase of entrainment in the delta band in response to the auditory and audio-visual stimulus streams. A different preferred phase has significant implications for the quality of speech information that is encoded neurally, as it implies enhanced neuronal processing (phase alignment) at less informative temporal points in the incoming signal. Consistent with this possibility, the cross-correlogram analysis revealed superior stimulus representation by the control children, who showed a trend for larger peak r-values and significantly later lags in peak r-values compared to participants with dyslexia. Significant relationships between both peak r-values and peak lags were found with behavioral measures of reading. The data indicate that the auditory temporal reference frame for speech processing is atypical in developmental dyslexia, with low frequency (delta) oscillations entraining to a different phase of the rhythmic syllabic input. This would affect the quality of encoding of speech, and could underlie the cognitive impairments in phonological representation that are the behavioral hallmark of this developmental disorder across languages. PMID:24376407

Out-of-synchrony speech entrainment in developmental dyslexia.

PubMed

Molinaro, Nicola; Lizarazu, Mikel; Lallier, Marie; Bourguignon, Mathieu; Carreiras, Manuel

2016-08-01

Developmental dyslexia is a reading disorder often characterized by reduced awareness of speech units. Whether the neural source of this phonological disorder in dyslexic readers results from the malfunctioning of the primary auditory system or damaged feedback communication between higher-order phonological regions (i.e., left inferior frontal regions) and the auditory cortex is still under dispute. Here we recorded magnetoencephalographic (MEG) signals from 20 dyslexic readers and 20 age-matched controls while they were listening to ∼10-s-long spoken sentences. Compared to controls, dyslexic readers had (1) an impaired neural entrainment to speech in the delta band (0.5-1 Hz); (2) a reduced delta synchronization in both the right auditory cortex and the left inferior frontal gyrus; and (3) an impaired feedforward functional coupling between neural oscillations in the right auditory cortex and the left inferior frontal regions. This shows that during speech listening, individuals with developmental dyslexia present reduced neural synchrony to low-frequency speech oscillations in primary auditory regions that hinders higher-order speech processing steps. The present findings, thus, strengthen proposals assuming that improper low-frequency acoustic entrainment affects speech sampling. This low speech-brain synchronization has the strong potential to cause severe consequences for both phonological and reading skills. Interestingly, the reduced speech-brain synchronization in dyslexic readers compared to normal readers (and its higher-order consequences across the speech processing network) appears preserved through the development from childhood to adulthood. Thus, the evaluation of speech-brain synchronization could possibly serve as a diagnostic tool for early detection of children at risk of dyslexia. Hum Brain Mapp 37:2767-2783, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

The Development of Children at Familial Risk for Dyslexia: Birth to Early School Age

ERIC Educational Resources Information Center

Lyytinen, Heikki; Aro, Mikko; Eklund, Kenneth; Erskine, Jane; Guttorm, Tomi; Laakso, Marja-Leena; Leppanen, Paavo H. T.; Lyytinen, Paula; Poikkeus, Anna-Maija; Richardson, Ulla; Torppa, Minna

2004-01-01

Children at risk for familial dyslexia (n = 107) and their controls (n = 93) have been followed from birth to school entry in the Jyvaskyla Longitudinal study of Dyslexia (JLD) on developmental factors linked to reading and dyslexia. At the point of school entry, the majority of the at-risk children displayed decoding ability that fell at least 1…

Music and Dyslexia: The Therapeutic Use of Instrument (Piano) Training with a Child with Dyslexia (A Case Study)

ERIC Educational Resources Information Center

Eren, Bilgehan

2017-01-01

Dyslexia is defined as a difficulty in learning at an expected level according to age, intelligence and education that is given, even though the intelligence level of the individual is normal or above normal. Individuals with dyslexia have difficulties in many developmental areas that can be considered in the scope of music therapy. Interventions…

Beyond Auditory Sensory Processing Deficits: Lexical Tone Perception Deficits in Chinese Children with Developmental Dyslexia

ERIC Educational Resources Information Center

Tong, Xiuhong; Tong, Xiuli; King Yiu, Fung

2018-01-01

Increasing evidence suggests that children with developmental dyslexia exhibit a deficit not only at the segmental level of phonological processing but also, by extension, at the suprasegmental level. However, it remains unclear whether such a suprasegmental phonological processing deficit is due to a difficulty in processing acoustic cues of…

Impaired Letter-String Processing in Developmental Dyslexia: What Visual-to-Phonology Code Mapping Disorder?

ERIC Educational Resources Information Center

Valdois, Sylviane; Lassus-Sangosse, Delphine; Lobier, Muriel

2012-01-01

Poor parallel letter-string processing in developmental dyslexia was taken as evidence of poor visual attention (VA) span, that is, a limitation of visual attentional resources that affects multi-character processing. However, the use of letter stimuli in oral report tasks was challenged on its capacity to highlight a VA span disorder. In…

Dissociation between the Procedural Learning of Letter Names and Motor Sequences in Developmental Dyslexia

ERIC Educational Resources Information Center

Gabay, Yafit; Schiff, Rachel; Vakil, Eli

2012-01-01

Motor sequence learning has been studied extensively in Developmental dyslexia (DD). The purpose of the present research was to examine procedural learning of letter names and motor sequences in individuals with DD and control groups. Both groups completed the Serial Search Task which enabled the assessment of learning of letter names and motor…

Neural Dissociation of Phonological and Visual Attention Span Disorders in Developmental Dyslexia: fMRI Evidence from Two Case Reports

ERIC Educational Resources Information Center

Peyrin, C.; Lallier, M.; Demonet, J. F.; Pernet, C.; Baciu, M.; Le Bas, J. F.; Valdois, S.

2012-01-01

A dissociation between phonological and visual attention (VA) span disorders has been reported in dyslexic children. This study investigates whether this cognitively-based dissociation has a neurobiological counterpart through the investigation of two cases of developmental dyslexia. LL showed a phonological disorder but preserved VA span whereas…

Performance of Children with Developmental Dyslexia on High and Low Topological Entropy Artificial Grammar Learning Task

ERIC Educational Resources Information Center

Katan, Pesia; Kahta, Shani; Sasson, Ayelet; Schiff, Rachel

2017-01-01

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…

Subtyping of Children with Developmental Dyslexia via Bootstrap Aggregated Clustering and the Gap Statistic: Comparison with the Double-Deficit Hypothesis

ERIC Educational Resources Information Center

King, Wayne M.; Giess, Sally A.; Lombardino, Linda J.

2007-01-01

Background: The marked degree of heterogeneity in persons with developmental dyslexia has motivated the investigation of possible subtypes. Attempts have proceeded both from theoretical models of reading and the application of unsupervised learning (clustering) methods. Previous cluster analyses of data obtained from persons with reading…

Neural Correlates of Temporal Auditory Processing in Developmental Dyslexia during German Vowel Length Discrimination: An fMRI Study

ERIC Educational Resources Information Center

Steinbrink, Claudia; Groth, Katarina; Lachmann, Thomas; Riecker, Axel

2012-01-01

This fMRI study investigated phonological vs. auditory temporal processing in developmental dyslexia by means of a German vowel length discrimination paradigm (Groth, Lachmann, Riecker, Muthmann, & Steinbrink, 2011). Behavioral and fMRI data were collected from dyslexics and controls while performing same-different judgments of vowel duration in…

A Visual Training Tool for Teaching Kanji to Children with Developmental Dyslexia

ERIC Educational Resources Information Center

Ikeshita-Yamazoe, Hanae; Miyao, Masutomo

2016-01-01

We developed a visual training tool to assist children with developmental dyslexia in learning to recognize and understand Chinese characters (kanji). The visual training tool presents the strokes of a kanji character as separate shapes and requires students to use these fragments to construct the character. Two types of experiments were conducted…

Rise Time and Formant Transition Duration in the Discrimination of Speech Sounds: The Ba-Wa Distinction in Developmental Dyslexia

ERIC Educational Resources Information Center

Goswami, Usha; Fosker, Tim; Huss, Martina; Mead, Natasha; Szucs, Denes

2011-01-01

Across languages, children with developmental dyslexia have a specific difficulty with the neural representation of the sound structure (phonological structure) of speech. One likely cause of their difficulties with phonology is a perceptual difficulty in auditory temporal processing (Tallal, 1980). Tallal (1980) proposed that basic auditory…

Slow Perceptual Processing at the Core of Developmental Dyslexia: A Parameter-Based Assessment of Visual Attention

ERIC Educational Resources Information Center

Stenneken, Prisca; Egetemeir, Johanna; Schulte-Korne, Gerd; Muller, Hermann J.; Schneider, Werner X.; Finke, Kathrin

2011-01-01

The cognitive causes as well as the neurological and genetic basis of developmental dyslexia, a complex disorder of written language acquisition, are intensely discussed with regard to multiple-deficit models. Accumulating evidence has revealed dyslexics' impairments in a variety of tasks requiring visual attention. The heterogeneity of these…

Performance of Children with Developmental Dyslexia on Two Skill Learning Tasks--Serial Reaction Time and Tower of Hanoi Puzzle

ERIC Educational Resources Information Center

Vakil, Eli; Lowe, Michal; Goldfus, Carol

2015-01-01

Among the various theories proposed to explain developmental dyslexia (DD), the theory of specific procedural learning difficulties has gained certain support and is the framework for the current research. This theory claims that an inability to achieve skill automaticity explains the difficulties experienced by individuals with DD. Previous…

The Cognitive Deficits Responsible for Developmental Dyslexia: Review of Evidence for a Selective Visual Attentional Disorder

ERIC Educational Resources Information Center

Valdois, Sylviane; Bosse, Marie-Line; Tainturier, Marie-Josephe

2004-01-01

There is strong converging evidence suggesting that developmental dyslexia stems from a phonological processing deficit. However, this hypothesis has been challenged by the widely admitted heterogeneity of the dyslexic population, and by several reports of dyslexic individuals with no apparent phonological deficit. In this paper, we discuss the…

Inclusive Music Teaching Strategies for Elementary-Age Children with Developmental Dyslexia

ERIC Educational Resources Information Center

Heikkila, Elizabeth; Knight, Andrew

2012-01-01

Developmental dyslexia (DD) is more prevalent as an "umbrella" disorder than many educators realize. The music educator can play a particularly useful role in helping children in the general or choral classroom cope with DD, given the temporal nature of cognitive issues inherent in the disorder. The purposes of this article are to…

What Can Reduce Letter Migrations in Letter Position Dyslexia?

ERIC Educational Resources Information Center

Friedmann, Naama; Rahamim, Einav

2014-01-01

Letter position dyslexia (LPD) is a peripheral dyslexia that causes errors of letter position within words, such as reading "cloud" as "could." In this study, we assessed the effect of various display manipulations and reading methods on the reading of 10 Hebrew readers with developmental LPD. These manipulations included…

Phonological Precedence in Dyslexia: A Case Study

ERIC Educational Resources Information Center

Schneider-Zioga, Patricia

2012-01-01

Developmental dyslexia is believed to involve a phonological deficit of which the exact properties have not been clearly established. This article presents the findings of a longitudinal case study that suggest that, at least for some people with dyslexia, the fundamental problem involves a disturbance of temporal-spatial ordering abilities. A…

Lexical decision performance in developmental surface dysgraphia: Evidence for a unitary orthographic system that is used in both reading and spelling.

PubMed

Sotiropoulos, Andreas; Hanley, J Richard

The relationship between spelling, written word recognition, and picture naming is investigated in a study of seven bilingual adults who have developmental surface dysgraphia in both Greek (their first language) and English (their second language). Four of the cases also performed poorly at orthographic lexical decision in both languages. This finding is consistent with similar results in Italian that have been taken as evidence of a developmental impairment to a single orthographic system that is used for both reading and spelling. The remaining three participants performed well at orthographic lexical decision. At first sight, preserved lexical decision in surface dysgraphia is less easy to explain in terms of a shared orthographic system. However, the results of subsequent experiments showed clear parallels between the nature of the reading and spelling difficulties that these three individuals experienced, consistent with the existence of a single orthographic system. The different patterns that were observed were consistent with the claims of Friedmann and Lukov (2008. Developmental surface dyslexias. Cortex, 44, 1146-1160) that several distinct sub-types of developmental surface dyslexia exist. We show that individual differences in spelling in surface dysgraphia are also consistent with these sub-types; there are different developmental deficits that can give rise, in an individual, to a combination of surface dyslexia and dysgraphia. Finally, we compare the theoretical framework used by Friedmann and her colleagues that is based upon the architecture of the DRC model with an account that relies instead upon the Triangle model of reading].

Cortical thickness abnormalities associated with dyslexia, independent of remediation status.

PubMed

Ma, Yizhou; Koyama, Maki S; Milham, Michael P; Castellanos, F Xavier; Quinn, Brian T; Pardoe, Heath; Wang, Xiuyuan; Kuzniecky, Ruben; Devinsky, Orrin; Thesen, Thomas; Blackmon, Karen

2015-01-01

Abnormalities in cortical structure are commonly observed in children with dyslexia in key regions of the "reading network." Whether alteration in cortical features reflects pathology inherent to dyslexia or environmental influence (e.g., impoverished reading experience) remains unclear. To address this question, we compared MRI-derived metrics of cortical thickness (CT), surface area (SA), gray matter volume (GMV), and their lateralization across three different groups of children with a historical diagnosis of dyslexia, who varied in current reading level. We compared three dyslexia subgroups with: (1) persistent reading and spelling impairment; (2) remediated reading impairment (normal reading scores), and (3) remediated reading and spelling impairments (normal reading and spelling scores); and a control group of (4) typically developing children. All groups were matched for age, gender, handedness, and IQ. We hypothesized that the dyslexia group would show cortical abnormalities in regions of the reading network relative to controls, irrespective of remediation status. Such a finding would support that cortical abnormalities are inherent to dyslexia and are not a consequence of abnormal reading experience. Results revealed increased CT of the left fusiform gyrus in the dyslexia group relative to controls. Similarly, the dyslexia group showed CT increase of the right superior temporal gyrus, extending into the planum temporale, which resulted in a rightward CT asymmetry on lateralization indices. There were no group differences in SA, GMV, or their lateralization. These findings held true regardless of remediation status. Each reading level group showed the same "double hit" of atypically increased left fusiform CT and rightward superior temporal CT asymmetry. Thus, findings provide evidence that a developmental history of dyslexia is associated with CT abnormalities, independent of remediation status.

Cortical thickness abnormalities associated with dyslexia, independent of remediation status

PubMed Central

Ma, Yizhou; Koyama, Maki S.; Milham, Michael P.; Castellanos, F. Xavier; Quinn, Brian T.; Pardoe, Heath; Wang, Xiuyuan; Kuzniecky, Ruben; Devinsky, Orrin; Thesen, Thomas; Blackmon, Karen

2014-01-01

Abnormalities in cortical structure are commonly observed in children with dyslexia in key regions of the “reading network.” Whether alteration in cortical features reflects pathology inherent to dyslexia or environmental influence (e.g., impoverished reading experience) remains unclear. To address this question, we compared MRI-derived metrics of cortical thickness (CT), surface area (SA), gray matter volume (GMV), and their lateralization across three different groups of children with a historical diagnosis of dyslexia, who varied in current reading level. We compared three dyslexia subgroups with: (1) persistent reading and spelling impairment; (2) remediated reading impairment (normal reading scores), and (3) remediated reading and spelling impairments (normal reading and spelling scores); and a control group of (4) typically developing children. All groups were matched for age, gender, handedness, and IQ. We hypothesized that the dyslexia group would show cortical abnormalities in regions of the reading network relative to controls, irrespective of remediation status. Such a finding would support that cortical abnormalities are inherent to dyslexia and are not a consequence of abnormal reading experience. Results revealed increased CT of the left fusiform gyrus in the dyslexia group relative to controls. Similarly, the dyslexia group showed CT increase of the right superior temporal gyrus, extending into the planum temporale, which resulted in a rightward CT asymmetry on lateralization indices. There were no group differences in SA, GMV, or their lateralization. These findings held true regardless of remediation status. Each reading level group showed the same “double hit” of atypically increased left fusiform CT and rightward superior temporal CT asymmetry. Thus, findings provide evidence that a developmental history of dyslexia is associated with CT abnormalities, independent of remediation status. PMID:25610779

Pay Attention!: Sluggish Multisensory Attentional Shifting as a Core Deficit in Developmental Dyslexia.

PubMed

Krause, Margaret B

2015-11-01

The aim of this review is to provide a background on the neurocognitive aspects of the reading process and review neuroscientific studies of individuals with developmental dyslexia, which provide evidence for amodal processing deficits. Hari, Renvall, and Tanskanen (2001) propose amodal sluggish attentional shifting (SAS) as a causal factor for temporal processing deficits in dyslexia. Undergirding this theory is the notion that when dyslexics are faced with rapid sequences of stimuli, their automatic attentional systems fail to disengage efficiently, which leads to difficulty when moving from one item to the next (Lallier et al., ). This results in atypical perception of rapid stimulus sequences. Until recently, the SAS theory, particularly the examination of amodal attentional deficits, was studied solely through the use of behavioural measures (Facoetti et al., ; Facoetti, Lorusso, Cattaneo, Galli, & Molteni, ). This paper examines evidence within the literature that provides a basis for further exploration of amodal SAS as an underlying deficit in developmental dyslexia. Copyright © 2015 John Wiley & Sons, Ltd.

Global and local pitch perception in children with developmental dyslexia.

PubMed

Ziegler, Johannes C; Pech-Georgel, Catherine; George, Florence; Foxton, Jessica M

2012-03-01

This study investigated global versus local pitch pattern perception in children with dyslexia aged between 8 and 11 years. Children listened to two consecutive 4-tone pitch sequences while performing a same/different task. On the different trials, sequences either preserved the contour (local condition) or they violated the contour (global condition). Compared to normally developing children, dyslexics showed robust pitch perception deficits in the local but not the global condition. This finding was replicated in a simple pitch direction task, which minimizes sequencing and short term memory. Results are consistent with a left-hemisphere deficit in dyslexia because local pitch changes are supposedly processed by the left hemisphere, whereas global pitch changes are processed by the right hemisphere. The present data suggest a link between impaired pitch processing and abnormal phonological development in children with dyslexia, which makes pitch pattern processing a potent tool for early diagnosis and remediation of dyslexia. Copyright © 2011 Elsevier Inc. All rights reserved.

Executive functions in adults with developmental dyslexia.

PubMed

Smith-Spark, James H; Henry, Lucy A; Messer, David J; Edvardsdottir, Elisa; Zięcik, Adam P

2016-01-01

Executive functioning (EF) deficits are well recognized in developmental dyslexia, yet the majority of studies have concerned children rather than adults, ignored the subjective experience of the individual with dyslexia (with regard to their own EFs), and have not followed current theoretical perspectives on EFs. The current study addressed these shortfalls by administering a self-report measure of EF (BRIEF-A; Roth, Isquith, & Gioia, 2005) and experimental tasks to IQ-matched groups of adults with and without dyslexia. The laboratory-based tasks tested the three factors constituting the framework of EF proposed by Miyake et al. (2000). In comparison to the group without dyslexia, the participants with dyslexia self-reported more frequent EF problems in day-to-day life, with these difficulties centering on metacognitive processes (working memory, planning, task monitoring, and organization) rather than on the regulation of emotion and behaviour. The participants with dyslexia showed significant deficits in EF (inhibition, set shifting, and working memory). The findings indicated that dyslexia-related problems have an impact on the daily experience of adults with the condition. Further, EF difficulties are present in adulthood across a range of laboratory-based measures, and, given the nature of the experimental tasks presented, extend beyond difficulties related solely to phonological processing. Copyright © 2016 Elsevier Ltd. All rights reserved.

False memory for orthographically versus semantically similar words in adolescents with dyslexia: a fuzzy-trace theory perspective.

PubMed

Obidziński, Michał; Nieznański, Marek

2017-10-01

The presented research was conducted in order to investigate the connections between developmental dyslexia and the functioning of verbatim and gist memory traces-assumed in the fuzzy-trace theory. The participants were 71 high school students (33 with dyslexia and 38 without learning difficulties). The modified procedure and multinomial model of Stahl and Klauer (simplified conjoint recognition model) was used to collect and analyze data. Results showed statistically significant differences in four of the model parameters: (a) the probability of verbatim trace recollection upon presentation of orthographically similar stimulus was higher in the control than dyslexia group, (b) the probability of verbatim trace recollection upon presentation of semantically similar stimulus was higher in the control than dyslexia group, (c) the probability of gist trace retrieval upon presentation of semantically similar stimulus was higher in the dyslexia than control group, and (d) the probability of gist trace retrieval upon target stimulus presentation (in the semantic condition) was higher in the control than dyslexia group. The obtained results suggest differences of memory functioning in terms of verbatim and gist trace retrieval between people with and without dyslexia on specific, elementary cognitive processes postulated by the fuzzy-trace theory. These can indicate new approaches in the education of persons with developmental dyslexia, focused on specific impairments and the strengths of their memory functioning.

Is the Phonological Deficit in Developmental Dyslexia Related to Impaired Phonological Representations and to Universal Phonological Grammar?

ERIC Educational Resources Information Center

Maionchi-Pino, Norbert; Taki, Yasuyuki; Yokoyama, Satoru; Magnan, Annie; Takahashi, Kei; Hashizume, Hiroshi; Ecalle, Jean; Kawashima, Ryuta

2013-01-01

To date, the nature of the phonological deficit in developmental dyslexia is still debated. We concur with possible impairments in the representations of the universal phonological constraints that universally govern how phonemes co-occur as a source of this deficit. We were interested in whether-and how-dyslexic children have sensitivity to…

Knowledge and Beliefs about Developmental Dyslexia: A Comparison between Pre-Service and In-Service Peruvian Teachers

ERIC Educational Resources Information Center

Echegaray-Bengoa, Joyce; Soriano-Ferrer, Manuel; Joshi, R. Malatesha

2017-01-01

The purpose of this study was to investigate the knowledge, misconceptions, and knowledge gaps of Peruvian pre-service teachers (PSTs) and in-service teachers (ISTs). To do so, 112 PSTs and 113 ISTs completed the Knowledge and Beliefs About Developmental Dyslexia Scale (KBDDS). Results show that ISTs scored significantly higher than PSTs.…

Parameter-Based Assessment of Disturbed and Intact Components of Visual Attention in Children with Developmental Dyslexia

ERIC Educational Resources Information Center

Bogon, Johanna; Finke, Kathrin; Schulte-Körne, Gerd; Müller, Hermann J.; Schneider, Werner X.; Stenneken, Prisca

2014-01-01

People with developmental dyslexia (DD) have been shown to be impaired in tasks that require the processing of multiple visual elements in parallel. It has been suggested that this deficit originates from disturbed visual attentional functions. The parameter-based assessment of visual attention based on Bundesen's (1990) theory of visual…

Working-memory training improves developmental dyslexia in Chinese children.

PubMed

Luo, Yan; Wang, Jing; Wu, Hanrong; Zhu, Dongmei; Zhang, Yu

2013-02-15

Although plasticity in the neural system underlies working memory, and working memory can be improved by training, there is thus far no evidence that children with developmental dyslexia can benefit from working-memory training. In the present study, thirty dyslexic children aged 8-11 years were recruited from an elementary school in Wuhan, China. They received working-memory training, including training in visuospatial memory, verbal memory, and central executive tasks. The difficulty of the tasks was adjusted based on the performance of each subject, and the training sessions lasted 40 minutes per day, for 5 weeks. The results showed that working-memory training significantly enhanced performance on the nontrained working memory tasks such as the visuospatial, the verbal domains, and central executive tasks in children with developmental dyslexia. More importantly, the visual rhyming task and reading fluency task were also significantly improved by training. Progress on working memory measures was related to changes in reading skills. These experimental findings indicate that working memory is a pivotal factor in reading development among children with developmental dyslexia, and interventions to improve working memory may help dyslexic children to become more proficient in reading.

Developmental Dyslexia: Early Precursors, Neurobehavioral Markers, and Biological Substrates

ERIC Educational Resources Information Center

Benasich, April A., Ed.; Fitch, R. Holly, Ed.

2012-01-01

Understanding the precursors and early indicators of dyslexia is key to early identification and effective intervention. Now there's a single research volume that brings together the very latest knowledge on the earliest stages of dyslexia and the diverse genetic, neurobiological, and cognitive factors that may contribute to it. Based on findings…

Non-Adjacent Dependency Learning in Infants at Familial Risk of Dyslexia

ERIC Educational Resources Information Center

Kerkhoff, Annemarie; de Bree, Elise; de Klerk, Maartje; Wijnen, Frank

2013-01-01

This study tests the hypothesis that developmental dyslexia is (partly) caused by a deficit in implicit sequential learning, by investigating whether infants at familial risk of dyslexia can track non-adjacent dependencies in an artificial language. An implicit learning deficit would hinder detection of such dependencies, which mark grammatical…

Impaired Perception of Syllable Stress in Children with Dyslexia: A Longitudinal Study

ERIC Educational Resources Information Center

Goswami, Usha; Mead, Natasha; Fosker, Tim; Huss, Martina; Barnes, Lisa; Leong, Victoria

2013-01-01

Prosodic patterning is a key structural element of spoken language. However, the potential role of prosodic awareness in the phonological difficulties that characterise children with developmental dyslexia has been little studied. Here we report the first longitudinal study of sensitivity to syllable stress in children with dyslexia, enabling the…

Genetics and Neuroscience in Dyslexia: Perspectives for Education and Remediation

ERIC Educational Resources Information Center

Schulte-Korne, Gerd; Ludwig, Kerstin U.; el Sharkawy, Jennifer; Nothen, Markus M.; Muller-Myhsok, Bertram; Hoffmann, Per

2007-01-01

Our understanding of the causes of a developmental disorder like dyslexia has received recent input from both neuroscience and genetics. The discovery of 4 candidate genes for dyslexia and the identification of neuronal networks engaged when children read and spell are the basis for introducing this knowledge into education. However, the input…

Longitudinal Stability of Pre-Reading Skill Profiles of Kindergarten Children: Implications for Early Screening and Theories of Reading

ERIC Educational Resources Information Center

Ozernov-Palchik, Ola; Norton, Elizabeth S.; Sideridis, Georgios; Beach, Sara D.; Wolf, Maryanne; Gabrieli, John D. E.; Gaab, Nadine

2017-01-01

Research suggests that early identification of developmental dyslexia is important for mitigating the negative effects of dyslexia, including reduced educational attainment and increased socioemotional difficulties. The strongest pre-literacy predictors of dyslexia are rapid automatized naming (RAN), phonological awareness (PA), letter knowledge,…

A Quasi-Experimental Analysis of Second Graders with Dyslexia Using the Motor Markers in the Cerebellar Deficit Hypothesis

ERIC Educational Resources Information Center

Stark, Sandra Kathleen

2013-01-01

Developmental dyslexia is a specific impairment of reading ability in the presence of normal intelligence and adequate reading instruction. Current research has linked dyslexia to genetic underpinnings, which are identifiable. Furthermore, there are cognitive processes that are influenced by unique genetically programmed neural networks that…

Reduced Sensitivity to Slow-Rate Dynamic Auditory Information in Children with Dyslexia

ERIC Educational Resources Information Center

Poelmans, Hanne; Luts, Heleen; Vandermosten, Maaike; Boets, Bart; Ghesquiere, Pol; Wouters, Jan

2011-01-01

The etiology of developmental dyslexia remains widely debated. An appealing theory postulates that the reading and spelling problems in individuals with dyslexia originate from reduced sensitivity to slow-rate dynamic auditory cues. This low-level auditory deficit is thought to provoke a cascade of effects, including inaccurate speech perception…

Beyond Auditory Sensory Processing Deficits: Lexical Tone Perception Deficits in Chinese Children With Developmental Dyslexia.

PubMed

Tong, Xiuhong; Tong, Xiuli; King Yiu, Fung

Increasing evidence suggests that children with developmental dyslexia exhibit a deficit not only at the segmental level of phonological processing but also, by extension, at the suprasegmental level. However, it remains unclear whether such a suprasegmental phonological processing deficit is due to a difficulty in processing acoustic cues of speech rhythm, such as rise time and intensity. This study set out to investigate to what extent suprasegmental phonological processing (i.e., Cantonese lexical tone perception) and rise time sensitivity could distinguish Chinese children with dyslexia from typically developing children. Sixteen children with dyslexia and 44 age-matched controls were administered a Cantonese lexical tone perception task, psychoacoustic tasks, a nonverbal reasoning ability task, and word reading and dictation tasks. Children with dyslexia performed worse than controls on Cantonese lexical tone perception, rise time, and intensity. Furthermore, Cantonese lexical tone perception appeared to be a stable indicator that distinguishes children with dyslexia from controls, even after controlling for basic auditory processing skills. These findings suggest that suprasegmental phonological processing (i.e., lexical tone perception) is a potential factor that accounts for reading difficulty in Chinese.

Balance and gait in children with dyslexia.

PubMed

Moe-Nilssen, Rolf; Helbostad, Jorunn L; Talcott, Joel B; Toennessen, Finn Egil

2003-05-01

Tests of postural stability have provided some evidence of a link between deficits in gross motor skills and developmental dyslexia. The ordinal-level scales used previously, however, have limited measurement sensitivity, and no studies have investigated motor performance during walking in participants with dyslexia. The purpose of this study was to investigate if continuous-scaled measures of standing balance and gait could discriminate between groups of impaired and normal readers when investigators were blind to group membership during testing. Children with dyslexia ( n=22) and controls ( n=18), aged 10-12 years, performed walking tests at four different speeds (slow-preferred-fast-very fast) on an even and an uneven surface, and tests of unperturbed and perturbed body sway during standing. Body movements were registered by a triaxial accelerometer over the lower trunk, and measures of reaction time, body sway, walking speed, step length and cadence were calculated. Results were controlled for gender differences. Tests of standing balance with eyes closed did not discriminate between groups. All unperturbed standing tests with eyes open showed significant group differences ( P<0.05) and classified correctly 70-77.5% of the subjects into their respective groups. Mean walking speed during very fast walking on both flat and uneven surface was > or =0.2 m/s ( P< or =0.01) faster for controls than for the group with dyslexia. This test classified 77.5% and 85% of the subjects correctly on flat and uneven surface, respectively. Cadence at preferred or very fast speed did not differ statistically between groups, but revealed significant group differences when all subjects were compared at a normalised walking speed ( P< or =0.04). Very fast walking speed as well as cadence at a normalised speed discriminated better between groups when subjects were walking on an uneven surface compared to a flat floor. Continuous-scaled walking tests performed in field settings may be suitable for motor skill assessment as a component of a screening tool for developmental dyslexia.

The Joint Effects of Risk Status, Gender, Early Literacy and Cognitive Skills on the Presence of Dyslexia among a Group of High-Risk Chinese Children

ERIC Educational Resources Information Center

Wong, Simpson W. L.; McBride-Chang, Catherine; Lam, Catherine; Chan, Becky; Lam, Fanny W. F.; Doo, Sylvia

2012-01-01

This study sought to examine factors that are predictive of future developmental dyslexia among a group of 5-year-old Chinese children at risk for dyslexia, including 62 children with a sibling who had been previously diagnosed with dyslexia and 52 children who manifested clinical at-risk factors in aspects of language according to testing by…

Developmental surface and phonological dyslexia in both Greek and English.

PubMed

Sotiropoulos, Andreas; Hanley, J Richard

2017-11-01

The hallmark of developmental surface dyslexia in English and French is inaccurate reading of words with atypical spelling-sound correspondences. According to Douklias, Masterson and Hanley (2009), surface dyslexia can also be observed in Greek (a transparent orthography for reading that does not contain words of this kind). Their findings suggested that surface dyslexia in Greek can be characterized by slow reading of familiar words, and by inaccurate spelling of words with atypical sound-spelling correspondences (Greek is less transparent for spelling than for reading). In this study, we report seven adult cases whose slow reading and impaired spelling accuracy satisfied these criteria for Greek surface dyslexia. When asked to read words with atypical grapheme-phoneme correspondences in English (their second language), their accuracy was severely impaired. A co-occurrence was also observed between impaired spelling of words with atypical phoneme-grapheme correspondences in English and Greek. These co-occurrences provide strong evidence that surface dyslexia genuinely exists in Greek and that slow reading of real words in Greek reflects the same underlying impairment as that which produces inaccurate reading of atypical words in English. Two further individuals were observed with impaired reading and spelling of nonwords in both languages, consistent with developmental phonological dyslexia. Neither of the phonological dyslexics read words slowly. In terms of computational models of reading aloud, these findings suggest that slow reading by dyslexics in transparent orthographies is the consequence of a developmental impairment of the lexical (Coltheart, Rastle, Perry, Langdon, & Zeigler, 2001; Perry, Ziegler, & Zorzi, 2010) or semantic reading route (Plaut, McClelland, Seidenberg, & Patterson, 1996). This outcome provides evidence that the neurophysiological substrate(s) that support the lexical/semantic and the phonological pathways that are involved in reading and spelling are the same in both Greek and English. Copyright © 2017 Elsevier B.V. All rights reserved.

Rapid Processing of Letters, Digits and Symbols: What Purely Visual-Attentional Deficit in Developmental Dyslexia?

ERIC Educational Resources Information Center

Ziegler, Johannes C.; Pech-Georgel, Catherine; Dufau, Stephane; Grainger, Jonathan

2010-01-01

Visual-attentional theories of dyslexia predict deficits for dyslexic children not only for the perception of letter strings but also for non-alphanumeric symbol strings. This prediction was tested in a two-alternative forced-choice paradigm with letters, digits, and symbols. Children with dyslexia showed significant deficits for letter and digit…

Putative Risk Factors in Developmental Dyslexia: A Case-Control Study of Italian Children

ERIC Educational Resources Information Center

Mascheretti, Sara; Marino, Cecilia; Simone, Daniela; Quadrelli, Ermanno; Riva, Valentina; Cellino, Maria Rosaria; Maziade, Michel; Brombin, Chiara; Battaglia, Marco

2015-01-01

Although dyslexia runs in families, several putative risk factors that cannot be immediately identified as genetic predict reading disability. Published studies analyzed one or a few risk factors at a time, with relatively inconsistent results. To assess the contribution of several putative risk factors to the development of dyslexia, we conducted…

Examination of the Double-Deficit Hypothesis with Adolescents and Young Adults with Dyslexia

ERIC Educational Resources Information Center

Nelson, Jason M.

2015-01-01

The double-deficit hypothesis (DDH) of the developmental dyslexias (Wolf and Bowers, "Journal of Educational Psychology", 91, 415-438, 1999) was investigated with 149 adolescents and young adults (age range?=?16 to 24 years) with dyslexia. Confirmatory factor analysis indicated that a two-factor model with separate naming speed (NS) and…

Neural signatures of phonological deficits in Chinese developmental dyslexia.

PubMed

Cao, Fan; Yan, Xin; Wang, Zhao; Liu, Yanni; Wang, Jin; Spray, Gregory J; Deng, Yuan

2017-02-01

There has been debate on whether phonological deficits explain reading difficulty in Chinese, since Chinese is a logographic language which does not employ grapheme-phoneme-correspondence rules and remote memorization seems to be the main method to acquire reading. In the current study, we present neuroimaging evidence that the phonological deficit is also a signature of Chinese dyslexia. Specifically, we found that Chinese children with dyslexia (DD) showed reduced brain activation in the left dorsal inferior frontal gyrus (dIFG) when compared to both age-matched controls (AC) and reading-matched controls (RC) during an auditory rhyming judgment task. This suggests that the phonological processing deficit in this region may be a signature of dyslexia in Chinese, rather than a difference due to task performance or reading ability, which was matched on DD and RC. At exactly the same region of the left dIFG, we found a positive correlation between brain activation and reading skill in DD, suggesting that the phonological deficit is associated with the severity of dyslexia. We also found increased brain activation in the right precentral gyrus in DD than both AC and RC, suggesting a compensation of reliance on articulation. Functional connectivity analyses revealed that DD had a weaker connection between the left superior temporal gyrus (STG) and fusiform gyrus (FG) than the two control groups, suggesting that the reduced connection between phonology and orthography is another neural signature of dyslexia. In contrast, DD showed greater connectivity between the left dIFG and the left inferior parietal lobule (IPL) than both control groups, suggesting a reduced segregation between the language network and default mode network in dyslexic children. We also found that connectivity between the left STG and the left dIFG was sensitive to task performance and/or reading skill rather than being dyslexic or not, because AC was greater than both RC and DD, while the connectivity between the left middle occipital gyrus (MOG) and left STG was sensitive to age, because both AC and DD were greater than RC. In summary, our study provides the very first neurological evidence of phonological deficits in Chinese developmental dyslexia and we successfully distinguished variations of brain activity/functional connectivity due to age, performance, and dyslexia by comparing AC, RC, and DD. Copyright © 2016 Elsevier Inc. All rights reserved.

Environmental Risk Factors in Han and Uyghur Children with Dyslexia: A Comparative Study.

PubMed

Zhao, Hua; Zhang, Baoping; Chen, Yun; Zhou, Xiang; Zuo, Pengxiang

2016-01-01

Several studies have been conducted to explore risk factors for dyslexia. However, most studies examining dyslexia have been skewed toward Western countries, and few have considered two nationalities simultaneously. This study focused on differences in dyslexia prevalence and potential environmental risk factors between Han and Uyghur children. A cross-sectional study was conducted in Kashgar and Aksu, cities in Xinjiang province, China. A two-stage sampling strategy was used to recruit 2,854 students in grades 3-6 from 5 primary schools in 5 districts; 2,348 valid student questionnaires were included in the analysis. Dyslexia checklists for Chinese and Uyghur children and pupil rating scales were used to identify children with dyslexia. Questions related to the home literacy environment and reading ability were used to evaluate potential environmental risk factors. Single factor analysis and multivariate logistic regression were used to examine prevalence and risk factors for dyslexia. Dyslexia prevalence differed significantly between Han (3.9%) and Uyghur (7.0%) children (P < 0.05), and the boy-to-girl diagnosis ratio was almost 2:1. Multiple logistic regression analysis showed that ethnic differences in dyslexia prevalence between Han and Uyghur children could have occurred because of factors such as mother's occupation (P = 0.02, OR = 0.04, 95% CI = 0.01-0.68) and the frequency with which parents told stories (P = 0.00, OR = 4.50, 95% CI = 1.67-12.11). The prevalence of dyslexia was high in all children, particularly those in the Uyghur group. Environmental factors could have been responsible for some of the differences observed. The results contribute to the early identification and management of dyslexia in children from these two groups and research examining developmental dyslexia and differences in racial genetics.

Self-Reports of Increased Prospective and Retrospective Memory Problems in Adults with Developmental Dyslexia.

PubMed

Smith-Spark, James H; Zięcik, Adam P; Sterling, Christopher

2016-08-01

Short-term and working memory problems in dyslexia are well-documented, but other memory domains have received little empirical scrutiny, despite some evidence to suggest that they might be impaired. Prospective memory is memory for delayed intentions, whilst retrospective memory relates to memory for personally experienced past events. To gain an understanding of subjective everyday memory experience, a self-report measure designed to tap prospective and retrospective memory was administered to 28 adults with dyslexia and 26 IQ-matched adults without dyslexia. Adults with dyslexia reported experiencing significantly more frequent problems with memory than the adults without dyslexia. Group differences were found across seven out of the eight questionnaire scales. Further to these analyses, the participants' own ratings were compared with proxy ratings provided by close associates. The perception of poorer memory abilities in the participants did not differ between respondent types. The self-reported difficulties are, thus, unlikely to be the result of lowered self-esteem or metacognitive awareness. More frequent difficulties with both types of memory would seem, therefore, to be experienced by adults with dyslexia in everyday life. Further laboratory-based research is recommended to explore both memory domains in dyslexia and to identify the cognitive mechanisms by which these problems occur. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Dissociation between exact and approximate addition in developmental dyslexia.

PubMed

Yang, Xiujie; Meng, Xiangzhi

2016-09-01

Previous research has suggested that number sense and language are involved in number representation and calculation, in which number sense supports approximate arithmetic, and language permits exact enumeration and calculation. Meanwhile, individuals with dyslexia have a core deficit in phonological processing. Based on these findings, we thus hypothesized that children with dyslexia may exhibit exact calculation impairment while doing mental arithmetic. The reaction time and accuracy while doing exact and approximate addition with symbolic Arabic digits and non-symbolic visual arrays of dots were compared between typically developing children and children with dyslexia. Reaction time analyses did not reveal any differences across two groups of children, the accuracies, interestingly, revealed a distinction of approximation and exact addition across two groups of children. Specifically, two groups of children had no differences in approximation. Children with dyslexia, however, had significantly lower accuracy in exact addition in both symbolic and non-symbolic tasks than that of typically developing children. Moreover, linguistic performances were selectively associated with exact calculation across individuals. These results suggested that children with dyslexia have a mental arithmetic deficit specifically in the realm of exact calculation, while their approximation ability is relatively intact. Copyright © 2016 Elsevier Ltd. All rights reserved.

Improved reading measures in adults with dyslexia following transcranial direct current stimulation treatment.

PubMed

Heth, Inbahl; Lavidor, Michal

2015-04-01

To better understand the contribution of the dorsal system to word reading, we explored transcranial direct current stimulation (tDCS) effects when adults with developmental dyslexia received active stimulation over the visual extrastriate area MT/V5, which is dominated by magnocellular input. Stimulation was administered in 5 sessions spread over two weeks, and reading speed and accuracy as well as reading fluency were assessed before, immediately after, and a week after the end of the treatment. A control group of adults with developmental dyslexia matched for age, gender, reading level, vocabulary and block-design WAIS-III sub-tests and reading level was exposed to the same protocol but with sham stimulation. The results revealed that active, but not sham stimulation, significantly improved reading speed and fluency. This finding suggests that the dorsal stream may play a role in efficient retrieval from the orthographic input lexicon in the lexical route. It also underscores the potential of tDCS as an intervention tool for improving reading speed, at least in adults with developmental dyslexia. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stress errors in a case of developmental surface dyslexia in Filipino.

PubMed

Dulay, Katrina May; Hanley, J Richard

2015-01-01

This paper reports the case of a dyslexic boy (L.A.) whose impaired reading of Filipino is consistent with developmental surface dyslexia. Filipino has a transparent alphabetic orthography with stress typically falling on the penultimate syllable of multisyllabic words. However, exceptions to the typical stress pattern are not marked in the Filipino orthography. L.A. read words with typical stress patterns as accurately as controls, but made many more stress errors than controls when reading Filipino words with atypical stress. He regularized the pronunciation of many of these words by incorrectly placing the stress on the penultimate syllable. Since he also read nonwords as accurately and quickly as controls and performed well on tests of phonological awareness, L.A. appears to present a clear case of developmental surface dyslexia in a transparent orthography.

An Investigation of the Incidence of Developmental Dyslexia and Selected Factors Associated With the Condition: Results of a Two Year Study.

ERIC Educational Resources Information Center

Gold, Lawrence; Huebner, Dale M.

An analysis was made of the factors associated with the condition of developmental dyslexia in pupils who were tutored in a Title III-funded learning disability center. During the 2-year period from September 1967 through June 1969, approximately 200 pupils were involved each year in an intensive diagnosis and remediation program. The ratio of…

Dyslexia in general practice education: considerations for recognition and support.

PubMed

Shrewsbury, Duncan

2016-07-01

Dyslexia is a common developmental learning difficulty, which persists throughout life. It is highly likely that those working in primary care will know, or even work with someone who has dyslexia. Dyslexia can impact on performance in postgraduate training and exams. The stereotypical characteristics of dyslexia, such as literacy difficulties, are often not obvious in adult learners. Instead, recognition requires a holistic approach to evaluating personal strengths and difficulties, in the context of a supportive relationship. Strategies to support dyslexic learners should consider recommendations made in formal diagnostic reports, and aim to address self-awareness and coping skills.

Adults with developmental dyslexia show selective impairments in time-based and self-initiated prospective memory: Self-report and clinical evidence.

PubMed

Smith-Spark, James H; Zięcik, Adam P; Sterling, Christopher

2017-03-01

Prospective memory (PM; memory for delayed intentions) would seem to be impaired in dyslexia but evidence is currently limited in scope. There is a need, therefore, firstly, to explore PM under controlled conditions using a broader range of PM tasks than used previously and, secondly, to determine whether objectively measured and self-reported PM problems can be found in the same individuals with dyslexia. The responses of 30 adults with dyslexia were compared with those of 30 IQ-matched adults without dyslexia on a self-report and a clinical measure of PM. Dyslexia-related deficits were shown on the clinical measure overall and, more particularly, when PM responses had to be made to cues based on time rather than environmental events. Adults with dyslexia were also more likely to forget to carry out an intention under naturalistic conditions 24h later. On the self-report questionnaire, the group with dyslexia reported significantly more frequent problems with PM overall, despite using more techniques to aid their memory. In particular, problems were identified with longer-term PM tasks and PM which had to be self-initiated. Dyslexia-related PM deficits were found under both laboratory and everyday conditions in the same participants; the first time that this has been demonstrated. These findings support previous experimental research which has highlighted dyslexia-related deficits in PM when the enacting of intentions is based on time cues and/or has to be self-initiated rather than being in prompted by environmental events. Copyright © 2017 Elsevier Ltd. All rights reserved.

False Memory for Orthographically versus Semantically Similar Words in Adolescents with Dyslexia: A Fuzzy-Trace Theory Perspective

ERIC Educational Resources Information Center

Obidzinski, Michal; Nieznanski, Marek

2017-01-01

The presented research was conducted in order to investigate the connections between developmental dyslexia and the functioning of verbatim and gist memory traces--assumed in the fuzzy-trace theory. The participants were 71 high school students (33 with dyslexia and 38 without learning difficulties). The modified procedure and multinomial model of…

Coherent Motion Sensitivity and Reading Development in the Transition from Prereading to Reading Stage

ERIC Educational Resources Information Center

Boets, Bart; Vandermosten, Maaike; Cornelissen, Piers; Wouters, Jan; Ghesquiere, Pol

2011-01-01

Evidence suggests that sensitivity to coherent motion (CM) is related to reading, but its role in the etiology of developmental dyslexia remains unclear. In this longitudinal study, CM sensitivity was measured in 31 children at family risk for dyslexia and 31 low-risk controls. Children, diagnosed with dyslexia in third grade (mean age = 8 years 3…

Impaired Visual Expertise for Print in French Adults with Dyslexia as Shown by N170 Tuning

ERIC Educational Resources Information Center

Mahe, Gwendoline; Bonnefond, Anne; Gavens, Nathalie; Dufour, Andre; Doignon-Camus, Nadege

2012-01-01

Efficient reading relies on expertise in the visual word form area, with abnormalities in the functional specialization of this area observed in individuals with developmental dyslexia. We have investigated event related potentials in print tuning in adults with dyslexia, based on their N170 response at 135-255 ms. Control and dyslexic adults…

Speech-in-Noise Perception Deficit in Adults with Dyslexia: Effects of Background Type and Listening Configuration

ERIC Educational Resources Information Center

Dole, Marjorie; Hoen, Michel; Meunier, Fanny

2012-01-01

Developmental dyslexia is associated with impaired speech-in-noise perception. The goal of the present research was to further characterize this deficit in dyslexic adults. In order to specify the mechanisms and processing strategies used by adults with dyslexia during speech-in-noise perception, we explored the influence of background type,…

Linking memory and language: Evidence for a serial-order learning impairment in dyslexia.

PubMed

Bogaerts, Louisa; Szmalec, Arnaud; Hachmann, Wibke M; Page, Mike P A; Duyck, Wouter

2015-01-01

The present study investigated long-term serial-order learning impairments, operationalized as reduced Hebb repetition learning (HRL), in people with dyslexia. In a first multi-session experiment, we investigated both the persistence of a serial-order learning impairment as well as the long-term retention of serial-order representations, both in a group of Dutch-speaking adults with developmental dyslexia and in a matched control group. In a second experiment, we relied on the assumption that HRL mimics naturalistic word-form acquisition and we investigated the lexicalization of novel word-forms acquired through HRL. First, our results demonstrate that adults with dyslexia are fundamentally impaired in the long-term acquisition of serial-order information. Second, dyslexic and control participants show comparable retention of the long-term serial-order representations in memory over a period of 1 month. Third, the data suggest weaker lexicalization of newly acquired word-forms in the dyslexic group. We discuss the integration of these findings into current theoretical views of dyslexia. Copyright © 2015 Elsevier Ltd. All rights reserved.

Functional Neuroanatomical Evidence for the Double-Deficit Hypothesis of Developmental Dyslexia

PubMed Central

Norton, Elizabeth S.; Black, Jessica M.; Stanley, Leanne M.; Tanaka, Hiroko; Gabrieli, John D. E.; Sawyer, Carolyn; Hoeft, Fumiko

2015-01-01

The double-deficit hypothesis of dyslexia posits that both rapid naming and phonological impairments can cause reading difficulties, and that individuals who have both of these deficits show greater reading impairments compared to those with a single deficit. Despite extensive behavioral research, the brain basis of poor reading with a double-deficit has never been investigated. The goal of the study was to evaluate the double-deficit hypothesis using functional MRI. Activation patterns during a printed word rhyme judgment task in 90 children with a wide range of reading abilities showed dissociation between brain regions that were sensitive to phonological awareness (left inferior frontal and inferior parietal regions) and rapid naming (right cerebellar lobule VI). More specifically, the double-deficit group showed less activation in the fronto-parietal reading network compared to children with only a deficit in phonological awareness, who in turn showed less activation than the typically-reading group. On the other hand, the double-deficit group showed less cerebellar activation compared to children with only a rapid naming deficit, who in turn showed less activation than the typically-reading children. Functional connectivity analyses revealed that bilateral prefrontal regions were key for linking brain regions associated with phonological awareness and rapid naming, with the double-deficit group being the most aberrant in their connectivity. Our study provides the first functional neuroanatomical evidence for the double-deficit hypothesis of developmental dyslexia. PMID:24953957

The functional anatomy of single-digit arithmetic in children with developmental dyslexia.

PubMed

Evans, Tanya M; Flowers, D Lynn; Napoliello, Eileen M; Olulade, Olumide A; Eden, Guinevere F

2014-11-01

Some arithmetic procedures, such as addition of small numbers, rely on fact retrieval mechanisms supported by left hemisphere perisylvian language areas, while others, such as subtraction, rely on procedural-based mechanisms subserved by bilateral parietal cortices. Previous work suggests that developmental dyslexia, a reading disability, is accompanied by subtle deficits in retrieval-based arithmetic, possibly because of compromised left hemisphere function. To test this prediction, we compared brain activity underlying arithmetic problem solving in children with and without dyslexia during addition and subtraction operations using a factorial design. The main effect of arithmetic operation (addition versus subtraction) for both groups combined revealed activity during addition in the left superior temporal gyrus and activity during subtraction in the bilateral intraparietal sulcus, the right supramarginal gyrus and the anterior cingulate, consistent with prior studies. For the main effect of diagnostic group (dyslexics versus controls), we found less activity in dyslexic children in the left supramarginal gyrus. Finally, the interaction analysis revealed that while the control group showed a strong response in the right supramarginal gyrus for subtraction but not for addition, the dyslexic group engaged this region for both operations. This provides physiological evidence in support of the theory that children with dyslexia, because of disruption to left hemisphere language areas, use a less optimal route for retrieval-based arithmetic, engaging right hemisphere parietal regions typically used by good readers for procedural-based arithmetic. Our results highlight the importance of language processing for mathematical processing and illustrate that children with dyslexia have impairments that extend beyond reading. Copyright © 2014 Elsevier Inc. All rights reserved.

The Functional Anatomy of Single-Digit Arithmetic in Children with Developmental Dyslexia

PubMed Central

Evans, Tanya M.; Flowers, D. Lynn; Napoliello, Eileen M.; Olulade, Olumide A.; Eden, Guinevere F.

2014-01-01

Some arithmetic procedures, such as addition of small numbers, rely on fact retrieval mechanisms supported by left hemisphere perisylvian language areas, while others, such as subtraction, rely on procedural-based mechanisms subserved by bilateral parietal cortices. Previous work suggests that developmental dyslexia, a reading disability, is accompanied by subtle deficits in retrieval-based arithmetic, possibly because of compromised left hemisphere function. To test this prediction, we compared brain activity underlying arithmetic problem solving in children with and without dyslexia during addition and subtraction operations using a factorial design. The main effect of arithmetic operation (addition versus subtraction) for both groups combined revealed activity during addition in the left superior temporal gyrus and activity during subtraction in bilateral intraparietal sulcus, right supramarginal gyrus and the anterior cingulate, consistent with prior studies. For the main effect of diagnostic group (dyslexics versus controls), we found less activity in dyslexic children in the left supramarginal gyrus. Finally, the interaction analysis revealed that while the control group showed a strong response in right supramarginal gyrus for subtraction but not for addition, the dyslexic group engaged this region for both operations. This provides physiological evidence in support of the theory that children with dyslexia, because of disruption to left hemisphere language areas, use a less optimal route for retrieval-based arithmetic, engaging right hemisphere parietal regions typically used by good readers for procedural-based arithmetic. Our results highlight the importance of language processing for mathematical processing and illustrate that children with dyslexia have impairments that extend beyond reading. PMID:25067820

The DCDC2/intron 2 deletion and white matter disorganization: focus on developmental dyslexia.

PubMed

Marino, Cecilia; Scifo, Paola; Della Rosa, Pasquale A; Mascheretti, Sara; Facoetti, Andrea; Lorusso, Maria L; Giorda, Roberto; Consonni, Monica; Falini, Andrea; Molteni, Massimo; Gruen, Jeffrey R; Perani, Daniela

2014-08-01

The DCDC2 gene is involved in neuronal migration. Heterotopias have been found within the white matter of DCDC2-knockdown rats. A deletion in DCDC2/intron 2 (DCDC2d), which encompasses a regulatory region named 'regulatory element associated with dyslexia 1' (READ1), increases the risk for dyslexia. We hypothesized that DCDC2d can be associated to alterations of the white matter structure in general and in dyslexic brains. Based on a full-factorial analysis of covariance (ANCOVA) model, we investigated voxel-based diffusion tensor imaging (VB-DTI) data of four groups of subjects: dyslexia with/without DCDC2d, and normal readers with/without DCDC2d. We also tested DCDC2d effects upon correlation patterns between fractional anisotropy (FA) and reading scores. We found that FA was reduced in the left arcuate fasciculus and splenium of the corpus callosum in subjects with versus without DCDC2d, irrespective of dyslexia. Subjects with dyslexia and DCDC2d showed reduced FA, mainly in the left hemisphere and in the corpus callosum; their counterpart without DCDC2d showed similar FA alterations. Noteworthy, a conjunction analysis in impaired readers revealed common regions with lower FA mainly in the left hemisphere. When we compared subjects with dyslexia with versus without DCDC2d, we found lower FA in the inferior longitudinal fasciculus and genu of the corpus callosum, bilaterally. Normal readers with versus without DCDC2d had FA increases and decreases in both the right and left hemisphere. The major contribution of our study was to provide evidence relating genes, brain and behaviour. Overall, our findings support the hypothesis that DCDC2d is associated with altered FA. In normal readers, DCDC2-related anatomical patterns may mark some developmental cognitive vulnerability to learning disabilities. In subjects with dyslexia, DCDC2d accounted for both common - mainly located in the left hemisphere - and unique - a more severe and extended pattern - alterations of white matter fibre tracts. Copyright © 2014 Elsevier Ltd. All rights reserved.

Shared vs. specific brain activation changes in dyslexia after training of phonology, attention, or reading.

PubMed

Heim, Stefan; Pape-Neumann, Julia; van Ermingen-Marbach, Muna; Brinkhaus, Moti; Grande, Marion

2015-07-01

Whereas the neurobiological basis of developmental dyslexia has received substantial attention, only little is known about the processes in the brain during remediation. This holds in particular in light of recent findings on cognitive subtypes of dyslexia which suggest interactions between individual profiles, training methods, and also the task in the scanner. Therefore, we trained three groups of German dyslexic primary school children in the domains of phonology, attention, or visual word recognition. We compared neurofunctional changes after 4 weeks of training in these groups to those in untrained normal readers in a reading task and in a task of visual attention. The overall reading improvement in the dyslexic children was comparable over groups. It was accompanied by substantial increase of the activation level in the visual word form area (VWFA) during a reading task inside the scanner. Moreover, there were activation increases that were unique for each training group in the reading task. In contrast, when children performed the visual attention task, shared training effects were found in the left inferior frontal sulcus and gyrus, which varied in amplitude between the groups. Overall, the data reveal that different remediation programmes matched to individual profiles of dyslexia may improve reading ability and commonly affect the VWFA in dyslexia as a shared part of otherwise distinct networks.

Sex-specific gray matter volume differences in females with developmental dyslexia.

PubMed

Evans, Tanya M; Flowers, D Lynn; Napoliello, Eileen M; Eden, Guinevere F

2014-05-01

Developmental dyslexia, characterized by unexpected reading difficulty, is associated with anomalous brain anatomy and function. Previous structural neuroimaging studies have converged in reports of less gray matter volume (GMV) in dyslexics within left hemisphere regions known to subserve language. Due to the higher prevalence of dyslexia in males, these studies are heavily weighted towards males, raising the question whether studies of dyslexia in females only and using the same techniques, would generate the same findings. In a replication study of men, we obtained the same findings of less GMV in dyslexics in left middle/inferior temporal gyri and right postcentral/supramarginal gyri as reported in the literature. However, comparisons in women with and without dyslexia did not yield left hemisphere differences, and instead, we found less GMV in right precuneus and paracentral lobule/medial frontal gyrus. In boys, we found less GMV in left inferior parietal cortex (supramarginal/angular gyri), again consistent with previous work, while in girls differences were within right central sulcus, spanning adjacent gyri, and left primary visual cortex. Our investigation into anatomical variants in dyslexia replicates existing studies in males, but at the same time shows that dyslexia in females is not characterized by involvement of left hemisphere language regions but rather early sensory and motor cortices (i.e., motor and premotor cortex, primary visual cortex). Our findings suggest that models on the brain basis of dyslexia, primarily developed through the study of males, may not be appropriate for females and suggest a need for more sex-specific investigations into dyslexia.

Sex-specific Gray Matter Volume Differences in Females with Developmental Dyslexia

PubMed Central

Evans, Tanya M.; Flowers, D. Lynn; Napoliello, Eileen M.; Eden, Guinevere F.

2013-01-01

Developmental dyslexia, characterized by unexpected reading difficulty, is associated with anomalous brain anatomy and function. Previous structural neuroimaging studies have converged in reports of less gray matter volume (GMV) in dyslexics within left hemisphere regions known to subserve language. Due to the higher prevalence of dyslexia in males, these studies are heavily weighted towards males, raising the question whether studies of dyslexia in females only and using the same techniques, would generate the same findings. In a replication study of men we obtained the same findings of less GMV in dyslexics in left middle/inferior temporal gyri and right postcentral/supramarginal gyri as reported in the literature. However, comparisons in women with and without dyslexia did not yield left hemisphere differences and instead we found less GMV in right precuneus and paracentral lobule/medial frontal gyrus. In boys, we found less GMV in left inferior parietal cortex (supramarginal/angular gyri), again consistent with previous work, while in girls differences were within right central sulcus, spanning adjacent gyri, and left primary visual cortex. Our investigation into anatomical variants in dyslexia replicates existing studies in males, but at the same time shows that dyslexia in females is not characterized by involvement of left hemisphere language regions but rather early sensory and motor cortices (i.e. motor and premotor cortex, primary visual cortex). Our findings suggest that models on the brain basis of dyslexia, primarily developed through the study of males, may not be appropriate for females and suggest a need for more sex-specific investigations into dyslexia. PMID:23625146

An investigation into the origin of anatomical differences in dyslexia.

PubMed

Krafnick, Anthony J; Flowers, D Lynn; Luetje, Megan M; Napoliello, Eileen M; Eden, Guinevere F

2014-01-15

Studies have converged in their findings of relatively less gray matter volume (GMV) in developmental dyslexia in bilateral temporoparietal and left occipitotemporal cortical regions. However, the interpretation of these results has been difficult. The reported neuroanatomical differences in dyslexia may be causal to the reading problems, following from, for example, neural migration errors that occurred during early human development and before learning to read. Alternatively, less GMV may represent the consequence of an impoverished reading experience, akin to the experience-dependent GMV differences attributed to illiterate compared with literate adults. Most likely, a combination of these factors is driving these observations. Here we attempt to disambiguate these influences by using a reading level-matched design, where dyslexic children were contrasted not only with age-matched controls, but also with younger controls who read at the same level as the dyslexics. Consistent with previous reports, dyslexics showed less GMV in multiple left and right hemisphere regions, including left superior temporal sulcus when compared with age-matched controls. However, not all of these differences emerged when dyslexics were compared with controls matched on reading abilities, with only right precentral gyrus GMV surviving this second analysis. When similar analyses were performed for white matter volume, no regions emerged from both comparisons. These results indicate that the GMV differences in dyslexia reported here and in prior studies are in large part the outcome of experience (e.g., disordered reading experience) compared with controls, with only a fraction of the differences being driven by dyslexia per se.

Impaired Oculomotor Behavior of Children with Developmental Dyslexia in Antisaccades and Predictive Saccades Tasks

PubMed Central

Lukasova, Katerina; Silva, Isadora P.; Macedo, Elizeu C.

2016-01-01

Analysis of eye movement patterns during tracking tasks represents a potential way to identify differences in the cognitive processing and motor mechanisms underlying reading in dyslexic children before the occurrence of school failure. The current study aimed to evaluate the pattern of eye movements in antisaccades, predictive saccades and visually guided saccades in typical readers and readers with developmental dyslexia. The study included 30 children (age M = 11; SD = 1.67), 15 diagnosed with developmental dyslexia (DG) and 15 regular readers (CG), matched by age, gender and school grade. Cognitive assessment was performed prior to the eye-tracking task during which both eyes were registered using the Tobii® 1750 eye-tracking device. The results demonstrated a lower correct antisaccades rate in dyslexic children compared to the controls (p < 0.001, DG = 25%, CC = 37%). Dyslexic children also made fewer saccades in predictive latency (p < 0.001, DG = 34%, CG = 46%, predictive latency within −300–120 ms with target as 0 point). No between-group difference was found for visually guided saccades. In this task, both groups showed shorter latency for right-side targets. The results indicated altered oculomotor behavior in dyslexic children, which has been reported in previous studies. We extend these findings by demonstrating impaired implicit learning of target's time/position patterns in dyslexic children. PMID:27445945

Abnormal Visual Motion Processing is not a Cause of Dyslexia

PubMed Central

Olulade, Olumide A.; Napoliello, Eileen M.; Eden, Guinevere F.

2013-01-01

SUMMARY Developmental dyslexia is a reading disorder, yet deficits also manifest in the magnocellular-dominated dorsal visual system. Uncertainty about whether visual deficits are causal or consequential to reading disability encumbers accurate identification and appropriate treatment of this common learning disability. Using fMRI, we demonstrate in typical readers a relationship between reading ability and activity in area V5/MT during visual motion processing and, as expected, also found lower V5/MT activity for dyslexic children compared to age-matched controls. However, when dyslexics were matched to younger controls on reading ability, no differences emerged, suggesting that weakness in V5/MT may not be causal to dyslexia. To further test for causality, dyslexics underwent a phonological-based reading intervention. Surprisingly, V5/MT activity increased along with intervention-driven reading gains, demonstrating that activity here is mobilized through reading. Our results provide strong evidence that visual magnocellular dysfunction is not causal to dyslexia, but may instead be consequential to impoverished reading. PMID:23746630

Phonological Awareness Deficits in Developmental Dyslexia and the Phonological Representations Hypothesis.

ERIC Educational Resources Information Center

Swan, Denise; Goswami, Usha

1997-01-01

Used picture-naming task to identify accurate/inaccurate phonological representations by dyslexic and control children; compared performance on phonological measures for words with precise/imprecise representations. Found that frequency effects in phonological tasks disappeared after considering representational quality, and that availability of…

Response to "The Many Faces of Dyslexia."

ERIC Educational Resources Information Center

Galaburda, Albert M.

1986-01-01

In response to M. Rawson's paper, the author uses an analogy with coronary artery disease to show that current brain research is not entirely at odds with the position that dyslexia may be a developmental variation, rather than a defect. (Author/DB)

Impaired letter-string processing in developmental dyslexia: what visual-to-phonology code mapping disorder?

PubMed

Valdois, Sylviane; Lassus-Sangosse, Delphine; Lobier, Muriel

2012-05-01

Poor parallel letter-string processing in developmental dyslexia was taken as evidence of poor visual attention (VA) span, that is, a limitation of visual attentional resources that affects multi-character processing. However, the use of letter stimuli in oral report tasks was challenged on its capacity to highlight a VA span disorder. In particular, report of poor letter/digit-string processing but preserved symbol-string processing was viewed as evidence of poor visual-to-phonology code mapping, in line with the phonological theory of developmental dyslexia. We assessed here the visual-to-phonological-code mapping disorder hypothesis. In Experiment 1, letter-string, digit-string and colour-string processing was assessed to disentangle a phonological versus visual familiarity account of the letter/digit versus symbol dissociation. Against a visual-to-phonological-code mapping disorder but in support of a familiarity account, results showed poor letter/digit-string processing but preserved colour-string processing in dyslexic children. In Experiment 2, two tasks of letter-string report were used, one of which was performed simultaneously to a high-taxing phonological task. Results show that dyslexic children are similarly impaired in letter-string report whether a concurrent phonological task is simultaneously performed or not. Taken together, these results provide strong evidence against a phonological account of poor letter-string processing in developmental dyslexia. Copyright © 2012 John Wiley & Sons, Ltd.

Family patterns of development dyslexia, Part II: Behavioral phenotypes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolff, P.H.; Melngailis, I.; Bedrosian, M.

1995-12-18

The motor control of bimanual coordination and motor speech was compared between first degree relatives from families with at least 2 dyslexic family members, and families where probands were the only affected family members. Half of affected relatives had motor coordination deficits; and they came from families in which probands also showed impaired motor coordination. By contrast, affected relatives without motor deficits came from dyslexia families where probands did not have motor deficits. Motor coordination deficits were more common and more severe among affected offspring in families where both parents were affected than among affected offspring in families where onlymore » one parent was affected. However, motor coordination deficits were also more common and more severe in affected parents when both parents were affected than among affected parents in families where only one parent was affected. We conclude that impaired temporal resolution in motor action identifies a behavioral phenotype in some subtypes of developmental dyslexia. The observed pattern of transmission for motor deficits and reading impairment in about half of dyslexia families was most congruent with a genetic model of dyslexia in which 2 codominant major genes cosegregate in dyslexia pedigrees where the proband is also motorically impaired. 54 refs., 5 figs., 5 tabs.« less

Auditory temporal perceptual learning and transfer in Chinese-speaking children with developmental dyslexia.

PubMed

Zhang, Manli; Xie, Weiyi; Xu, Yanzhi; Meng, Xiangzhi

2018-03-01

Perceptual learning refers to the improvement of perceptual performance as a function of training. Recent studies found that auditory perceptual learning may improve phonological skills in individuals with developmental dyslexia in alphabetic writing system. However, whether auditory perceptual learning could also benefit the reading skills of those learning the Chinese logographic writing system is, as yet, unknown. The current study aimed to investigate the remediation effect of auditory temporal perceptual learning on Mandarin-speaking school children with developmental dyslexia. Thirty children with dyslexia were screened from a large pool of students in 3th-5th grades. They completed a series of pretests and then were assigned to either a non-training control group or a training group. The training group worked on a pure tone duration discrimination task for 7 sessions over 2 weeks with thirty minutes per session. Post-tests immediately after training and a follow-up test 2 months later were conducted. Analyses revealed a significant training effect in the training group relative to non-training group, as well as near transfer to the temporal interval discrimination task and far transfer to phonological awareness, character recognition and reading fluency. Importantly, the training effect and all the transfer effects were stable at the 2-month follow-up session. Further analyses found that a significant correlation between character recognition performance and learning rate mainly existed in the slow learning phase, the consolidation stage of perceptual learning, and this effect was modulated by an individuals' executive function. These findings indicate that adaptive auditory temporal perceptual learning can lead to learning and transfer effects on reading performance, and shed further light on the potential role of basic perceptual learning in the remediation and prevention of developmental dyslexia. Copyright © 2018 Elsevier Ltd. All rights reserved.

Reading, Dyslexia and the Brain

ERIC Educational Resources Information Center

Goswami, Usha

2008-01-01

Background: Neuroimaging offers unique opportunities for understanding the acquisition of reading by children and for unravelling the mystery of developmental dyslexia. Here, I provide a selective overview of recent neuroimaging studies, drawing out implications for education and the teaching of reading. Purpose: The different neuroimaging…

Audio-visual speech perception in adult readers with dyslexia: an fMRI study.

PubMed

Rüsseler, Jascha; Ye, Zheng; Gerth, Ivonne; Szycik, Gregor R; Münte, Thomas F

2018-04-01

Developmental dyslexia is a specific deficit in reading and spelling that often persists into adulthood. In the present study, we used slow event-related fMRI and independent component analysis to identify brain networks involved in perception of audio-visual speech in a group of adult readers with dyslexia (RD) and a group of fluent readers (FR). Participants saw a video of a female speaker saying a disyllabic word. In the congruent condition, audio and video input were identical whereas in the incongruent condition, the two inputs differed. Participants had to respond to occasionally occurring animal names. The independent components analysis (ICA) identified several components that were differently modulated in FR and RD. Two of these components including fusiform gyrus and occipital gyrus showed less activation in RD compared to FR possibly indicating a deficit to extract face information that is needed to integrate auditory and visual information in natural speech perception. A further component centered on the superior temporal sulcus (STS) also exhibited less activation in RD compared to FR. This finding is corroborated in the univariate analysis that shows less activation in STS for RD compared to FR. These findings suggest a general impairment in recruitment of audiovisual processing areas in dyslexia during the perception of natural speech.

Mindful Reading: Mindfulness Meditation Helps Keep Readers with Dyslexia and ADHD on the Lexical Track.

PubMed

Tarrasch, Ricardo; Berman, Zohar; Friedmann, Naama

2016-01-01

This study explored the effects of a Mindfulness-Based Stress Reduction (MBSR) intervention on reading, attention, and psychological well-being among people with developmental dyslexia and/or attention deficits. Various types of dyslexia exist, characterized by different error types. We examined a question that has not been tested so far: which types of errors (and dyslexias) are affected by MBSR training. To do so, we tested, using an extensive battery of reading tests, whether each participant had dyslexia, and which errors types s/he makes, and then compared the rate of each error type before and after the MBSR workshop. We used a similar approach to attention disorders: we evaluated the participants' sustained, selective, executive, and orienting of attention to assess whether they had attention-disorders, and if so, which functions were impaired. We then evaluated the effect of MBSR on each of the attention functions. Psychological measures including mindfulness, stress, reflection and rumination, lifesatisfaction, depression, anxiety, and sleep-disturbances were also evaluated. Nineteen Hebrew-readers completed a 2-month mindfulness workshop. The results showed that whereas reading errors of letter-migrations within and between words and vowelletter errors did not decrease following the workshop, most participants made fewer reading errors in general following the workshop, with a significant reduction of 19% from their original number of errors. This decrease mainly resulted from a decrease in errors that occur due to reading via the sublexical rather than the lexical route. It seems, therefore, that mindfulness helped reading by keeping the readers on the lexical route. This improvement in reading probably resulted from improved sustained attention: the reduction in sublexical reading was significant for the dyslexic participants who also had attention deficits, and there were significant correlations between reduced reading errors and decreases in impulsivity. Following the meditation workshop, the rate of commission errors decreased, indicating decreased impulsivity, and the variation in RTs in the CPT task decreased, indicating improved sustained attention. Significant improvements were obtained in participants' mindfulness, perceived-stress, rumination, depression, state-anxiety, and sleep-disturbances. Correlations were also obtained between reading improvement and increased mindfulness following the workshop. Thus, whereas mindfulness training did not affect specific types of errors and did not improve dyslexia, it did affect the reading of adults with developmental dyslexia and ADHD, by helping them to stay on the straight path of the lexical route while reading. Thus, the reading improvement induced by mindfulness sheds light on the intricate relation between attention and reading. Mindfulness reduced impulsivity and improved sustained attention, and this, in turn, improved reading of adults with developmental dyslexia and ADHD, by helping them to read via the straight path of the lexical route.

Mindful Reading: Mindfulness Meditation Helps Keep Readers with Dyslexia and ADHD on the Lexical Track

PubMed Central

Tarrasch, Ricardo; Berman, Zohar; Friedmann, Naama

2016-01-01

This study explored the effects of a Mindfulness-Based Stress Reduction (MBSR) intervention on reading, attention, and psychological well-being among people with developmental dyslexia and/or attention deficits. Various types of dyslexia exist, characterized by different error types. We examined a question that has not been tested so far: which types of errors (and dyslexias) are affected by MBSR training. To do so, we tested, using an extensive battery of reading tests, whether each participant had dyslexia, and which errors types s/he makes, and then compared the rate of each error type before and after the MBSR workshop. We used a similar approach to attention disorders: we evaluated the participants’ sustained, selective, executive, and orienting of attention to assess whether they had attention-disorders, and if so, which functions were impaired. We then evaluated the effect of MBSR on each of the attention functions. Psychological measures including mindfulness, stress, reflection and rumination, lifesatisfaction, depression, anxiety, and sleep-disturbances were also evaluated. Nineteen Hebrew-readers completed a 2-month mindfulness workshop. The results showed that whereas reading errors of letter-migrations within and between words and vowelletter errors did not decrease following the workshop, most participants made fewer reading errors in general following the workshop, with a significant reduction of 19% from their original number of errors. This decrease mainly resulted from a decrease in errors that occur due to reading via the sublexical rather than the lexical route. It seems, therefore, that mindfulness helped reading by keeping the readers on the lexical route. This improvement in reading probably resulted from improved sustained attention: the reduction in sublexical reading was significant for the dyslexic participants who also had attention deficits, and there were significant correlations between reduced reading errors and decreases in impulsivity. Following the meditation workshop, the rate of commission errors decreased, indicating decreased impulsivity, and the variation in RTs in the CPT task decreased, indicating improved sustained attention. Significant improvements were obtained in participants’ mindfulness, perceived-stress, rumination, depression, state-anxiety, and sleep-disturbances. Correlations were also obtained between reading improvement and increased mindfulness following the workshop. Thus, whereas mindfulness training did not affect specific types of errors and did not improve dyslexia, it did affect the reading of adults with developmental dyslexia and ADHD, by helping them to stay on the straight path of the lexical route while reading. Thus, the reading improvement induced by mindfulness sheds light on the intricate relation between attention and reading. Mindfulness reduced impulsivity and improved sustained attention, and this, in turn, improved reading of adults with developmental dyslexia and ADHD, by helping them to read via the straight path of the lexical route. PMID:27242565

Precursors of developmental dyslexia: an overview of the longitudinal Dutch Dyslexia Programme study.

PubMed

van der Leij, Aryan; van Bergen, Elsje; van Zuijen, Titia; de Jong, Peter; Maurits, Natasha; Maassen, Ben

2013-11-01

Converging evidence suggests that developmental dyslexia is a neurobiological disorder, characterized by deficits in the auditory, visual, and linguistic domains. In the longitudinal project of the Dutch Dyslexia Programme, 180 children with a familial risk of dyslexia (FR) and a comparison group of 120 children without FR (noFR) were followed from the age of 2 months up to 9 years. Children were assessed on (1) auditory, speech, and visual event-related potentials every half year between 2 and 41 months; (2) expressive and receptive language, motor development, behaviour problems, and home-literacy environment by questionnaires at the age of 2 and 3; (3) speech-language and cognitive development from 47 months onwards; and (4) preliteracy and subskills of reading, and reading development during kindergarten and Grades 2 and 3. With regard to precursors of reading disability, first analyses showed specific differences between FR and noFR children in neurophysiological, cognitive, and early language measures. Once reading tests administered from age 7 to 9 years were available, the children were divided into three groups: FR children with and without dyslexia, and controls. Analyses of the differences between reading groups yielded distinct profiles and developmental trajectories. On early speech and visual processing, and several cognitive measures, performance of the non-dyslexic FR group differed from the dyslexic FR group and controls, indicating continuity of the influence of familial risk. Parental reading and rapid naming skills appeared to indicate their offspring's degree of familial risk. Furthermore, on rapid naming and nonverbal IQ, the non-dyslexic FR group performed similarly to the controls, suggesting protective factors. There are indications of differences between the FR and control groups, irrespective of reading outcome. These results contribute to the distinction between the deficits correlated to dyslexia as a manifest reading disorder and deficits correlated to familial risk only. Copyright © 2013 John Wiley & Sons, Ltd.

Children with developmental dyslexia showed greater sleep disturbances than controls, including problems initiating and maintaining sleep.

PubMed

Carotenuto, M; Esposito, M; Cortese, S; Laino, D; Verrotti, A

2016-09-01

Although there have been frequent clinical reports about sleep disturbances in children with learning disabilities, no data are available about the prevalence of sleep disturbances in children with developmental dyslexia (DD). This study evaluated sleep disturbances in children with DD referred to a hospital clinic and compared their scores with healthy controls. We consecutively enrolled 147 children (66% male) aged 10.26 ± 2.63 years who were referred by clinical paediatricians to the Clinic for Child and Adolescent Neuropsychiatry at the Second University of Naples with DD and 766 children without DD (60% male) aged 10.49 ± 2.39 years recruited from schools in the same urban area. Sleep disturbances were assessed with the Sleep Disturbances Scale for Children (SDSC), which was filled out by the children's main carers. Compared with the controls, the children with DD showed significantly higher rates of above threshold scores on the total SDSC score (p < 0.001) and on the subscales for disorders in initiating and maintaining sleep (p < 0.001), sleep breathing disorders (p < 0.001) and disorders of arousal (p < 0.001). Sleep disorders were significantly more frequent in children with DD than in healthy controls. A possible relationship between dyslexia and sleep disorders may have relevant clinical implications. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Perceptual organization of speech signals by children with and without dyslexia

PubMed Central

Nittrouer, Susan; Lowenstein, Joanna H.

2013-01-01

Developmental dyslexia is a condition in which children encounter difficulty learning to read in spite of adequate instruction. Although considerable effort has been expended trying to identify the source of the problem, no single solution has been agreed upon. The current study explored a new hypothesis, that developmental dyslexia may be due to faulty perceptual organization of linguistically relevant sensory input. To test that idea, sentence-length speech signals were processed to create either sine-wave or noise-vocoded analogs. Seventy children between 8 and 11 years of age, with and without dyslexia participated. Children with dyslexia were selected to have phonological awareness deficits, although those without such deficits were retained in the study. The processed sentences were presented for recognition, and measures of reading, phonological awareness, and expressive vocabulary were collected. Results showed that children with dyslexia, regardless of phonological subtype, had poorer recognition scores than children without dyslexia for both kinds of degraded sentences. Older children with dyslexia recognized the sine-wave sentences better than younger children with dyslexia, but no such effect of age was found for the vocoded materials. Recognition scores were used as predictor variables in regression analyses with reading, phonological awareness, and vocabulary measures used as dependent variables. Scores for both sorts of sentence materials were strong predictors of performance on all three dependent measures when all children were included, but only performance for the sine-wave materials explained significant proportions of variance when only children with dyslexia were included. Finally, matching young, typical readers with older children with dyslexia on reading abilities did not mitigate the group difference in recognition of vocoded sentences. Conclusions were that children with dyslexia have difficulty organizing linguistically relevant sensory input, but learn to do so for the structure preserved by sine-wave signals before they do so for other sorts of signal structure. These perceptual organization deficits could account for difficulties acquiring refined linguistic representations, including those of a phonological nature, although ramifications are different across affected children. PMID:23702597

Perceptual organization of speech signals by children with and without dyslexia.

PubMed

Nittrouer, Susan; Lowenstein, Joanna H

2013-08-01

Developmental dyslexia is a condition in which children encounter difficulty learning to read in spite of adequate instruction. Although considerable effort has been expended trying to identify the source of the problem, no single solution has been agreed upon. The current study explored a new hypothesis, that developmental dyslexia may be due to faulty perceptual organization of linguistically relevant sensory input. To test that idea, sentence-length speech signals were processed to create either sine-wave or noise-vocoded analogs. Seventy children between 8 and 11 years of age, with and without dyslexia participated. Children with dyslexia were selected to have phonological awareness deficits, although those without such deficits were retained in the study. The processed sentences were presented for recognition, and measures of reading, phonological awareness, and expressive vocabulary were collected. Results showed that children with dyslexia, regardless of phonological subtype, had poorer recognition scores than children without dyslexia for both kinds of degraded sentences. Older children with dyslexia recognized the sine-wave sentences better than younger children with dyslexia, but no such effect of age was found for the vocoded materials. Recognition scores were used as predictor variables in regression analyses with reading, phonological awareness, and vocabulary measures used as dependent variables. Scores for both sorts of sentence materials were strong predictors of performance on all three dependent measures when all children were included, but only performance for the sine-wave materials explained significant proportions of variance when only children with dyslexia were included. Finally, matching young, typical readers with older children with dyslexia on reading abilities did not mitigate the group difference in recognition of vocoded sentences. Conclusions were that children with dyslexia have difficulty organizing linguistically relevant sensory input, but learn to do so for the structure preserved by sine-wave signals before they do so for other sorts of signal structure. These perceptual organization deficits could account for difficulties acquiring refined linguistic representations, including those of a phonological nature, although ramifications are different across affected children. Copyright © 2013 Elsevier Ltd. All rights reserved.

Neural dissociation of phonological and visual attention span disorders in developmental dyslexia: FMRI evidence from two case reports.

PubMed

Peyrin, C; Lallier, M; Démonet, J F; Pernet, C; Baciu, M; Le Bas, J F; Valdois, S

2012-03-01

A dissociation between phonological and visual attention (VA) span disorders has been reported in dyslexic children. This study investigates whether this cognitively-based dissociation has a neurobiological counterpart through the investigation of two cases of developmental dyslexia. LL showed a phonological disorder but preserved VA span whereas FG exhibited the reverse pattern. During a phonological rhyme judgement task, LL showed decreased activation of the left inferior frontal gyrus whereas this region was activated at the level of the controls in FG. Conversely, during a visual categorization task, FG demonstrated decreased activation of the parietal lobules whereas these regions were activated in LL as in the controls. These contrasted patterns of brain activation thus mirror the cognitive disorders' dissociation. These findings provide the first evidence for an association between distinct brain mechanisms and distinct cognitive deficits in developmental dyslexia, emphasizing the importance of taking into account the heterogeneity of the reading disorder. Copyright © 2012 Elsevier Inc. All rights reserved.

Adult Developmental Dyslexia in a Shallow Orthography: Are There Subgroups?

ERIC Educational Resources Information Center

Laasonen, Marja; Service, Elisabet; Lipsanen, Jari; Virsu, Veijo

2012-01-01

The existence and stability of subgroups among adult dyslexic readers of a shallow orthography was explored by comparing three different cluster analyses based on previously suggested combinations of two variables. These were oral reading speed versus accuracy, word versus pseudoword reading speed, and phonological awareness versus rapid naming.…

Perceptual Learning of Acoustic Noise by Individuals with Dyslexia

ERIC Educational Resources Information Center

Agus, Trevor R.; Carrión-Castillo, Amaia; Pressnitzer, Daniel; Ramus, Franck

2014-01-01

Purpose: A phonological deficit is thought to affect most individuals with developmental dyslexia. The present study addresses whether the phonological deficit is caused by difficulties with perceptual learning of fine acoustic details. Method: A demanding test of nonverbal auditory memory, "noise learning," was administered to both…

Encoding order and developmental dyslexia: A family of skills predicting different orthographic components

PubMed Central

Romani, Cristina; Tsouknida, Effie; Olson, Andrew

2015-01-01

We investigated order encoding in developmental dyslexia using a task that presented nonalphanumeric visual characters either simultaneously or sequentially—to tap spatial and temporal order encoding, respectively—and asked participants to reproduce their order. Dyslexic participants performed poorly in the sequential condition, but normally in the simultaneous condition, except for positions most susceptible to interference. These results are novel in demonstrating a selective difficulty with temporal order encoding in a dyslexic group. We also tested the associations between our order reconstruction tasks and: (a) lexical learning and phonological tasks; and (b) different reading and spelling tasks. Correlations were extensive when the whole group of participants was considered together. When dyslexics and controls were considered separately, different patterns of association emerged between orthographic tasks on the one side and tasks tapping order encoding, phonological processing, and written learning on the other. These results indicate that different skills support different aspects of orthographic processing and are impaired to different degrees in individuals with dyslexia. Therefore, developmental dyslexia is not caused by a single impairment, but by a family of deficits loosely related to difficulties with order. Understanding the contribution of these different deficits will be crucial to deepen our understanding of this disorder. PMID:25246235

Genetic dyslexia risk variant is related to neural connectivity patterns underlying phonological awareness in children.

PubMed

Skeide, Michael A; Kirsten, Holger; Kraft, Indra; Schaadt, Gesa; Müller, Bent; Neef, Nicole; Brauer, Jens; Wilcke, Arndt; Emmrich, Frank; Boltze, Johannes; Friederici, Angela D

2015-09-01

Phonological awareness is the best-validated predictor of reading and spelling skill and therefore highly relevant for developmental dyslexia. Prior imaging genetics studies link several dyslexia risk genes to either brain-functional or brain-structural factors of phonological deficits. However, coherent evidence for genetic associations with both functional and structural neural phenotypes underlying variation in phonological awareness has not yet been provided. Here we demonstrate that rs11100040, a reported modifier of SLC2A3, is related to the functional connectivity of left fronto-temporal phonological processing areas at resting state in a sample of 9- to 12-year-old children. Furthermore, we provide evidence that rs11100040 is related to the fractional anisotropy of the arcuate fasciculus, which forms the structural connection between these areas. This structural connectivity phenotype is associated with phonological awareness, which is in turn associated with the individual retrospective risk scores in an early dyslexia screening as well as to spelling. These results suggest a link between a dyslexia risk genotype and a functional as well as a structural neural phenotype, which is associated with a phonological awareness phenotype. The present study goes beyond previous work by integrating genetic, brain-functional and brain-structural aspects of phonological awareness within a single approach. These combined findings might be another step towards a multimodal biomarker for developmental dyslexia. Copyright © 2015 Elsevier Inc. All rights reserved.

Brain Hemisphericity and Developmental Dyslexia

ERIC Educational Resources Information Center

Vlachos, Filippos; Andreou, Eleni; Delliou, Afroditi

2013-01-01

The present study examined the link between brain hemisphericity and dyslexia in secondary school students, using the Preference Test (PT), a widely used self-report index of preferred hemisphere thinking styles. The hypothesis was that differences would be revealed between the dyslexic group and their peers in hemispheric preference. A total of…

Audio-Visual Speech in Noise Perception in Dyslexia

ERIC Educational Resources Information Center

van Laarhoven, Thijs; Keetels, Mirjam; Schakel, Lemmy; Vroomen, Jean

2018-01-01

Individuals with developmental dyslexia (DD) may experience, besides reading problems, other speech-related processing deficits. Here, we examined the influence of visual articulatory information (lip-read speech) at various levels of background noise on auditory word recognition in children and adults with DD. We found that children with a…

Understanding Chinese Developmental Dyslexia: Morphological Awareness as a Core Cognitive Construct

ERIC Educational Resources Information Center

Shu, Hua; McBride-Chang, Catherine; Wu, Sina; Liu, Hongyun

2006-01-01

Tasks representing 9 cognitive constructs of potential importance to understanding Chinese reading development and impairment were administered to 75 children with dyslexia and 77 age-matched children without reading difficulties in 5th and 6th grade. Logistic regression analyses revealed that dyslexic readers were best distinguished from…

Auditory Frequency Discrimination in Children with Dyslexia

ERIC Educational Resources Information Center

Halliday, Lorna F.; Bishop, Dorothy V. M.

2006-01-01

A popular hypothesis holds that developmental dyslexia is caused by phonological processing problems and is therefore linked to difficulties in the analysis of spoken as well as written language. It has been suggested that these phonological deficits might be attributable to low-level problems in processing the temporal fine structure of auditory…

Dyslexia and Specific Language Impairment: The Role of Phonology and Auditory Processing

ERIC Educational Resources Information Center

Fraser, Jill; Goswami, Usha; Conti-Ramsden, Gina

2010-01-01

We explore potential similarities between developmental dyslexia (specific reading disability [SRD]) and specific language impairment (SLI) in terms of phonological skills, underlying auditory processing abilities, and nonphonological language skills. Children aged 9 to 11 years with reading and/or language difficulties were recruited and compared…

Sub-Lexical Reading Intervention in a Student with Dyslexia and Asperger's Disorder

ERIC Educational Resources Information Center

Wright, Craig; Conlon, Elizabeth; Wright, Michalle; Dyck, Murray

2011-01-01

Dyslexia is a common presenting condition in clinic and educational settings. Unlike the homogenous groups used in randomised trials, educators typically manage children who have multiple developmental problems. Investigations are required into how these complex cases respond to treatment identified as efficacious by controlled trials. This study…

Neuropsychological Treatment of Dyslexia: Does Type of Treatment Matter?

ERIC Educational Resources Information Center

Lorusso, Maria Lulsa; Facoetti, Andrea; Bakker, Dirk J.

2011-01-01

In this study, 123 children with a diagnosis of developmental dyslexia were assigned to different treatment groups, either variations of Bakker's intervention program based on the balance model or a control, a specific reading training group. Thorough cognitive and neuropsychological assessment allowed determination of the subtype of dyslexia…

Are Auditory and Visual Processing Deficits Related to Developmental Dyslexia?

ERIC Educational Resources Information Center

Georgiou, George K.; Papadopoulos, Timothy C.; Zarouna, Elena; Parrila, Rauno

2012-01-01

The purpose of this study was to examine if children with dyslexia learning to read a consistent orthography (Greek) experience auditory and visual processing deficits and if these deficits are associated with phonological awareness, rapid naming speed and orthographic processing. We administered measures of general cognitive ability, phonological…

Morphosyntax and Logical Abilities in Italian Poor Readers: The Problem of SLI Under-Identification

ERIC Educational Resources Information Center

Arosio, Fabrizio; Pagliarini, Elena; Perugini, Maria; Barbieri, Lina; Guasti, Maria Teresa

2016-01-01

The study investigated morphosyntactic abilities and semantic-pragmatic competence in 24 children with developmental dyslexia aged 7-12 years. Morphosyntactic abilities were investgated in a direct object clitic production task, semantic-pragmatic competence in a quantifier comprehension task. Children with dyslexia produced fewer clitics than…

Conceptual size in developmental dyscalculia and dyslexia.

PubMed

Gliksman, Yarden; Henik, Avishai

2018-02-01

People suffering from developmental dyscalculia (DD) are known to have impairment in numerical abilities and have been found to have weaker processing of countable magnitudes. However, not much research was done on their abilities to process noncountable magnitudes. An example of noncountable magnitude is conceptual size (e.g., mouse is small and elephant is big). Recently, we found that adults process conceptual size automatically. The current study examined automatic processing of conceptual size in students with DD and developmental dyslexia. Conceptual and physical sizes were manipulated orthogonally to create congruent (e.g., a physically small apple compared to a physically large violin) and incongruent (e.g., a physically large apple compared to a physically small violin) conditions. Participants were presented with 2 objects and had to choose the larger one. Each trial began with an instruction to respond to the physical or to the conceptual dimension. Control and the dyslexic groups presented automatic processing of both conceptual and physical sizes. The dyscalculic group presented automatic processing of physical size but not automaticity of processing conceptual size. Our results fit with previous findings of weaker magnitude representation in those with DD, specifically regarding noncountable magnitudes, and support theories of a shared neurocognitive substrate for different types of magnitudes. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

I can read it in your eyes: what eye movements tell us about visuo-attentional processes in developmental dyslexia.

PubMed

Bellocchi, Stéphanie; Muneaux, Mathilde; Bastien-Toniazzo, Mireille; Ducrot, Stéphanie

2013-01-01

Most studies today agree about the link between visual-attention and oculomotor control during reading: attention seems to affect saccadic programming, that is, the position where the eyes land in a word. Moreover, recent studies show that visuo-attentional processes are strictly linked to normal and impaired reading. In particular, a large body of research has found evidence of defective visuo-attentional processes in dyslexics. What do eye movements tell us about visuo-attentional deficits in developmental dyslexia? The purpose of this paper is to explore the link between oculomotor control and dyslexia, taking into account its heterogeneous manifestation and comorbidity. Clinical perspectives in the use of the eye-movements approach to better explore and understand reading impairments are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Rapid Naming in Brazilian Students with Dyslexia and Attention Deficit Hyperactivity Disorder

PubMed Central

Alves, Luciana Mendonça; Siqueira, Cláudia M.; Ferreira, Maria do Carmo Mangelli; Alves, Juliana Flores Mendonça; Lodi, Débora F.; Bicalho, Lorena; Celeste, Letícia C.

2016-01-01

Introduction: The effective development of reading and writing skills requires the concerted action of several abilities, one of which is phonological processing. One of the main components of phonological processing is rapid automatized naming (RAN)—the ability to identify and recognize a given item by the activation and concomitant articulation of its name. Objective: To assess the RAN performance of schoolchildren with dyslexia and attention deficit hyperactivity disorder (ADHD) compared with their peers. Methods: In total, 70 schoolchildren aged between 8 and 11 years participated in the study. Of these, 16 children had a multiprofessional diagnosis of ADHD while 14 were diagnosed with dyslexia. Matched with these groups, 40 schoolchildren with no history of developmental impairments were also evaluated. The RAN test was administered to assess the length of time required to name a series of familiar visual stimuli. The statistical analysis was conducted using measures of descriptive statistics and the 2-sample t-test at the 5% significance level. Results: The performance of the group with dyslexia was inferior to that of the control group in all tasks and the ADHD group had inferior performance for color and letters-naming tasks. The schoolchildren with dyslexia and those with ADHD showed very similar response times. Age was an important variable to be analyzed separately. As they aged, children with typical language development had fast answers on colors and digits tasks while children with dyslexia or ADHD did not show improvement with age. Conclusions: The schoolchildren with dyslexia took longer to complete all tasks and ADHD took longer to complete digits and objects tasks in comparison to their peers with typical development. This ability tended to improve with age, which was not the case, however, with schoolchildren who had ADHD or dyslexia. PMID:26858672

Vocabulary skills are well developed in university students with dyslexia: Evidence from multiple case studies.

PubMed

Cavalli, Eddy; Casalis, Séverine; El Ahmadi, Abdessadek; Zira, Mélody; Poracchia-George, Florence; Colé, Pascale

2016-01-01

Most studies in adults with developmental dyslexia have focused on identifying the deficits responsible for their persistent reading difficulties, but little is known on how these readers manage the intensive exposure to written language required to obtain a university degree. The main objective of this study was to identify certain skills, and specifically vocabulary skills, that French university students with dyslexia have developed and that may contribute to their literacy skills. We tested 20 university students with dyslexia and 20 normal readers (matched on chronological age, gender, nonverbal IQ, and level of education) in reading, phonological, vocabulary breadth (number of known words), and vocabulary depth (accuracy and precision) tasks. In comparing vocabulary measures, we used both Rasch model and single case study methodologies. Results on reading and phonological tasks confirmed the persistence of deficits in written word recognition and phonological skills. However, using the Rasch model we found that the two groups performed at the same level in the vocabulary breadth task, whereas dyslexics systematically outperformed their chronological age controls in the vocabulary depth task. These results are supplemented by multiple case studies. The vocabulary skills of French university students with dyslexia are well developed. Possible interpretations of these results are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Connectionist neuropsychology: uncovering ultimate causes of acquired dyslexia.

PubMed

Woollams, Anna M

2014-01-01

Acquired dyslexia offers a unique window on to the nature of the cognitive and neural architecture supporting skilled reading. This paper provides an integrative overview of recent empirical and computational work on acquired dyslexia within the context of the primary systems framework as implemented in connectionist neuropsychological models. This view proposes that damage to general visual, phonological or semantic processing abilities are the root causes of different forms of acquired dyslexia. Recent case-series behavioural evidence concerning pure alexia, phonological dyslexia and surface dyslexia that supports this perspective is presented. Lesion simulations of these findings within connectionist models of reading demonstrate the viability of this approach. The commitment of such models to learnt representations allows them to capture key aspects of performance in each type of acquired dyslexia, particularly the associated non-reading deficits, the role of relearning and the influence of individual differences in the premorbid state of the reading system. Identification of these factors not only advances our understanding of acquired dyslexia and the mechanisms of normal reading but they are also relevant to the complex interactions underpinning developmental reading disorders.

Connectionist neuropsychology: uncovering ultimate causes of acquired dyslexia

PubMed Central

Woollams, Anna M.

2014-01-01

Acquired dyslexia offers a unique window on to the nature of the cognitive and neural architecture supporting skilled reading. This paper provides an integrative overview of recent empirical and computational work on acquired dyslexia within the context of the primary systems framework as implemented in connectionist neuropsychological models. This view proposes that damage to general visual, phonological or semantic processing abilities are the root causes of different forms of acquired dyslexia. Recent case-series behavioural evidence concerning pure alexia, phonological dyslexia and surface dyslexia that supports this perspective is presented. Lesion simulations of these findings within connectionist models of reading demonstrate the viability of this approach. The commitment of such models to learnt representations allows them to capture key aspects of performance in each type of acquired dyslexia, particularly the associated non-reading deficits, the role of relearning and the influence of individual differences in the premorbid state of the reading system. Identification of these factors not only advances our understanding of acquired dyslexia and the mechanisms of normal reading but they are also relevant to the complex interactions underpinning developmental reading disorders. PMID:24324241

The Perception of "Sine-Wave Speech" by Adults with Developmental Dyslexia.

ERIC Educational Resources Information Center

Rosner, Burton S.; Talcott, Joel B.; Witton, Caroline; Hogg, James D.; Richardson, Alexandra J.; Hansen, Peter C.; Stein, John F.

2003-01-01

"Sine-wave speech" sentences contain only four frequency-modulated sine waves, lacking many acoustic cues present in natural speech. Adults with (n=19) and without (n=14) dyslexia were asked to reproduce orally sine-wave utterances in successive trials. Results suggest comprehension of sine-wave sentences is impaired in some adults with…

Space, Time, and Dyslexia: Central Nervous System Factors in Reading Disability.

ERIC Educational Resources Information Center

Krippner, Stanley

Developmental and post-traumatic dyslexia are discussed in terms of a dysfunction of the central nervous system resulting in reading disabilities. The relationship of reading to other language functions is considered, with emphasis on the temporal aspects of speech and reading. An interdisciplinary approach is held necessary for the diagnosis of…

Novel Spoken Word Learning in Adults with Developmental Dyslexia

ERIC Educational Resources Information Center

Conner, Peggy S.

2013-01-01

A high percentage of individuals with dyslexia struggle to learn unfamiliar spoken words, creating a significant obstacle to foreign language learning after early childhood. The origin of spoken-word learning difficulties in this population, generally thought to be related to the underlying literacy deficit, is not well defined (e.g., Di Betta…

Global and Local Pitch Perception in Children with Developmental Dyslexia

ERIC Educational Resources Information Center

Ziegler, Johannes C.; Pech-Georgel, Catherine; George, Florence; Foxton, Jessica M.

2012-01-01

This study investigated global versus local pitch pattern perception in children with dyslexia aged between 8 and 11 years. Children listened to two consecutive 4-tone pitch sequences while performing a same/different task. On the different trials, sequences either preserved the contour (local condition) or they violated the contour (global…

Diagnostic Assessment and Treatment of Reading Difficulties: A Case Study of Dyslexia

ERIC Educational Resources Information Center

Oviedo, Paula Outon; Gonzalez, Rebeca Abal

2013-01-01

Dyslexia is a specific learning disability in reading and writing, which requires adequate early intervention to prevent future school failure. We describe the diagnostic assessment of a 7-year-old boy labelled "dyslexic", the evaluation of his family, social, medical, developmental, and academic status as a preliminary for the design…

Increased White Matter Gyral Depth in Dyslexia: Implications for Corticocortical Connectivity

ERIC Educational Resources Information Center

Casanova, Manuel F.; El-Baz, Ayman S.; Giedd, Jay; Rumsey, Judith M.; Switala, Andrew E.

2010-01-01

Recent studies provide credence to the minicolumnar origin of several developmental conditions, including dyslexia. Characteristics of minicolumnopathies include abnormalities in how the cortex expands and folds. This study examines the depth of the gyral white matter measured in an MRI series of 15 dyslexic adult men and eleven age-matched…

The Double-Deficit Hypothesis: A Comprehensive Analysis of the Evidence

ERIC Educational Resources Information Center

Vukovic, Rose K.; Siegel, Linda S.

2006-01-01

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…

Preschool Impairments in Auditory Processing and Speech Perception Uniquely Predict Future Reading Problems

ERIC Educational Resources Information Center

Boets, Bart; Vandermosten, Maaike; Poelmans, Hanne; Luts, Heleen; Wouters, Jan; Ghesquiere, Pol

2011-01-01

Developmental dyslexia is characterized by severe reading and spelling difficulties that are persistent and resistant to the usual didactic measures and remedial efforts. It is well established that a major cause of these problems lies in poorly specified phonological representations. Many individuals with dyslexia also present impairments in…

Reading for Meaning in Dyslexic and Young Children: Distinct Neural Pathways but Common Endpoints

ERIC Educational Resources Information Center

Schulz, Enrico; Maurer, Urs; van der Mark, Sanne; Bucher, Kerstin; Brem, Silvia; Martin, Ernst; Brandeis, Daniel

2009-01-01

Developmental dyslexia is a highly prevalent and specific disorder of reading acquisition characterised by impaired reading fluency and comprehension. We have previously identified fMRI- and ERP-based neural markers of impaired sentence reading in dyslexia that indicated both deviant basic word processing and deviant semantic incongruency…

Cognitive Processing Skills and Developmental Dyslexia in Chinese

ERIC Educational Resources Information Center

Wang, Xiaochen; Georgiou, George K.; Das, J. P.; Li, Qing

2012-01-01

The purpose of the present study was twofold: (a) to examine the extent to which Chinese dyslexic children experience deficits in phonological and orthographic processing skills and (b) to examine if Chinese dyslexia is associated with deficits in Planning, Attention, Simultaneous, and Successive (PASS) processing. A total of 27 Grade 4 children…

Measurement error: Implications for diagnosis and discrepancy models of developmental dyslexia.

PubMed

Cotton, Sue M; Crewther, David P; Crewther, Sheila G

2005-08-01

The diagnosis of developmental dyslexia (DD) is reliant on a discrepancy between intellectual functioning and reading achievement. Discrepancy-based formulae have frequently been employed to establish the significance of the difference between 'intelligence' and 'actual' reading achievement. These formulae, however, often fail to take into consideration test reliability and the error associated with a single test score. This paper provides an illustration of the potential effects that test reliability and measurement error can have on the diagnosis of dyslexia, with particular reference to discrepancy models. The roles of reliability and standard error of measurement (SEM) in classic test theory are also briefly reviewed. This is followed by illustrations of how SEM and test reliability can aid with the interpretation of a simple discrepancy-based formula of DD. It is proposed that a lack of consideration of test theory in the use of discrepancy-based models of DD can lead to misdiagnosis (both false positives and false negatives). Further, misdiagnosis in research samples affects reproducibility and generalizability of findings. This in turn, may explain current inconsistencies in research on the perceptual, sensory, and motor correlates of dyslexia.

Feedforward motor control in developmental dyslexia and developmental coordination disorder: Does comorbidity matter?

PubMed

Cignetti, Fabien; Vaugoyeau, Marianne; Fontan, Aurelie; Jover, Marianne; Livet, Marie-Odile; Hugonenq, Catherine; Audic, Frédérique; Chabrol, Brigitte; Assaiante, Christine

2018-05-01

Feedforward and online controls are two facets of predictive motor control from internal models, which is suspected to be impaired in learning disorders. We examined whether the feedforward component is affected in children (8-12 years) with developmental dyslexia (DD) and/or with developmental coordination disorder (DCD) compared to typically developing (TD) children. Children underwent a bimanual unloading paradigm during which a load supported to one arm, the postural arm, was either unexpectedly unloaded by a computer or voluntary unloaded by the subject with the other arm. All children showed a better stabilization (lower flexion) of the postural arm and an earlier inhibition of the arm flexors during voluntary unloading, indicating anticipation of unloading. Between-group comparisons of kinematics and electromyographic activity of the postural arm revealed that the difference during voluntary unloading was between DD-DCD children and the other groups, with the former showing a delayed inhibition of the flexor muscles. Deficit of the feedforward component of motor control may particularly apply to comorbid subtypes, here the DD-DCD subtype. The development of a comprehensive framework for motor performance deficits in children with learning disorders will be achieved only by dissociating key components of motor prediction and focusing on subtypes and comorbidities. Copyright © 2018 Elsevier Ltd. All rights reserved.

Changes in reading strategies in school-age children.

PubMed

Sanabria Díaz, Gretel; Torres, María del Rosario; Iglesias, Jorge; Mosquera, Raysil; Reigosa, Vivian; Santos, Elsa; Lage, Agustín; Estévez, Nancy; Galán, Lidice

2009-11-01

Learning to read is one of the most important cognitive milestones in the human social environment. One of the most accepted models explaining such process is the Double-Route Cascaded Model. It suggests the existence of two reading strategies: lexical and sublexical. In the Spanish language there are some contradictions about how these strategies are applied for reading. In addition, there are only a few studies dealing with the analysis of shifts between them, achieving a fluent reading process. In this paper we use a reading task including words and pseudowords for characterizing the cost of shifting between reading strategies in children with developmental dyslexia and normal controls. Our results suggest the presence of both strategies in these two experimental groups. In controls, both strategies become more efficient in correspondence to the increased exposition to written material. However, in children with developmental dyslexia only the lexical strategy exhibits such improvement. Their also point to a low cost for shifting between strategies in controls and a much more significant one in children with developmental dyslexia, differentiating subgroups with distinct shifting patterns.

A longitudinal study investigating neural processing of speech envelope modulation rates in children with (a family risk for) dyslexia.

PubMed

De Vos, Astrid; Vanvooren, Sophie; Vanderauwera, Jolijn; Ghesquière, Pol; Wouters, Jan

2017-08-01

Recent evidence suggests that a fundamental deficit in the synchronization of neural oscillations to temporal information in speech may underlie phonological processing problems in dyslexia. Since previous studies were performed cross-sectionally in school-aged children or adults, developmental aspects of neural auditory processing in relation to reading acquisition and dyslexia remain to be investigated. The present longitudinal study followed 68 children during development from pre-reader (5 years old) to beginning reader (7 years old) and more advanced reader (9 years old). Thirty-six children had a family risk for dyslexia and 14 children eventually developed dyslexia. EEG recordings of auditory steady-state responses to 4 and 20 Hz modulations, corresponding to syllable and phoneme rates, were collected at each point in time. Our results demonstrate an increase in neural synchronization to phoneme-rate modulations around the onset of reading acquisition. This effect was negatively correlated with later reading and phonological skills, indicating that children who exhibit the largest increase in neural synchronization to phoneme rates, develop the poorest reading and phonological skills. Accordingly, neural synchronization to phoneme-rate modulations was found to be significantly higher in beginning and more advanced readers with dyslexia. We found no developmental effects regarding neural synchronization to syllable rates, nor any effects of a family risk for dyslexia. Altogether, our findings suggest that the onset of reading instruction coincides with an increase in neural responsiveness to phoneme-rate modulations, and that the extent of this increase is related to (the outcome of) reading development. Hereby, dyslexic children persistently demonstrate atypically high neural synchronization to phoneme rates from the beginning of reading acquisition onwards. Copyright © 2017 Elsevier Ltd. All rights reserved.

Investigating the role of visual and auditory search in reading and developmental dyslexia

PubMed Central

Lallier, Marie; Donnadieu, Sophie; Valdois, Sylviane

2013-01-01

It has been suggested that auditory and visual sequential processing deficits contribute to phonological disorders in developmental dyslexia. As an alternative explanation to a phonological deficit as the proximal cause for reading disorders, the visual attention span hypothesis (VA Span) suggests that difficulties in processing visual elements simultaneously lead to dyslexia, regardless of the presence of a phonological disorder. In this study, we assessed whether deficits in processing simultaneously displayed visual or auditory elements is linked to dyslexia associated with a VA Span impairment. Sixteen children with developmental dyslexia and 16 age-matched skilled readers were assessed on visual and auditory search tasks. Participants were asked to detect a target presented simultaneously with 3, 9, or 15 distracters. In the visual modality, target detection was slower in the dyslexic children than in the control group on a “serial” search condition only: the intercepts (but not the slopes) of the search functions were higher in the dyslexic group than in the control group. In the auditory modality, although no group difference was observed, search performance was influenced by the number of distracters in the control group only. Within the dyslexic group, not only poor visual search (high reaction times and intercepts) but also low auditory search performance (d′) strongly correlated with poor irregular word reading accuracy. Moreover, both visual and auditory search performance was associated with the VA Span abilities of dyslexic participants but not with their phonological skills. The present data suggests that some visual mechanisms engaged in “serial” search contribute to reading and orthographic knowledge via VA Span skills regardless of phonological skills. The present results further open the question of the role of auditory simultaneous processing in reading as well as its link with VA Span skills. PMID:24093014

Investigating the role of visual and auditory search in reading and developmental dyslexia.

PubMed

Lallier, Marie; Donnadieu, Sophie; Valdois, Sylviane

2013-01-01

It has been suggested that auditory and visual sequential processing deficits contribute to phonological disorders in developmental dyslexia. As an alternative explanation to a phonological deficit as the proximal cause for reading disorders, the visual attention span hypothesis (VA Span) suggests that difficulties in processing visual elements simultaneously lead to dyslexia, regardless of the presence of a phonological disorder. In this study, we assessed whether deficits in processing simultaneously displayed visual or auditory elements is linked to dyslexia associated with a VA Span impairment. Sixteen children with developmental dyslexia and 16 age-matched skilled readers were assessed on visual and auditory search tasks. Participants were asked to detect a target presented simultaneously with 3, 9, or 15 distracters. In the visual modality, target detection was slower in the dyslexic children than in the control group on a "serial" search condition only: the intercepts (but not the slopes) of the search functions were higher in the dyslexic group than in the control group. In the auditory modality, although no group difference was observed, search performance was influenced by the number of distracters in the control group only. Within the dyslexic group, not only poor visual search (high reaction times and intercepts) but also low auditory search performance (d') strongly correlated with poor irregular word reading accuracy. Moreover, both visual and auditory search performance was associated with the VA Span abilities of dyslexic participants but not with their phonological skills. The present data suggests that some visual mechanisms engaged in "serial" search contribute to reading and orthographic knowledge via VA Span skills regardless of phonological skills. The present results further open the question of the role of auditory simultaneous processing in reading as well as its link with VA Span skills.

Uncoupling of reading and IQ over time: empirical evidence for a definition of dyslexia.

PubMed

Ferrer, Emilio; Shaywitz, Bennett A; Holahan, John M; Marchione, Karen; Shaywitz, Sally E

2010-01-01

Developmental dyslexia is defined as an unexpected difficulty in reading in individuals who otherwise possess the intelligence and motivation considered necessary for fluent reading, and who also have had reasonable reading instruction. Identifying factors associated with normative and impaired reading development has implications for diagnosis, intervention, and prevention. We show that in typical readers, reading and IQ development are dynamically linked over time. Such mutual interrelationships are not perceptible in dyslexic readers, which suggests that reading and cognition develop more independently in these individuals. To our knowledge, these findings provide the first empirical demonstration of a coupling between cognition and reading in typical readers and a developmental uncoupling between cognition and reading in dyslexic readers. This uncoupling was the core concept of the initial description of dyslexia and remains the focus of the current definitional model of this learning disability.

N300 Indexes Deficient Integration of Orthographic and Phonological Representations in Children with Dyslexia

ERIC Educational Resources Information Center

Hasko, Sandra; Bruder, Jennifer; Bartling, Jurgen; Schulte-Korne, Gerd

2012-01-01

In transparent orthographies, like German, children with developmental dyslexia (DD) are mainly characterized by a reading fluency deficit. The reading fluency deficit might be traced back to a scarce integration of orthographic and phonological representations. In order to address this question, the present study used EEG to investigate the N300,…

Durations of Recognition for Single Letters, with and without Visual Masking, by Dyslexics and Normal Readers.

ERIC Educational Resources Information Center

Grosser, George S.; Trzeciak, Gerda M.

1981-01-01

Two sets of letters, those subject to reversal/rotation and others, were tachistoscopically presented singly to normal readers and dyslexic children. The data support the hypothesis that letters subject to reversal have no special relation to dyslexia. The view that dyslexia is a developmental anomaly was supported. (Author/AL)

Phonological Skills, Visual Attention Span, and Visual Stress in Developmental Dyslexia

ERIC Educational Resources Information Center

Saksida, Amanda; Iannuzzi, Stéphanie; Bogliotti, Caroline; Chaix, Yves; Démonet, Jean-François; Bricout, Laure; Billard, Catherine; Nguyen-Morel, Marie-Ange; Le Heuzey, Marie-France; Soares-Boucaud, Isabelle; George, Florence; Ziegler, Johannes C.; Ramus, Franck

2016-01-01

In this study, we concurrently investigated 3 possible causes of dyslexia--a phonological deficit, visual stress, and a reduced visual attention span--in a large population of 164 dyslexic and 118 control French children, aged between 8 and 13 years old. We found that most dyslexic children showed a phonological deficit, either in terms of…

Are the Literacy Difficulties That Characterize Developmental Dyslexia Associated with a Failure to Integrate Letters and Speech Sounds?

ERIC Educational Resources Information Center

Nash, Hannah M.; Gooch, Debbie; Hulme, Charles; Mahajan, Yatin; McArthur, Genevieve; Steinmetzger, Kurt; Snowling, Margaret J.

2017-01-01

The "automatic letter-sound integration hypothesis" (Blomert, [Blomert, L., 2011]) proposes that dyslexia results from a failure to fully integrate letters and speech sounds into automated audio-visual objects. We tested this hypothesis in a sample of English-speaking children with dyslexic difficulties (N = 13) and samples of…

Balancing and Pointing Tasks in Dyslexic and Control Adults

ERIC Educational Resources Information Center

Stoodley, Catherine J.; Fawcett, Angela J.; Nicolson, Roderick I.; Stein, John F.

2006-01-01

Developmental dyslexia may affect as much as 15% of the population, but the aetiology of the disorder is still being debated. The cerebellar theory of dyslexia proposes that cerebellar dysfunction could lead to the myriad of symptoms seen in dyslexic individuals, both in literacy and non-literacy domains. The cerebellum is crucial to the fluent…

Short-Term Memory for Order but Not for Item Information Is Impaired in Developmental Dyslexia

ERIC Educational Resources Information Center

Hachmann, Wibke M.; Bogaerts, Louisa; Szmalec, Arnaud; Woumans, Evy; Duyck, Wouter; Job, Remo

2014-01-01

Recent findings suggest that people with dyslexia experience difficulties with the learning of serial order information during the transition from short-to long-term memory (Szmalec et al. "Journal of Experimental Psychology: Learning, Memory, & Cognition" 37(5): 1270-1279, 2011). At the same time, models of short-term memory…

Implicit Phonological and Semantic Processing in Children with Developmental Dyslexia: Evidence from Event-Related Potentials

ERIC Educational Resources Information Center

Jednorog, K.; Marchewka, A.; Tacikowski, P.; Grabowska, A.

2010-01-01

Dyslexia is characterized by a core phonological deficit, although recent studies indicate that semantic impairment also contributes to this condition. In this study, event-related potentials (ERP) were used to examine whether the N400 wave in dyslexic children is modulated by phonological or semantic priming, similarly to age-matched controls.…

Co-Occurrence of Developmental Disorders: The Case of Developmental Dyscalculia

ERIC Educational Resources Information Center

Rubinsten, Orly

2009-01-01

Five to seven percent of children experience severe difficulties in learning mathematics and/or reading. Current trials that are focused on identifying biological markers suggest that these learning disabilities, known as Developmental Dyscalculia (DD) and Dyslexia (for reading), are due to underlying brain dysfunctions. One ongoing controversy…

Spelling well Despite Developmental Language Disorder: What Makes It Possible?

ERIC Educational Resources Information Center

Rakhlin, Natalia; Cardoso-Martins, Cláudia; Kornilov, Sergey A.; Grigorenko, Elena L.

2013-01-01

The goal of the study was to investigate the overlap between developmental language disorder (DLD) and developmental dyslexia, identified through spelling difficulties (SD), in Russian-speaking children. In particular, we studied the role of phoneme awareness (PA), rapid automatized naming (RAN), pseudoword repetition (PWR), morphological (MA),…

Screening for Dyslexia in French-Speaking University Students: An Evaluation of the Detection Accuracy of the Alouette Test.

PubMed

Cavalli, Eddy; Colé, Pascale; Leloup, Gilles; Poracchia-George, Florence; Sprenger-Charolles, Liliane; El Ahmadi, Abdessadek

Developmental dyslexia is a lifelong impairment affecting 5% to 10% of the population. In French-speaking countries, although a number of standardized tests for dyslexia in children are available, tools suitable to screen for dyslexia in adults are lacking. In this study, we administered the Alouette reading test to a normative sample of 164 French university students without dyslexia and a validation sample of 83 students with dyslexia. The Alouette reading test is designed to screen for dyslexia in children, since it taps skills that are typically deficient in dyslexia (i.e., phonological skills). However, the test's psychometric properties have not previously been available, and it is not standardized for adults. The results showed that, on the Alouette test, dyslexic readers were impaired on measures of accuracy, speed, and efficiency (accuracy/reading time). We also found significant correlations between the Alouette reading efficiency and phonological efficiency scores. Finally, in terms of the Alouette test, speed-accuracy trade-offs were found in both groups, and optimal cutoff scores were determined with receiver operator characteristic curves analysis, yielding excellent discriminatory power, with 83.1% sensitivity and 100% specificity for reading efficiency. Thus, this study supports the Alouette test as a sensitive and specific screening tool for adults with dyslexia.

Impaired extraction of speech rhythm from temporal modulation patterns in speech in developmental dyslexia

PubMed Central

Leong, Victoria; Goswami, Usha

2014-01-01

Dyslexia is associated with impaired neural representation of the sound structure of words (phonology). The “phonological deficit” in dyslexia may arise in part from impaired speech rhythm perception, thought to depend on neural oscillatory phase-locking to slow amplitude modulation (AM) patterns in the speech envelope. Speech contains AM patterns at multiple temporal rates, and these different AM rates are associated with phonological units of different grain sizes, e.g., related to stress, syllables or phonemes. Here, we assess the ability of adults with dyslexia to use speech AMs to identify rhythm patterns (RPs). We study 3 important temporal rates: “Stress” (~2 Hz), “Syllable” (~4 Hz) and “Sub-beat” (reduced syllables, ~14 Hz). 21 dyslexics and 21 controls listened to nursery rhyme sentences that had been tone-vocoded using either single AM rates from the speech envelope (Stress only, Syllable only, Sub-beat only) or pairs of AM rates (Stress + Syllable, Syllable + Sub-beat). They were asked to use the acoustic rhythm of the stimulus to identity the original nursery rhyme sentence. The data showed that dyslexics were significantly poorer at detecting rhythm compared to controls when they had to utilize multi-rate temporal information from pairs of AMs (Stress + Syllable or Syllable + Sub-beat). These data suggest that dyslexia is associated with a reduced ability to utilize AMs <20 Hz for rhythm recognition. This perceptual deficit in utilizing AM patterns in speech could be underpinned by less efficient neuronal phase alignment and cross-frequency neuronal oscillatory synchronization in dyslexia. Dyslexics' perceptual difficulties in capturing the full spectro-temporal complexity of speech over multiple timescales could contribute to the development of impaired phonological representations for words, the cognitive hallmark of dyslexia across languages. PMID:24605099

Verbal and Non-verbal Fluency in Adults with Developmental Dyslexia: Phonological Processing or Executive Control Problems?

PubMed

Smith-Spark, James H; Henry, Lucy A; Messer, David J; Zięcik, Adam P

2017-08-01

The executive function of fluency describes the ability to generate items according to specific rules. Production of words beginning with a certain letter (phonemic fluency) is impaired in dyslexia, while generation of words belonging to a certain semantic category (semantic fluency) is typically unimpaired. However, in dyslexia, verbal fluency has generally been studied only in terms of overall words produced. Furthermore, performance of adults with dyslexia on non-verbal design fluency tasks has not been explored but would indicate whether deficits could be explained by executive control, rather than phonological processing, difficulties. Phonemic, semantic and design fluency tasks were presented to adults with dyslexia and without dyslexia, using fine-grained performance measures and controlling for IQ. Hierarchical regressions indicated that dyslexia predicted lower phonemic fluency, but not semantic or design fluency. At the fine-grained level, dyslexia predicted a smaller number of switches between subcategories on phonemic fluency, while dyslexia did not predict the size of phonemically related clusters of items. Overall, the results suggested that phonological processing problems were at the root of dyslexia-related fluency deficits; however, executive control difficulties could not be completely ruled out as an alternative explanation. Developments in research methodology, equating executive demands across fluency tasks, may resolve this issue. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Increased Response to Altered Auditory Feedback in Dyslexia: A Weaker Sensorimotor Magnet Implied in the Phonological Deficit

ERIC Educational Resources Information Center

van den Bunt, Mark R.; Groen, Margriet A.; Ito, Takayuki; Francisco, Ana A.; Gracco, Vincent L.; Pugh, Ken R.; Verhoeven, Ludo

2017-01-01

Purpose: The purpose of this study was to examine whether developmental dyslexia (DD) is characterized by deficiencies in speech sensory and motor feedforward and feedback mechanisms, which are involved in the modulation of phonological representations. Method: A total of 42 adult native speakers of Dutch (22 adults with DD; 20 participants who…

The Representation and Processing of Familiar Faces in Dyslexia: Differences in Age of Acquisition Effects

ERIC Educational Resources Information Center

Smith-Spark, James H.; Moore, Viv

2009-01-01

Two under-explored areas of developmental dyslexia research, face naming and age of acquisition (AoA), were investigated. Eighteen dyslexic and 18 non-dyslexic university students named the faces of 50 well-known celebrities, matched for facial distinctiveness and familiarity. Twenty-five of the famous people were learned early in life, while the…

Early communicative gestures and play as predictors of language development in children born with and without family risk for dyslexia.

PubMed

Unhjem, Astrid; Eklund, Kenneth; Nergård-Nilssen, Trude

2014-08-01

The present study investigated early communicative gestures, play, and language skills in children born with family risk for dyslexia (FR) and a control group of children without this inheritable risk at ages 12, 15, 18, and 24 months. Participants were drawn from the Tromsø Longitudinal study of Dyslexia (TLD) which follows children's cognitive and language development from age 12 months through Grade 2 in order to identify early markers of developmental dyslexia. Results showed that symbolic play and parent reported play at age 12 months and communicative gestures at age 15 months explained 61% of the variance in productive language at 24 months in the FR group. These early nonlinguistic measures seem to be potentially interesting markers of later language development in children born at risk for dyslexia. © 2014 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Seminar: Developmental Dyslexia

PubMed Central

Peterson, Robin L.; Pennington, Bruce F.

2012-01-01

Summary Dyslexia is a neurodevelopmental disorder that is characterized by slow and inaccurate word recognition. Dyslexia has been found in every culture studied, and mounting evidence underscores cross-linguistic similarity in its neurobiological and neurocognitive bases. There has been considerable progress across levels of analysis in the last five years. At a neuropsychological level, the phonological theory remains the most compelling, though it is increasingly clear that phonological problems interact with other cognitive risk factors. At a neurobiological level, recent research confirms that dyslexia is characterized by dysfunction of the normal left hemisphere language network and also implicates abnormal white matter development. Studies accounting for reading experience demonstrate that many observed neural differences reflect causes rather than effects of dyslexia. At an etiologic risk level, six candidate genes have been identified, and there is evidence for gene by environment interaction. This review includes a focus on these and other recent developments. PMID:22513218

Atypical Cerebral Lateralisation in Adults with Compensated Developmental Dyslexia Demonstrated Using Functional Transcranial Doppler Ultrasound

ERIC Educational Resources Information Center

Illingworth, Sarah; Bishop, Dorothy V. M.

2009-01-01

Functional transcranial Doppler ultrasound (fTCD) is a relatively new and non-invasive technique that assesses cerebral lateralisation through measurements of blood flow velocity in the middle cerebral arteries. In this study fTCD was used to compare functional asymmetry during a word generation task between a group of 30 dyslexic adults and a…

Developmental Trajectories for Children with Dyslexia and Low IQ Poor Readers

ERIC Educational Resources Information Center

Kuppen, Sarah E. A.; Goswami, Usha

2016-01-01

Reading difficulties are found in children with both high and low IQ and it is now clear that both groups exhibit difficulties in phonological processing. Here, we apply the developmental trajectories approach, a new methodology developed for studying language and cognitive impairments in developmental disorders, to both poor reader groups. The…

Reading Acquisition, Developmental Dyslexia, and Skilled Reading Across Languages: A Psycholinguistic Grain Size Theory

ERIC Educational Resources Information Center

Ziegler, Johannes C.; Goswami, Usha

2005-01-01

The development of reading depends on phonological awareness across all languages so far studied. Languages vary in the consistency with which phonology is represented in orthography. This results in developmental differences in the grain size of lexical representations and accompanying differences in developmental reading strategies and the…

[Phonological awareness, working memory, reading and writing performances in familial dyslexia].

PubMed

Capellini, Simone Aparecida; Padula, Niura Aparecida de Mouro Ribeiro; Santos, Lara Cristina Antunes Dos; Lourenceti, Maria Dalva; Carrenho, Erika Hasse; Ribeiro, Lucilene Arilho

2007-01-01

familial dyslexia. to characterize and compare the phonological awareness, working memory, reading and writing abilities of individuals whose family members are also affected. in this study 10 familial nuclei of natural family relationship of individuals with dyslexia were analyzed. Families of natural individuals living in the west region of the state of São Paulo were selected. Inclusion criteria were: to be a native speaker of the Brazilian Portuguese language, to have 8 years of age or more, to present positive familial history for learning disabilities, that is, to present at least one relative with difficulties in learning. Exclusion criteria were: to present any neurological disorder genetically caused or not, in any of the family members, such as dystonia, extra pyramidal diseases, mental disorder, epilepsy, attention deficit and hyperactivity disorder (ADHA); psychiatric symptoms or conditions; or any other pertinent conditions that could cause errors in the diagnosis. As for the diagnosis of developmental dyslexia, information about the familial history of the adolescents and children was gathered with the parents, so that a detailed pedigree could be delineated. Neurological, psychological, speech-language, and school performance evaluations were made with the individuals and their families. the results of this study suggest that the dyslexic individuals and their respective relatives, also with dyslexia, presented lower performances than the control group in terms of rapid automatic naming, reading, writing and phonological awareness. deficits in phonological awareness, working memory, reading and writing seem to have genetic susceptibility that possibly determine, when in interaction with the environment, the manifestation of dyslexia.

Inflectional Morphology and Dyslexia: Italian Children's Performance in a Nonword Pluralization Task

ERIC Educational Resources Information Center

Vender, Maria; Mantione, Federica; Savazzi, Silvia; Delfitto, Denis; Melloni, Chiara

2017-01-01

In this study, we present the results of an original experimental protocol designed to assess the performance in a pluralization task of 52 Italian children divided into two groups: 24 children with developmental dyslexia (mean age 10.0 years old) and 28 typically developing children (mean age 9.11 years old). Our task, inspired by Berko's Wug…

Writing Problems in Developmental Dyslexia: Under-Recognized and Under-Treated2,3

PubMed Central

Berninger, Virginia W.; Nielsen, Kathleen H.; Abbott, Robert D.; Wijsman, Ellen; Raskind, Wendy

2008-01-01

The International Dyslexia Association defines dyslexia as unexpected problems of neurobiological origin in accuracy and rate of oral reading of single real words, single pseudowords, or text or of written spelling. However, prior research has focused more on the reading than the spelling problems of students with dyslexia. A test battery was administered to 122 children who met inclusion criteria for dyslexia and qualified their families for participation in a family genetics study that has been ongoing for over a decade. Their parents completed the same test battery. Although a past structural equation modeling study of typically developing children identified a significant path from handwriting to composition quality, the current structural equation modeling study identified a significant path from spelling to composition for children and their parents with dyslexia. Grapho-motor planning did not contribute uniquely to their composition, showing that writing is not just a motor skill. Students with dyslexia do have a problem in automatic letter writing and naming, which was related to impaired inhibition and verbal fluency, and may explain their spelling problems. Results are discussed in reference to the importance of providing explicit instruction in the phonological, orthographic, and morphological processes of spelling and in composition to students with dyslexia and not only offering accommodation for their writing problems. PMID:18438452

The Nature of Verbal Short-Term Impairment in Dyslexia: The Importance of Serial Order

PubMed Central

Majerus, Steve; Cowan, Nelson

2016-01-01

Verbal short-term memory (STM) impairment is one of the most consistent associated deficits observed in developmental reading disorders such as dyslexia. Few studies have addressed the nature of this STM impairment, especially as regards the ability to temporarily store serial order information. This question is important as studies in typically developing children have shown that serial order STM abilities are predictors of oral and written language development. Associated serial order STM deficits in dyslexia may therefore further increase the learning difficulties in these populations. In this mini review, we show that specific serial order STM impairment is frequently reported in both dyslexic children and adults with a history of dyslexia. Serial order STM impairment appears to occur for the retention of both verbal and visuo-spatial sequence information. Serial order STM impairment is, however, not a characteristic of every individual dyslexic subject and is not specific to dyslexia. Future studies need to determine whether serial order STM impairment is a risk factor which, in association with phonological processing deficits, can lead to dyslexia or whether serial order STM impairment reflects associated deficits causally unrelated to dyslexia. PMID:27752247

What is Developmental Dyslexia?

PubMed Central

Stein, John

2018-01-01

Until the 1950s, developmental dyslexia was defined as a hereditary visual disability, selectively affecting reading without compromising oral or non-verbal reasoning skills. This changed radically after the development of the phonological theory of dyslexia; this not only ruled out any role for visual processing in its aetiology, but it also cast doubt on the use of discrepancy between reading and reasoning skills as a criterion for diagnosing it. Here I argue that this theory is set at too high a cognitive level to be explanatory; we need to understand the pathophysiological visual and auditory mechanisms that cause children’s phonological problems. I discuss how the ‘magnocellular theory’ attempts to do this in terms of slowed and error prone temporal processing which leads to dyslexics’ defective visual and auditory sequencing when attempting to read. I attempt to deal with the criticisms of this theory and show how it leads to a number of successful ways of helping dyslexic children to overcome their reading difficulties. PMID:29401712

Is Dyslexia a Brain Disorder?

PubMed Central

Parrila, Rauno

2018-01-01

Specific word reading difficulty, commonly termed ‘developmental dyslexia’, refers to the low end of the word reading skill distribution but is frequently considered to be a neurodevelopmental disorder. This term implies that brain development is thought to be disrupted, resulting in an abnormal and dysfunctional brain. We take issue with this view, pointing out that there is no evidence of any obvious neurological abnormality in the vast majority of cases of word reading difficulty cases. The available relevant evidence from neuroimaging studies consists almost entirely of correlational and group-differences studies. However, differences in brains are certain to exist whenever differences in behavior exist, including differences in ability and performance. Therefore, findings of brain differences do not constitute evidence for abnormality; rather, they simply document the neural substrate of the behavioral differences. We suggest that dyslexia is best viewed as one of many expressions of ordinary ubiquitous individual differences in normal developmental outcomes. Thus, terms such as “dysfunctional” or “abnormal” are not justified when referring to the brains of persons with dyslexia. PMID:29621138

A perceptual learning deficit in Chinese developmental dyslexia as revealed by visual texture discrimination training.

PubMed

Wang, Zhengke; Cheng-Lai, Alice; Song, Yan; Cutting, Laurie; Jiang, Yuzheng; Lin, Ou; Meng, Xiangzhi; Zhou, Xiaolin

2014-08-01

Learning to read involves discriminating between different written forms and establishing connections with phonology and semantics. This process may be partially built upon visual perceptual learning, during which the ability to process the attributes of visual stimuli progressively improves with practice. The present study investigated to what extent Chinese children with developmental dyslexia have deficits in perceptual learning by using a texture discrimination task, in which participants were asked to discriminate the orientation of target bars. Experiment l demonstrated that, when all of the participants started with the same initial stimulus-to-mask onset asynchrony (SOA) at 300 ms, the threshold SOA, adjusted according to response accuracy for reaching 80% accuracy, did not show a decrement over 5 days of training for children with dyslexia, whereas this threshold SOA steadily decreased over the training for the control group. Experiment 2 used an adaptive procedure to determine the threshold SOA for each participant during training. Results showed that both the group of dyslexia and the control group attained perceptual learning over the sessions in 5 days, although the threshold SOAs were significantly higher for the group of dyslexia than for the control group; moreover, over individual participants, the threshold SOA negatively correlated with their performance in Chinese character recognition. These findings suggest that deficits in visual perceptual processing and learning might, in part, underpin difficulty in reading Chinese. Copyright © 2014 John Wiley & Sons, Ltd.

Dyslexia and Developmental Co-Ordination Disorder in Further and Higher Education--Similarities and Differences. Does the "Label" Influence the Support Given?

ERIC Educational Resources Information Center

Kirby, Amanda; Sugden, David; Beveridge, Sally; Edwards, Lisa; Edwards, Rachel

2008-01-01

Developmental co-ordination disorder (DCD) is a developmental disorder affecting motor co-ordination. The "Diagnostics Statistics Manual"--IV classification for DCD describes difficulties across a range of activities of daily living, impacting on everyday skills and academic performance in school. Recent evidence has shown that…

The double-deficit hypothesis: a comprehensive analysis of the evidence.

PubMed

Vukovic, Rose K; Siegel, Linda S

2006-01-01

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.

The overstimulated state of dyslexia: perception, knowledge, and learning.

PubMed

Arkowitz, S W

2000-01-01

Dyslexia is far more than a learning disorder; it has significant impact on personality organization. While dyslexia usually begins to manifest most clearly in early latency when the challenge of learning to read is at its height, often the dyslexic child's ego development and functioning has already been adversely affected. The literature from neuropsychology suggests that dyslexia is a subtle language-processing disorder that affects emotional, cognitive, and social development. The neuroanatomical literature also suggests a significant correlation between the neurodevelopmental basis for dyslexia, the caregiving environment, and psychological development. These two bodies of literature and analytic observations of a dyslexic patient suggest that the dyslexic individual may have a neurological deficit that increases vulnerability to overstimulation. The author hypothesizes that emotional and cognitive states result and reappear within the analytic encounter. This complicates clinical assessment and technical decisions. The author presents an analytic case and examines (1) the impact of deficit on the development of conflict; (2) the impact of the overwhelmed ego on the mastery of developmental tasks; and (3) the impact of dyslexia on dysgnosia, transference, and analytic process and technique.

Morphological differences in the lateral geniculate nucleus associated with dyslexia

PubMed Central

Giraldo-Chica, Mónica; Hegarty, John P.; Schneider, Keith A.

2015-01-01

Developmental dyslexia is a common learning disability characterized by normal intelligence but difficulty in skills associated with reading, writing and spelling. One of the most prominent, albeit controversial, theories of dyslexia is the magnocellular theory, which suggests that malfunction of the magnocellular system in the brain is responsible for the behavioral deficits. We sought to test the basis of this theory by directly measuring the lateral geniculate nucleus (LGN), the only location in the brain where the magnocellular and parvocellular streams are spatially disjoint. Using high-resolution proton-density weighted MRI scans, we precisely measured the anatomical boundaries of the LGN in 13 subjects with dyslexia (five female) and 13 controls (three female), all 22–26 years old. The left LGN was significantly smaller in volume in subjects with dyslexia and also differed in shape; no differences were observed in the right LGN. The functional significance of this asymmetry is unknown, but these results are consistent with the magnocellular theory and support theories of dyslexia that involve differences in the early visual system. PMID:26082892

Effect of Chunk Strength on the Performance of Children with Developmental Dyslexia on Artificial Grammar Learning Task May Be Related to Complexity

ERIC Educational Resources Information Center

Schiff, Rachel; Katan, Pesia; Sasson, Ayelet; Kahta, Shani

2017-01-01

There is 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…

Neurocognitive functioning in children with developmental dyslexia and attention-deficit/hyperactivity disorder: Multiple deficits and diagnostic accuracy.

PubMed

Moura, Octávio; Pereira, Marcelino; Alfaiate, Cláudia; Fernandes, Eva; Fernandes, Boavida; Nogueira, Susana; Moreno, Joana; Simões, Mário R

2017-04-01

This study aimed to investigate the neurocognitive functioning of children with developmental dyslexia (DD) and attention-deficit/hyperactivity disorder (ADHD). Four groups of children between the ages of 8 and 10 years participated in the study: typically developing children (TDC; N = 34), children with DD-only (N = 32), children with ADHD-only (N = 32), and children with DD+ADHD (N = 18). Children with DD and ADHD exhibited significant weaknesses on almost all neurocognitive measures compared with TDC. Large effect sizes were observed for naming speed and phonological awareness. The comorbid group showed deficits consistent with both DD and ADHD without additional impairments. Results from binary logistic regression and receiver-operating characteristic (ROC) curve analyses suggested that some neurocognitive measures revealed an adequate sensitivity for the clinical diagnosis of both neurodevelopmental disorders. Specifically, naming speed and phonological awareness were the strongest predictors to correctly discriminate both disorders. Taken together, the results lend support to the multiple cognitive deficit hypothesis showing a considerable overlap of neurocognitive deficits between both disorders.

Neurocognitive Development and Predictors of L1 and L2 Literacy Skills in Dyslexia: A Longitudinal Study of Children 5–11 Years Old

PubMed Central

Morken, Frøydis

2015-01-01

The aim of this study was to find valid neurocognitive precursors of literacy development in first language (L1, Norwegian) and second language (L2, English) in a group of children during their Pre‐literacy, Emergent Literacy and Literacy stages, by comparing children with dyslexia and a typical group. Children who were 5 years old at project start were followed until the age of 11, when dyslexia was identified and data could be analysed in retrospect. The children's neurocognitive pattern changed both by literacy stage and domain. Visuo‐spatial recall and RAN appeared as early precursors of L1 literacy, while phonological awareness appeared as early precursor of L2 English. Verbal long term memory was associated with both L1 and L2 skills in the Literacy stage. Significant group differences seen in the Pre‐literacy and Emergent literacy stages decreased in the Literacy stage. The developmental variations by stage and domain may explain some of the inconsistencies seen in dyslexia research. Early identification and training are essential to avoid academic failure, and our data show that visuo‐spatial memory and RAN could be suitable early markers in transparent orthographies like Norwegian. Phonological awareness was here seen as an early precursor of L2 English, but not of L1 Norwegian. © 2015 The Authors. Dyslexia published by John Wiley & Sons Ltd. PMID:26511662

Neurocognitive Development and Predictors of L1 and L2 Literacy Skills in Dyslexia: A Longitudinal Study of Children 5-11 Years Old.

PubMed

Helland, Turid; Morken, Frøydis

2016-02-01

The aim of this study was to find valid neurocognitive precursors of literacy development in first language (L1, Norwegian) and second language (L2, English) in a group of children during their Pre-literacy, Emergent Literacy and Literacy stages, by comparing children with dyslexia and a typical group. Children who were 5 years old at project start were followed until the age of 11, when dyslexia was identified and data could be analysed in retrospect. The children's neurocognitive pattern changed both by literacy stage and domain. Visuo-spatial recall and RAN appeared as early precursors of L1 literacy, while phonological awareness appeared as early precursor of L2 English. Verbal long term memory was associated with both L1 and L2 skills in the Literacy stage. Significant group differences seen in the Pre-literacy and Emergent literacy stages decreased in the Literacy stage. The developmental variations by stage and domain may explain some of the inconsistencies seen in dyslexia research. Early identification and training are essential to avoid academic failure, and our data show that visuo-spatial memory and RAN could be suitable early markers in transparent orthographies like Norwegian. Phonological awareness was here seen as an early precursor of L2 English, but not of L1 Norwegian. © 2015 The Authors. Dyslexia published by John Wiley & Sons Ltd.

Genetic and environmental risk factors for developmental dyslexia in children: systematic review of the last decade.

PubMed

Becker, Natalia; Vasconcelos, Mailton; Oliveira, Vanessa; Santos, Fernanda Caroline Dos; Bizarro, Lisiane; Almeida, Rosa M M De; Salles, Jerusa Fumagalli De; Carvalho, Maria Raquel Santos

2017-01-01

Despite advances in the characterization of developmental dyslexia (DD), several questions regarding the interplay between DD-susceptibility genes and environmental risk factors remain open. This systematic review aimed at answering the following questions: What has been the impact of new resources on the knowledge about DD? Which questions remain open? What is the investigative agenda for the short term? Forty-six studies were analyzed. Despite the growing literature on DD candidate genes, most studies have not been replicated. We found large effects on causative genes and smaller environmental contributions, involving maternal smoking during pregnancy, SES and the DYX1C1-1259C/G marker. Implications are discussed.

Visual Illusions: An Interesting Tool to Investigate Developmental Dyslexia and Autism Spectrum Disorder

PubMed Central

Gori, Simone; Molteni, Massimo; Facoetti, Andrea

2016-01-01

A visual illusion refers to a percept that is different in some aspect from the physical stimulus. Illusions are a powerful non-invasive tool for understanding the neurobiology of vision, telling us, indirectly, how the brain processes visual stimuli. There are some neurodevelopmental disorders characterized by visual deficits. Surprisingly, just a few studies investigated illusory perception in clinical populations. Our aim is to review the literature supporting a possible role for visual illusions in helping us understand the visual deficits in developmental dyslexia and autism spectrum disorder. Future studies could develop new tools – based on visual illusions – to identify an early risk for neurodevelopmental disorders. PMID:27199702

When Diglossia Meets Dyslexia: The Effect of Diglossia on Voweled and Unvoweled Word Reading among Native Arabic-Speaking Dyslexic Children

ERIC Educational Resources Information Center

Schiff, Rachel; Saiegh-Haddad, Elinor

2017-01-01

Native Arabic speakers read in a language variety that is different from the one they use for everyday speech. The aim of the present study was: (1) to examine Spoken Arabic (SpA) and Standard Arabic (StA) voweled and unvoweled word reading among native-speaking sixth graders with developmental dyslexia; and (2) to determine whether SpA reading…

KIAA0319 gene polymorphisms are associated with developmental dyslexia in Chinese Uyghur children

PubMed Central

Zhao, Hua; Chen, Yun; Zhang, Bao-ping; Zuo, Peng-xiang

2016-01-01

The gene KIAA0319 has been reported to be associated with developmental dyslexia (DD) in previous studies, although the results have not always been consistent. However, few studies have been conducted in Uyghur populations. In the present study, we aimed to investigate the association of KIAA0319 polymorphisms and DD in individuals of Uyghurian descent. We used a custom-by-design 48-Plex SNPscan Kit to genotype 18 single-nucleotide polymorphisms (SNPs) of KIAA0319 in a group of 196 children with dyslexia and 196 controls of Uyghur descent aged 8–12 years. As a result, 7 SNPs (Pmin=0.001) of KIAA0319 had nominal significant differences between the cases and controls under specific genotypic models. The two SNPs rs6935076 (P=0.020 under dominant model; P=0.028 under additive model) and rs3756821 (P=0.021 under additive model) remained significantly associated with dyslexia after Bonferroni correction. Linkage disequilibrium analysis showed three blocks within KIAA0319, and only a 10-SNP haplotype in block 3 was present at significantly different frequencies in the dyslexic children and controls. This study indicated that genetic polymorphisms of KIAA0319 are associated with an increased risk of DD in the Uyghur population. PMID:27098879

Lessons to be learned: how a comprehensive neurobiological framework of atypical reading development can inform educational practice

PubMed Central

Ozernov-Palchik, Ola; Yu, Xi; Wang, Yingying; Gaab, Nadine

2016-01-01

Dyslexia is a heritable reading disorder with an estimated prevalence of 5–17%. A multiple deficit model has been proposed that illustrates dyslexia as an outcome of multiple risks and protective factors interacting at the genetic, neural, cognitive, and environmental levels. Here we review the evidence on each of these levels and discuss possible underlying mechanisms and their reciprocal interactions along a developmental timeline. Current and potential implications of neuroscientific findings for contemporary challenges in the field of dyslexia, as well as for reading development and education in general, are then discussed. PMID:27766284

A Selective Deficit in Phonetic Recalibration by Text in Developmental Dyslexia.

PubMed

Keetels, Mirjam; Bonte, Milene; Vroomen, Jean

2018-01-01

Upon hearing an ambiguous speech sound, listeners may adjust their perceptual interpretation of the speech input in accordance with contextual information, like accompanying text or lipread speech (i.e., phonetic recalibration; Bertelson et al., 2003). As developmental dyslexia (DD) has been associated with reduced integration of text and speech sounds, we investigated whether this deficit becomes manifest when text is used to induce this type of audiovisual learning. Adults with DD and normal readers were exposed to ambiguous consonants halfway between /aba/ and /ada/ together with text or lipread speech. After this audiovisual exposure phase, they categorized auditory-only ambiguous test sounds. Results showed that individuals with DD, unlike normal readers, did not use text to recalibrate their phoneme categories, whereas their recalibration by lipread speech was spared. Individuals with DD demonstrated similar deficits when ambiguous vowels (halfway between /wIt/ and /wet/) were recalibrated by text. These findings indicate that DD is related to a specific letter-speech sound association deficit that extends over phoneme classes (vowels and consonants), but - as lipreading was spared - does not extend to a more general audio-visual integration deficit. In particular, these results highlight diminished reading-related audiovisual learning in addition to the commonly reported phonological problems in developmental dyslexia.

Reading Strategies in Spanish Developmental Dyslexics

ERIC Educational Resources Information Center

Suarez-Coalla, Paz; Cuetos, Fernando

2012-01-01

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…

Reading speed and phonological awareness deficits among Arabic-speaking children with dyslexia.

PubMed

Layes, Smail; Lalonde, Robert; Rebaï, Mohamed

2015-02-01

Although reading accuracy of isolated words and phonological awareness represent the main criteria of subtyping developmental dyslexia, there is increasing evidence that reduced reading speed also represents a defining characteristic. In the present study, reading speed and accuracy were measured in Arabic-speaking phonological and mixed dyslexic children matched with controls of the same age. Participants in third and fourth grades, aged from 9-10 to 9-8 years, were given single frequent and infrequent word and pseudo-word reading and phonological awareness tasks. Results showed that the group with dyslexia scored significantly lower than controls in accuracy and speed in reading tasks. Phonological and mixed dyslexic subgroups differed in infrequent and frequent word reading accuracy, the latter being worse. In contrast, the subgroups were comparable in pseudo-word identification and phonological awareness. Delayed phonological and recognition processes of infrequent and frequent words, respectively, were placed in the context of the dual route model of reading and the specific orthographic features of the Arabic language. Copyright © 2014 John Wiley & Sons, Ltd.

WISC-III cognitive profiles in children with developmental dyslexia: specific cognitive disability and diagnostic utility.

PubMed

Moura, Octávio; Simões, Mário R; Pereira, Marcelino

2014-02-01

This study analysed the usefulness of the Wechsler Intelligence Scale for Children-Third Edition in identifying specific cognitive impairments that are linked to developmental dyslexia (DD) and the diagnostic utility of the most common profiles in a sample of 100 Portuguese children (50 dyslexic and 50 normal readers) between the ages of 8 and 12 years. Children with DD exhibited significantly lower scores in the Verbal Comprehension Index (except the Vocabulary subtest), Freedom from Distractibility Index (FDI) and Processing Speed Index subtests, with larger effect sizes than normal readers in Information, Arithmetic and Digit Span. The Verbal-Performance IQs discrepancies, Bannatyne pattern and the presence of FDI; Arithmetic, Coding, Information and Digit Span subtests (ACID) and Symbol Search, Coding, Arithmetic and Digit Span subtests (SCAD) profiles (full or partial) in the lowest subtests revealed a low diagnostic utility. However, the receiver operating characteristic curve and the optimal cut-off score analyses of the composite ACID; FDI and SCAD profiles scores showed moderate accuracy in correctly discriminating dyslexic readers from normal ones. These results suggested that in the context of a comprehensive assessment, the Wechsler Intelligence Scale for Children-Third Edition provides some useful information about the presence of specific cognitive disabilities in DD. Practitioner Points. Children with developmental dyslexia revealed significant deficits in the Wechsler Intelligence Scale for Children-Third Edition subtests that rely on verbal abilities, processing speed and working memory. The composite Arithmetic, Coding, Information and Digit Span subtests (ACID); Freedom from Distractibility Index and Symbol Search, Coding, Arithmetic and Digit Span subtests (SCAD) profile scores showed moderate accuracy in correctly discriminating dyslexics from normal readers. Wechsler Intelligence Scale for Children-Third Edition may provide some useful information about the presence of specific cognitive disabilities in developmental dyslexia. Copyright © 2013 John Wiley & Sons, Ltd.

Gender Differences in Developmental Dyscalculia Depend on Diagnostic Criteria

ERIC Educational Resources Information Center

Devine, Amy; Soltesz, Fruzsina; Nobes, Alison; Goswami, Usha; Szucs, Denes

2013-01-01

Developmental dyscalculia (DD) is a learning difficulty specific to mathematics learning. The prevalence of DD may be equivalent to that of dyslexia, posing an important challenge for effective educational provision. Nevertheless, there is no agreed definition of DD and there are controversies surrounding cutoff decisions, specificity and gender…

The impact of developmental dyslexia and dysgraphia on movement production during word writing.

PubMed

Kandel, Sonia; Lassus-Sangosse, Delphine; Grosjacques, Géraldine; Perret, Cyril

This study investigated how deficits in orthographic processing affect movement production during word writing. Children with dyslexia and dysgraphia wrote words and pseudo-words on a digitizer. The words were orthographically regular and irregular of varying frequency. The group analysis revealed that writing irregular words and pseudo-words increased movement duration and dysfluency. This indicates that the spelling processes were active while the children were writing the words. The impact of these spelling processes was stronger for the children with dyslexia and dysgraphia. The analysis of individual performance revealed that most dyslexic/dysgraphic children presented similar writing patterns. However, selective lexical processing deficits affected irregular word writing but not pseudo-word writing. Selective poor sublexical processing affected pseudo-word writing more than irregular word writing. This study suggests that the interaction between orthographic and motor processing constitutes an important cognitive load that may disrupt the graphic outcome of the children with dyslexia/dysgraphia.

Unstable Binocular Fixation Affects Reaction Times But Not Implicit Motor Learning in Dyslexia.

PubMed

Przekoracka-Krawczyk, Anna; Brenk-Krakowska, Alicja; Nawrot, Pawel; Rusiak, Patrycja; Naskrecki, Ryszard

2017-12-01

Individuals with developmental dyslexia suffer not only from reading problems as more general motor deficits can also be observed in this patient group. Both psychometric clinical tests and objective eyetracking methods suggest that unstable binocular fixation may contribute to reading problems. Because binocular instability may cause poor eye-hand coordination and impair motor control, the primary aim of this study was to explore in dyslexic subjects the influence of unstable binocular fixation on reaction times (RTs) and implicit motor learning (IML), which is one of the fundamental cerebellar functions. Fixation disparity (FD) and instability of FD were assessed subjectively using the Wesson card and a modified Mallett test. A modified version of the Serial Reaction Time Task (SRTT) was used to measure the RTs and IML skills. The results for the dyslexic group (DG), which included 29 adult subjects (15 were tested binocularly, DGbin; 14 were tested monocularly, DGmono), were compared with data from the control group (CG), which consisted of 30 age-matched nondyslexic subjects (15 tested binocularly, CGbin; and the other 15 tested monocularly, CGmono). The results indicated that the DG showed poorer binocular stability and longer RTs in the groups tested binocularly (RTs: 534 vs. 411 ms for DGbin and CGbin, respectively; P < 0.001) as compared with the groups examined monocularly (RTs: 431 vs. 424 ms for DGmono and CGmono, respectively; P = 0.996). The DG also exhibited impaired IML when compared with the CG (EFIML: 25 vs. 50 ms for DG and CG, respectively; P = 0.012). Unstable binocularity in dyslexia may affect RTs but was not related to poor IML skills. Impaired IML in dyslexia was independent of the viewing conditions (monocular versus binocular) and may be related to cerebellar deficits.

[5-year course of dyslexia – Persistence, sex effects, performance in reading and spelling, and school-related success].

PubMed

Wyschkon, Anne; Schulz, Franziska; Gallit, Finja Sunnyi; Poltz, Nadine; Kohn, Juliane; Moraske, Svenja; Bondü, Rebecca; von Aster, Michael; Esser, Günter

2018-03-01

The study examines the 5-year course of children with dyslexia with regard to their sex. Furthermore, the study investigates the impact of dyslexia on the performance in reading and spelling skills and school-related success. A group of 995 6- to 16-year-olds were examined at the initial assessment. Part of the initial sample was then re-examined after 43 and 63 months. The diagnosis of dyslexia was based on the double discrepancy criterion using a standard deviation of 1.5. Though they had no intellectual deficits, the children showed a considerable discrepancy between their reading or writing abilities and (1) their nonverbal intelligence and (2) the mean of their grade norm. Nearly 70 % of those examined had a persisting diagnosis of dyslexia over a period of 63 months. The 5-year course was not influenced by sex. Despite average intelligence, the performance in writing and spelling of children suffering from dyslexia was one standard deviation below a control group without dyslexia with average intelligence and 0.5 standard deviations below a group of children suffering from intellectual deficits. Furthermore, the school-related success of the dyslexics was significantly lower than those of children with average intelligence. Dyslexics showed similar school-related success rates to children suffering from intellectual deficits. Dyslexia represents a considerable developmental risk. The adverse impact of dyslexia on school-related success supports the importance of early diagnostics and intervention. It also underlines the need for reliable and general accepted diagnostic criteria. It is important to define such criteria in light of the prevalence rates.

A structural–functional basis for dyslexia in the cortex of Chinese readers

PubMed Central

Siok, Wai Ting; Niu, Zhendong; Jin, Zhen; Perfetti, Charles A.; Tan, Li Hai

2008-01-01

Developmental dyslexia is a neurobiologically based disorder that affects ≈5–17% of school children and is characterized by a severe impairment in reading skill acquisition. For readers of alphabetic (e.g., English) languages, recent neuroimaging studies have demonstrated that dyslexia is associated with weak reading-related activity in left temporoparietal and occipitotemporal regions, and this activity difference may reflect reductions in gray matter volume in these areas. Here, we find different structural and functional abnormalities in dyslexic readers of Chinese, a nonalphabetic language. Compared with normally developing controls, children with impaired reading in logographic Chinese exhibited reduced gray matter volume in a left middle frontal gyrus region previously shown to be important for Chinese reading and writing. Using functional MRI to study language-related activation of cortical regions in dyslexics, we found reduced activation in this same left middle frontal gyrus region in Chinese dyslexics versus controls, and there was a significant correlation between gray matter volume and activation in the language task in this same area. By contrast, Chinese dyslexics did not show functional or structural (i.e., volumetric gray matter) differences from normal subjects in the more posterior brain systems that have been shown to be abnormal in alphabetic-language dyslexics. The results suggest that the structural and functional basis for dyslexia varies between alphabetic and nonalphabetic languages. PMID:18391194

Short-term memory for order but not for item information is impaired in developmental dyslexia.

PubMed

Hachmann, Wibke M; Bogaerts, Louisa; Szmalec, Arnaud; Woumans, Evy; Duyck, Wouter; Job, Remo

2014-07-01

Recent findings suggest that people with dyslexia experience difficulties with the learning of serial order information during the transition from short- to long-term memory (Szmalec et al. Journal of Experimental Psychology: Learning, Memory, & Cognition 37(5): 1270-1279, 2011). At the same time, models of short-term memory increasingly incorporate a distinction of order and item processing (Majerus et al. Cognition 107: 395-419, 2008). The current study is aimed to investigate whether serial order processing deficiencies in dyslexia can be traced back to a selective impairment of short-term memory for serial order and whether this impairment also affects processing beyond the verbal domain. A sample of 26 adults with dyslexia and a group of age and IQ-matched controls participated in a 2 × 2 × 2 experiment in which we assessed short-term recognition performance for order and item information, using both verbal and nonverbal material. Our findings indicate that, irrespective of the type of material, participants with dyslexia recalled the individual items with the same accuracy as the matched control group, whereas the ability to recognize the serial order in which those items were presented appeared to be affected in the dyslexia group. We conclude that dyslexia is characterized by a selective impairment of short-term memory for serial order, but not for item information, and discuss the integration of these findings into current theoretical views on dyslexia and its associated dysfunctions.

A Comprehensive Evaluation of Lexical Reading in Italian Developmental Dyslexics

ERIC Educational Resources Information Center

Paizi, Despina; De Luca, Maria; Zoccolotti, Pierluigi; Burani, Cristina

2013-01-01

Italian developmental dyslexic readers show a striking length effect and have been hypothesised to rely mostly on nonlexical reading. Our experiments tested this hypothesis by assessing whether or not the deficit underlying dyslexia is specific to lexical reading. The effects of lexicality, word frequency and length were investigated in the same…

Decoding ability makes waves in reading: deficient interactions between attention and phonological analysis in developmental dyslexia.

PubMed

Savill, Nicola J; Thierry, Guillaume

2012-06-01

Whilst there is general consensus that phonological processing is deficient in developmental dyslexia, recent research also implicates visuo-attentional contributions. Capitalising on the P3a wave of event-related potentials as an index of attentional capture, we tested dyslexic and normal readers on a novel variant of a visual oddball task to examine the interplay of orthographic-phonological integration and attentional engagement. Targets were animal words (10% occurrence). Amongst nontarget stimuli were two critical conditions: pseudohomophones of targets (10%) and control pseudohomophones (of fillers; 10%). Pseudohomophones of targets (but not control pseudohomophones) elicited a large P3 wave in normal readers only, revealing a lack of attentional engagement with these phonologically salient stimuli in dyslexic participants. Critically, both groups showed similar early phonological discrimination as indexed by posterior P2 modulations. Furthermore, phonological engagement, as indexed by P3a differences between pseudohomophone conditions, correlated with several measures of reading. Meanwhile, an analogous experiment using coloured shapes instead of orthographic stimuli failed to show group differences between experimental modulations in the P2 or P3 ranges. Overall, our results show that, whilst automatic aspects of phonological processing appear intact in developmental dyslexia, the breakdown in pseudoword reading occurs at a later stage, when attention is oriented to orthographic-phonological information. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Short-term sentence memory in children with auditory processing disorders].

PubMed

Kiese-Himmel, C

2010-05-01

To compare sentence repetition performance of different groups of children with Auditory Processing Disorders (APD) and to examine the relationship between age or respectively nonverbal intelligence and sentence recall. Nonverbal intelligence was measured with the COLOURED MATRICES, in addition the children completed a standardized test of SENTENCE REPETITION (SR) which requires to repeat spoken sentences (subtest of the HEIDELBERGER SPRACHENTWICKLUNGSTEST). Three clinical groups (n=49 with monosymptomatic APD; n=29 with APD+developmental language impairment; n=14 with APD+developmental dyslexia); two control groups (n=13 typically developing peers without any clinical developmental disorder; n=10 children with slight reduced nonverbal intelligence). The analysis showed a significant group effect (p=0.0007). The best performance was achieved by the normal controls (T-score 52.9; SD 6.4; Min 42; Max 59) followed by children with monosymptomatic APD (43.2; SD 9.2), children with the co-morbid-conditions APD+developmental dyslexia (43.1; SD 10.3), and APD+developmental language impairment (39.4; SD 9.4). The clinical control group presented the lowest performance, on average (38.6; SD 9.6). Accordingly, language-impaired children and children with slight reductions in intelligence could poorly use their grammatical knowledge for SR. A statistically significant improvement in SR was verified with the increase of age with the exception of children belonging to the small group with lowered intelligence. This group comprised the oldest children. Nonverbal intelligence correlated positively with SR only in children with below average-range intelligence (0.62; p=0.054). The absence of APD, SLI as well as the presence of normal intelligence facilitated the use of phonological information for SR.

An investigation into prospective memory in children with developmental dyslexia.

PubMed

Khan, Azizuddin

2014-01-01

Developmental dyslexia hinders reading and writing acquisition of around 5-10% of the children all over the world. However, little is known about role of prospective memory among dyslexics. Prospective memory is realization of delayed intention. Realization of delayed intention requires self initiated process. The present study explored the role of memory (prospective and retrospective memory), meta-memory and attention among dyslexic's children. One hundred and fifteen children (51 dyslexics and 64 normal controls) participated in the study. Prospective and retrospective memory questionnaire, everyday attention questionnaire and meta-memory were administered on children. Analysis of variance was used to analyses the data. All the main effects were significant. Some interactions were also found to be significant. Results suggest that dyslexic's performance on memory (prospective and retrospective memory) was worse than normal control. Meta-memory influences both dyslexics and normal control on prospective and retrospective memory. However, meta-memory affected dyslexics much more than normal control group. Similarly, significant differential effects were observed for simple, difficult and mixed attentional condition among between dyslexics and normal control. Dyslexic's performance was deteriorated as compared to normal control group. The findings of the study are discussed in the light of the existing literature.

An investigation into prospective memory in children with developmental dyslexia

PubMed Central

Khan, Azizuddin

2014-01-01

Developmental dyslexia hinders reading and writing acquisition of around 5–10% of the children all over the world. However, little is known about role of prospective memory among dyslexics. Prospective memory is realization of delayed intention. Realization of delayed intention requires self initiated process. The present study explored the role of memory (prospective and retrospective memory), meta-memory and attention among dyslexic's children. One hundred and fifteen children (51 dyslexics and 64 normal controls) participated in the study. Prospective and retrospective memory questionnaire, everyday attention questionnaire and meta-memory were administered on children. Analysis of variance was used to analyses the data. All the main effects were significant. Some interactions were also found to be significant. Results suggest that dyslexic's performance on memory (prospective and retrospective memory) was worse than normal control. Meta-memory influences both dyslexics and normal control on prospective and retrospective memory. However, meta-memory affected dyslexics much more than normal control group. Similarly, significant differential effects were observed for simple, difficult and mixed attentional condition among between dyslexics and normal control. Dyslexic's performance was deteriorated as compared to normal control group. The findings of the study are discussed in the light of the existing literature. PMID:25538638

Automated identification of ERP peaks through Dynamic Time Warping: an application to developmental dyslexia.

PubMed

Assecondi, Sara; Bianchi, A M; Hallez, H; Staelens, S; Casarotto, S; Lemahieu, I; Chiarenza, G A

2009-10-01

This article proposes a method to automatically identify and label event-related potential (ERP) components with high accuracy and precision. We present a framework, referred to as peak-picking Dynamic Time Warping (ppDTW), where a priori knowledge about the ERPs under investigation is used to define a reference signal. We developed a combination of peak-picking and Dynamic Time Warping (DTW) that makes the temporal intervals for peak-picking adaptive on the basis of the morphology of the data. We tested the procedure on experimental data recorded from a control group and from children diagnosed with developmental dyslexia. We compared our results with the traditional peak-picking. We demonstrated that our method achieves better performance than peak-picking, with an overall precision, recall and F-score of 93%, 86% and 89%, respectively, versus 93%, 80% and 85% achieved by peak-picking. We showed that our hybrid method outperforms peak-picking, when dealing with data involving several peaks of interest. The proposed method can reliably identify and label ERP components in challenging event-related recordings, thus assisting the clinician in an objective assessment of amplitudes and latencies of peaks of clinical interest.

TVA-based assessment of visual attentional functions in developmental dyslexia

PubMed Central

Bogon, Johanna; Finke, Kathrin; Stenneken, Prisca

2014-01-01

There is an ongoing debate whether an impairment of visual attentional functions constitutes an additional or even an isolated deficit of developmental dyslexia (DD). Especially performance in tasks that require the processing of multiple visual elements in parallel has been reported to be impaired in DD. We review studies that used parameter-based assessment for identifying and quantifying impaired aspect(s) of visual attention that underlie this multi-element processing deficit in DD. These studies used the mathematical framework provided by the “theory of visual attention” (Bundesen, 1990) to derive quantitative measures of general attentional resources and attentional weighting aspects on the basis of behavioral performance in whole- and partial-report tasks. Based on parameter estimates in children and adults with DD, the reviewed studies support a slowed perceptual processing speed as an underlying primary deficit in DD. Moreover, a reduction in visual short term memory storage capacity seems to present a modulating component, contributing to difficulties in written language processing. Furthermore, comparing the spatial distributions of attentional weights in children and adults suggests that having limited reading and writing skills might impair the development of a slight leftward bias, that is typical for unimpaired adult readers. PMID:25360129

Developmental dyslexia and phonological processing in European Portuguese orthography.

PubMed

Moura, Octávio; Moreno, Joana; Pereira, Marcelino; Simões, Mário R

2015-02-01

This study analysed the performance of phonological processing, the diagnostic accuracy and the influence on reading in children who were native speakers of an orthography of intermediate depth. Portuguese children with developmental dyslexia (DD; N=24; aged 10-12 years), chronological age (CA)-matched controls (N=24; aged 10-12 years) and reading level (RL)-matched controls (N=24; aged 7-9 years) were tested on measures of phonological processing (phonological awareness, naming speed and verbal short-term memory) and reading. The results indicated that the children with DD performed significantly poorer in all measures compared with the CA and RL. Phonological awareness and naming speed showed a high accuracy (receiver operating characteristics curve analysis) for discriminating the children with DD from the CA and RL, whereas the presence of abnormally low scores in phonological awareness and naming speed was more frequent in the DD group than in the controls and the normative population. Hierarchical linear regression analyses revealed that phonological awareness was the most important predictor of all reading accuracy measures, whereas naming speed was particularly related to text reading fluency. Copyright © 2014 John Wiley & Sons, Ltd.

What Is a Developmental-Behavioral Pediatrician?

MedlinePlus

... dyslexia, writing diffi culties, math disorders, and other school-related learning problems Attention and behavioral disorders including attention-deficit/hyperactivity disorder and associated conditions including oppositional-defiant behavior, conduct ...

Normal radial migration and lamination are maintained in dyslexia-susceptibility candidate gene homolog Kiaa0319 knockout mice.

PubMed

Martinez-Garay, Isabel; Guidi, Luiz G; Holloway, Zoe G; Bailey, Melissa A G; Lyngholm, Daniel; Schneider, Tomasz; Donnison, Timothy; Butt, Simon J B; Monaco, Anthony P; Molnár, Zoltán; Velayos-Baeza, Antonio

2017-04-01

Developmental dyslexia is a common disorder with a strong genetic component, but the underlying molecular mechanisms are still unknown. Several candidate dyslexia-susceptibility genes, including KIAA0319, DYX1C1, and DCDC2, have been identified in humans. RNA interference experiments targeting these genes in rat embryos have shown impairments in neuronal migration, suggesting that defects in radial cortical migration could be involved in the disease mechanism of dyslexia. Here we present the first characterisation of a Kiaa0319 knockout mouse line. Animals lacking KIAA0319 protein do not show anatomical abnormalities in any of the layered structures of the brain. Neurogenesis and radial migration of cortical projection neurons are not altered, and the intrinsic electrophysiological properties of Kiaa0319-deficient neurons do not differ from those of wild-type neurons. Kiaa0319 overexpression in cortex delays radial migration, but does not affect final neuronal position. However, knockout animals show subtle differences suggesting possible alterations in anxiety-related behaviour and in sensorimotor gating. Our results do not reveal a migration disorder in the mouse model, adding to the body of evidence available for Dcdc2 and Dyx1c1 that, unlike in the rat in utero knockdown models, the dyslexia-susceptibility candidate mouse homolog genes do not play an evident role in neuronal migration. However, KIAA0319 protein expression seems to be restricted to the brain, not only in early developmental stages but also in adult mice, indicative of a role of this protein in brain function. The constitutive and conditional knockout lines reported here will be useful tools for further functional analyses of Kiaa0319.

Developmental dyslexia: predicting individual risk

PubMed Central

Thompson, Paul A; Hulme, Charles; Nash, Hannah M; Gooch, Debbie; Hayiou-Thomas, Emma; Snowling, Margaret J

2015-01-01

Background Causal theories of dyslexia suggest that it is a heritable disorder, which is the outcome of multiple risk factors. However, whether early screening for dyslexia is viable is not yet known. Methods The study followed children at high risk of dyslexia from preschool through the early primary years assessing them from age 3 years and 6 months (T1) at approximately annual intervals on tasks tapping cognitive, language, and executive-motor skills. The children were recruited to three groups: children at family risk of dyslexia, children with concerns regarding speech, and language development at 3;06 years and controls considered to be typically developing. At 8 years, children were classified as ‘dyslexic’ or not. Logistic regression models were used to predict the individual risk of dyslexia and to investigate how risk factors accumulate to predict poor literacy outcomes. Results Family-risk status was a stronger predictor of dyslexia at 8 years than low language in preschool. Additional predictors in the preschool years include letter knowledge, phonological awareness, rapid automatized naming, and executive skills. At the time of school entry, language skills become significant predictors, and motor skills add a small but significant increase to the prediction probability. We present classification accuracy using different probability cutoffs for logistic regression models and ROC curves to highlight the accumulation of risk factors at the individual level. Conclusions Dyslexia is the outcome of multiple risk factors and children with language difficulties at school entry are at high risk. Family history of dyslexia is a predictor of literacy outcome from the preschool years. However, screening does not reach an acceptable clinical level until close to school entry when letter knowledge, phonological awareness, and RAN, rather than family risk, together provide good sensitivity and specificity as a screening battery. PMID:25832320

Cognitive levels of performance account for hemispheric lateralisation effects in dyslexic and normally reading children.

PubMed

Heim, Stefan; Grande, Marion; Meffert, Elisabeth; Eickhoff, Simon B; Schreiber, Helen; Kukolja, Juraj; Shah, Nadim Jon; Huber, Walter; Amunts, Katrin

2010-12-01

Recent theories of developmental dyslexia explain reading deficits in terms of deficient phonological awareness, attention, visual and auditory processing, or automaticity. Since dyslexia has a neurobiological basis, the question arises how the reader's proficiency in these cognitive variables affects the brain regions involved in visual word recognition. This question was addressed in two fMRI experiments with 19 normally reading children (Experiment 1) and 19 children with dyslexia (Experiment 2). First, reading-specific brain activation was assessed by contrasting the BOLD signal for reading aloud words vs. overtly naming pictures of real objects. Next, ANCOVAs with brain activation during reading the individuals' scores for all five cognitive variables assessed outside the scanner as covariates were performed. Whereas the normal readers' brain activation during reading showed co-variation effects predominantly in the right hemisphere, the reverse pattern was observed for the dyslexics. In particular, middle frontal gyrus, inferior parietal cortex, and precuneus showed contralateral effects for controls as compared to dyslexics. In line with earlier findings in the literature, these data hint at a global change in hemispheric asymmetry during cognitive processing in dyslexic readers, which, in turn, might affect reading proficiency. Copyright © 2010 Elsevier Inc. All rights reserved.

Cortical Signatures of Dyslexia and Remediation: An Intrinsic Functional Connectivity Approach

PubMed Central

Koyama, Maki S.; Di Martino, Adriana; Kelly, Clare; Jutagir, Devika R.; Sunshine, Jessica; Schwartz, Susan J.; Castellanos, Francisco X.; Milham, Michael P.

2013-01-01

This observational, cross-sectional study investigates cortical signatures of developmental dyslexia, particularly from the perspective of behavioral remediation. We employed resting-state fMRI, and compared intrinsic functional connectivity (iFC) patterns of known reading regions (seeds) among three dyslexia groups characterized by (a) no remediation (current reading and spelling deficits), (b) partial remediation (only reading deficit remediated), and (c) full remediation (both reading and spelling deficits remediated), and a group of age- and IQ-matched typically developing children (TDC) (total N = 44, age range = 7–15 years). We observed significant group differences in iFC of two seeds located in the left posterior reading network – left intraparietal sulcus (L.IPS) and left fusiform gyrus (L.FFG). Specifically, iFC between L.IPS and left middle frontal gyrus was significantly weaker in all dyslexia groups, irrespective of remediation status/literacy competence, suggesting that persistent dysfunction in the fronto-parietal attention network characterizes dyslexia. Additionally, relative to both TDC and the no remediation group, the remediation groups exhibited stronger iFC between L.FFG and right middle occipital gyrus (R.MOG). The full remediation group also exhibited stronger negative iFC between the same L.FFG seed and right medial prefrontal cortex (R.MPFC), a core region of the default network These results suggest that behavioral remediation may be associated with compensatory changes anchored in L.FFG, which reflect atypically stronger coupling between posterior visual regions (L.FFG-R.MOG) and greater functional segregation between task-positive and task-negative regions (L.FFG-R.MPFC). These findings were bolstered by significant relationships between the strength of the identified functional connections and literacy scores. We conclude that examining iFC can reveal cortical signatures of dyslexia with particular promise for monitoring neural changes associated with behavioral remediation. PMID:23408984

Spelling impairments in Spanish dyslexic adults.

PubMed

Afonso, Olivia; Suárez-Coalla, Paz; Cuetos, Fernando

2015-01-01

Spelling deficits have repeatedly been observed in children with dyslexia. However, the few studies addressing this issue in dyslexic adults have reported contradictory results. We investigated whether Spanish dyslexics show spelling deficits in adulthood and which components of the writing production process might be impaired in developmental dyslexia. In order to evaluate the involvement of the lexical and the sublexical routes of spelling as well as the graphemic buffer, lexical frequency, phonology-to-orthography consistency and word length were manipulated in two writing tasks: a direct copy transcoding task and a spelling-to-dictation task. Results revealed that adults with dyslexia produced longer written latencies, inter-letter intervals, writing durations and more errors than their peers without dyslexia. Moreover, the dyslexics were more affected by lexical frequency and word length than the controls, but both groups showed a similar effect of P-O consistency. Written latencies also revealed that while the dyslexics initiated the response later in the direct copy transcoding task than in the spelling-to-dictation task, the controls showed the opposite pattern. However, the dyslexics were slower than the controls in both tasks. Results were consistent with the hypothesis that spelling difficulties are present in adults with dyslexia, at least in a language with a transparent orthography such as Spanish. These difficulties seem to be associated with a deficit affecting both lexical processing and the ability to maintain information about the serial order of the letters in a word. However, the dyslexic group did not differ from the control group in the application of the P-O conversion procedures. The spelling impairment would be in addition to the reading deficit, leading to poorer performance in direct copy transcoding compared to spelling-to-dictation.

Spelling impairments in Spanish dyslexic adults

PubMed Central

Afonso, Olivia; Suárez-Coalla, Paz; Cuetos, Fernando

2015-01-01

Spelling deficits have repeatedly been observed in children with dyslexia. However, the few studies addressing this issue in dyslexic adults have reported contradictory results. We investigated whether Spanish dyslexics show spelling deficits in adulthood and which components of the writing production process might be impaired in developmental dyslexia. In order to evaluate the involvement of the lexical and the sublexical routes of spelling as well as the graphemic buffer, lexical frequency, phonology-to-orthography consistency and word length were manipulated in two writing tasks: a direct copy transcoding task and a spelling-to-dictation task. Results revealed that adults with dyslexia produced longer written latencies, inter-letter intervals, writing durations and more errors than their peers without dyslexia. Moreover, the dyslexics were more affected by lexical frequency and word length than the controls, but both groups showed a similar effect of P-O consistency. Written latencies also revealed that while the dyslexics initiated the response later in the direct copy transcoding task than in the spelling-to-dictation task, the controls showed the opposite pattern. However, the dyslexics were slower than the controls in both tasks. Results were consistent with the hypothesis that spelling difficulties are present in adults with dyslexia, at least in a language with a transparent orthography such as Spanish. These difficulties seem to be associated with a deficit affecting both lexical processing and the ability to maintain information about the serial order of the letters in a word. However, the dyslexic group did not differ from the control group in the application of the P-O conversion procedures. The spelling impairment would be in addition to the reading deficit, leading to poorer performance in direct copy transcoding compared to spelling-to-dictation. PMID:25941507

Multi-parameter machine learning approach to the neuroanatomical basis of developmental dyslexia.

PubMed

Płoński, Piotr; Gradkowski, Wojciech; Altarelli, Irene; Monzalvo, Karla; van Ermingen-Marbach, Muna; Grande, Marion; Heim, Stefan; Marchewka, Artur; Bogorodzki, Piotr; Ramus, Franck; Jednoróg, Katarzyna

2017-02-01

Despite decades of research, the anatomical abnormalities associated with developmental dyslexia are still not fully described. Studies have focused on between-group comparisons in which different neuroanatomical measures were generally explored in isolation, disregarding potential interactions between regions and measures. Here, for the first time a multivariate classification approach was used to investigate grey matter disruptions in children with dyslexia in a large (N = 236) multisite sample. A variety of cortical morphological features, including volumetric (volume, thickness and area) and geometric (folding index and mean curvature) measures were taken into account and generalizability of classification was assessed with both 10-fold and leave-one-out cross validation (LOOCV) techniques. Classification into control vs. dyslexic subjects achieved above chance accuracy (AUC = 0.66 and ACC = 0.65 in the case of 10-fold CV, and AUC = 0.65 and ACC = 0.64 using LOOCV) after principled feature selection. Features that discriminated between dyslexic and control children were exclusively situated in the left hemisphere including superior and middle temporal gyri, subparietal sulcus and prefrontal areas. They were related to geometric properties of the cortex, with generally higher mean curvature and a greater folding index characterizing the dyslexic group. Our results support the hypothesis that an atypical curvature pattern with extra folds in left hemispheric perisylvian regions characterizes dyslexia. Hum Brain Mapp 38:900-908, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Relating Pitch Awareness to Phonemic Awareness in Children: Implications for Tone-Deafness and Dyslexia

PubMed Central

Loui, Psyche; Kroog, Kenneth; Zuk, Jennifer; Winner, Ellen; Schlaug, Gottfried

2011-01-01

Language and music are complex cognitive and neural functions that rely on awareness of one's own sound productions. Information on the awareness of vocal pitch, and its relation to phonemic awareness which is crucial for learning to read, will be important for understanding the relationship between tone-deafness and developmental language disorders such as dyslexia. Here we show that phonemic awareness skills are positively correlated with pitch perception–production skills in children. Children between the ages of seven and nine were tested on pitch perception and production, phonemic awareness, and IQ. Results showed a significant positive correlation between pitch perception–production and phonemic awareness, suggesting that the relationship between musical and linguistic sound processing is intimately linked to awareness at the level of pitch and phonemes. Since tone-deafness is a pitch-related impairment and dyslexia is a deficit of phonemic awareness, we suggest that dyslexia and tone-deafness may have a shared and/or common neural basis. PMID:21687467

Molecular genetics of dyslexia: an overview.

PubMed

Carrion-Castillo, Amaia; Franke, Barbara; Fisher, Simon E

2013-11-01

Dyslexia is a highly heritable learning disorder with a complex underlying genetic architecture. Over the past decade, researchers have pinpointed a number of candidate genes that may contribute to dyslexia susceptibility. Here, we provide an overview of the state of the art, describing how studies have moved from mapping potential risk loci, through identification of associated gene variants, to characterization of gene function in cellular and animal model systems. Work thus far has highlighted some intriguing mechanistic pathways, such as neuronal migration, axon guidance, and ciliary biology, but it is clear that we still have much to learn about the molecular networks that are involved. We end the review by highlighting the past, present, and future contributions of the Dutch Dyslexia Programme to studies of genetic factors. In particular, we emphasize the importance of relating genetic information to intermediate neurobiological measures, as well as the value of incorporating longitudinal and developmental data into molecular designs. Copyright © 2013 John Wiley & Sons, Ltd.

Cognitive subtypes of dyslexia are characterized by distinct patterns of grey matter volume.

PubMed

Jednoróg, Katarzyna; Gawron, Natalia; Marchewka, Artur; Heim, Stefan; Grabowska, Anna

2014-09-01

The variety of different causal theories together with inconsistencies about the anatomical brain markers emphasize the heterogeneity of developmental dyslexia. Attempts were made to test on a behavioral level the existence of subtypes of dyslexia showing distinguishable cognitive deficits. Importantly, no research was directly devoted to the investigation of structural brain correlates of these subtypes. Here, for the first time, we applied voxel-based morphometry (VBM) to study grey matter volume (GMV) differences in a relatively large sample (n = 46) of dyslexic children split into three subtypes based on the cognitive deficits: phonological, rapid naming, magnocellular/dorsal, and auditory attention shifting. VBM revealed GMV clusters specific for each studied group including areas of left inferior frontal gyrus, cerebellum, right putamen, and bilateral parietal cortex. In addition, using discriminant analysis on these clusters 79% of cross-validated cases were correctly re-classified into four groups (controls vs. three subtypes). Current results indicate that dyslexia may result from distinct cognitive impairments characterized by distinguishable anatomical markers.

Aggression and risk of future violence in forensic psychiatric patients with and without dyslexia.

PubMed

Selenius, Heidi; Hellström, Ake; Belfrage, Henrik

2011-05-01

Dyslexia does not cause criminal behaviour, but it may worsen aggressive behaviour tendencies. In this study, aggressive behaviour and risk of future violence were compared between forensic psychiatric patients with and without dyslexia. Dyslexia was assessed using the Swedish phonological processing battery 'The Pigeon'. The patients filled in the Aggression Questionnaire, and trained assessors performed the risk assessments using HCR-20 version 2. Patients with dyslexia self-reported more aggressive behaviour compared with those without dyslexia. There was only a nearly significant tendency (p = 0.06) for the patients with dyslexia to receive higher scores in the HCR-20 compared with the patients without dyslexia, and phonological processing skills did not significantly predict aggression or risk of future violence. However, regression analyses demonstrated that poor phonological processing skills are a significant predictor of anger, which in turn significantly predicts risk of future violence. Copyright © 2011 John Wiley & Sons, Ltd.

A functional near-infrared spectroscopy study of lexical decision task supports the dual route model and the phonological deficit theory of dyslexia.

PubMed

Sela, Itamar; Izzetoglu, Meltem; Izzetoglu, Kurtulus; Onaral, Banu

2014-01-01

The dual route model (DRM) of reading suggests two routes of reading development: the phonological and the orthographic routes. It was proposed that although the two routes are active in the process of reading; the first is more involved at the initial stages of reading acquisition, whereas the latter needs more reading training to mature. A number of studies have shown that deficient phonological processing is a core deficit in developmental dyslexia. According to the DRM, when the Lexical Decision Task (LDT) is performed, the orthographic route should also be involved when decoding words, whereas it is clear that when decoding pseudowords the phonological route should be activated. Previous functional near-infrared spectroscopy (fNIR) studies have suggested that the upper left frontal lobe is involved in decision making in the LDT. The current study used fNIR to compare left frontal lobe activity during LDT performance among three reading-level groups: 12-year-old children, young adult dyslexic readers, and young adult typical readers. Compared to typical readers, the children demonstrated lower activity under the word condition only, whereas the dyslexic readers showed lower activity under the pseudoword condition only. The results provide evidence for upper left frontal lobe involvement in LDT and support the DRM and the phonological deficit theory of dyslexia.

Inter-relationships among behavioral markers, genes, brain and treatment in dyslexia and dysgraphia

PubMed Central

Berninger, Virginia; Richards, Todd

2010-01-01

Cross-country, longitudinal twin studies provide strong evidence for both the biological and environmental basis of dyslexia, and the stability of genetic influences on reading and spelling, even when skills improve in response to instruction. Although DNA studies aimed at identifying gene candidates in dyslexia and related phenotypes (behavioral expression of underlying genotypes); and imaging studies of brain differences between individuals with and without dyslexia and the brain’s response to instructional treatment are increasing, this review illustrates, with the findings of one multidisciplinary research center, an emerging trend to investigate the inter-relationships among genetic, brain and instructional treatment findings in the same sample, which are interpreted in reference to a working-memory architecture, for dyslexia (impaired decoding and spelling) and/or dysgraphia (impaired handwriting). General principles for diagnosis and treatment, based on research with children who failed to respond to the regular instructional program, are summarized for children meeting research criteria for having or being at risk for dyslexia or dysgraphia. Research documenting earlier emerging specific oral language impairment during preschool years associated with reading and writing disabilities during school years is also reviewed. Recent seminal advances and projected future trends are discussed for linking brain endophenotypes and gene candidates, identifying transchromosomal interactions, and exploring epigenetics (chemic al modifications of gene expression in response to developmental or environmental changes). Rather than providing final answers, this review highlights past, current and emerging issues in dyslexia research and practice. PMID:20953351

Profile of language and cognitive functions in children with dyslexia in speakers of Brazilian Portuguese.

PubMed

Barbosa, Thais; Rodrigues, Camila Cruz; Toledo-Piza, Carolina Mattar; Navas, Ana Luiza Gomes Pinto; Bueno, Orlando Francisco Amodeu

2015-01-01

To verify the language and cognitive profile of children with dyslexia, contributing to the diagnosis of this condition in readers of a regular orthography, such as Brazilian Portuguese. In this study, 47 children with dyslexia (GD) and two controlled groups, one composed of 41 age controls (GCI) and the other with 31 reading controls (GCL), participated. All children were submitted to a battery involving the above-mentioned abilities. GD demonstrated predominant deficits in phonological processing, which were not compatible with a delay in the development of such abilities, indicating an atypical development. The GD also obtained lower scores in both basic and more complex reading and writing skills (i.e., letters, words, pseudowords, and texts, respectively), as well as in other domains, such as language (syntactic processing and oral sentence comprehension), which may be a result of a deficit in phonological skills, that interfered with higher complexity linguistic skills. Phonological abilities demonstrated to be the main difficulty observed in children with dyslexia investigated in this study, corroborating previous studies in other languages. This demonstrates that, independently of the language regularity, phonological skills are fundamental to the diagnosis of developmental dyslexia.

Do dual-route models accurately predict reading and spelling performance in individuals with acquired alexia and agraphia?

PubMed

Rapcsak, Steven Z; Henry, Maya L; Teague, Sommer L; Carnahan, Susan D; Beeson, Pélagie M

2007-06-18

Coltheart and co-workers [Castles, A., Bates, T. C., & Coltheart, M. (2006). John Marshall and the developmental dyslexias. Aphasiology, 20, 871-892; Coltheart, M., Rastle, K., Perry, C., Langdon, R., & Ziegler, J. (2001). DRC: A dual route cascaded model of visual word recognition and reading aloud. Psychological Review, 108, 204-256] have demonstrated that an equation derived from dual-route theory accurately predicts reading performance in young normal readers and in children with reading impairment due to developmental dyslexia or stroke. In this paper, we present evidence that the dual-route equation and a related multiple regression model also accurately predict both reading and spelling performance in adult neurological patients with acquired alexia and agraphia. These findings provide empirical support for dual-route theories of written language processing.

Artistic talent in dyslexia--a hypothesis.

PubMed

Chakravarty, Ambar

2009-10-01

The present article hints at a curious neurocognitive phenomenon of development of artistic talents in some children with dyslexia. The article also takes note of the phenomenon of creating in the midst of language disability as observed in the lives of such creative people like Leonardo da Vinci and Albert Einstein who were most probably affected with developmental learning disorders. It has been hypothesised that a developmental delay in the dominant hemisphere most likely 'disinhibits' the non-dominant parietal lobe to unmask talents, artistic or otherwise, in some such individuals. The present hypothesis follows the phenomenon of paradoxical functional facilitation described earlier. It has been suggested that children with learning disorders be encouraged to develop such hidden talents to full capacity, rather than be subjected to overemphasising on the correction of the disturbed coded symbol operations, in remedial training.

Speech-language pathology program for reading comprehension and orthography: effects on the spelling of dyslexic individuals.

PubMed

Nogueira, Débora Manzano; Cárnio, Maria Silvia

2018-01-01

Purpose Prepare a Speech-language Pathology Program for Reading Comprehension and Orthography and verify its effects on the reading comprehension and spelling of students with Developmental Dyslexia. Methods The study sample was composed of eleven individuals (eight males), diagnosed with Developmental Dyslexia, aged 09-11 years. All participants underwent a Speech-language Pathology Program in Reading Comprehension and Orthography comprising 16 individual weekly sessions. In each session, tasks of reading comprehension of texts and orthography were developed. At the beginning and end of the Program, the participants were submitted to a specific assessment (pre- and post-test). Results The individuals presented difficulty in reading comprehension, but the Cloze technique proved to be a useful remediation tool, and significant improvement in their performance was observed in the post-test evaluation. The dyslexic individuals showed poor performance for their educational level in the spelling assessment. At the end of the program, their performance evolved, but it remained below the expected, showing the same error pattern at the pre- and post-tests, with errors in both natural and arbitrary spelling. Conclusion The proposed Speech-language Pathology Program for Reading Comprehension and Orthography produced positive effects on the reading comprehension, spelling, and motivation to reading and writing of the participants. This study presents an unprecedented contribution by proposing joint stimulation of reading and writing by means of a program easy to apply and analyze in individuals with Developmental Dyslexia.

Relationships between Categorical Perception of Phonemes, Phoneme Awareness, and Visual Attention Span in Developmental Dyslexia.

PubMed

Zoubrinetzky, Rachel; Collet, Gregory; Serniclaes, Willy; Nguyen-Morel, Marie-Ange; Valdois, Sylviane

2016-01-01

We tested the hypothesis that the categorical perception deficit of speech sounds in developmental dyslexia is related to phoneme awareness skills, whereas a visual attention (VA) span deficit constitutes an independent deficit. Phoneme awareness tasks, VA span tasks and categorical perception tasks of phoneme identification and discrimination using a d/t voicing continuum were administered to 63 dyslexic children and 63 control children matched on chronological age. Results showed significant differences in categorical perception between the dyslexic and control children. Significant correlations were found between categorical perception skills, phoneme awareness and reading. Although VA span correlated with reading, no significant correlations were found between either categorical perception or phoneme awareness and VA span. Mediation analyses performed on the whole dyslexic sample suggested that the effect of categorical perception on reading might be mediated by phoneme awareness. This relationship was independent of the participants' VA span abilities. Two groups of dyslexic children with a single phoneme awareness or a single VA span deficit were then identified. The phonologically impaired group showed lower categorical perception skills than the control group but categorical perception was similar in the VA span impaired dyslexic and control children. The overall findings suggest that the link between categorical perception, phoneme awareness and reading is independent from VA span skills. These findings provide new insights on the heterogeneity of developmental dyslexia. They suggest that phonological processes and VA span independently affect reading acquisition.

Relationships between Categorical Perception of Phonemes, Phoneme Awareness, and Visual Attention Span in Developmental Dyslexia

PubMed Central

Zoubrinetzky, Rachel; Collet, Gregory; Serniclaes, Willy; Nguyen-Morel, Marie-Ange; Valdois, Sylviane

2016-01-01

We tested the hypothesis that the categorical perception deficit of speech sounds in developmental dyslexia is related to phoneme awareness skills, whereas a visual attention (VA) span deficit constitutes an independent deficit. Phoneme awareness tasks, VA span tasks and categorical perception tasks of phoneme identification and discrimination using a d/t voicing continuum were administered to 63 dyslexic children and 63 control children matched on chronological age. Results showed significant differences in categorical perception between the dyslexic and control children. Significant correlations were found between categorical perception skills, phoneme awareness and reading. Although VA span correlated with reading, no significant correlations were found between either categorical perception or phoneme awareness and VA span. Mediation analyses performed on the whole dyslexic sample suggested that the effect of categorical perception on reading might be mediated by phoneme awareness. This relationship was independent of the participants’ VA span abilities. Two groups of dyslexic children with a single phoneme awareness or a single VA span deficit were then identified. The phonologically impaired group showed lower categorical perception skills than the control group but categorical perception was similar in the VA span impaired dyslexic and control children. The overall findings suggest that the link between categorical perception, phoneme awareness and reading is independent from VA span skills. These findings provide new insights on the heterogeneity of developmental dyslexia. They suggest that phonological processes and VA span independently affect reading acquisition. PMID:26950210

The "where" and "what" in developmental dyscalculia.

PubMed

Henik, Avishai; Rubinsten, Orly; Ashkenazi, Sarit

2011-08-01

Developmental dyscalculia (DD) is a congenital deficit that affects the ability to acquire arithmetical skills. Individuals with DD have problems learning standard number facts and procedures. Estimates of the prevalence rate of DD are similar to those of developmental dyslexia. Recent reports and discussions suggest that those with DD suffer from specific deficits (e.g., subitizing, comparative judgment). Accordingly, DD has been described as a domain-specific disorder that involves particular brain areas (e.g., intra-parietal sulcus). However, we and others have found that DD is characterized by additional deficiencies and may be affected by domain-general (e.g., attention) factors. Hence "pure DD" might be rather rare and not as pure as one would think. We suggest that the heterogeneity of symptoms that commonly characterize learning disabilities needs to be taken into account in future research and treatment.

[From brain imaging to good teaching? implicating from neuroscience for research on learning and instruction].

PubMed

Stubenrauch, Christa; Krinzinger, Helga; Konrad, Kerstin

2014-07-01

Psychiatric disorders in childhood and adolescence, in particular attention deficit disorder or specific learning disorders like developmental dyslexia and developmental dyscalculia, affect academic performance and learning at school. Recent advances in neuroscientific research have incited an intensive debate both in the general public and in the field of educational and instructional science as well as to whether and to what extent these new findings in the field of neuroscience might be of importance for school-related learning and instruction. In this review, we first summarize neuroscientific findings related to the development of attention, working memory and executive functions in typically developing children and then evaluate their relevance for school-related learning. We present an overview of neuroimaging studies of specific learning disabilities such as developmental dyslexia and developmental dyscalculia, and critically discuss their practical implications for educational and teaching practice, teacher training, early diagnosis as well as prevention and disorder-specific therapy. We conclude that the new interdisciplinary field of neuroeducation cannot be expected to provide direct innovative educational applications (e.g., teaching methods). Rather, the future potential of neuroscience lies in creating a deeper understanding of the underlying cognitive mechanisms and pathomechanisms of learning processes and learning disorders.

Reading Performance Is Enhanced by Visual Texture Discrimination Training in Chinese-Speaking Children with Developmental Dyslexia

PubMed Central

Meng, Xiangzhi; Lin, Ou; Wang, Fang; Jiang, Yuzheng; Song, Yan

2014-01-01

Background High order cognitive processing and learning, such as reading, interact with lower-level sensory processing and learning. Previous studies have reported that visual perceptual training enlarges visual span and, consequently, improves reading speed in young and old people with amblyopia. Recently, a visual perceptual training study in Chinese-speaking children with dyslexia found that the visual texture discrimination thresholds of these children in visual perceptual training significantly correlated with their performance in Chinese character recognition, suggesting that deficits in visual perceptual processing/learning might partly underpin the difficulty in reading Chinese. Methodology/Principal Findings To further clarify whether visual perceptual training improves the measures of reading performance, eighteen children with dyslexia and eighteen typically developed readers that were age- and IQ-matched completed a series of reading measures before and after visual texture discrimination task (TDT) training. Prior to the TDT training, each group of children was split into two equivalent training and non-training groups in terms of all reading measures, IQ, and TDT. The results revealed that the discrimination threshold SOAs of TDT were significantly higher for the children with dyslexia than for the control children before training. Interestingly, training significantly decreased the discrimination threshold SOAs of TDT for both the typically developed readers and the children with dyslexia. More importantly, the training group with dyslexia exhibited significant enhancement in reading fluency, while the non-training group with dyslexia did not show this improvement. Additional follow-up tests showed that the improvement in reading fluency is a long-lasting effect and could be maintained for up to two months in the training group with dyslexia. Conclusion/Significance These results suggest that basic visual perceptual processing/learning and reading ability in Chinese might at least partially rely on overlapping mechanisms. PMID:25247602

Triple X Syndrome: Symptoms and Causes

MedlinePlus

... be more pronounced — possibly including developmental delays and learning disabilities. Treatment for triple X syndrome depends on which ... motor skills, such as sitting up and walking Learning disabilities, such as difficulty with reading (dyslexia), understanding or ...

Letter-sound processing deficits in children with developmental dyslexia: An ERP study.

PubMed

Moll, Kristina; Hasko, Sandra; Groth, Katharina; Bartling, Jürgen; Schulte-Körne, Gerd

2016-04-01

The time course during letter-sound processing was investigated in children with developmental dyslexia (DD) and typically developing (TD) children using electroencephalography. Thirty-eight children with DD and 25 TD children participated in a visual-auditory oddball paradigm. Event-related potentials (ERPs) elicited by standard and deviant stimuli in an early (100-190 ms) and late (560-750 ms) time window were analysed. In the early time window, ERPs elicited by the deviant stimulus were delayed and less left lateralized over fronto-temporal electrodes for children with DD compared to TD children. In the late time window, children with DD showed higher amplitudes extending more over right frontal electrodes. Longer latencies in the early time window and stronger right hemispheric activation in the late time window were associated with slower reading and naming speed. Additionally, stronger right hemispheric activation in the late time window correlated with poorer phonological awareness skills. Deficits in early stages of letter-sound processing influence later more explicit cognitive processes during letter-sound processing. Identifying the neurophysiological correlates of letter-sound processing and their relation to reading related skills provides insight into the degree of automaticity during letter-sound processing beyond behavioural measures of letter-sound-knowledge. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Speech Recognition in Noise by Children with and without Dyslexia: How is it Related to Reading?

PubMed

Nittrouer, Susan; Krieg, Letitia M; Lowenstein, Joanna H

2018-06-01

Developmental dyslexia is commonly viewed as a phonological deficit that makes it difficult to decode written language. But children with dyslexia typically exhibit other problems, as well, including poor speech recognition in noise. The purpose of this study was to examine whether the speech-in-noise problems of children with dyslexia are related to their reading problems, and if so, if a common underlying factor might explain both. The specific hypothesis examined was that a spectral processing disorder results in these children receiving smeared signals, which could explain both the diminished sensitivity to phonological structure - leading to reading problems - and the speech recognition in noise difficulties. The alternative hypothesis tested in this study was that children with dyslexia simply have broadly based language deficits. Ninety-seven children between the ages of 7 years; 10 months and 12 years; 9 months participated: 46 with dyslexia and 51 without dyslexia. Children were tested on two dependent measures: word reading and recognition in noise with two types of sentence materials: as unprocessed (UP) signals, and as spectrally smeared (SM) signals. Data were collected for four predictor variables: phonological awareness, vocabulary, grammatical knowledge, and digit span. Children with dyslexia showed deficits on both dependent and all predictor variables. Their scores for speech recognition in noise were poorer than those of children without dyslexia for both the UP and SM signals, but by equivalent amounts across signal conditions indicating that they were not disproportionately hindered by spectral distortion. Correlation analyses on scores from children with dyslexia showed that reading ability and speech-in-noise recognition were only mildly correlated, and each skill was related to different underlying abilities. No substantial evidence was found to support the suggestion that the reading and speech recognition in noise problems of children with dyslexia arise from a single factor that could be defined as a spectral processing disorder. The reading and speech recognition in noise deficits of these children appeared to be largely independent. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Principled Relation between Reading and Naming in Acquired and Developmental Anomia: Surface Dyslexia Following Impairment in the Phonological Output Lexicon

PubMed Central

Gvion, Aviah; Friedmann, Naama

2016-01-01

Lexical retrieval and reading aloud are often viewed as two separate processes. However, they are not completely separate—they share components. This study assessed the effect of an impairment in a shared component, the phonological output lexicon, on lexical retrieval and on reading aloud. Because the phonological output lexicon is part of the lexical route for reading, individuals with an impairment in this lexicon may be forced to read aloud via the sublexical route and therefore show a reading pattern that is typical of surface dyslexia. To examine the effect of phonological output lexicon deficit on reading, we tested the reading of 16 Hebrew-speaking individuals with phonological output lexicon anomia, eight with acquired anomia following brain damage and eight with developmental anomia. We established that they had a phonological output lexicon deficit according to the types of errors and the effects on their naming in a picture naming task, and excluded other deficit loci in the lexical retrieval process according to a line of tests assessing their picture and word comprehension, word and non-word repetition, and phonological working memory. After we have established that the participants have a phonological output lexicon deficit, we tested their reading. To assess their reading and type of reading impairment, we tested their reading aloud, lexical decision, and written word comprehension. We found that all of the participants with phonological output lexicon impairment showed, in addition to anomia, also the typical surface dyslexia errors in reading aloud of irregular words, words with ambiguous conversion to phonemes, and potentiophones (words like “now” that, when read via the sublexical route, can be sounded out as another word, “know”). Importantly, the participants performed normally on pseudohomophone lexical decision and on homophone/potentiophone reading comprehension, indicating spared orthographic input lexicon and spared access to it and from it to lexical semantics. This pattern was shown both by the adults with acquired anomia and by the participants with developmental anomia. These results thus suggest a principled relation between anomia and dyslexia, and point to a distinct type of surface dyslexia. They further show the possibility of good comprehension of written words when the phonological output stages are impaired. PMID:27065897

Assessment of rhythmic entrainment at multiple timescales in dyslexia: evidence for disruption to syllable timing.

PubMed

Leong, Victoria; Goswami, Usha

2014-02-01

Developmental dyslexia is associated with rhythmic difficulties, including impaired perception of beat patterns in music and prosodic stress patterns in speech. Spoken prosodic rhythm is cued by slow (<10 Hz) fluctuations in speech signal amplitude. Impaired neural oscillatory tracking of these slow amplitude modulation (AM) patterns is one plausible source of impaired rhythm tracking in dyslexia. Here, we characterise the temporal profile of the dyslexic rhythm deficit by examining rhythmic entrainment at multiple speech timescales. Adult dyslexic participants completed two experiments aimed at testing the perception and production of speech rhythm. In the perception task, participants tapped along to the beat of 4 metrically-regular nursery rhyme sentences. In the production task, participants produced the same 4 sentences in time to a metronome beat. Rhythmic entrainment was assessed using both traditional rhythmic indices and a novel AM-based measure, which utilised 3 dominant AM timescales in the speech signal each associated with a different phonological grain-sized unit (0.9-2.5 Hz, prosodic stress; 2.5-12 Hz, syllables; 12-40 Hz, phonemes). The AM-based measure revealed atypical rhythmic entrainment by dyslexic participants to syllable patterns in speech, in perception and production. In the perception task, both groups showed equally strong phase-locking to Syllable AM patterns, but dyslexic responses were entrained to a significantly earlier oscillatory phase angle than controls. In the production task, dyslexic utterances showed shorter syllable intervals, and differences in Syllable:Phoneme AM cross-frequency synchronisation. Our data support the view that rhythmic entrainment at slow (∼5 Hz, Syllable) rates is atypical in dyslexia, suggesting that neural mechanisms for syllable perception and production may also be atypical. These syllable timing deficits could contribute to the atypical development of phonological representations for spoken words, the central cognitive characteristic of developmental dyslexia across languages. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Assessment of rhythmic entrainment at multiple timescales in dyslexia: Evidence for disruption to syllable timing☆

PubMed Central

Leong, Victoria; Goswami, Usha

2014-01-01

Developmental dyslexia is associated with rhythmic difficulties, including impaired perception of beat patterns in music and prosodic stress patterns in speech. Spoken prosodic rhythm is cued by slow (<10 Hz) fluctuations in speech signal amplitude. Impaired neural oscillatory tracking of these slow amplitude modulation (AM) patterns is one plausible source of impaired rhythm tracking in dyslexia. Here, we characterise the temporal profile of the dyslexic rhythm deficit by examining rhythmic entrainment at multiple speech timescales. Adult dyslexic participants completed two experiments aimed at testing the perception and production of speech rhythm. In the perception task, participants tapped along to the beat of 4 metrically-regular nursery rhyme sentences. In the production task, participants produced the same 4 sentences in time to a metronome beat. Rhythmic entrainment was assessed using both traditional rhythmic indices and a novel AM-based measure, which utilised 3 dominant AM timescales in the speech signal each associated with a different phonological grain-sized unit (0.9–2.5 Hz, prosodic stress; 2.5–12 Hz, syllables; 12–40 Hz, phonemes). The AM-based measure revealed atypical rhythmic entrainment by dyslexic participants to syllable patterns in speech, in perception and production. In the perception task, both groups showed equally strong phase-locking to Syllable AM patterns, but dyslexic responses were entrained to a significantly earlier oscillatory phase angle than controls. In the production task, dyslexic utterances showed shorter syllable intervals, and differences in Syllable:Phoneme AM cross-frequency synchronisation. Our data support the view that rhythmic entrainment at slow (∼5 Hz, Syllable) rates is atypical in dyslexia, suggesting that neural mechanisms for syllable perception and production may also be atypical. These syllable timing deficits could contribute to the atypical development of phonological representations for spoken words, the central cognitive characteristic of developmental dyslexia across languages. This article is part of a Special Issue entitled . PMID:23916752

Developmental dyslexia: predicting individual risk.

PubMed

Thompson, Paul A; Hulme, Charles; Nash, Hannah M; Gooch, Debbie; Hayiou-Thomas, Emma; Snowling, Margaret J

2015-09-01

Causal theories of dyslexia suggest that it is a heritable disorder, which is the outcome of multiple risk factors. However, whether early screening for dyslexia is viable is not yet known. The study followed children at high risk of dyslexia from preschool through the early primary years assessing them from age 3 years and 6 months (T1) at approximately annual intervals on tasks tapping cognitive, language, and executive-motor skills. The children were recruited to three groups: children at family risk of dyslexia, children with concerns regarding speech, and language development at 3;06 years and controls considered to be typically developing. At 8 years, children were classified as 'dyslexic' or not. Logistic regression models were used to predict the individual risk of dyslexia and to investigate how risk factors accumulate to predict poor literacy outcomes. Family-risk status was a stronger predictor of dyslexia at 8 years than low language in preschool. Additional predictors in the preschool years include letter knowledge, phonological awareness, rapid automatized naming, and executive skills. At the time of school entry, language skills become significant predictors, and motor skills add a small but significant increase to the prediction probability. We present classification accuracy using different probability cutoffs for logistic regression models and ROC curves to highlight the accumulation of risk factors at the individual level. Dyslexia is the outcome of multiple risk factors and children with language difficulties at school entry are at high risk. Family history of dyslexia is a predictor of literacy outcome from the preschool years. However, screening does not reach an acceptable clinical level until close to school entry when letter knowledge, phonological awareness, and RAN, rather than family risk, together provide good sensitivity and specificity as a screening battery. © 2015 The Authors. Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health.

RADAR: A novel fast-screening method for reading difficulties with special focus on dyslexia.

PubMed

Smyrnakis, Ioannis; Andreadakis, Vassilios; Selimis, Vassilios; Kalaitzakis, Michail; Bachourou, Theodora; Kaloutsakis, Georgios; Kymionis, George D; Smirnakis, Stelios; Aslanides, Ioannis M

2017-01-01

Dyslexia is a developmental learning disorder of single word reading accuracy and/or fluency, with compelling research directed towards understanding the contributions of the visual system. While dyslexia is not an oculomotor disease, readers with dyslexia have shown different eye movements than typically developing students during text reading. Readers with dyslexia exhibit longer and more frequent fixations, shorter saccade lengths, more backward refixations than typical readers. Furthermore, readers with dyslexia are known to have difficulty in reading long words, lower skipping rate of short words, and high gaze duration on many words. It is an open question whether it is possible to harness these distinctive oculomotor scanning patterns observed during reading in order to develop a screening tool that can reliably identify struggling readers, who may be candidates for dyslexia. Here, we introduce a novel, fast, objective, non-invasive method, named Rapid Assessment of Difficulties and Abnormalities in Reading (RADAR) that screens for features associated with the aberrant visual scanning of reading text seen in dyslexia. Eye tracking parameter measurements that are stable under retest and have high discriminative power, as indicated by their ROC (receiver operating characteristic) curves, were obtained during silent text reading. These parameters were combined to derive a total reading score (TRS) that can reliably separate readers with dyslexia from typical readers. We tested TRS in a group of school-age children ranging from 8.5 to 12.5 years of age. TRS achieved 94.2% correct classification of children tested. Specifically, 35 out of 37 control (specificity 94.6%) and 30 out of 32 readers with dyslexia (sensitivity 93.8%) were classified correctly using RADAR, under a circular validation condition (see section Results/Total Reading Score) where the individual evaluated was not included in the test construction group. In conclusion, RADAR is a novel, automated, fast and reliable way to identify children at high risk of dyslexia that is amenable to large-scale screening. Moreover, analysis of eye movement parameters obtained with RADAR during reading will likely be useful for implementing individualized treatment strategies and for monitoring objectively the success of chosen interventions. We envision that it will be possible to use RADAR as a sensitive, objective, and quantitative first pass screen to identify individuals with reading disorders that manifest with abnormal oculomotor reading strategies, like dyslexia.

RADAR: A novel fast-screening method for reading difficulties with special focus on dyslexia

PubMed Central

Smyrnakis, Ioannis; Andreadakis, Vassilios; Selimis, Vassilios; Kalaitzakis, Michail; Bachourou, Theodora; Kaloutsakis, Georgios; Kymionis, George D.; Smirnakis, Stelios; Aslanides, Ioannis M.

2017-01-01

Dyslexia is a developmental learning disorder of single word reading accuracy and/or fluency, with compelling research directed towards understanding the contributions of the visual system. While dyslexia is not an oculomotor disease, readers with dyslexia have shown different eye movements than typically developing students during text reading. Readers with dyslexia exhibit longer and more frequent fixations, shorter saccade lengths, more backward refixations than typical readers. Furthermore, readers with dyslexia are known to have difficulty in reading long words, lower skipping rate of short words, and high gaze duration on many words. It is an open question whether it is possible to harness these distinctive oculomotor scanning patterns observed during reading in order to develop a screening tool that can reliably identify struggling readers, who may be candidates for dyslexia. Here, we introduce a novel, fast, objective, non-invasive method, named Rapid Assessment of Difficulties and Abnormalities in Reading (RADAR) that screens for features associated with the aberrant visual scanning of reading text seen in dyslexia. Eye tracking parameter measurements that are stable under retest and have high discriminative power, as indicated by their ROC (receiver operating characteristic) curves, were obtained during silent text reading. These parameters were combined to derive a total reading score (TRS) that can reliably separate readers with dyslexia from typical readers. We tested TRS in a group of school-age children ranging from 8.5 to 12.5 years of age. TRS achieved 94.2% correct classification of children tested. Specifically, 35 out of 37 control (specificity 94.6%) and 30 out of 32 readers with dyslexia (sensitivity 93.8%) were classified correctly using RADAR, under a circular validation condition (see section Results/Total Reading Score) where the individual evaluated was not included in the test construction group. In conclusion, RADAR is a novel, automated, fast and reliable way to identify children at high risk of dyslexia that is amenable to large-scale screening. Moreover, analysis of eye movement parameters obtained with RADAR during reading will likely be useful for implementing individualized treatment strategies and for monitoring objectively the success of chosen interventions. We envision that it will be possible to use RADAR as a sensitive, objective, and quantitative first pass screen to identify individuals with reading disorders that manifest with abnormal oculomotor reading strategies, like dyslexia. PMID:28800632

Verbal Short-Term Memory Deficits in Chinese Children with Dyslexia may not be a Problem with the Activation of Phonological Representations.

PubMed

Zhao, Jing; Yang, Yang; Song, Yao-Wu; Bi, Hong-Yan

2015-11-01

This study explored the underlying mechanism of the verbal short-term memory deficit in Chinese children with developmental dyslexia. Twenty-four children with dyslexia and 28 age-matched normal readers participated in the study. They were required to memorize a visually presented series of six Chinese characters and identify them from a list also including code-specific distracters and non-code-specific distracters. Error rates were recorded and were higher for code-specific distracters in all three conditions, revealing phonological, visual, and semantic similarity effects respectively. Group comparisons showed a stronger phonological similarity effect in dyslexic group, suggesting intact activation of phonological representations of target characters. Children with dyslexia also exhibited a greater semantic similarity effect, revealing stronger activation of semantic representations, while visual similarity effects were equivalent to controls. These results suggest that the verbal short-term memory deficit in Chinese dyslexics might not stem from insufficient activation of phonological information. Based the semantic activation of target characters in dyslexics is greater than in controls, it is possible that the memory deficit of dyslexia is related with deficient inhibition of target semantic representations in short-term memory. Copyright © 2015 John Wiley & Sons, Ltd.

Music Training Increases Phonological Awareness and Reading Skills in Developmental Dyslexia: A Randomized Control Trial

PubMed Central

Flaugnacco, Elena; Lopez, Luisa; Terribili, Chiara; Montico, Marcella; Zoia, Stefania; Schön, Daniele

2015-01-01

There is some evidence for a role of music training in boosting phonological awareness, word segmentation, working memory, as well as reading abilities in children with typical development. Poor performance in tasks requiring temporal processing, rhythm perception and sensorimotor synchronization seems to be a crucial factor underlying dyslexia in children. Interestingly, children with dyslexia show deficits in temporal processing, both in language and in music. Within this framework, we test the hypothesis that music training, by improving temporal processing and rhythm abilities, improves phonological awareness and reading skills in children with dyslexia. The study is a prospective, multicenter, open randomized controlled trial, consisting of test, rehabilitation and re-test (ID NCT02316873). After rehabilitation, the music group (N = 24) performed better than the control group (N = 22) in tasks assessing rhythmic abilities, phonological awareness and reading skills. This is the first randomized control trial testing the effect of music training in enhancing phonological and reading abilities in children with dyslexia. The findings show that music training can modify reading and phonological abilities even when these skills are severely impaired. Through the enhancement of temporal processing and rhythmic skills, music might become an important tool in both remediation and early intervention programs. Trial Registration ClinicalTrials.gov NCT02316873 PMID:26407242

Music Training Increases Phonological Awareness and Reading Skills in Developmental Dyslexia: A Randomized Control Trial.

PubMed

Flaugnacco, Elena; Lopez, Luisa; Terribili, Chiara; Montico, Marcella; Zoia, Stefania; Schön, Daniele

2015-01-01

There is some evidence for a role of music training in boosting phonological awareness, word segmentation, working memory, as well as reading abilities in children with typical development. Poor performance in tasks requiring temporal processing, rhythm perception and sensorimotor synchronization seems to be a crucial factor underlying dyslexia in children. Interestingly, children with dyslexia show deficits in temporal processing, both in language and in music. Within this framework, we test the hypothesis that music training, by improving temporal processing and rhythm abilities, improves phonological awareness and reading skills in children with dyslexia. The study is a prospective, multicenter, open randomized controlled trial, consisting of test, rehabilitation and re-test (ID NCT02316873). After rehabilitation, the music group (N = 24) performed better than the control group (N = 22) in tasks assessing rhythmic abilities, phonological awareness and reading skills. This is the first randomized control trial testing the effect of music training in enhancing phonological and reading abilities in children with dyslexia. The findings show that music training can modify reading and phonological abilities even when these skills are severely impaired. Through the enhancement of temporal processing and rhythmic skills, music might become an important tool in both remediation and early intervention programs.Trial Registration: ClinicalTrials.gov NCT02316873

A familial factor in the development of colour agnosia.

PubMed

Nijboer, Tanja C W; van Zandvoort, Martine J E; de Haan, Edward H F

2007-04-09

An important aspect of research into the link between genes and behaviour concerns the identification of familial determination. There is evidence for familial factors in selective deficits, such as developmental dyslexia and developmental prosopagnosia. Colour agnosia concerns a selective neuropsychological condition in which colour perception is intact, while the identification and naming of colour is disrupted. We recently demonstrated that this deficit can occur as a developmental deficit. Here, we show that there is a familial factor in the development of colour agnosia by reporting the colour processing abilities of the mother and the daughters of a man with developmental colour agnosia.

Reading comprehension skills of young adults with childhood diagnoses of dyslexia.

PubMed

Ransby, Marilyn J; Swanson, H Lee

2003-01-01

This study explores the contribution of cognitive processes to comprehension skills in adults who suffered from childhood developmental dyslexia (CD). The performance of adults with CD (ages 17 to 23), chronological age-matched (CA) adults, and reading level-matched (RL) children was compared on measures of phonological processing, naming speed, working memory (WM), general knowledge, vocabulary, and comprehension. The results showed that adults with CD scored lower on measures of phonological processing, naming speed, WM, general knowledge, and vocabulary when compared to CA readers but were comparable to RL children on the majority of process measures. Phonological processing, naming speed, vocabulary, general knowledge, and listening comprehension contributed independent variance to reading comprehension accuracy, whereas WM, intelligence, phonological processing, and listening comprehension contributed independent variance to comprehension fluency. Adults with CD scored lower than CA adults and higher than RL children on measures of lexical processing, WM, and listening comprehension when word recognition and intelligence were partialed from the analysis. In summary, constraints in phonological processing and naming speed mediate only some of the influence of high-order processes on reading comprehension. Furthermore, adults with CD experience difficulties in WM, listening comprehension, and vocabulary independently of their word recognition problems and intellectual ability.

Neural changes associated to procedural learning and automatization process in Developmental Coordination Disorder and/or Developmental Dyslexia.

PubMed

Biotteau, Maëlle; Péran, Patrice; Vayssière, Nathalie; Tallet, Jessica; Albaret, Jean-Michel; Chaix, Yves

2017-03-01

Recent theories hypothesize that procedural learning may support the frequent overlap between neurodevelopmental disorders. The neural circuitry supporting procedural learning includes, among others, cortico-cerebellar and cortico-striatal loops. Alteration of these loops may account for the frequent comorbidity between Developmental Coordination Disorder (DCD) and Developmental Dyslexia (DD). The aim of our study was to investigate cerebral changes due to the learning and automatization of a sequence learning task in children with DD, or DCD, or both disorders. fMRI on 48 children (aged 8-12) with DD, DCD or DD + DCD was used to explore their brain activity during procedural tasks, performed either after two weeks of training or in the early stage of learning. Firstly, our results indicate that all children were able to perform the task with the same level of automaticity, but recruit different brain processes to achieve the same performance. Secondly, our fMRI results do not appear to confirm Nicolson and Fawcett's model. The neural correlates recruited for procedural learning by the DD and the comorbid groups are very close, while the DCD group presents distinct characteristics. This provide a promising direction on the neural mechanisms associated with procedural learning in neurodevelopmental disorders and for understanding comorbidity. Published by Elsevier Ltd.

On children's dyslexia with NIRS

NASA Astrophysics Data System (ADS)

Gan, Zhuo; Li, Chengjun; Gong, Hui; Luo, Qingming; Yao, Bin; Song, Ranran; Wu, Hanrong

2003-12-01

Developmental dyslexia is a kind of prevalent psychologic disease. Some functional imaging technologies, such as FMRI and PET, have been used to study the brain activities of dyslexics. NIRS is a kind of novel technology which is more and more widely being used for study of the cognitive psychology. However, there aren"t reports about the dyslexic research using NIRS to be found until now. This paper introduces a NIRS system of four measuring channels. Brain activities of dyslexic subjects and normal subjects during reading task were studied with the NIRS system. Two groups of subjects, the group of dyslexia and the group of normal, were appointed to perform two reading tasks. At the same time, their cortical activities were measured with the NIRS system. This experimental result indicates that the brain activities of the dyslexic group were significantly higher than the control group in BA 48 and that NIRS can be used for the study of human brain activity.

[Neurobiology and neurogenetics of dyslexia].

PubMed

Benítez-Burraco, A

2010-01-01

Dyslexia is a learning disability in which reading (but not any other) impairment is the most prominent symptom. There seems to be a high comorbidity among dyslexia and other learning disabilities, such as SLI, SSD or ADHD. The nulear deficit in dyslexia appears to correspond to an impairment in phonological processing. Structural and functional studies in dyslexic readers converge to indicate the presence of malformations in the brain areas corresponding to the reading systems, but also a failure of these systems to function properly during reading. Genes linked (or associated) to dyslexia have been shown to be involved in neuronal migration and axon guidance during the formation of the cortex. In the developing cerebral neocortex of rats, local loss of function of most of these genes not only results in abnormal neuronal migration and neocortical and hippocampal malformations, but also in deficits related to auditory processing and learning. While the structural malformations resemble neuronal migration abnormalities observed in the brains of individuals with developmental dyslexia, processing/learning deficits also resemble deficits described in individuals affected by the disease. On the whole, dyslexia seems to be on a continuum with typical reading at different biological levels (genetic, biochemical, physiological, cognitive). Furthermore, certain elements belonging to some of these levels (mainly -some of the- genes linked or associated to the disease, but also -some of the- neuronal structures whose development is regulated by these genes) would simultaneously belong to those of other cognitive abilities, which give rise to diseases of a different nature (i.e. non- dyslexic impairments) when they are impaired. Copyright © 2009 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

Analyzing Global Components in Developmental Dyscalculia and Dyslexia.

PubMed

Filippo, Gloria Di; Zoccolotti, Pierluigi

2018-01-01

The study examined whether developmental deficits in reading and numerical skills could be expressed in terms of global factors by reference to the rate and amount (RAM) and difference engine (DEM) models. From a sample of 325 fifth grade children, we identified 5 children with dyslexia, 16 with dyscalculia, 7 with a "mixed pattern," and 49 control children. Children were asked to read aloud words presented individually that varied for frequency and length and to respond (either vocally or manually) to a series of simple number tasks (addition, subtraction, number reading, and number comparisons). Reaction times were measured. Results indicated that the deficit of children with dyscalculia and children with a mixed pattern on numerical tasks could be explained by a single global factor, similarly to the reading deficit shown by children with dyslexia. As predicted by the DEM, increases in task difficulty were accompanied by a corresponding increase in inter-individual variability for both the reading and numerical tasks. These relationships were constant across the four groups of children but differed in terms of slope and intercept on the x -axis, indicating that two different general rules underlie performance in reading and numerical skills. The study shows for the first time that, as previously shown for reading, also numerical performance can be explained with reference to a global factor. The advantage of this approach is that it takes into account the over-additivity effect, i.e., the presence of larger group differences in the case of more difficult conditions over and above the characteristics of the experimental conditions. It is concluded that reference to models such as the RAM and DEM can be useful in delineating the characteristics of the dyscalculic deficit as well as in the description of co-morbid disturbances, as in the case of dyslexia and dyscalculia.

Cognitive Endophenotypes of Dyslexia

ERIC Educational Resources Information Center

Moll, Kristina; Loff, Ariana; Snowling, Margaret J.

2013-01-01

The study investigated cognitive deficits associated with dyslexia and familial risk of dyslexia (endophenotypes) by comparing children from families with and without a history of dyslexia. Eighty-eight school-aged children were assessed on measures of phonology, language and rapid automatized naming. A series of regression analyses with family…

Effect of Atomoxetine Treatment on Reading and Phonological Skills in Children with Dyslexia or Attention-Deficit/Hyperactivity Disorder and Comorbid Dyslexia in a Randomized, Placebo-Controlled Trial.

PubMed

Shaywitz, Sally; Shaywitz, Bennett; Wietecha, Linda; Wigal, Sharon; McBurnett, Keith; Williams, David; Kronenberger, William G; Hooper, Stephen R

2017-02-01

Evaluated the effects of atomoxetine on the reading abilities of children with dyslexia only or attention-deficit/hyperactivity disorder (ADHD) and comorbid dyslexia. Children aged 10-16 years (N = 209) met Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR) criteria for dyslexia only (n = 58), ADHD and comorbid dyslexia (n = 124), or ADHD only (n = 27) and were of normal intelligence. Patients were treated with atomoxetine (1.0-1.4 mg/kg/day) or placebo in a 16-week, randomized, placebo-controlled, double-blind trial. The dyslexia-only and ADHD and comorbid dyslexia groups were randomized 1:1; the ADHD-only group received atomoxetine in a blinded manner. Reading abilities were measured with the Woodcock Johnson III (WJIII), Comprehensive Test of Phonological Processing (CTOPP), Gray Oral Reading Tests-4, and Test of Word Reading Efficiency. Atomoxetine-treated dyslexia-only patients compared with placebo patients had significantly greater improvement (p < 0.02) with moderate to approaching high effect sizes (ES) on WJIII Word Attack (ES = 0.72), Basic Reading Skills (ES = 0.48), and Reading Vocabulary (ES = 0.73). In the atomoxetine-treated ADHD and comorbid dyslexia group, improvement on the CTOPP Elision measure (ES = 0.50) was significantly greater compared with placebo (p < 0.02). Total, inattentive, and hyperactive/impulsive ADHD symptom reductions were significant in the atomoxetine-treated ADHD and comorbid dyslexia group compared with placebo, and from baseline in the ADHD-only group (p ≤ 0.02). ADHD symptom improvements in the ADHD and comorbid dyslexia group were not correlated with improvements in reading. Atomoxetine treatment improved reading scores in patients with dyslexia only and ADHD and comorbid dyslexia. Improvements for patients with dyslexia only were in critical components of reading, including decoding and reading vocabulary. For patients with ADHD and comorbid dyslexia, improvements in reading scores were distinct from improvement in ADHD inattention symptoms alone. These data represent the first report of improvements in reading measures following pharmacotherapy treatment in patients with dyslexia only evaluated in a randomized, double-blind trial.

Effect of Atomoxetine Treatment on Reading and Phonological Skills in Children with Dyslexia or Attention-Deficit/Hyperactivity Disorder and Comorbid Dyslexia in a Randomized, Placebo-Controlled Trial

PubMed Central

Shaywitz, Bennett; Wietecha, Linda; Wigal, Sharon; McBurnett, Keith; Williams, David; Kronenberger, William G.; Hooper, Stephen R.

2017-01-01

Abstract Objectives: Evaluated the effects of atomoxetine on the reading abilities of children with dyslexia only or attention-deficit/hyperactivity disorder (ADHD) and comorbid dyslexia. Methods: Children aged 10–16 years (N = 209) met Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR) criteria for dyslexia only (n = 58), ADHD and comorbid dyslexia (n = 124), or ADHD only (n = 27) and were of normal intelligence. Patients were treated with atomoxetine (1.0–1.4 mg/kg/day) or placebo in a 16-week, randomized, placebo-controlled, double-blind trial. The dyslexia-only and ADHD and comorbid dyslexia groups were randomized 1:1; the ADHD-only group received atomoxetine in a blinded manner. Reading abilities were measured with the Woodcock Johnson III (WJIII), Comprehensive Test of Phonological Processing (CTOPP), Gray Oral Reading Tests-4, and Test of Word Reading Efficiency. Results: Atomoxetine-treated dyslexia-only patients compared with placebo patients had significantly greater improvement (p < 0.02) with moderate to approaching high effect sizes (ES) on WJIII Word Attack (ES = 0.72), Basic Reading Skills (ES = 0.48), and Reading Vocabulary (ES = 0.73). In the atomoxetine-treated ADHD and comorbid dyslexia group, improvement on the CTOPP Elision measure (ES = 0.50) was significantly greater compared with placebo (p < 0.02). Total, inattentive, and hyperactive/impulsive ADHD symptom reductions were significant in the atomoxetine-treated ADHD and comorbid dyslexia group compared with placebo, and from baseline in the ADHD-only group (p ≤ 0.02). ADHD symptom improvements in the ADHD and comorbid dyslexia group were not correlated with improvements in reading. Conclusions: Atomoxetine treatment improved reading scores in patients with dyslexia only and ADHD and comorbid dyslexia. Improvements for patients with dyslexia only were in critical components of reading, including decoding and reading vocabulary. For patients with ADHD and comorbid dyslexia, improvements in reading scores were distinct from improvement in ADHD inattention symptoms alone. These data represent the first report of improvements in reading measures following pharmacotherapy treatment in patients with dyslexia only evaluated in a randomized, double-blind trial. PMID:27410907

Reasoning and dyslexia: a spatial strategy may impede reasoning with visually rich information.

PubMed

Bacon, Alison M; Handley, Simon J; McDonald, Emma L

2007-02-01

Bacon, Handley, and Newstead (2003, 2004), have presented evidence for individual differences in reasoning strategies, with most people seeming to represent and manipulate problem information using either a verbal or a spatial strategy. There is also evidence that individuals with dyslexia are inclined to conceptualise information in a visuo-spatial, rather than a verbal, way (e.g. von Károlyi et al., 2003). If so, we might expect a higher proportion of individuals with dyslexia to be spatial reasoners, compared with individuals who do not have dyslexia. The study reported here directly compared strategies reported by these two groups of participants on a syllogistic reasoning task. Moreover, problem content was manipulated so that reasoning across concrete and abstract materials could be compared. The findings suggest that whilst most individuals without dyslexia use a verbal strategy, reasoners with dyslexia do tend to adopt a spatial approach, though their performance is impaired with visually concrete materials. However, when reasoning with more abstract content, they perform comparably with non-dyslexic controls. The paper discusses these results in the light of recent research which has suggested that visual images may impede reasoning, and considers how individuals with dyslexia may differ from other reasoners.

Cognitive Linguistic Performances of Multilingual University Students Suspected of Dyslexia

ERIC Educational Resources Information Center

Lindgren, Signe-Anita; Laine, Matti

2011-01-01

High-performing adults with compensated dyslexia pose particular challenges to dyslexia diagnostics. We compared the performance of 20 multilingual Finnish university students with suspected dyslexia with 20 age-matched and education-matched controls on an extensive test battery. The battery tapped various aspects of reading, writing, word…

Pleiotropic Effects of DCDC2 and DYX1C1 Genes on Language and Mathematics Traits in Nuclear Families of Developmental Dyslexia

PubMed Central

Mascheretti, Sara; Riva, Valentina; Cattaneo, Francesca; Rigoletto, Catia; Rusconi, Marianna; Gruen, Jeffrey R.; Giorda, Roberto; Lazazzera, Claudio; Molteni, Massimo

2014-01-01

Converging evidence indicates that developmental problems in oral language and mathematics can predate or co-occur with developmental dyslexia (DD). Substantial genetic correlations have been found between language, mathematics and reading traits, independent of the method of sampling. We tested for association of variants of two DD susceptibility genes, DCDC2 and DYX1C1, in nuclear families ascertained through a proband with DD using concurrent measurements of language and mathematics in both probands and siblings by the Quantitative Transmission Disequilibrium Test. Evidence for significant associations was found between DCDC2 and ‘Numerical Facts’ (p value = 0.02, with 85 informative families, genetic effect = 0.57) and between ‘Mental Calculation’ and DYX1C1 markers −3GA (p value = 0.05, with 40 informative families, genetic effect = −0.67) and 1249GT (p value = 0.02, with 49 informative families, genetic effect = −0.65). No statistically significant associations were found between DCDC2 or DYX1C1 and language phenotypes. Both DCDC2 and DYX1C1 DD susceptibility genes appear to have a pleiotropic role on mathematics but not language phenotypes. PMID:21046216

Pleiotropic effects of DCDC2 and DYX1C1 genes on language and mathematics traits in nuclear families of developmental dyslexia.

PubMed

Marino, Cecilia; Mascheretti, Sara; Riva, Valentina; Cattaneo, Francesca; Rigoletto, Catia; Rusconi, Marianna; Gruen, Jeffrey R; Giorda, Roberto; Lazazzera, Claudio; Molteni, Massimo

2011-01-01

Converging evidence indicates that developmental problems in oral language and mathematics can predate or co-occur with developmental dyslexia (DD). Substantial genetic correlations have been found between language, mathematics and reading traits, independent of the method of sampling. We tested for association of variants of two DD susceptibility genes, DCDC2 and DYX1C1, in nuclear families ascertained through a proband with DD using concurrent measurements of language and mathematics in both probands and siblings by the Quantitative Transmission Disequilibrium Test. Evidence for significant associations was found between DCDC2 and 'Numerical Facts' (p value = 0.02, with 85 informative families, genetic effect = 0.57) and between 'Mental Calculation' and DYX1C1 markers -3GA (p value = 0.05, with 40 informative families, genetic effect = -0.67) and 1249GT (p value = 0.02, with 49 informative families, genetic effect = -0.65). No statistically significant associations were found between DCDC2 or DYX1C1 and language phenotypes. Both DCDC2 and DYX1C1 DD susceptibility genes appear to have a pleiotropic role on mathematics but not language phenotypes.

Multiple Causal Links Between Magnocellular-Dorsal Pathway Deficit and Developmental Dyslexia.

PubMed

Gori, Simone; Seitz, Aaron R; Ronconi, Luca; Franceschini, Sandro; Facoetti, Andrea

2016-10-17

Although impaired auditory-phonological processing is the most popular explanation of developmental dyslexia (DD), the literature shows that the combination of several causes rather than a single factor contributes to DD. Functioning of the visual magnocellular-dorsal (MD) pathway, which plays a key role in motion perception, is a much debated, but heavily suspected factor contributing to DD. Here, we employ a comprehensive approach that incorporates all the accepted methods required to test the relationship between the MD pathway dysfunction and DD. The results of 4 experiments show that (1) Motion perception is impaired in children with dyslexia in comparison both with age-match and with reading-level controls; (2) pre-reading visual motion perception-independently from auditory-phonological skill-predicts future reading development, and (3) targeted MD trainings-not involving any auditory-phonological stimulation-leads to improved reading skill in children and adults with DD. Our findings demonstrate, for the first time, a causal relationship between MD deficits and DD, virtually closing a 30-year long debate. Since MD dysfunction can be diagnosed much earlier than reading and language disorders, our findings pave the way for low resource-intensive, early prevention programs that could drastically reduce the incidence of DD. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Altered brain activity for phonological manipulation in dyslexic Japanese children.

PubMed

Kita, Yosuke; Yamamoto, Hisako; Oba, Kentaro; Terasawa, Yuri; Moriguchi, Yoshiya; Uchiyama, Hitoshi; Seki, Ayumi; Koeda, Tatsuya; Inagaki, Masumi

2013-12-01

Because of unique linguistic characteristics, the prevalence rate of developmental dyslexia is relatively low in the Japanese language. Paradoxically, Japanese children have serious difficulty analysing phonological processes when they have dyslexia. Neurobiological deficits in Japanese dyslexia remain unclear and need to be identified, and may lead to better understanding of the commonality and diversity in the disorder among different linguistic systems. The present study investigated brain activity that underlies deficits in phonological awareness in Japanese dyslexic children using functional magnetic resonance imaging. We developed and conducted a phonological manipulation task to extract phonological processing skills and to minimize the influence of auditory working memory on healthy adults, typically developing children, and dyslexic children. Current experiments revealed that several brain regions participated in manipulating the phonological information including left inferior and middle frontal gyrus, left superior temporal gyrus, and bilateral basal ganglia. Moreover, dyslexic children showed altered activity in two brain regions. They showed hyperactivity in the basal ganglia compared with the two other groups, which reflects inefficient phonological processing. Hypoactivity in the left superior temporal gyrus was also found, suggesting difficulty in composing and processing phonological information. The altered brain activity shares similarity with those of dyslexic children in countries speaking alphabetical languages, but disparity also occurs between these two populations. These are initial findings concerning the neurobiological impairments in dyslexic Japanese children.

Altered brain activity for phonological manipulation in dyslexic Japanese children

PubMed Central

Yamamoto, Hisako; Oba, Kentaro; Terasawa, Yuri; Moriguchi, Yoshiya; Uchiyama, Hitoshi; Seki, Ayumi; Koeda, Tatsuya; Inagaki, Masumi

2013-01-01

Because of unique linguistic characteristics, the prevalence rate of developmental dyslexia is relatively low in the Japanese language. Paradoxically, Japanese children have serious difficulty analysing phonological processes when they have dyslexia. Neurobiological deficits in Japanese dyslexia remain unclear and need to be identified, and may lead to better understanding of the commonality and diversity in the disorder among different linguistic systems. The present study investigated brain activity that underlies deficits in phonological awareness in Japanese dyslexic children using functional magnetic resonance imaging. We developed and conducted a phonological manipulation task to extract phonological processing skills and to minimize the influence of auditory working memory on healthy adults, typically developing children, and dyslexic children. Current experiments revealed that several brain regions participated in manipulating the phonological information including left inferior and middle frontal gyrus, left superior temporal gyrus, and bilateral basal ganglia. Moreover, dyslexic children showed altered activity in two brain regions. They showed hyperactivity in the basal ganglia compared with the two other groups, which reflects inefficient phonological processing. Hypoactivity in the left superior temporal gyrus was also found, suggesting difficulty in composing and processing phonological information. The altered brain activity shares similarity with those of dyslexic children in countries speaking alphabetical languages, but disparity also occurs between these two populations. These are initial findings concerning the neurobiological impairments in dyslexic Japanese children. PMID:24052613

Visual naming deficits in dyslexia: An ERP investigation of different processing domains.

PubMed

Araújo, Susana; Faísca, Luís; Reis, Alexandra; Marques, J Frederico; Petersson, Karl Magnus

2016-10-01

Naming speed deficits are well documented in developmental dyslexia, expressed by slower naming times and more errors in response to familiar items. Here we used event-related potentials (ERPs) to examine at what processing level the deficits in dyslexia emerge during a discrete-naming task. Dyslexic and skilled adult control readers performed a primed object-naming task, in which the relationship between the prime and the target was manipulated along perceptual, semantic and phonological dimensions. A 3×2 design that crossed Relationship Type (Visual, Phonemic Onset, and Semantic) with Relatedness (Related and Unrelated) was used. An attenuated N/P190 - indexing early visual processing - and N300 - which index late visual processing - was observed to pictures preceded by perceptually related (vs. unrelated) primes in the control but not in the dyslexic group. These findings suggest suboptimal processing in early stages of object processing in dyslexia, when integration and mapping of perceptual information to a more form-specific percept in memory take place. On the other hand, both groups showed an N400 effect associated with semantically related pictures (vs. unrelated), taken to reflect intact integration of semantic similarities in both dyslexic and control readers. We also found an electrophysiological effect of phonological priming in the N400 range - that is, an attenuated N400 to objects preceded by phonemic related primes vs. unrelated - while it showed a more widespread distributed and more pronounced over the right hemisphere in the dyslexics. Topographic differences between groups might have originated from a word form encoding process with different characteristics in dyslexics compared to control readers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Basic Auditory Processing and Developmental Dyslexia in Chinese

ERIC Educational Resources Information Center

Wang, Hsiao-Lan Sharon; Huss, Martina; Hamalainen, Jarmo A.; Goswami, Usha

2012-01-01

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…

Norman Geschwind Lecture: Geschwind's Lesson.

ERIC Educational Resources Information Center

Duane, Drake D.

2002-01-01

This article reviews the contributions of Norman Geschwind on behavioral neurology. It discusses his novel associations between brain function/structure and behavior and findings from a recent study of 200 individuals with developmental disorders that indicate altered neuroanatomy in dyslexia may be accompanied by altered clinical neurophysiology.…

Developmental Dyslexia, Neurolinguistic Theory and Deviations in Brain Morphology.

ERIC Educational Resources Information Center

Hynd, George W.; And Others

1991-01-01

Reviews computer tomography and magnetic resonance imaging studies examining deviations in brain morphology. Discusses methodological and technical issues. Concludes that dyslexics show variations in specific brain regions. Suggests that neuroimaging procedures appear to provide direct evidence supporting the importance of deviations in normal…

Developmental dyslexia and vision

PubMed Central

Quercia, Patrick; Feiss, Léonard; Michel, Carine

2013-01-01

Developmental dyslexia affects almost 10% of school-aged children and represents a significant public health problem. Its etiology is unknown. The consistent presence of phonological difficulties combined with an inability to manipulate language sounds and the grapheme–phoneme conversion is widely acknowledged. Numerous scientific studies have also documented the presence of eye movement anomalies and deficits of perception of low contrast, low spatial frequency, and high frequency temporal visual information in dyslexics. Anomalies of visual attention with short visual attention spans have also been demonstrated in a large number of cases. Spatial orientation is also affected in dyslexics who manifest a preference for spatial attention to the right. This asymmetry may be so pronounced that it leads to a veritable neglect of space on the left side. The evaluation of treatments proposed to dyslexics whether speech or oriented towards the visual anomalies remains fragmentary. The advent of new explanatory theories, notably cerebellar, magnocellular, or proprioceptive, is an incentive for ophthalmologists to enter the world of multimodal cognition given the importance of the eye’s visual input. PMID:23690677

Aggression and Risk of Future Violence in Forensic Psychiatric Patients with and without Dyslexia

ERIC Educational Resources Information Center

Selenius, Heidi; Hellstrom, Ake; Belfrage, Henrik

2011-01-01

Dyslexia does not cause criminal behaviour, but it may worsen aggressive behaviour tendencies. In this study, aggressive behaviour and risk of future violence were compared between forensic psychiatric patients with and without dyslexia. Dyslexia was assessed using the Swedish phonological processing battery "The Pigeon". The patients…

Differences in Learning Volitional (Manual) and Non-Volitional (Posture) Aspects of a Complex Motor Skill in Young Adult Dyslexic and Skilled Readers

PubMed Central

Sela, Itamar; Karni, Avi

2012-01-01

The ‘Cerebellar Deficit Theory’ of developmental dyslexia proposes that a subtle developmental cerebellar dysfunction leads to deficits in attaining ‘automatic’ procedures and therefore manifests as subtle motor impairments (e.g., balance control, motor skill learning) in addition to the reading and phonological difficulties. A more recent version of the theory suggests a core deficit in motor skill acquisition. This study was undertaken to compare the time-course and the nature of practice-related changes in volitional (manual) and non-volitional (posture) motor performance in dyslexic and typical readers while learning a new movement sequence. Seventeen dyslexic and 26 skilled young adult readers underwent a three-session training program in which they practiced a novel sequence of manual movements while standing in a quiet stance position. Both groups exhibited robust and well-retained gains in speed, with no loss of accuracy, on the volitional, manual, aspects of the task, with a time-course characteristic of procedural learning. However, the dyslexic readers exhibited a pervasive slowness in the initiation of volitional performance. In addition, while typical readers showed clear and well-retained task-related adaptation of the balance and posture control system, the dyslexic readers had significantly larger sway and variance of sway throughout the three sessions and were less efficient in adapting the posture control system to support the acquisition of the novel movement sequence. These results support the notion of a non-language-related deficit in developmental dyslexia, one related to the recruitment of motor systems for effective task performance rather than to a general motor learning disability. PMID:23049736

Adult Dyslexia and Attention Deficit Disorder in Finland--Project DyAdd: WAIS-III Cognitive Profiles

ERIC Educational Resources Information Center

Laasonen, Marja; Leppamaki, Sami; Tani, Pekka; Hokkanen, Laura

2009-01-01

The project Adult Dyslexia and Attention Deficit Disorder in Finland (Project DyAdd) compares adults (n = 119, 18-55 years) with dyslexia, attention-deficit/hyperactivity disorder (ADHD), dyslexia together with ADHD (comorbid), and healthy controls with neuropsychological, psychophysical, and biological methods. The focus of this article is on the…

Exploring Dyslexics' Phonological Deficit II: Phonological Grammar

ERIC Educational Resources Information Center

Szenkovits, Gayaneh; Darma, Quynliaan; Darcy, Isabelle; Ramus, Franck

2016-01-01

Language learners have to acquire the phonological grammar of their native language, and different levels of representations on which the grammar operates. Developmental dyslexia is associated with a phonological deficit, which is commonly assumed to stem from degraded phonological representations. The present study investigates one aspect of the…

Children with Dyslexia Are Slow Writers Because They Pause More Often and Not Because They Are Slow at Handwriting Execution

ERIC Educational Resources Information Center

Sumner, Emma; Connelly, Vincent; Barnett, Anna L.

2013-01-01

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…

Analysing Conflicting Approaches to Dyslexia on a European Project: Moving to a More Strategic, Participatory, Strength-Based and Integrated Approach

ERIC Educational Resources Information Center

Davis, J. M.; Deponio, P.

2014-01-01

This paper draws from our experiences of an EU Life Long Learning Programme Project: GATE Understanding Dyslexia Phenomena Between Pre-Primary And Primary (2009-2011) to discuss different conceptual positions concerning dyslexia. It compares medical notions of dyslexia with perspectives from childhood and disability studies to question the ways in…

Mental additions and verbal-domain interference in children with developmental dyscalculia.

PubMed

Mammarella, Irene C; Caviola, Sara; Cornoldi, Cesare; Lucangeli, Daniela

2013-09-01

This study examined the involvement of verbal and visuo-spatial domains in solving addition problems with carrying in a sample of children diagnosed with developmental dyscalculia (DD) divided into two groups: (i) those with DD alone and (ii) those with DD and dyslexia. Age and stage matched typically developing (TD) children were also studied. The addition problems were presented horizontally or vertically and associated with verbal or visuo-spatial information. Study results showed that DD children's performance on mental calculation tasks was more impaired when they tackled horizontally presented addition problems compared to vertically presented ones that are associated to verbal domain involvement. The performance pattern in the two DD groups was found to be similar. The theoretical, clinical and educational implications of these findings are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Prevalence of Developmental Dyslexia in Spanish University Students

PubMed Central

López-Escribano, Carmen; Suro Sánchez, Judith; Leal Carretero, Fernando

2018-01-01

A recent concern in the field of dyslexia studies is the lack of awareness and attention to university students suffering from this condition. If this problem is serious in countries where the relative opacity of the writing system allows for an early detection and, therefore, effective interventions, it is most critical in countries where transparent spelling makes such detection difficult, except in the most severe cases. In Spain, the diagnosis of dyslexia is rare among university-level adults. The present study pursues three aims: (a) to put forward a screening instrument for the detection of university students at risk of dyslexia, (b) to determine the ratio of university students that could be at risk of dyslexia by means of two different procedures, and (c) to create awareness for a disorder that causes hitherto unrecognized difficulties for an important subgroup of the college population. Six hundred and eighty-six university students in four different fields of study within the general area of Social Sciences from a public University in Madrid completed a Spanish-adapted version of a protocol including stress assignment, spelling words and nonwords, and timed phonological working memory of reading and writing task. Results showed that between 1.6% and 6.4% of this population could be at risk of suffering dyslexia. Such risk is not evenly distributed across the four fields of study. As for gender, the first criterion used yields 1.8 males at risk for every female, but the second criterion has as many males as females at risk. Women were significantly better than men in word spelling. Spelling was best predicted by the timed phonological working memory task of reading and writing. PMID:29738440

An Evaluation of Syntactic-Semantic Processing in Developmental Dyslexia

ERIC Educational Resources Information Center

Jimenez, Juan E.; Garcia, Eduardo; Estevez, Adelina; Diaz, Alicia; Guzman, Remedios; Hernandez-Valle, Isabel; Rosario, Maria; Rodrigo, Mercedes; Hernandez, Sergio

2004-01-01

Introduction: The main purpose of this study is to investigate whether children who have reading disabilities in an alphabetically transparent orthography show a syntactic processing deficit. This research focuses on exploring syntactic processing and the use of morphological markers by subjects with reading disabilities. We analyze these groups'…

Lexical Stress Assignment in Italian Developmental Dyslexia

ERIC Educational Resources Information Center

Paizi, Despina; Zoccolotti, Pierluigi; Burani, Cristina

2011-01-01

Stress assignment to Italian polysyllabic words is unpredictable, because stress is neither marked nor predicted by rule. Stress assignment, especially to low frequency words, has been reported to be a function of stress dominance and stress neighbourhood. Two experiments investigate stress assignment in sixth-grade, skilled and dyslexic, readers.…

Dynamic Visual Perception and Reading Development in Chinese School Children

ERIC Educational Resources Information Center

Meng, Xiangzhi; Cheng-Lai, Alice; Zeng, Biao; Stein, John F.; Zhou, Xiaolin

2011-01-01

The development of reading skills may depend to a certain extent on the development of basic visual perception. The magnocellular theory of developmental dyslexia assumes that deficits in the magnocellular pathway, indicated by less sensitivity in perceiving dynamic sensory stimuli, are responsible for a proportion of reading difficulties…

What does the brain of children with developmental dyslexia tell us about reading improvement? ERP evidence from an intervention study

PubMed Central

Hasko, Sandra; Groth, Katarina; Bruder, Jennifer; Bartling, Jürgen; Schulte-Körne, Gerd

2014-01-01

Intervention is key to managing developmental dyslexia (DD), but not all children with DD benefit from treatment. Some children improve (improvers, IMP), whereas others do not improve (non-improvers, NIMP). Neurobiological differences between IMP and NIMP have been suggested, but studies comparing IMP and NIMP in childhood are missing. The present study examined whether ERP patterns change with treatment and differ between IMP and NIMP. We investigated the ERPs of 28 children with DD and 25 control children (CON) while performing a phonological lexical decision (PLD) task before and after a 6-month intervention. After intervention children with DD were divided into IMP (n = 11) and NIMP (n = 17). In the PLD–task children were visually presented with words, pseudohomophones, pseudowords, and false fonts and had to decide whether the presented stimulus sounded like an existing German word or not. Prior to intervention IMP showed higher N300 amplitudes over fronto-temporal electrodes compared to NIMP and CON and N400 amplitudes were attenuated in both IMP and NIMP compared to CON. After intervention N300 amplitudes of IMP were comparable to those of CON and NIMP. This suggests that the N300, which has been related to phonological access of orthographic stimuli and integration of orthographic and phonological representations, might index a compensatory mechanism or precursor that facilitates reading improvement. The N400, which is thought to reflect grapheme-phoneme conversion or the access to the orthographic lexicon increased in IMP from pre to post and was comparable to CON after intervention. Correlations between N300 amplitudes pre, growth in reading ability and N400 amplitudes post indicated that higher N300 amplitudes might be important for reading improvement and increase in N400 amplitudes. The results suggest that children with DD, showing the same cognitive profile might differ regarding their neuronal profile which could further influence reading improvement. PMID:25018723

Morpheme-based Reading and Spelling in Italian Children with Developmental Dyslexia and Dysorthography.

PubMed

Angelelli, Paola; Marinelli, Chiara Valeria; De Salvatore, Marinella; Burani, Cristina

2017-11-01

Italian sixth graders, with and without dyslexia, read pseudowords and low-frequency words that include high-frequency morphemes better than stimuli not including any morpheme. The present study assessed whether morphemes affect (1) younger children, with and without dyslexia; (2) spelling as well as reading; and (3) words with low-frequency morphemes. Two groups of third graders (16 children with dyslexia and dysorthography and 16 age-matched typically developing children) read aloud and spelt to dictation pseudowords and words. Pseudowords included (1) root + suffix in not existing combinations (e.g. lampadista, formed by lampad-, 'lamp', and -ista, '-ist') and (2) orthographic sequences not corresponding to any Italian root or suffix (e.g. livonosto). Words had low frequency and included: (1) root + suffix, both of high frequency (e.g. bestiale, 'beastly'); (2) root + suffix, both of low frequency (e.g. asprigno, 'rather sour'); and (3) simple words (e.g. insulso, 'vapid'). Children with dyslexia and dysorthography were less accurate than typically developing children. Root + suffix pseudowords were read and spelt more accurately than non-morphological pseudowords by both groups. Morphologically complex (root + suffix) words were read and spelt better than simple words. However, task interacted with morphology: reading was not facilitated by low-frequency morphemes. We conclude that children acquiring a transparent orthography exploit morpheme-based reading and spelling to face difficulties in processing long unfamiliar stimuli. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Study the left prefrontal cortex activity of Chinese children with dyslexia in phonological processing by NIRS

NASA Astrophysics Data System (ADS)

Zhang, Zhili; Li, Ting; Zheng, Yi; Luo, Qingming; Song, Ranran; Gong, Hui

2006-02-01

Developmental dyslexia, a kind of prevalent psychological disease, represents that dyslexic children have unexpected difficulties in phonological processing and recognition test of Chinese characters. Some functional imaging technologies, such as fMRI and PET, have been used to study the brain activities of the children with dyslexia whose first language is English. In this paper, a portable, 16-channel, continuous-wave (CW) NIRS instrument was used to monitor the concentration changes of each hemoglobin species when Chinese children did the task of phonological processing and recognition test. The NIRS recorded the hemodynamic changes in the left prefrontal cortex of the children. 20 dyslexia-reading children (10~12 years old) and 20 normal-reading children took part in the phonological processing of Chinese characters including the phonological awareness section and the phonological decoding section. During the phonological awareness section, the changed concentration of deoxy-hemoglobin in dyslexia-reading children were significantly higher (p<0.05) than normal-reading children in the left ventrolateral prefrontal cortex (VLPFC). While in the phonological decoding section, both normal and dyslexic reading children had more activity in the left VLPFC, but only normal-reading children had activity in the left middorsal prefrontal cortex. In conclusion, both dyslexic and normal-reading children have activity in the left prefrontal cortex, but the degree and the areas of the prefrontal cortex activity are different between them when they did phonological processing.

Age, dyslexia subtype and comorbidity modulate rapid auditory processing in developmental dyslexia.

PubMed

Lorusso, Maria Luisa; Cantiani, Chiara; Molteni, Massimo

2014-01-01

The nature of Rapid Auditory Processing (RAP) deficits in dyslexia remains debated, together with the specificity of the problem to certain types of stimuli and/or restricted subgroups of individuals. Following the hypothesis that the heterogeneity of the dyslexic population may have led to contrasting results, the aim of the study was to define the effect of age, dyslexia subtype and comorbidity on the discrimination and reproduction of non-verbal tone sequences. Participants were 46 children aged 8-14 (26 with dyslexia, subdivided according to age, presence of a previous language delay, and type of dyslexia). Experimental tasks were a Temporal Order Judgment (TOJ) (manipulating tone length, ISI and sequence length), and a Pattern Discrimination Task. Dyslexic children showed general RAP deficits. Tone length and ISI influenced dyslexic and control children's performance in a similar way, but dyslexic children were more affected by an increase from 2 to 5 sounds. As to age, older dyslexic children's difficulty in reproducing sequences of 4 and 5 tones was similar to that of normally reading younger (but not older) children. In the analysis of subgroup profiles, the crucial variable appears to be the advantage, or lack thereof, in processing long vs. short sounds. Dyslexic children with a previous language delay obtained the lowest scores in RAP measures, but they performed worse with shorter stimuli, similar to control children, while dyslexic-only children showed no advantage for longer stimuli. As to dyslexia subtype, only surface dyslexics improved their performance with longer stimuli, while phonological dyslexics did not. Differential scores for short vs. long tones and for long vs. short ISIs predict non-word and word reading, respectively, and the former correlate with phonemic awareness. In conclusion, the relationship between non-verbal RAP, phonemic skills and reading abilities appears to be characterized by complex interactions with subgroup characteristics.

Age, dyslexia subtype and comorbidity modulate rapid auditory processing in developmental dyslexia

PubMed Central

Lorusso, Maria Luisa; Cantiani, Chiara; Molteni, Massimo

2014-01-01

The nature of Rapid Auditory Processing (RAP) deficits in dyslexia remains debated, together with the specificity of the problem to certain types of stimuli and/or restricted subgroups of individuals. Following the hypothesis that the heterogeneity of the dyslexic population may have led to contrasting results, the aim of the study was to define the effect of age, dyslexia subtype and comorbidity on the discrimination and reproduction of non-verbal tone sequences. Participants were 46 children aged 8–14 (26 with dyslexia, subdivided according to age, presence of a previous language delay, and type of dyslexia). Experimental tasks were a Temporal Order Judgment (TOJ) (manipulating tone length, ISI and sequence length), and a Pattern Discrimination Task. Dyslexic children showed general RAP deficits. Tone length and ISI influenced dyslexic and control children's performance in a similar way, but dyslexic children were more affected by an increase from 2 to 5 sounds. As to age, older dyslexic children's difficulty in reproducing sequences of 4 and 5 tones was similar to that of normally reading younger (but not older) children. In the analysis of subgroup profiles, the crucial variable appears to be the advantage, or lack thereof, in processing long vs. short sounds. Dyslexic children with a previous language delay obtained the lowest scores in RAP measures, but they performed worse with shorter stimuli, similar to control children, while dyslexic-only children showed no advantage for longer stimuli. As to dyslexia subtype, only surface dyslexics improved their performance with longer stimuli, while phonological dyslexics did not. Differential scores for short vs. long tones and for long vs. short ISIs predict non-word and word reading, respectively, and the former correlate with phonemic awareness. In conclusion, the relationship between non-verbal RAP, phonemic skills and reading abilities appears to be characterized by complex interactions with subgroup characteristics. PMID:24904356

Reading in dyslexia across literacy development: A longitudinal study of effective connectivity.

PubMed

Morken, Frøydis; Helland, Turid; Hugdahl, Kenneth; Specht, Karsten

2017-01-01

Dyslexia is a literacy disorder affecting the efficient acquisition of reading and writing skills. The disorder is neurobiological in origin. Due to its developmental nature, longitudinal studies of dyslexia are of essence. They are, however, relatively scarce. The present study took a longitudinal approach to cortical connectivity of brain imaging data in reading tasks in children with dyslexia and children with typical reading development. The participants were followed with repeated measurements through Pre-literacy (6 years old), Emergent Literacy (8 years old) and Literacy (12 years old) stages, using Dynamic Causal Modelling (DCM) when analysing functional magnetic resonance imaging (fMRI) data. Even though there are a few longitudinal studies on effective connectivity in typical reading, to our knowledge, no studies have previously investigated these issues in relation to dyslexia. We set up a model of a brain reading network involving five cortical regions (inferior frontal gyrus, precentral gyrus, superior temporal gyrus, inferior parietal lobule, and occipito-temporal cortex). Using DCM, connectivity measures were calculated for each connection in the model. These measures were further analysed using factorial ANOVA. The results showed that the difference between groups centred on connections going to and from the inferior frontal gyrus (two connections) and the occipito-temporal cortex (three connections). For all five connections, the typical group showed stable or decreasing connectivity measures. The dyslexia group, on the other hand, showed a marked up-regulation (occipito-temporal connections) or down-regulation (inferior frontal gyrus connections) from 6 years to 8 years, followed by normalization from 8 years to 12 years. We interpret this as a delay in the dyslexia group in developing into the Pre-literacy and Emergent literacy stages. This delay could possibly be detrimental to literacy development. By age 12, there was no statistically significant difference in connectivity between the groups, but differences in literacy skills were still present, and were in fact larger than when measured at younger ages. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

The Effect of a Specialized Dyslexia Font, Opendyslexic, on Reading Rate and Accuracy

ERIC Educational Resources Information Center

Wery, Jessica J.; Diliberto, Jennifer A.

2017-01-01

A single-subject alternating treatment design was used to investigate the extent to which a specialized dyslexia font, OpenDyslexic, impacted reading rate or accuracy compared to two commonly used fonts when used with elementary students identified as having dyslexia. OpenDyslexic was compared to Arial and Times New Roman in three reading tasks:…

The locus of impairment in English developmental letter position dyslexia

PubMed Central

Kezilas, Yvette; Kohnen, Saskia; McKague, Meredith; Castles, Anne

2014-01-01

Many children with reading difficulties display phonological deficits and struggle to acquire non-lexical reading skills. However, not all children with reading difficulties have these problems, such as children with selective letter position dyslexia (LPD), who make excessive migration errors (such as reading slime as “smile”). Previous research has explored three possible loci for the deficit – the phonological output buffer, the orthographic input lexicon, and the orthographic-visual analysis stage of reading. While there is compelling evidence against a phonological output buffer and orthographic input lexicon deficit account of English LPD, the evidence in support of an orthographic-visual analysis deficit is currently limited. In this multiple single-case study with three English-speaking children with developmental LPD, we aimed to both replicate and extend previous findings regarding the locus of impairment in English LPD. First, we ruled out a phonological output buffer and an orthographic input lexicon deficit by administering tasks that directly assess phonological processing and lexical guessing. We then went on to directly assess whether or not children with LPD have an orthographic-visual analysis deficit by modifying two tasks that have previously been used to localize processing at this level: a same-different decision task and a non-word reading task. The results from these tasks indicate that LPD is most likely caused by a deficit specific to the coding of letter positions at the orthographic-visual analysis stage of reading. These findings provide further evidence for the heterogeneity of dyslexia and its underlying causes. PMID:24917802

Neural Biomarkers for Dyslexia, ADHD, and ADD in the Auditory Cortex of Children.

PubMed

Serrallach, Bettina; Groß, Christine; Bernhofs, Valdis; Engelmann, Dorte; Benner, Jan; Gündert, Nadine; Blatow, Maria; Wengenroth, Martina; Seitz, Angelika; Brunner, Monika; Seither, Stefan; Parncutt, Richard; Schneider, Peter; Seither-Preisler, Annemarie

2016-01-01

Dyslexia, attention deficit hyperactivity disorder (ADHD), and attention deficit disorder (ADD) show distinct clinical profiles that may include auditory and language-related impairments. Currently, an objective brain-based diagnosis of these developmental disorders is still unavailable. We investigated the neuro-auditory systems of dyslexic, ADHD, ADD, and age-matched control children (N = 147) using neuroimaging, magnetencephalography and psychoacoustics. All disorder subgroups exhibited an oversized left planum temporale and an abnormal interhemispheric asynchrony (10-40 ms) of the primary auditory evoked P1-response. Considering right auditory cortex morphology, bilateral P1 source waveform shapes, and auditory performance, the three disorder subgroups could be reliably differentiated with outstanding accuracies of 89-98%. We therefore for the first time provide differential biomarkers for a brain-based diagnosis of dyslexia, ADHD, and ADD. The method allowed not only allowed for clear discrimination between two subtypes of attentional disorders (ADHD and ADD), a topic controversially discussed for decades in the scientific community, but also revealed the potential for objectively identifying comorbid cases. Noteworthy, in children playing a musical instrument, after three and a half years of training the observed interhemispheric asynchronies were reduced by about 2/3, thus suggesting a strong beneficial influence of music experience on brain development. These findings might have far-reaching implications for both research and practice and enable a profound understanding of the brain-related etiology, diagnosis, and musically based therapy of common auditory-related developmental disorders and learning disabilities.

Neural Biomarkers for Dyslexia, ADHD, and ADD in the Auditory Cortex of Children

PubMed Central

Serrallach, Bettina; Groß, Christine; Bernhofs, Valdis; Engelmann, Dorte; Benner, Jan; Gündert, Nadine; Blatow, Maria; Wengenroth, Martina; Seitz, Angelika; Brunner, Monika; Seither, Stefan; Parncutt, Richard; Schneider, Peter; Seither-Preisler, Annemarie

2016-01-01

Dyslexia, attention deficit hyperactivity disorder (ADHD), and attention deficit disorder (ADD) show distinct clinical profiles that may include auditory and language-related impairments. Currently, an objective brain-based diagnosis of these developmental disorders is still unavailable. We investigated the neuro-auditory systems of dyslexic, ADHD, ADD, and age-matched control children (N = 147) using neuroimaging, magnetencephalography and psychoacoustics. All disorder subgroups exhibited an oversized left planum temporale and an abnormal interhemispheric asynchrony (10–40 ms) of the primary auditory evoked P1-response. Considering right auditory cortex morphology, bilateral P1 source waveform shapes, and auditory performance, the three disorder subgroups could be reliably differentiated with outstanding accuracies of 89–98%. We therefore for the first time provide differential biomarkers for a brain-based diagnosis of dyslexia, ADHD, and ADD. The method allowed not only allowed for clear discrimination between two subtypes of attentional disorders (ADHD and ADD), a topic controversially discussed for decades in the scientific community, but also revealed the potential for objectively identifying comorbid cases. Noteworthy, in children playing a musical instrument, after three and a half years of training the observed interhemispheric asynchronies were reduced by about 2/3, thus suggesting a strong beneficial influence of music experience on brain development. These findings might have far-reaching implications for both research and practice and enable a profound understanding of the brain-related etiology, diagnosis, and musically based therapy of common auditory-related developmental disorders and learning disabilities. PMID:27471442

A review of the neurobiological basis of dyslexia in the adult population.

PubMed

Soriano-Ferrer, M; Piedra Martínez, E

Adult dyslexia affects about 4% of the population. However, studies on the neurobiological basis of dyslexia in adulthood are scarce compared to paediatric studies. This review investigates the neurobiological basis of dyslexia in adulthood. Using PsycINFO, a database of psychology abstracts, we identified 11 studies on genetics, 9 neurostructural studies, 13 neurofunctional studies and 24 neurophysiological studies. Results from the review show that dyslexia is highly heritable and displays polygenic transmission. Likewise, adult neuroimaging studies found structural, functional, and physiological changes in the parieto-occipital and occipito-temporal regions, and in the inferior frontal gyrus, in adults with dyslexia. According to different studies, aetiology in cases of adult dyslexia is complex. We stress the need for neurobiological studies of dyslexia in languages with transparent spelling systems. Copyright © 2014 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Cognitive-linguistic performances of multilingual university students suspected of dyslexia.

PubMed

Lindgrén, Signe-Anita; Laine, Matti

2011-05-01

High-performing adults with compensated dyslexia pose particular challenges to dyslexia diagnostics. We compared the performance of 20 multilingual Finnish university students with suspected dyslexia with 20 age-matched and education-matched controls on an extensive test battery. The battery tapped various aspects of reading, writing, word retrieval, phonological processing and other cognitive functions relevant for dyslexia. Reading and writing were examined in the two domestic languages, Swedish and Finnish. The most prominent group differences in reading and writing emerged on accuracy measures in both languages (reading text aloud, proofreading, writing to dictation, free writing). The dyslexia group also performed less well on speeded segmentation of written input, complex speeded naming and complex phoneme manipulation. The pattern of results fits the phonological deficit hypothesis of dyslexia and indicates the presence of pervasive underlying defects in compensated dyslexia. Copyright © 2010 John Wiley & Sons, Ltd.

Dysfunction of Rapid Neural Adaptation in Dyslexia.

PubMed

Perrachione, Tyler K; Del Tufo, Stephanie N; Winter, Rebecca; Murtagh, Jack; Cyr, Abigail; Chang, Patricia; Halverson, Kelly; Ghosh, Satrajit S; Christodoulou, Joanna A; Gabrieli, John D E

2016-12-21

Identification of specific neurophysiological dysfunctions resulting in selective reading difficulty (dyslexia) has remained elusive. In addition to impaired reading development, individuals with dyslexia frequently exhibit behavioral deficits in perceptual adaptation. Here, we assessed neurophysiological adaptation to stimulus repetition in adults and children with dyslexia for a wide variety of stimuli, spoken words, written words, visual objects, and faces. For every stimulus type, individuals with dyslexia exhibited significantly diminished neural adaptation compared to controls in stimulus-specific cortical areas. Better reading skills in adults and children with dyslexia were associated with greater repetition-induced neural adaptation. These results highlight a dysfunction of rapid neural adaptation as a core neurophysiological difference in dyslexia that may underlie impaired reading development. Reduced neurophysiological adaptation may relate to prior reports of reduced behavioral adaptation in dyslexia and may reveal a difference in brain functions that ultimately results in a specific reading impairment. Copyright © 2016 Elsevier Inc. All rights reserved.

Dyslexia in higher education: implications for maths anxiety, statistics anxiety and psychological well-being.

PubMed

Jordan, Julie-Ann; McGladdery, Gary; Dyer, Kevin

2014-08-01

This study examined levels of mathematics and statistics anxiety, as well as general mental health amongst undergraduate students with dyslexia (n = 28) and those without dyslexia (n = 71). Students with dyslexia had higher levels of mathematics anxiety relative to those without dyslexia, while statistics anxiety and general mental health were comparable for both reading ability groups. In terms of coping strategies, undergraduates with dyslexia tended to use planning-based strategies and seek instrumental support more frequently than those without dyslexia. Higher mathematics anxiety was associated with having a dyslexia diagnosis, as well as greater levels of worrying, denial, seeking instrumental support and less use of the positive reinterpretation coping strategy. By contrast, statistics anxiety was not predicted by dyslexia diagnosis, but was instead predicted by overall worrying and the use of denial and emotion focused coping strategies. The results suggest that disability practitioners should be aware that university students with dyslexia are at risk of high mathematics anxiety. Additionally, effective anxiety reduction strategies such as positive reframing and thought challenging would form a useful addition to the support package delivered to many students with dyslexia. Copyright © 2014 John Wiley & Sons, Ltd.

Analyzing Global Components in Developmental Dyscalculia and Dyslexia

PubMed Central

Filippo, Gloria Di; Zoccolotti, Pierluigi

2018-01-01

The study examined whether developmental deficits in reading and numerical skills could be expressed in terms of global factors by reference to the rate and amount (RAM) and difference engine (DEM) models. From a sample of 325 fifth grade children, we identified 5 children with dyslexia, 16 with dyscalculia, 7 with a “mixed pattern,” and 49 control children. Children were asked to read aloud words presented individually that varied for frequency and length and to respond (either vocally or manually) to a series of simple number tasks (addition, subtraction, number reading, and number comparisons). Reaction times were measured. Results indicated that the deficit of children with dyscalculia and children with a mixed pattern on numerical tasks could be explained by a single global factor, similarly to the reading deficit shown by children with dyslexia. As predicted by the DEM, increases in task difficulty were accompanied by a corresponding increase in inter-individual variability for both the reading and numerical tasks. These relationships were constant across the four groups of children but differed in terms of slope and intercept on the x-axis, indicating that two different general rules underlie performance in reading and numerical skills. The study shows for the first time that, as previously shown for reading, also numerical performance can be explained with reference to a global factor. The advantage of this approach is that it takes into account the over-additivity effect, i.e., the presence of larger group differences in the case of more difficult conditions over and above the characteristics of the experimental conditions. It is concluded that reference to models such as the RAM and DEM can be useful in delineating the characteristics of the dyscalculic deficit as well as in the description of co-morbid disturbances, as in the case of dyslexia and dyscalculia. PMID:29515490

Is season of birth related to developmental dyslexia?

PubMed

Donfrancesco, Renato; Iozzino, Roberto; Caruso, Barbara; Ferrante, Laura; Mugnaini, Daniele; Talamo, Alessandra; Miano, Silvia; Dimitri, Andrea; Masi, Gabriele

2010-12-01

Different moderators/mediators of risk are involved in developmental dyslexia (DD), but data are inconsistent. We explored the prevalence of season of birth and its association with gender and age of school entry in an Italian sample of dyslexic children compared to an Italian normal control group. The clinical sample included 498 children (345 boys, mean age 10.3 ± 2.1 years) with DD, the control sample 1,276 children (658 boys, mean age 10.8 ± 2.2 years) from four elementary schools from the same urban area, and with the same socio-economic status level. A prevalence of birth in autumn was found among children with DD compared to controls (34% versus 24%, p < 0.0001). Children with DD were more frequently males (p < 0.0001) and had a lower mean age of school entry (p < 0.0001). Regarding the distribution of ages, 11.4% of children with DD, but none of the subjects in the control group, started school before 5.7 years. Therefore, greater risk of DD was related to age of school entry (OR = 2.72), gender (OR = 2.16), and season of birth (OR = 1.21). Significant interactions between boys with DD born in autumn, and correct school of entry (OR = 2.56) were joint predictors of higher risk of DD. The association between birth in autumn and DD may be explained by the earlier age of school entry, which may be a critical element in the youngest children with DD or at risk to DD. Whether Italian school policy is oriented to anticipate the school entry, a closer detection of early learning disorders and associated risk factors (familial load, specific language disorders, and attention deficit hyperactivity disorder) should be warranted.

Development of Tract-Specific White Matter Pathways During Early Reading Development in At-Risk Children and Typical Controls.

PubMed

Wang, Yingying; Mauer, Meaghan V; Raney, Talia; Peysakhovich, Barbara; Becker, Bryce L C; Sliva, Danielle D; Gaab, Nadine

2017-04-01

Developmental dyslexia is a neurodevelopmental disorder with a strong genetic basis. Previous studies observed white matter alterations in the left posterior brain regions in adults and school-age children with dyslexia. However, no study yet has examined the development of tract-specific white matter pathways from the pre-reading to the fluent reading stage in children at familial risk for dyslexia (FHD+) versus controls (FHD-). This study examined white matter integrity at pre-reading, beginning, and fluent reading stages cross-sectionally ( n = 78) and longitudinally (n = 45) using an automated fiber-tract quantification method. Our findings depict white matter alterations and atypical lateralization of the arcuate fasciculus at the pre-reading stage in FHD+ versus FHD- children. Moreover, we demonstrate faster white matter development in subsequent good versus poor readers and a positive association between white matter maturation and reading development using a longitudinal design. Additionally, the combination of white matter maturation, familial risk, and psychometric measures best predicted later reading abilities. Furthermore, within FHD+ children, subsequent good readers exhibited faster white matter development in the right superior longitudinal fasciculus compared with subsequent poor readers, suggesting a compensatory mechanism. Overall, our findings highlight the importance of white matter pathway maturation in the development of typical and atypical reading skills. Published by Oxford University Press 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Speech Research.

DTIC Science & Technology

1979-12-31

629. Mattis, S., French, J. H., & Rapin, I. Dyslexia in children and young adults: Three independent neuropsychological syndromes. Developmental...Knights & D. K. Bakker (Eds.), Neuropsychology ofA learning disorders: Theoretical approaches. Baltimore: University Park Press, 1976. Shankweiler...sounds connected with comfort, discomfort, and hunger . When babbling appears, it is mixed in with cooing but distinguished by its syllable-like

Individual Differences in Anatomy Predict Reading and Oral Language Impairments in Children

ERIC Educational Resources Information Center

Leonard, Christiana; Eckert, Mark; Given, Barbara; Virginia, Berninger; Eden, Guinevere

2006-01-01

Developmental dyslexia (DD) and specific language impairment (SLI) are disorders of language that differ in diagnostic criteria and outcome. DD is defined by isolated reading deficits. SLI is defined by poor receptive and expressive oral language skills. Reading deficits, although prevalent, are not necessary for the diagnosis of SLI. An enduring…

Timing Precision and Rhythm in Developmental Dyslexia.

ERIC Educational Resources Information Center

Wolff, Peter H.

2002-01-01

Indicates that during a motor sequencing task, dyslexic students anticipated the signal of an isochronic pacing metronome by intervals that were two or three times as long as those of age matched normal readers or normal adults. Discusses the implications of the findings for temporal information processing deficits on one hand, and impaired…

Topography of Syllable Change-Detection Electrophysiological Indices in Children and Adults with Reading Disabilities

ERIC Educational Resources Information Center

Hommet, Caroline; Vidal, Julie; Roux, Sylvie; Blanc, Romuald; Barthez, Marie Anne; De Becque, Brigitte; Barthelemy, Catherine; Bruneau, Nicole; Gomot, Marie

2009-01-01

Introduction: Developmental dyslexia (DD) is a frequent language-based learning disorder. The predominant etiological view postulates that reading problems originate from a phonological impairment. Method: We studied mismatch negativity (MMN) and Late Discriminative Negativity (LDN) to syllables change in both children (n = 12; 8-12 years) and…

Language Profiles and Literacy Outcomes of Children with Resolving, Emerging, or Persisting Language Impairments

ERIC Educational Resources Information Center

Snowling, Margaret J.; Duff, Fiona J.; Nash, Hannah M.; Hulme, Charles

2016-01-01

Background: Children with language impairment (LI) show heterogeneity in development. We tracked children from pre-school to middle childhood to characterize three developmental trajectories: resolving, persisting and emerging LI. Methods: We analyzed data from children identified as having preschool LI, or being at family risk of dyslexia,…

Facial Speech Gestures: The Relation between Visual Speech Processing, Phonological Awareness, and Developmental Dyslexia in 10-Year-Olds

ERIC Educational Resources Information Center

Schaadt, Gesa; Männel, Claudia; van der Meer, Elke; Pannekamp, Ann; Friederici, Angela D.

2016-01-01

Successful communication in everyday life crucially involves the processing of auditory and visual components of speech. Viewing our interlocutor and processing visual components of speech facilitates speech processing by triggering auditory processing. Auditory phoneme processing, analyzed by event-related brain potentials (ERP), has been shown…

The Development of Executive Function and Language Skills in the Early School Years

ERIC Educational Resources Information Center

Gooch, Debbie; Thompson, Paul; Nash, Hannah M.; Snowling, Margaret J.; Hulme, Charles

2016-01-01

Background: The developmental relationships between executive functions (EF) and early language skills are unclear. This study explores the longitudinal relationships between children's early EF and language skills in a sample of children with a wide range of language abilities including children at risk of dyslexia. In addition, we investigated…

Developmental Dyslexia and Explicit Long-Term Memory

ERIC Educational Resources Information Center

Menghini, Deny; Carlesimo, Giovanni Augusto; Marotta, Luigi; Finzi, Alessandra; Vicari, Stefano

2010-01-01

The reduced verbal long-term memory capacities often reported in dyslexics are generally interpreted as a consequence of their deficit in phonological coding. The present study was aimed at evaluating whether the learning deficit exhibited by dyslexics was restricted only to the verbal component of the long-term memory abilities or also involved…

Practitioner Review: Reading Disorders--What Are the Effective Interventions and How Should They Be Implemented and Evaluated?

ERIC Educational Resources Information Center

Duff, Fiona J.; Clarke, Paula J.

2011-01-01

Background: Two developmental reading disorders, dyslexia and reading comprehension impairment, are identified by different behavioural characteristics and traced back to different underlying cognitive impairments. Thus, reading interventions designed to address each of these reading disorders differ in content. Method: This review summarises the…

Developmental Reading Disorders in Japan--Prevalence, Profiles, and Possible Mechanisms

ERIC Educational Resources Information Center

Welty, Yumiko Tanaka; Menn, Lise; Oishi, Noriko

2014-01-01

Japan has been considered dyslexia-free because of the nature of the orthography, which consists of the visually simple kana syllabary and some thousands of visually complex, logographic kanji characters. It is true that few children struggle with learning kana, which provide consistent mappings between symbols and their pronunciation. Indeed,…

Cortical Reorganization in Dyslexic Children after Phonological Training: Evidence from Early Evoked Potentials

ERIC Educational Resources Information Center

Spironelli, Chiara; Penolazzi, Barbara; Vio, Claudio; Angrilli, Alessandro

2010-01-01

Brain plasticity was investigated in 14 Italian children affected by developmental dyslexia after 6 months of phonological training. The means used to measure language reorganization was the recognition potential, an early wave, also called N150, elicited by automatic word recognition. This component peaks over the left temporo-occipital cortex…

Increased Intraindividual Variability Is a Marker of ADHD but Also of Dyslexia: A Study on Handwriting

ERIC Educational Resources Information Center

Borella, Erika; Chicherio, Christian; Re, Anna Maria; Sensini, Vanessa; Cornoldi, Cesare

2011-01-01

It has been suggested that intraindividual variability (IIV) in neuropsychological tasks may be a specific characteristic of Attention-Deficit Hyperactivity Disorder (ADHD), but previous research has not thoroughly examined whether IIV also concerns academic performance or other types of developmental disabilities. The present study investigates…

The Utility of Neuroimaging Studies for Informing Educational Practice and Policy in Reading Disorders

ERIC Educational Resources Information Center

Black, Jessica M.; Myers, Chelsea A.; Hoeft, Fumiko

2015-01-01

Educational neuroscience is an emerging scientific field that brings together researchers from neuroscience, psychology, and education to explore the neurocognitive processes underlying educational practice and theory. In this brief article, we take reading disorder (RD, also known as developmental dyslexia) as an example, and explore trends in…

Developmental Learning Disorders: From Generic Interventions to Individualized Remediation

PubMed Central

Moreau, David; Waldie, Karen E.

2016-01-01

Developmental learning disorders affect many children, impairing their experience in the classroom and hindering many aspects of their life. Once a bleak sentence associated with life-long difficulties, several learning disorders can now be successfully alleviated, directly benefiting from promising interventions. In this review, we focus on two of the most prevalent learning disorders, dyslexia and attention-deficit/hyperactivity disorder (ADHD). Recent advances have refined our understanding of the specific neural networks that are altered in these disorders, yet questions remain regarding causal links between neural changes and behavioral improvements. After briefly reviewing the theoretical foundations of dyslexia and ADHD, we explore their distinct and shared characteristics, and discuss the comorbidity of the two disorders. We then examine current interventions, and consider the benefits of approaches that integrate remediation within other activities to encourage sustained motivation and improvements. Finally, we conclude with a reflection on the potential for remediation programs to be personalized by taking into account the specificities and demands of each individual. The effective remediation of learning disorders is critical to modern societies, especially considering the far-reaching ramifications of successful early interventions. PMID:26793160

The role of visual spatial attention in adult developmental dyslexia.

PubMed

Collis, Nathan L; Kohnen, Saskia; Kinoshita, Sachiko

2013-01-01

The present study investigated the nature of visual spatial attention deficits in adults with developmental dyslexia, using a partial report task with five-letter, digit, and symbol strings. Participants responded by a manual key press to one of nine alternatives, which included other characters in the string, allowing an assessment of position errors as well as intrusion errors. The results showed that the dyslexic adults performed significantly worse than age-matched controls with letter and digit strings but not with symbol strings. Both groups produced W-shaped serial position functions with letter and digit strings. The dyslexics' deficits with letter string stimuli were limited to position errors, specifically at the string-interior positions 2 and 4. These errors correlated with letter transposition reading errors (e.g., reading slat as "salt"), but not with the Rapid Automatized Naming (RAN) task. Overall, these results suggest that the dyslexic adults have a visual spatial attention deficit; however, the deficit does not reflect a reduced span in visual-spatial attention, but a deficit in processing a string of letters in parallel, probably due to difficulty in the coding of letter position.

Classifying acoustic signals into phoneme categories: average and dyslexic readers make use of complex dynamical patterns and multifractal scaling properties of the speech signal

PubMed Central

2015-01-01

Several competing aetiologies of developmental dyslexia suggest that the problems with acquiring literacy skills are causally entailed by low-level auditory and/or speech perception processes. The purpose of this study is to evaluate the diverging claims about the specific deficient peceptual processes under conditions of strong inference. Theoretically relevant acoustic features were extracted from a set of artificial speech stimuli that lie on a /bAk/-/dAk/ continuum. The features were tested on their ability to enable a simple classifier (Quadratic Discriminant Analysis) to reproduce the observed classification performance of average and dyslexic readers in a speech perception experiment. The ‘classical’ features examined were based on component process accounts of developmental dyslexia such as the supposed deficit in Envelope Rise Time detection and the deficit in the detection of rapid changes in the distribution of energy in the frequency spectrum (formant transitions). Studies examining these temporal processing deficit hypotheses do not employ measures that quantify the temporal dynamics of stimuli. It is shown that measures based on quantification of the dynamics of complex, interaction-dominant systems (Recurrence Quantification Analysis and the multifractal spectrum) enable QDA to classify the stimuli almost identically as observed in dyslexic and average reading participants. It seems unlikely that participants used any of the features that are traditionally associated with accounts of (impaired) speech perception. The nature of the variables quantifying the temporal dynamics of the speech stimuli imply that the classification of speech stimuli cannot be regarded as a linear aggregate of component processes that each parse the acoustic signal independent of one another, as is assumed by the ‘classical’ aetiologies of developmental dyslexia. It is suggested that the results imply that the differences in speech perception performance between average and dyslexic readers represent a scaled continuum rather than being caused by a specific deficient component. PMID:25834769

Cognitive Profiles of Chinese Adolescents with Dyslexia

ERIC Educational Resources Information Center

Chung, Kevin K. H.; Ho, Connie Suk-Han; Chan, David W.; Tsang, Suk-Man; Lee, Suk-Han

2010-01-01

The present study sought to identify cognitive abilities that might distinguish Hong Kong Chinese adolescents with and without dyslexia and examined the cognitive profile of dyslexic adolescents in order to better understand this important problem. The performance of 27 Chinese adolescents with childhood diagnoses of dyslexia was compared with 27…

Pinpointing the deficit in executive functions in adolescents with dyslexia performing the Wisconsin card sorting test: an ERP study.

PubMed

Horowitz-Kraus, Tzipi

2014-01-01

Adolescents with dyslexia exhibit well-established impairments in executive abilities. The Wisconsin card sorting test (WCST) is an executive test that yields surprisingly inconsistent results with this population. The current study aimed to shed light on the contradictory findings in the literature regarding the performance levels by individuals with dyslexia in WCST. We used a computerized-WCST (named the 'Madrid-Card Sorting Test') assessing executive functions using the Event-Related Potentials (ERPs) methodology. Adolescents with dyslexia exhibited a higher error rate and slower reaction times. This was most evident in the later trials of the series. However, differences in ERPs between the two groups were found only in the "target-locked" conditions, where individuals with dyslexia displayed decreased ERP components (N100, P300) compared to skilled readers. The changes between the groups in the "shift" compared to the "stay" conditions suggest the central role of working memory both in basic (e.g., shifting) and higher order (e.g., reading) processes in individuals with dyslexia. These findings suggest the central role of working memory both in basic (e.g., shifting) and higher order (e.g., reading) processes in individuals with dyslexia. The intact shifting mechanism and the working memory deficit may guide the building of more efficient intervention programs for individuals with dyslexia in the future.

Psychological Well-being Trajectories of Individuals with Dyslexia Aged 3-11 Years.

PubMed

Jordan, Julie-Ann; Dyer, Kevin

2017-05-01

Dyslexia has been associated with a range of psychological well-being issues in childhood. However, it is unclear if these difficulties stem from coping with academic struggles at school, or from other pre-existing diagnoses that sometimes co-occur with dyslexia. Using UK Millennium Cohort Study data (n = 7224) from 2003 to 2011, the present study compared psychological well-being development from ages 3-11 years for children with (1) dyslexia only; (2) special educational needs excluding dyslexia; (3) comorbid dyslexia and other special educational needs; and (4) no special educational needs. Growth curve modelling results controlling for race, gender, age and family income suggested that with the exception of conduct difficulties, psychological well-being issues related to dyslexia do not occur preschool; rather, they commence upon starting school. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

A survey-based exploration of the impact of dyslexia on career progression of UK registered nurses.

PubMed

Morris, David; Turnbull, Patricia

2007-01-01

To explore the effects of dyslexia on the practice and career progression of UK registered nurses (RN). Literature suggests dyslexia can have a negative impact in the workplace and may pose particular difficulties for nurses, where accuracy in information processing activities is essential for practice. A questionnaire was used to survey RNs with dyslexia (n = 116) and results analysed using content analysis. Dyslexia provided a challenge to the everyday work of RNs, which was often met successfully using a range of individualized strategies. Career progression was achievable but compared with peers, was perceived to take longer. Disclosure of dyslexia to work-colleagues was selective and dependent on the perceived benefits. Informal support mechanisms were commonly utilized with formal management support less well defined. Dyslexia appears to have a negative impact on working practices and career progression, but remains a poorly understood and often hidden disability.

Quantitative assessment of drawing tests in children with dyslexia and dysgraphia.

PubMed

Galli, Manuela; Cimolin, Veronica; Stella, Giacomo; De Pandis, Maria Francesca; Ancillao, Andrea; Condoluci, Claudia

2018-05-07

Drawing tests in children diagnosed with dyslexia and dysgraphia were quantitatively compared. Fourteen children with dysgraphia, 19 with dyslexia and 13 normally developing were asked to copy 3 figures: a circle, a square and a cross. An optoelectronic system allowed the acquisition of the drawing track in three-dimensions. The participants' head position and upper limb movements were measured as well. A set of parameters including movement duration, velocity, length of the trace, Range of Motion of the upper limb, was computed and compared among the 3 groups. Children with dyslexia traced the circle faster than the other groups. In the cross test, dyslexic participants showed a reduced execution time and increased velocity while drawing the horizontal line. Children with dyslexia were also faster in drawing certain sides of square with respect to the other groups. Copyright © 2018 Elsevier B.V. All rights reserved.

A Comparative Case Study of Learning Strategies and Recommendations of Five Professional Musicians with Dyslexia

ERIC Educational Resources Information Center

Nelson, Kent Peter; Hourigan, Ryan M.

2016-01-01

Many of the characteristics of dyslexia--such as difficulties with decoding written symbols, phonemic awareness, physical coordination, and readable handwriting--may adversely affect music learning. Despite challenges, individuals with dyslexia can succeed in music. The purpose of this study was to examine the perceptions of five professional…

Dyslexia Profiles across Orthographies Differing in Transparency: An Evaluation of Theoretical Predictions Contrasting English and Greek

ERIC Educational Resources Information Center

Diamanti, Vassiliki; Goulandris, Nata; Campbell, Ruth; Protopapas, Athanassios

2018-01-01

We examined the manifestation of dyslexia in a cross-linguistic study contrasting English and Greek children with dyslexia compared to chronological age and reading-level control groups on reading accuracy and fluency, phonological awareness, short-term memory, rapid naming, orthographic choice, and spelling. Materials were carefully matched…

Impaired Visual Attention in Children with Dyslexia.

ERIC Educational Resources Information Center

Heiervang, Einar; Hugdahl, Kenneth

2003-01-01

A cue-target visual attention task was administered to 25 children (ages 10-12) with dyslexia. Results showed a general pattern of slower responses in the children with dyslexia compared to controls. Subjects also had longer reaction times in the short and long cue-target interval conditions (covert and overt shift of attention). (Contains…

Successful Strategies of Individuals with Dyslexia in the Field of Music: A Comparative Case Study

ERIC Educational Resources Information Center

Nelson, Kent Peter

2014-01-01

Many of the symptoms of dyslexia--such as difficulties with decoding written symbols, phonemic awareness, physical coordination, and readable handwriting--may adversely affect music learning. Despite challenges, some individuals with dyslexia succeed in music. The purpose of this study was to examine the perceptions of five professional musicians…

Postural Control and Automaticity in Dyslexic Children: The Relationship between Visual Information and Body Sway

ERIC Educational Resources Information Center

Barela, Jose A.; Dias, Josenaldo L.; Godoi, Daniela; Viana, Andre R.; de Freitas, Paulo B.

2011-01-01

Difficulty with literacy acquisition is only one of the symptoms of developmental dyslexia. Dyslexic children also show poor motor coordination and postural control. Those problems could be associated with automaticity, i.e., difficulty in performing a task without dispending a fair amount of conscious efforts. If this is the case, dyslexic…

Influence of the Visual Attention Span on Child Reading Performance: A Cross-Sectional Study

ERIC Educational Resources Information Center

Bosse, Marie-Line; Valdois, Sylviane

2009-01-01

The visual attention (VA) span deficit hypothesis was found successfully to account for variability in developmental dyslexia (Bosse, Tainturier & Valdois, 2007). We conducted a cross-sectional study on 417 typically developing children from first, third and fifth grades examining the role of VA span on the development of reading skills. A battery…

Developmental Dyslexia: Exploring How Much Phonological and Visual Attention Span Disorders Are Linked to Simultaneous Auditory Processing Deficits

ERIC Educational Resources Information Center

Lallier, Marie; Donnadieu, Sophie; Valdois, Sylviane

2013-01-01

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…

Do Dyslexic Individuals Present a Reduced Visual Attention Span? Evidence from Visual Recognition Tasks of Non-Verbal Multi-Character Arrays

ERIC Educational Resources Information Center

Yeari, Menahem; Isser, Michal; Schiff, Rachel

2017-01-01

A controversy has recently developed regarding the hypothesis that developmental dyslexia may be caused, in some cases, by a reduced visual attention span (VAS). To examine this hypothesis, independent of phonological abilities, researchers tested the ability of dyslexic participants to recognize arrays of unfamiliar visual characters. Employing…

The Procedural Learning Deficit Hypothesis of Language Learning Disorders: We See Some Problems

ERIC Educational Resources Information Center

West, Gillian; Vadillo, Miguel A.; Shanks, David R.; Hulme, Charles

2018-01-01

Impaired procedural learning has been suggested as a possible cause of developmental dyslexia (DD) and specific language impairment (SLI). This study examined the relationship between measures of verbal and non-verbal implicit and explicit learning and measures of language, literacy and arithmetic attainment in a large sample of 7 to 8-year-old…

Old and New Ways to Study Characteristics of Reading Disability: The Case of the Nonword-Reading Deficit

ERIC Educational Resources Information Center

Van den Broeck, Wim; Geudens, Astrid

2012-01-01

Theoretical and computational models of reading have traditionally been informed by specific characteristics of disabled readers. One of the most frequently studied marker effects of developmental dyslexia is the nonword-reading deficit. Disabled readers are generally believed to show a specific problem in reading nonwords. This study presents a…

Decreased Sensitivity to Phonemic Mismatch in Spoken Word Processing in Adult Developmental Dyslexia

ERIC Educational Resources Information Center

Janse, Esther; de Bree, Elise; Brouwer, Susanne

2010-01-01

Initial lexical activation in typical populations is a direct reflection of the goodness of fit between the presented stimulus and the intended target. In this study, lexical activation was investigated upon presentation of polysyllabic pseudowords (such as "procodile for crocodile") for the atypical population of dyslexic adults to see to what…

Brain Connectivity in Non-Reading Impaired Children and Children Diagnosed with Developmental Dyslexia

ERIC Educational Resources Information Center

Odegard, Timothy N.; Farris, Emily A.; Ring, Jeremiah; McColl, Roderick; Black, Jeffrey

2009-01-01

Diffusion Tensor Imaging (DTI) was used to investigate the relationship between white matter and reading abilities in reading impaired and non-reading impaired children. Seventeen children (7 non-reading impaired, 10 reading impaired) participated in this study. DTI was performed with 2 mm isotropic resolution to cover the entire brain along 30…

Electrophysiological Indices of Spatial Attention during Global/Local Processing in Good and Poor Phonological Decoders

ERIC Educational Resources Information Center

Matthews, Allison Jane; Martin, Frances Heritage

2009-01-01

Previous research suggests a relationship between spatial attention and phonological decoding in developmental dyslexia. The aim of this study was to examine differences between good and poor phonological decoders in the allocation of spatial attention to global and local levels of hierarchical stimuli. A further aim was to investigate the…

Speech-in-noise perception deficit in adults with dyslexia: effects of background type and listening configuration.

PubMed

Dole, Marjorie; Hoen, Michel; Meunier, Fanny

2012-06-01

Developmental dyslexia is associated with impaired speech-in-noise perception. The goal of the present research was to further characterize this deficit in dyslexic adults. In order to specify the mechanisms and processing strategies used by adults with dyslexia during speech-in-noise perception, we explored the influence of background type, presenting single target-words against backgrounds made of cocktail party sounds, modulated speech-derived noise or stationary noise. We also evaluated the effect of three listening configurations differing in terms of the amount of spatial processing required. In a monaural condition, signal and noise were presented to the same ear while in a dichotic situation, target and concurrent sound were presented to two different ears, finally in a spatialised configuration, target and competing signals were presented as if they originated from slightly differing positions in the auditory scene. Our results confirm the presence of a speech-in-noise perception deficit in dyslexic adults, in particular when the competing signal is also speech, and when both signals are presented to the same ear, an observation potentially relating to phonological accounts of dyslexia. However, adult dyslexics demonstrated better levels of spatial release of masking than normal reading controls when the background was speech, suggesting that they are well able to rely on denoising strategies based on spatial auditory scene analysis strategies. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Cerebellum and Neurodevelopmental Disorders.

PubMed

Stoodley, Catherine J

2016-02-01

Cerebellar dysfunction is evident in several developmental disorders, including autism, attention deficit-hyperactivity disorder (ADHD), and developmental dyslexia, and damage to the cerebellum early in development can have long-term effects on movement, cognition, and affective regulation. Early cerebellar damage is often associated with poorer outcomes than cerebellar damage in adulthood, suggesting that the cerebellum is particularly important during development. Differences in cerebellar development and/or early cerebellar damage could impact a wide range of behaviors via the closed-loop circuits connecting the cerebellum with multiple cerebral cortical regions. Based on these anatomical circuits, behavioral outcomes should depend on which cerebro-cerebellar circuits are affected. Here, we briefly review cerebellar structural and functional differences in autism, ADHD, and developmental dyslexia, and discuss clinical outcomes following pediatric cerebellar damage. These data confirm the prediction that abnormalities in different cerebellar subregions produce behavioral symptoms related to the functional disruption of specific cerebro-cerebellar circuits. These circuits might also be crucial to structural brain development, as peri-natal cerebellar lesions have been associated with impaired growth of the contralateral cerebral cortex. The specific contribution of the cerebellum to typical development may therefore involve the optimization of both the structure and function of cerebro-cerebellar circuits underlying skill acquisition in multiple domains; when this process is disrupted, particularly in early development, there could be long-term alterations of these neural circuits, with significant impacts on behavior.

The cerebellum and neurodevelopmental disorders

PubMed Central

Stoodley, Catherine J.

2015-01-01

Cerebellar dysfunction is evident in several developmental disorders, including autism, attention deficit hyperactivity disorder (ADHD), and developmental dyslexia, and damage to the cerebellum early in development can have long-term effects on movement, cognition, and affective regulation. Early cerebellar damage is often associated with poorer outcomes than cerebellar damage in adulthood, suggesting that the cerebellum is particularly important during development. Differences in cerebellar development and/or early cerebellar damage could impact a wide range of behaviors via the closed-loop circuits connecting the cerebellum with multiple cerebral cortical regions. Based on these anatomical circuits, behavioral outcomes should depend on which cerebro-cerebellar circuits are affected. Here, we briefly review cerebellar structural and functional differences in autism, ADHD, and developmental dyslexia, and discuss clinical outcomes following pediatric cerebellar damage. These data confirm the prediction that abnormalities in different cerebellar subregions produce behavioral symptoms related to the functional disruption of specific cerebro-cerebellar circuits. These circuits might also be crucial to structural brain development, as peri-natal cerebellar lesions have been associated with impaired growth of the contralateral cerebral cortex. The specific contribution of the cerebellum to typical development may therefore involve the optimization of both the structure and function of cerebro-cerebellar circuits underlying skill acquisition in multiple domains; when this process is disrupted, particularly in early development, there could be long-term alterations of these neural circuits, with significant impacts on behavior. PMID:26298473

Knockdown of Dyslexia-Gene Dcdc2 Interferes with Speech Sound Discrimination in Continuous Streams.

PubMed

Centanni, Tracy Michelle; Booker, Anne B; Chen, Fuyi; Sloan, Andrew M; Carraway, Ryan S; Rennaker, Robert L; LoTurco, Joseph J; Kilgard, Michael P

2016-04-27

Dyslexia is the most common developmental language disorder and is marked by deficits in reading and phonological awareness. One theory of dyslexia suggests that the phonological awareness deficit is due to abnormal auditory processing of speech sounds. Variants in DCDC2 and several other neural migration genes are associated with dyslexia and may contribute to auditory processing deficits. In the current study, we tested the hypothesis that RNAi suppression of Dcdc2 in rats causes abnormal cortical responses to sound and impaired speech sound discrimination. In the current study, rats were subjected in utero to RNA interference targeting of the gene Dcdc2 or a scrambled sequence. Primary auditory cortex (A1) responses were acquired from 11 rats (5 with Dcdc2 RNAi; DC-) before any behavioral training. A separate group of 8 rats (3 DC-) were trained on a variety of speech sound discrimination tasks, and auditory cortex responses were acquired following training. Dcdc2 RNAi nearly eliminated the ability of rats to identify specific speech sounds from a continuous train of speech sounds but did not impair performance during discrimination of isolated speech sounds. The neural responses to speech sounds in A1 were not degraded as a function of presentation rate before training. These results suggest that A1 is not directly involved in the impaired speech discrimination caused by Dcdc2 RNAi. This result contrasts earlier results using Kiaa0319 RNAi and suggests that different dyslexia genes may cause different deficits in the speech processing circuitry, which may explain differential responses to therapy. Although dyslexia is diagnosed through reading difficulty, there is a great deal of variation in the phenotypes of these individuals. The underlying neural and genetic mechanisms causing these differences are still widely debated. In the current study, we demonstrate that suppression of a candidate-dyslexia gene causes deficits on tasks of rapid stimulus processing. These animals also exhibited abnormal neural plasticity after training, which may be a mechanism for why some children with dyslexia do not respond to intervention. These results are in stark contrast to our previous work with a different candidate gene, which caused a different set of deficits. Our results shed some light on possible neural and genetic mechanisms causing heterogeneity in the dyslexic population. Copyright © 2016 the authors 0270-6474/16/364895-12$15.00/0.

Knockdown of Dyslexia-Gene Dcdc2 Interferes with Speech Sound Discrimination in Continuous Streams

PubMed Central

Booker, Anne B.; Chen, Fuyi; Sloan, Andrew M.; Carraway, Ryan S.; Rennaker, Robert L.; LoTurco, Joseph J.; Kilgard, Michael P.

2016-01-01

Dyslexia is the most common developmental language disorder and is marked by deficits in reading and phonological awareness. One theory of dyslexia suggests that the phonological awareness deficit is due to abnormal auditory processing of speech sounds. Variants in DCDC2 and several other neural migration genes are associated with dyslexia and may contribute to auditory processing deficits. In the current study, we tested the hypothesis that RNAi suppression of Dcdc2 in rats causes abnormal cortical responses to sound and impaired speech sound discrimination. In the current study, rats were subjected in utero to RNA interference targeting of the gene Dcdc2 or a scrambled sequence. Primary auditory cortex (A1) responses were acquired from 11 rats (5 with Dcdc2 RNAi; DC−) before any behavioral training. A separate group of 8 rats (3 DC−) were trained on a variety of speech sound discrimination tasks, and auditory cortex responses were acquired following training. Dcdc2 RNAi nearly eliminated the ability of rats to identify specific speech sounds from a continuous train of speech sounds but did not impair performance during discrimination of isolated speech sounds. The neural responses to speech sounds in A1 were not degraded as a function of presentation rate before training. These results suggest that A1 is not directly involved in the impaired speech discrimination caused by Dcdc2 RNAi. This result contrasts earlier results using Kiaa0319 RNAi and suggests that different dyslexia genes may cause different deficits in the speech processing circuitry, which may explain differential responses to therapy. SIGNIFICANCE STATEMENT Although dyslexia is diagnosed through reading difficulty, there is a great deal of variation in the phenotypes of these individuals. The underlying neural and genetic mechanisms causing these differences are still widely debated. In the current study, we demonstrate that suppression of a candidate-dyslexia gene causes deficits on tasks of rapid stimulus processing. These animals also exhibited abnormal neural plasticity after training, which may be a mechanism for why some children with dyslexia do not respond to intervention. These results are in stark contrast to our previous work with a different candidate gene, which caused a different set of deficits. Our results shed some light on possible neural and genetic mechanisms causing heterogeneity in the dyslexic population. PMID:27122044

Longitudinal stability of pre-reading skill profiles of kindergarten children: implications for early screening and theories of reading.

PubMed

Ozernov-Palchik, Ola; Norton, Elizabeth S; Sideridis, Georgios; Beach, Sara D; Wolf, Maryanne; Gabrieli, John D E; Gaab, Nadine

2017-09-01

Research suggests that early identification of developmental dyslexia is important for mitigating the negative effects of dyslexia, including reduced educational attainment and increased socioemotional difficulties. The strongest pre-literacy predictors of dyslexia are rapid automatized naming (RAN), phonological awareness (PA), letter knowledge, and verbal short-term memory. The relationship among these constructs has been debated, and several theories have emerged to explain the unique role of each in reading ability/disability. Furthermore, the stability of identification of risk based on these measures varies widely across studies, due in part to the different cut-offs employed to designate risk. We applied a latent profile analysis technique with a diverse sample of 1215 kindergarten and pre-kindergarten students from 20 schools, to investigate whether PA, RAN, letter knowledge, and verbal short-term memory measures differentiated between homogenous profiles of performance on these measures. Six profiles of performance emerged from the data: average performers, below average performers, high performers, PA risk, RAN risk, and double-deficit risk (both PA and RAN). A latent class regression model was employed to investigate the longitudinal stability of these groups in a representative subset of children (n = 95) nearly two years later, at the end of 1st grade. Profile membership in the spring semester of pre-kindergarten or fall semester of kindergarten was significantly predictive of later reading performance, with the specific patterns of performance on the different constructs remaining stable across the years. There was a higher frequency of PA and RAN deficits in children from lower socioeconomic status (SES) backgrounds. There was no evidence for the IQ-achievement discrepancy criterion traditionally used to diagnose dyslexia. Our results support the feasibility of early identification of dyslexia risk and point to the heterogeneity of risk profiles. These findings carry important implications for improving outcomes for children with dyslexia, based on more targeted interventions. © 2016 John Wiley & Sons Ltd.

Exploring the learning experiences of nursing students with dyslexia.

PubMed

Child, J; Langford, E

To examine the learning experiences of nursing students with dyslexia during clinical placements to establish ways of improving support in practice, A phenomenological lifeworld approach was adopted using semi-structured interviews. Students reflected on their experiences during clinical placements, allowing the researcher to gain an in-depth knowledge of the students' lived experience of dyslexia. Twelve student nurses, six with dyslexia and six without, were interviewed using a standard set of questions, and the data were collated and analysed. Using a comparison group of students without dyslexia was felt to be important to contextualise and compare the students' experiences. Three main themes emerged: the value of work-based learning days, the importance of the clinical placement mentor role and the need for advocacy. Both groups of nursing students contributed to recommendations relating to support in practice and those with dyslexia also shared their individual coping strategies, Nursing students with dyslexia may benefit from sharing placement experiences with colleagues outside the clinical environment. They may also benefit from receiving support from their placement mentor and a representative from the university who knows about dyslexia.

Socioemotional Features and Resilience in Italian University Students with and without Dyslexia

PubMed Central

Ghisi, Marta; Bottesi, Gioia; Re, Anna M.; Cerea, Silvia; Mammarella, Irene C.

2016-01-01

Dyslexia is a permanent condition characterized by reading difficulties that include inaccurate or slow and effortful word reading, poor decoding, and poor spelling abilities. People with dyslexia may have psychological and psychopathological issues such as low self-esteem, poor resilience, and symptoms of depression and anxiety. They may also develop social problems and emotional issues, as well as low academic and social self-efficacy. The present study aimed to assess the psychological features of a sample of 28 Italian university students with dyslexia, comparing them with a control group of typically developing students matched for gender, education, and academic discipline, to enhance our knowledge of dyslexia outcomes in an Italian setting. The results show that university students with dyslexia experience higher levels of somatic complaints, social and attentional problems, lower self-esteem, and higher depression scores than controls, while no difference emerged between the two groups’ resilience scores. In conclusion, the present findings suggest that university students with dyslexia report more psychological issues than students without dyslexia and could benefit from intervention to improve their psychological and physical well-being. PMID:27065220

Mathematical abilities in dyslexic children: a diffusion tensor imaging study.

PubMed

Koerte, Inga K; Willems, Anna; Muehlmann, Marc; Moll, Kristina; Cornell, Sonia; Pixner, Silvia; Steffinger, Denise; Keeser, Daniel; Heinen, Florian; Kubicki, Marek; Shenton, Martha E; Ertl-Wagner, Birgit; Schulte-Körne, Gerd

2016-09-01

Dyslexia is characterized by a deficit in language processing which mainly affects word decoding and spelling skills. In addition, children with dyslexia also show problems in mathematics. However, for the latter, the underlying structural correlates have not been investigated. Sixteen children with dyslexia (mean age 9.8 years [0.39]) and 24 typically developing children (mean age 9.9 years [0.29]) group matched for age, gender, IQ, and handedness underwent 3 T MR diffusion tensor imaging as well as cognitive testing. Tract-Based Spatial Statistics were performed to correlate behavioral data with diffusion data. Children with dyslexia performed worse than controls in standardized verbal number tasks, such as arithmetic efficiency tests (addition, subtraction, multiplication, division). In contrast, the two groups did not differ in the nonverbal number line task. Arithmetic efficiency, representing the total score of the four arithmetic tasks, multiplication, and division, correlated with diffusion measures in widespread areas of the white matter, including bilateral superior and inferior longitudinal fasciculi in children with dyslexia compared to controls. Children with dyslexia demonstrated lower performance in verbal number tasks but performed similarly to controls in a nonverbal number task. Further, an association between verbal arithmetic efficiency and diffusion measures was demonstrated in widespread areas of the white matter suggesting compensatory mechanisms in children with dyslexia compared to controls. Taken together, poor fact retrieval in children with dyslexia is likely a consequence of deficits in the language system, which not only affects literacy skills but also impacts on arithmetic skills.

Assessing Dyslexia in Higher Education: The "York Adult Assessment Battery-Revised"

ERIC Educational Resources Information Center

Warmington, Meesha; Stothard, Susan E.; Snowling, Margaret J.

2013-01-01

Although there are a number of standardised measures to assess dyslexia in children, there are comparatively fewer instruments suitable for the assessment of dyslexia in adults. Given the growing number of students entering UK higher education institutions, there is a need to develop reliable tools for assessing the additional needs of those with…

Sight Word and Phonics Training in Children with Dyslexia

ERIC Educational Resources Information Center

McArthur, Genevieve; Castles, Anne; Kohnen, Saskia; Larsen, Linda; Jones, Kristy; Anandakumar, Thushara; Banales, Erin

2015-01-01

The aims of this study were to (a) compare sight word training and phonics training in children with dyslexia, and (b) determine if different orders of sight word and phonics training have different effects on the reading skills of children with dyslexia. One group of children (n = 36) did 8 weeks of phonics training (reading via grapheme-phoneme…

What's in a Name? Students with Dyslexia: Their Use of Metaphor in Making Sense of Their Disability

ERIC Educational Resources Information Center

Burden, Robert; Burdett, Julia

2007-01-01

Research and practice involving children and adults with dyslexia has tended to focus on identifying difficulties in developing literacy skills and associated cognitive variables. Comparatively few investigations have focused on affective factors or on finding ways of enabling those with dyslexia to express their own attitudes, thoughts and…

The Role of Sensorimotor Impairments in Dyslexia: A Multiple Case Study of Dyslexic Children

ERIC Educational Resources Information Center

White, Sarah; Milne, Elizabeth; Rosen, Stuart; Hansen, Peter; Swettenham, John; Frith, Uta; Ramus, Franck

2006-01-01

This study attempts to investigate the role of sensorimotor impairments in the reading disability that characterizes dyslexia. Twenty-three children with dyslexia were compared to 22 control children, matched for age and non-verbal intelligence, on tasks assessing literacy as well as phonological, visual, auditory and motor abilities. The dyslexic…

Reading under the Skin: Physiological Activation during Reading in Children with Dyslexia and Typical Readers

ERIC Educational Resources Information Center

Tobia, Valentina; Bonifacci, Paola; Ottaviani, Cristina; Borsato, Thomas; Marzocchi, Gian Marco

2016-01-01

The aim of this study was to investigate physiological activation during reading and control tasks in children with dyslexia and typical readers. Skin conductance response (SCR) recorded during four tasks involving reading aloud, reading silently, and describing illustrated stories aloud and silently was compared for children with dyslexia (n =…

Developmental dyslexia in adults: behavioural manifestations and cognitive correlates.

PubMed

Nergård-Nilssen, Trude; Hulme, Charles

2014-08-01

This paper explores the nature of residual literacy and cognitive deficits in self-reported dyslexic Norwegian adults. The performance of 26 self-reported dyslexic adults was compared with that of a comparison group of 47 adults with no history of reading or spelling difficulties. Participants completed standardized and experimental measures tapping literacy skills, working memory, phonological awareness and rapid naming. Spelling problems were the most prominent marker of dyslexia in adults, followed by text reading fluency and nonword decoding. Working memory and phoneme awareness explained unique variance in spelling, whereas rapid automatized naming explained unique variance in reading fluency and nonword reading. The moderate to strong correlations between self-reported history, self-rating of current literacy skills and outcomes on literacy tests indicate that adults estimated their literacy skills fairly well. Results suggest that spelling impairments, more strongly than reading impairments, make adults perceive themselves as being dyslexic. A combination of three literacy and three cognitive tests predicted group membership with 90.4% accuracy. It appears that weaknesses in phoneme awareness, rapid automatized naming and working memory are strong and persistent correlates of literacy problems even in adults learning a relatively transparent orthography. Copyright © 2014 John Wiley & Sons, Ltd.

Rapid Automatized Naming, Verbal Working Memory, and Rhythm Discrimination as Predictors of Reading in Italian Undergraduate Students with and without Dyslexia.

PubMed

Cancer, Alice; Antonietti, Alessandro

2018-05-13

Whereas the clinical manifestations and the neuropsychological predictors of Developmental Dyslexia (DD) are already well documented in Italian-speaking children, empirical evidence on DD in Italian adults is in contrast rather scarce. The aim of the present study was to investigate the role of a subset of neuropsychological skills, which have been identified by previous literature to be related to reading, in the decoding abilities of a group of Italian undergraduates with and without DD. For this purpose, 39 university students aged between 19 and 27 years, 19 of whom with a diagnosis of DD, underwent an assessment battery including standardized reading tests, rapid automatized naming (RAN), verbal working memory, and rhythmic pattern discrimination tests. Cross-group differences confirmed significantly lower performances of undergraduates with DD in all measures but rhythm discrimination, compared to typical readers, thus showing a non-compensated neuropsychological profile. Regression analyses showed that, while reading speed was strongly and uniquely predicted by RAN speed, reading accuracy was concurrently predicted by RAN and rhythmic abilities. Finally, RAN speed emerged as a strong predictor of reading performance and risk of receiving a diagnosis of DD.

Effect of chunk strength on the performance of children with developmental dyslexia on artificial grammar learning task may be related to complexity.

PubMed

Schiff, Rachel; Katan, Pesia; Sasson, Ayelet; Kahta, Shani

2017-07-01

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.

Increased prevalence of sex chromosome aneuploidies in specific language impairment and dyslexia.

PubMed

Simpson, Nuala H; Addis, Laura; Brandler, William M; Slonims, Vicky; Clark, Ann; Watson, Jocelynne; Scerri, Thomas S; Hennessy, Elizabeth R; Bolton, Patrick F; Conti-Ramsden, Gina; Fairfax, Benjamin P; Knight, Julian C; Stein, John; Talcott, Joel B; O'Hare, Anne; Baird, Gillian; Paracchini, Silvia; Fisher, Simon E; Newbury, Dianne F

2014-04-01

Sex chromosome aneuploidies increase the risk of spoken or written language disorders but individuals with specific language impairment (SLI) or dyslexia do not routinely undergo cytogenetic analysis. We assess the frequency of sex chromosome aneuploidies in individuals with language impairment or dyslexia. Genome-wide single nucleotide polymorphism genotyping was performed in three sample sets: a clinical cohort of individuals with speech and language deficits (87 probands: 61 males, 26 females; age range 4 to 23 years), a replication cohort of individuals with SLI, from both clinical and epidemiological samples (209 probands: 139 males, 70 females; age range 4 to 17 years), and a set of individuals with dyslexia (314 probands: 224 males, 90 females; age range 7 to 18 years). In the clinical language-impaired cohort, three abnormal karyotypic results were identified in probands (proband yield 3.4%). In the SLI replication cohort, six abnormalities were identified providing a consistent proband yield (2.9%). In the sample of individuals with dyslexia, two sex chromosome aneuploidies were found giving a lower proband yield of 0.6%. In total, two XYY, four XXY (Klinefelter syndrome), three XXX, one XO (Turner syndrome), and one unresolved karyotype were identified. The frequency of sex chromosome aneuploidies within each of the three cohorts was increased over the expected population frequency (approximately 0.25%) suggesting that genetic testing may prove worthwhile for individuals with language and literacy problems and normal non-verbal IQ. Early detection of these aneuploidies can provide information and direct the appropriate management for individuals. © 2013 The Authors. Developmental Medicine & Child Neurology published by John Wiley & Sons Ltd on behalf of Mac Keith Press.

Identifying dyslexia in adults: an iterative method using the predictive value of item scores and self-report questions.

PubMed

Tamboer, Peter; Vorst, Harrie C M; Oort, Frans J

2014-04-01

Methods for identifying dyslexia in adults vary widely between studies. Researchers have to decide how many tests to use, which tests are considered to be the most reliable, and how to determine cut-off scores. The aim of this study was to develop an objective and powerful method for diagnosing dyslexia. We took various methodological measures, most of which are new compared to previous methods. We used a large sample of Dutch first-year psychology students, we considered several options for exclusion and inclusion criteria, we collected as many cognitive tests as possible, we used six independent sources of biographical information for a criterion of dyslexia, we compared the predictive power of discriminant analyses and logistic regression analyses, we used both sum scores and item scores as predictor variables, we used self-report questions as predictor variables, and we retested the reliability of predictions with repeated prediction analyses using an adjusted criterion. We were able to identify 74 dyslexic and 369 non-dyslexic students. For 37 students, various predictions were too inconsistent for a final classification. The most reliable predictions were acquired with item scores and self-report questions. The main conclusion is that it is possible to identify dyslexia with a high reliability, although the exact nature of dyslexia is still unknown. We therefore believe that this study yielded valuable information for future methods of identifying dyslexia in Dutch as well as in other languages, and that this would be beneficial for comparing studies across countries.

Learning Disabilities Spectrum: ADD, ADHD, and LD. Proceedings of the Annual Spectrum of Developmental Disabilities Course (15th, Baltimore, Maryland, March 16-18, 1992).

ERIC Educational Resources Information Center

Capute, Arnold J., Ed.; And Others

This volume, the proceedings of a 1992 conference, presents 14 papers which take a neuropsychological approach to attention deficit disorder, attention deficit disorder with hyperactivity, and learning disabilities. Papers have the following titles and authors: "A New Conceptual Model for Dyslexia" (Sally E. Shaywitz et al.);…

Impaired Orthographic Processing in Chinese Dyslexic Children: Evidence from the Lexicality Effect on N400

ERIC Educational Resources Information Center

Tzeng, Yu-Lin; Hsu, Chun-Hsien; Lin, Wan-Hsuan; Lee, Chia-Ying

2017-01-01

This study used the lexicality effects on N400 to investigate orthographic processing in children with developmental dyslexia. Participants performed a Go/No-Go semantic judgment task; three types of stimuli--real characters (RC), pseudocharacters (PC), and noncharacters (NC)--were embedded in No-Go trials. Two types of lexicality effects (RC vs.…

Right Fronto-Parietal Dysfunction in Children with ADHD and Developmental Dyslexia as Determined by Line Bisection Judgements

ERIC Educational Resources Information Center

Waldie, Karen E.; Hausmann, Markus

2010-01-01

Visual line bisection is a reliable and valid laterality task that is typically used with patients with acquired brain damage to assess right hemisphere functioning. Neurologically normal individuals tend to bisect lines to the left of the objective midline whereas those with right parietal damage bisect lines to the right. In this study children…

Elucidating the Component Processes Involved in Dyslexic and Non-Dyslexic Reading Fluency: An Eye-Tracking Study

ERIC Educational Resources Information Center

Jones, Manon W.; Obregon, Mateo; Kelly, M. Louise; Branigan, Holly P.

2008-01-01

The relationship between rapid automatized naming (RAN) and reading fluency is well documented (see Wolf, M. & Bowers, P.G. (1999). "The double-deficit hypothesis for the 'developmental dyslexias.'" "Journal of Educational Psychology," 91(3), 415-438, for a review), but little is known about which component processes are important in RAN, and why…

New Insights on Developmental Dyslexia Subtypes: Heterogeneity of Mixed Reading Profiles

PubMed Central

Zoubrinetzky, Rachel; Bielle, Frédérique; Valdois, Sylviane

2014-01-01

We examined whether classifications based on reading performance are relevant to identify cognitively homogeneous subgroups of dyslexic children. Each of the 71 dyslexic participants was selected to have a mixed reading profile, i.e. poor irregular word and pseudo-word reading performance (accuracy and speed). Despite their homogeneous reading profile, the participants were found to split into four distinct cognitive subgroups, characterized by a single phonological disorder, a single visual attention span disorder, a double deficit or none of these disorders. The two subgroups characterized by single and contrasted cognitive disorders were found to exhibit a very similar reading pattern but more contrasted spelling performance (quantitative analysis). A qualitative analysis of the error types produced in reading and spelling provided some cues about the participants' underlying cognitive deficit. The overall findings disqualify subtyping based on reading profiles as a classification method to identify cognitively homogeneous subgroups of dyslexic children. They rather show an opaque relationship between the cognitive underpinnings of developmental dyslexia and their behavioral manifestations in reading and spelling. Future neuroimaging and genetic studies should take this issue into account since synthesizing over cognitively heterogeneous children would entail potential pitfalls. PMID:24918441

Influence of Verbal Working Memory Depends on Vocabulary: Oral Reading Fluency in Adolescents with Dyslexia

ERIC Educational Resources Information Center

Rose, L. Todd; Rouhani, Parisa

2012-01-01

Most research on dyslexia to date has focused on early childhood, while comparatively little is known about the nature of dyslexia in adolescence. The current study had two objectives. The first was to investigate the relative contributions of several cognitive and linguistic factors to connected-text oral reading fluency in a sample of…

Investigating Self-Regulated Study Strategies among Postsecondary Students with and without Dyslexia: A Diary Method Study

ERIC Educational Resources Information Center

Andreassen, Rune; Jensen, Magne S.; Bråten, Ivar

2017-01-01

We investigated the use of self-regulated study strategies among undergraduates with dyslexia by means of extensive web-based diary data, comparing their strategy use to that of matched students without dyslexia who completed the diary in the same period. Additionally, we examined the perceived benefits of using the recorded strategies in both…

How Do Students with Dyslexia Perform in Extended Matching Questions, Short Answer Questions and Observed Structured Clinical Examinations?

ERIC Educational Resources Information Center

Gibson, Sandra; Leinster, Samuel

2011-01-01

There are an increasing number of students with learning difficulties attending university, and currently much debate about the suitability and ability of students with dyslexia at both medical school and once they graduate into clinical practice. In this study we describe the performance of students with dyslexia compared to fellow students in…

Can you spell dyslexia without SLI? Comparing the cognitive profiles of dyslexia and specific language impairment and their roles in learning.

PubMed

Alloway, Tracy Packiam; Tewolde, Furtuna; Skipper, Dakota; Hijar, David

2017-06-01

The aim of the present study is to explore whether those with Specific Language Impairment (SLI) and dyslexia display distinct or overlapping cognitive profiles with respect to learning outcomes. In particular, we were interested in two key cognitive skills associated with academic performance - working memory and IQ. We recruited three groups of children - those with SLI, those with dyslexia, and a control group. All children were given standardized tests of working memory, IQ (vocabulary and matrix), spelling, and math. The pattern of results suggests that both children with dyslexia and SLI are characterized with poorer verbal working memory and IQ compared to controls, but preserved nonverbal cognitive skills. It appears that that these two disorder groups cannot be distinguished by the severity of their cognitive deficits. However, there was a differential pattern with respect to learning outcomes, where the children with dyslexia rely more on visual skills in spelling, while those with SLI use their relative strengths in vocabulary. These findings can have important implications for how intervention is tailored in the classroom, as disorder-specific support could yield important gains in learning. Copyright © 2017. Published by Elsevier Ltd.

The effect of a specialized dyslexia font, OpenDyslexic, on reading rate and accuracy.

PubMed

Wery, Jessica J; Diliberto, Jennifer A

2017-07-01

A single-subject alternating treatment design was used to investigate the extent to which a specialized dyslexia font, OpenDyslexic, impacted reading rate or accuracy compared to two commonly used fonts when used with elementary students identified as having dyslexia. OpenDyslexic was compared to Arial and Times New Roman in three reading tasks: (a) letter naming, (b) word reading, and (c) nonsense word reading. Data were analyzed through visual analysis and improvement rate difference, a nonparametric measure of nonoverlap for comparing treatments. Results from this alternating treatment experiment show no improvement in reading rate or accuracy for individual students with dyslexia, as well as the group as a whole. While some students commented that the font was "new" or "different", none of the participants reported preferring to read material presented in that font. These results indicate there may be no benefit for translating print materials to this font.

Neural processing of amplitude and formant rise time in dyslexia.

PubMed

Peter, Varghese; Kalashnikova, Marina; Burnham, Denis

2016-06-01

This study aimed to investigate how children with dyslexia weight amplitude rise time (ART) and formant rise time (FRT) cues in phonetic discrimination. Passive mismatch responses (MMR) were recorded for a/ba/-/wa/contrast in a multiple deviant odd-ball paradigm to identify the neural response to cue weighting in 17 children with dyslexia and 17 age-matched control children. The deviant stimuli had either partial or full ART or FRT cues. The results showed that ART did not generate an MMR in either group, whereas both partial and full FRT cues generated MMR in control children while only full FRT cues generated MMR in children with dyslexia. These findings suggest that children, both controls and those with dyslexia, discriminate speech based on FRT cues and not ART cues. However, control children have greater sensitivity to FRT cues in speech compared to children with dyslexia. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Similar alterations in brain function for phonological and semantic processing to visual characters in Chinese dyslexia.

PubMed

Liu, Li; Wang, Wenjing; You, Wenping; Li, Yi; Awati, Neha; Zhao, Xu; Booth, James R; Peng, Danling

2012-07-01

Dyslexia in alphabetic languages has been extensively investigated and suggests a central deficit in orthography to phonology mapping in the left hemisphere. Compared to dyslexia in alphabetic languages, the central deficit for Chinese dyslexia is still unclear. Because of the logographic nature of Chinese characters, some have suggested that Chinese dyslexia should have larger deficits in the semantic system. To investigate this, Chinese children with reading disability (RD) were compared to typically developing (TD) children using functional magnetic resonance imaging (fMRI) on a rhyming judgment task and on a semantic association judgment task. RD children showed less activation for both tasks in right visual (BA18, 19) and left occipito-temporal cortex (BA 37), suggesting a deficit in visuo-orthographic processing. RD children also showed less activation for both tasks in left inferior frontal gyrus (BA44), which additionally showed significant correlations with activation of bilateral visuo-orthographic regions in the RD group, suggesting that the abnormalities in frontal cortex and in posterior visuo-orthographic regions may reflect a deficit in the connection between brain regions. Analyses failed to reveal larger differences between groups for the semantic compared to the rhyming task, suggesting that Chinese dyslexia is similarly impaired in the access to phonology and to semantics from the visual orthography. Copyright © 2012 Elsevier Ltd. All rights reserved.

Postural Control in Children with Dyslexia: Effects of Emotional Stimuli in a Dual-Task Environment.

PubMed

Goulème, Nathalie; Gerard, Christophe-Loïc; Bucci, Maria Pia

2017-08-01

The aim of this study was to compare the visual exploration strategies used during a postural control task across participants with and without dyslexia. We simultaneously recorded eye movements and postural control while children were viewing different types of emotional faces. Twenty-two children with dyslexia and twenty-two aged-matched children without dyslexia participated in the study. We analysed the surface area, the length and the mean velocity of the centre of pressure for balance in parallel with visual saccadic latency, the number of saccades and the time spent in regions of interest. Our results showed that postural stability in children with dyslexia was weaker and the surface area of their centre of pressure increased significantly when they viewed an unpleasant face. Moreover, children with dyslexia had different strategies to those used by children without dyslexia during visual exploration, and in particular when they viewed unpleasant emotional faces. We suggest that lower performance in emotional face processing in children with dyslexia could be due to a difference in their visual strategies, linked to their identification of unpleasant emotional faces. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Simulation of dyslexia. How literacy and cognitive skills can help distinguish college students with dyslexia from malingerers

PubMed Central

de Bree, Elise H.; de Jong, Peter F.

2018-01-01

Academic accommodations associated with a diagnosis of dyslexia might be incentives for college students without reading or spelling difficulties to feign dyslexia and obtain the diagnosis unfairly. In the current study we examined malingering practices by comparing the performance of college students instructed to malinger dyslexia (n = 28) to that of students actually diagnosed with dyslexia (n = 16). We also included a control group of students without reading and spelling difficulties (n = 28). The test battery included tasks tapping literacy skills as well as underlying cognitive skills associated with literacy outcomes. These tasks are commonly used in diagnosing dyslexia. We examined patterns in the performance of malingerers across tasks and tested whether malingerers could be identified based on their performance on a limited number of tasks. Results indicated that malingerers scored significantly lower than students with dyslexia on reading and spelling skills; i.e., the core characteristics of dyslexia. Especially reading performance was extremely low and not in line with students’ age and level of education. Findings for underlying cognitive skills were mixed. Overall, malingerers scored lower than students with dyslexia on tasks tapping mainly speed, whereas the two groups did not differ on tasks reflecting mainly accuracy. Based on word and pseudoword reading and letter and digit naming, the three groups could be distinguished with reasonable sensitivity and specificity. In all, results indicate that college students seem to understand on which tasks they should feign dyslexia, but tend to exaggerate difficulties on these tasks to the point where diagnosticians should mistrust performance. PMID:29782515

Foreign language reading and spelling in gifted students with dyslexia in secondary education.

PubMed

van Viersen, Sietske; de Bree, Elise H; Kalee, Lilian; Kroesbergen, Evelyn H; de Jong, Peter F

2017-01-01

A few studies suggest that gifted children with dyslexia have better literacy skills than averagely intelligent children with dyslexia. This finding aligns with the hypothesis that giftedness-related factors provide compensation for poor reading. The present study investigated whether, as in the native language (NL), the level of foreign language (FL) literacy of gifted students with dyslexia is higher than the literacy level of averagely intelligent students with dyslexia and whether this difference can be accounted for by the difference in their NL literacy level. The sample consisted of 148 Dutch native speaking secondary school students divided in four groups: dyslexia, gifted/dyslexia, typically developing (TD), and gifted. All students were assessed on word reading and orthographic knowledge in Dutch and English when they were in 7th or 8th grade. A subsample ( n  = 71) was (re)assessed on Dutch, English, French, and German literacy one year later. Results showed that Dutch gifted students with dyslexia have higher NL literacy levels than averagely intelligent students with dyslexia. As in the NL, a stepwise pattern of group differences was found for English word reading and spelling, i.e., dyslexia < gifted/dyslexia < TD < gifted. However, it was not found for French and German literacy performance. These results point towards compensation: the higher English literacy levels of gifted/dyslexic students compared to their averagely intelligent dyslexic peers result from mechanisms that are unique to English as a FL. Differences in results between FLs are discussed in terms of variation in orthographic transparency and exposure.

Factors influencing work participation of adults with developmental dyslexia: a systematic review

PubMed Central

2014-01-01

Background Evidence has been synthesized to determine hindering and facilitating factors associated with the work participation of adults with developmental dyslexia (DD), classified according to the International Classification of Functioning, Disability and Health (ICF). Methods A systematic literature review has been performed. Two search strings were used to determine the population and the context of work. The ICF was expanded with two subdivisions: one that made the environmental factors more work-related and a subdivision of personal factors. For data extraction the method known as qualitative metasummary was used and the manifest frequency effect size (MFES) for each category in the ICF was calculated. Results From 33 included studies 318 factors have been extracted and classified in the ICF. In the classification the frequency of occurrences and the consistency in direction (i.e., hindering or facilitating) have been made visible. The ICF categories with the highest MFES were mental functions with factors like feelings and emotions about dyslexia; activities like reading or writing/spelling; participation with factors like acquiring and keeping a job; social relationships at work where the attitudes and support of the employer and co-workers are important; working conditions with factors like the availability of assistive technology and accommodations on the job; and personal factors like self-disclosure and coping strategies. Conclusions In the context of work DD affects nearly all domains of functioning, mostly in a negative way. Within each domain the impact of DD increases over the course of life. To overcome that negative influence, many forms of adaptation, compensation, or coping are mentioned. Also notable is the lack of positive attitudes toward DD of the participants with DD—with the exception of the attitudes of teachers with DD—as well as on the part of colleagues, supervisors, and employers. PMID:24460949

Factors influencing work participation of adults with developmental dyslexia: a systematic review.

PubMed

de Beer, Joost; Engels, Josephine; Heerkens, Yvonne; van der Klink, Jac

2014-01-24

Evidence has been synthesized to determine hindering and facilitating factors associated with the work participation of adults with developmental dyslexia (DD), classified according to the International Classification of Functioning, Disability and Health (ICF). A systematic literature review has been performed. Two search strings were used to determine the population and the context of work. The ICF was expanded with two subdivisions: one that made the environmental factors more work-related and a subdivision of personal factors. For data extraction the method known as qualitative metasummary was used and the manifest frequency effect size (MFES) for each category in the ICF was calculated. From 33 included studies 318 factors have been extracted and classified in the ICF. In the classification the frequency of occurrences and the consistency in direction (i.e., hindering or facilitating) have been made visible. The ICF categories with the highest MFES were mental functions with factors like feelings and emotions about dyslexia; activities like reading or writing/spelling; participation with factors like acquiring and keeping a job; social relationships at work where the attitudes and support of the employer and co-workers are important; working conditions with factors like the availability of assistive technology and accommodations on the job; and personal factors like self-disclosure and coping strategies. In the context of work DD affects nearly all domains of functioning, mostly in a negative way. Within each domain the impact of DD increases over the course of life. To overcome that negative influence, many forms of adaptation, compensation, or coping are mentioned. Also notable is the lack of positive attitudes toward DD of the participants with DD-with the exception of the attitudes of teachers with DD-as well as on the part of colleagues, supervisors, and employers.

Speed of Processing and Reading Disability: A Cross-Linguistic Investigation of Dyslexia and Borderline Intellectual Functioning

ERIC Educational Resources Information Center

Bonifacci, Paola; Snowling, Margaret J.

2008-01-01

English and Italian children with dyslexia were compared with children with reading difficulties associated with low-IQ on tests of simple and choice RT, and in number and symbol scanning tasks. On all four speed-of-processing tasks, children with low-IQ responded more slowly than children with dyslexia and age-controls. In the choice RT task, the…

Subtypes of Reading Disability in a Shallow Orthography: A Double Dissociation between Accuracy-Disabled and Rate-Disabled Readers of Hebrew

ERIC Educational Resources Information Center

Shany, Michal; Share, David L.

2011-01-01

Whereas most English language sub-typing schemes for dyslexia (e.g., Castles & Coltheart, "1993") have focused on reading accuracy for words varying in regularity, such an approach may have limited utility for reading disability sub-typing beyond English in which fluency rather than accuracy is the key discriminator of developmental and individual…

Auditory Short-Term Memory Capacity Correlates with Gray Matter Density in the Left Posterior STS in Cognitively Normal and Dyslexic Adults

ERIC Educational Resources Information Center

Richardson, Fiona M.; Ramsden, Sue; Ellis, Caroline; Burnett, Stephanie; Megnin, Odette; Catmur, Caroline; Schofield, Tom M.; Leff, Alex P.; Price, Cathy J.

2011-01-01

A central feature of auditory STM is its item-limited processing capacity. We investigated whether auditory STM capacity correlated with regional gray and white matter in the structural MRI images from 74 healthy adults, 40 of whom had a prior diagnosis of developmental dyslexia whereas 34 had no history of any cognitive impairment. Using…

I Can Read It in Your Eyes: What Eye Movements Tell Us about Visuo-Attentional Processes in Developmental Dyslexia

ERIC Educational Resources Information Center

Bellocchi, Stephanie; Muneaux, Mathilde; Bastien-Toniazzo, Mireille; Ducrot, Stephanie

2013-01-01

Most studies today agree about the link between visual-attention and oculomotor control during reading: attention seems to affect saccadic programming, that is, the position where the eyes land in a word. Moreover, recent studies show that visuo-attentional processes are strictly linked to normal and impaired reading. In particular, a large body…

Literacy Skill Development of Children with Familial Risk for Dyslexia through Grades 2, 3, and 8

ERIC Educational Resources Information Center

Eklund, Kenneth; Torppa, Minna; Aro, Mikko; Leppänen, Paavo H. T.; Lyytinen, Heikki

2015-01-01

This study followed the development of reading speed, reading accuracy, and spelling in transparent Finnish orthography in children through Grades 2, 3, and 8. We compared 2 groups of children with familial risk for dyslexia--1 group with dyslexia (Dys _FR, n = 35) and 1 group without (NoDys_FR, n = 66) in Grade 2--with a group of children without…

The Influence of Spelling Ability on Vocabulary Choices When Writing for Children With Dyslexia.

PubMed

Sumner, Emma; Connelly, Vincent; Barnett, Anna L

2016-01-01

Spelling is a prerequisite to expressing vocabulary in writing. Research has shown that children with dyslexia are hesitant spellers when composing. This study aimed to determine whether the hesitant spelling of children with dyslexia, evidenced by frequent pausing, affects vocabulary choices when writing. A total of 31 children with dyslexia, mean age 9 years, were compared to typically developing groups of children: the first matched by age, the second by spelling ability. Oral vocabulary was measured and children completed a written and verbal compositional task. Lexical diversity comparisons were made across written and verbal compositions to highlight the constraint of having to select and spell words. A digital writing tablet recorded the writing. Children with dyslexia and the spelling-ability group made a high proportion of spelling errors and within-word pauses, and had a lower lexical diversity within their written compositions compared to their verbal compositions. The age-matched peers demonstrated the opposite pattern. Spelling ability and pausing predicted 53% of the variance in written lexical diversity of children with dyslexia, demonstrating the link between spelling and vocabulary when writing. Oral language skills had no effect. Lexical diversity correlated with written and verbal text quality for all groups. Practical implications are discussed and related to writing models. © Hammill Institute on Disabilities 2014.

The cost-effectiveness of an intensive treatment protocol for severe dyslexia in children.

PubMed

Hakkaart-van Roijen, Leona; Goettsch, Wim G; Ekkebus, Michel; Gerretsen, Patty; Stolk, Elly A

2011-08-01

Studies of interventions for dyslexia have focused entirely on outcomes related to literacy. In this study, we considered a broader picture assessing improved quality of life compared with costs. A model served as a tool to compare costs and effects of treatment according to a new protocol and care as usual. Quality of life was measured and valued by proxies using a general quality-of-life instrument (EQ-5D). We considered medical cost and non-medical cost (e.g. remedial teaching). The model computed cost per successful treatment and cost per quality adjusted life year (QALY) in time. About 75% of the total costs was related to diagnostic tests to distinguish between children with severe dyslexia and children who have reading difficulties for other reasons. The costs per successful treatment of severe dyslexia were €36 366. Successful treatment showed a quality-of-life gain of about 11%. At primary school, the average cost per QALY for severe dyslexia amounted to €58 647. In the long term, the cost per QALY decreased to €26 386 at secondary school and €17 663 thereafter. The results of this study provide evidence that treatment of severe dyslexia is cost-effective when the investigated protocol is followed. Copyright © 2011 John Wiley & Sons, Ltd.

Effective learning and retention of braille letter tactile discrimination skills in children with developmental dyslexia.

PubMed

Hayek, Maisam; Dorfberger, Shoshi; Karni, Avi

2016-01-01

Children with developmental dyslexia (DD) may differ from typical readers in aspects other than reading. The notion of a general deficit in the ability to acquire and retain procedural ('how to') knowledge as long-term procedural memory has been proposed. Here, we compared the ability of elementary school children, with and without reading difficulties (DD, typical readers), to improve their tactile discrimination with practice and tested the children's ability to retain the gains. Forty 10-11-year-olds practiced the tactile discrimination of four braille letters, presented as pairs, while blindfolded. In a trial, participants were asked to report whether the target stimuli were identical or different from each other. The structured training session consisted of six blocks of 16 trials each. Performance was re-tested at 24 hours and two weeks post-training. Both groups improved in speed and in accuracy. In session 1, children with DD started as significantly less accurate and were slower than the typical readers but showed rapid learning and successfully closed the gap. Only two children with DD failed to benefit from training and were not included in subsequent data analyses. At 24 hours post-training both groups showed effective retention of the gains in speed and accuracy. Importantly, children with DD were able to retain the gains in speed and accuracy, over a two-week interval as effectively as typical readers. Thus, children with DD were as effective in the acquisition and retention of tactile discrimination of braille letters as typical readers of the same age. The results do not support the notion of a general procedural learning disability in DD. © 2015 John Wiley & Sons Ltd.

[Relationship between clinical symptoms and Hiragana reading ability in children with difficulties in reading and writing:usefulness of a clinical-symptoms-checklist].

PubMed

Kita, Yosuke; Kobayashi, Tomoka; Koike, Toshihide; Koeda, Tatsuya; Wakamiya, Eiji; Hosokawa, Torn; Kaga, Makiko; Inagaki, Masumi

2010-11-01

We investigated the clinical symptoms of children with developmental dyslexia (DD) and evaluated the relationship between these symptoms and their Hiragana reading abilities. In order to detect the clinical symptoms of DD, we newly developed a clinical-symptoms-checklist (CL), which consisted of a total of 30 yes/no questions regarding symptoms linked to reading (15 questions) and writing (15 questions). Subjects were 98 Japanese school grade (1 to 9) children, aged 6 to 15 years old, with normal intelligence confirmed by the Wechsler Intelligence Test for Children (WISC-Ill) and they were divided into 2 groups according to their diagnosis. Twenty four children diagnosed as developmental dyslexia consisted the DD group, and the remaining 74 children were grouped in the non-DD group. CL showed significant construct validity (p<0.05) and inner consistency (reading: a =0.82, writing: a =0.72) after deleting two questions from the originals. The number of questions checked in the CL reading subcategory significantly correlated with the Hiragana reading ability of articulation time in all Hiragana reading tasks (p<0.001). More severe clinical symptoms and lower reading ability were observed in the DD group compared to the non-DD group. Receiver Operating Characteristics (ROC) analysis indicated that these two groups could be discriminated by the CL and the results of the reading task, and both sensitivity and specificity rate were approximately 80%. It was suggested that 7 or more positive checks in the CL and 2 or more abnormal scores in the reading tasks might discriminate DD from other conditions which cause difficulties in reading and writing in Japanese children.

Attention Dysfunction Subtypes of Developmental Dyslexia

PubMed Central

Lewandowska, Monika; Milner, Rafał; Ganc, Małgorzata; Włodarczyk, Elżbieta; Skarżyński, Henryk

2014-01-01

Background Previous studies indicate that many different aspects of attention are impaired in children diagnosed with developmental dyslexia (DD). The objective of the present study was to identify cognitive profiles of DD on the basis of attentional test performance. Material/Methods 78 children with DD (30 girls, 48 boys, mean age of 12 years ±8 months) and 32 age- and sex-matched non-dyslexic children (14 girls, 18 boys) were examined using a battery of standardized tests of reading, phonological and attentional processes (alertness, covert shift of attention, divided attention, inhibition, flexibility, vigilance, and visual search). Cluster analysis was used to identify subtypes of DD. Results Dyslexic children showed deficits in alertness, covert shift of attention, divided attention, flexibility, and visual search. Three different subtypes of DD were identified, each characterized by poorer performance on the reading, phonological awareness, and visual search tasks. Additionally, children in cluster no. 1 displayed deficits in flexibility and divided attention. In contrast to non-dyslexic children, cluster no. 2 performed poorer in tasks involving alertness, covert shift of attention, divided attention, and vigilance. Cluster no. 3 showed impaired covert shift of attention. Conclusions These results indicate different patterns of attentional impairments in dyslexic children. Remediation programs should address the individual child’s deficit profile. PMID:25387479

Defective chromatic and achromatic visual pathways in developmental dyslexia: Cues for an integrated intervention programme.

PubMed

Bonfiglio, Luca; Bocci, Tommaso; Minichilli, Fabrizio; Crecchi, Alessandra; Barloscio, Davide; Spina, Donata Maria; Rossi, Bruno; Sartucci, Ferdinando

2017-01-01

As well as obtaining confirmation of the magnocellular system involvement in developmental dyslexia (DD); the aim was primarily to search for a possible involvement of the parvocellular system; and, furthermore, to complete the assessment of the visual chromatic axis by also analysing the koniocellular system. Visual evoked potentials (VEPs) in response to achromatic stimuli with low luminance contrast and low spatial frequency, and isoluminant red/green and blue/yellow stimuli with high spatial frequency were recorded in 10 dyslexic children and 10 age- and sex-matched, healthy subjects. Dyslexic children showed delayed VEPs to both achromatic stimuli (magnocellular-dorsal stream) and isoluminant red/green and blue/yellow stimuli (parvocellular-ventral and koniocellular streams). To our knowledge, this is the first time that a dysfunction of colour vision has been brought to light in an objective way (i.e., by means of electrophysiological methods) in children with DD. These results give rise to speculation concerning the need for a putative approach for promoting both learning how to read and/or improving existing reading skills of children with or at risk of DD. The working hypothesis would be to combine two integrated interventions in a single programme aimed at fostering the function of both the magnocellular and the parvocellular streams.

Temporal order and processing acuity of visual, auditory, and tactile perception in developmentally dyslexic young adults.

PubMed

Laasonen, M; Service, E; Virsu, V

2001-12-01

We studied the temporal acuity of 16 developmentally dyslexic young adults in three perceptual modalities. The control group consisted of 16 age- and IQ-matched normal readers. Two methods were used. In the temporal order judgment (TOJ) method, the stimuli were spatially separate fingertip indentations in the tactile system, tone bursts of different pitches in audition, and light flashes in vision. Participants indicated which one of two stimuli appeared first. To test temporal processing acuity (TPA), the same 8-msec nonspeech stimuli were presented as two parallel sequences of three stimulus pulses. Participants indicated, without order judgments, whether the pulses of the two sequences were simultaneous or nonsimultaneous. The dyslexic readers were somewhat inferior to the normal readers in all six temporal acuity tasks on average. Thus, our results agreed with the existence of a pansensory temporal processing deficit associated with dyslexia in a language with shallow orthography (Finnish) and in well-educated adults. The dyslexic and normal readers' temporal acuities overlapped so much, however, that acuity deficits alone would not allow dyslexia diagnoses. It was irrelevant whether or not the acuity task required order judgments. The groups did not differ in the nontemporal aspects of our experiments. Correlations between temporal acuity and reading-related tasks suggested that temporal acuity is associated with phonological awareness.

Impaired Statistical Learning in Developmental Dyslexia

PubMed Central

Thiessen, Erik D.; Holt, Lori L.

2015-01-01

Purpose Developmental dyslexia (DD) is commonly thought to arise from phonological impairments. However, an emerging perspective is that a more general procedural learning deficit, not specific to phonological processing, may underlie DD. The current study examined if individuals with DD are capable of extracting statistical regularities across sequences of passively experienced speech and nonspeech sounds. Such statistical learning is believed to be domain-general, to draw upon procedural learning systems, and to relate to language outcomes. Method DD and control groups were familiarized with a continuous stream of syllables or sine-wave tones, the ordering of which was defined by high or low transitional probabilities across adjacent stimulus pairs. Participants subsequently judged two 3-stimulus test items with either high or low statistical coherence as being the most similar to the sounds heard during familiarization. Results As with control participants, the DD group was sensitive to the transitional probability structure of the familiarization materials as evidenced by above-chance performance. However, the performance of participants with DD was significantly poorer than controls across linguistic and nonlinguistic stimuli. In addition, reading-related measures were significantly correlated with statistical learning performance of both speech and nonspeech material. Conclusion Results are discussed in light of procedural learning impairments among participants with DD. PMID:25860795

The effect of learning on feedback-related potentials in adolescents with dyslexia: an EEG-ERP study.

PubMed

Kraus, Dror; Horowitz-Kraus, Tzipi

2014-01-01

Individuals with dyslexia exhibit associated learning deficits and impaired executive functions. The Wisconsin Card Sorting Test (WCST) is a learning-based task that relies heavily on executive functioning, in particular, attention shift and working memory. Performance during early and late phases of a series within the task represents learning and implementation of a newly learned rule. Here, we aimed to examine two event-related potentials associated with learning, feedback-related negativity (FRN)-P300 complex, in individuals with dyslexia performing the WCST. Adolescents with dyslexia and age-matched typical readers performed the Madrid card sorting test (MCST), a computerized version of the WCST. Task performance, reading measures, and cognitive measures were collected. FRN and the P300 complex were acquired using the event-related potentials methodology and were compared in early vs late errors within a series. While performing the MCST, both groups showed a significant reduction in average reaction times and a trend toward decreased error rates. Typical readers performed consistently better than individuals with dyslexia. FRN amplitudes in early phases were significantly smaller in dyslexic readers, but were essentially equivalent to typical readers in the late phase. P300 amplitudes were initially smaller among readers with dyslexia and tended to decrease further in late phases. Differences in FRN amplitudes for early vs late phases were positively correlated with those of P300 amplitudes in the entire sample. Individuals with dyslexia demonstrate a behavioral and electrophysiological change within single series of the MCST. However, learning patterns seem to differ between individuals with dyslexia and typical readers. We attribute these differences to the lower baseline performance of individuals with dyslexia. We suggest that these changes represent a fast compensatory mechanism, demonstrating the importance of learning strategies on reading among individuals with dyslexia.

Intervention for a multi-character processing deficit in a Greek-speaking child with surface dyslexia.

PubMed

Niolaki, Georgia Z; Masterson, Jackie

2013-01-01

A case study with a 12-year-old boy, R.F., who was a monolingual speaker of Greek is reported. R.F. showed slow word reading and a difficulty in spelling irregular words but not nonwords. Assessments revealed that R.F. did not appear to have a phonological deficit, but indicated impaired multicharacter processing ability for visually presented letter arrays. On the basis of previous research linking multicharacter processing and reading we developed an intervention aimed at improving R.F.'s ability to report letter arrays of increasing length. Following a 9-week programme, improvement was observed, and investigation of R.F.'s reading revealed gains in single word reading speed and accuracy. The findings support the significance of intervention studies for testing hypotheses regarding causal relationships among cognitive processes and the notion of specific profiles of developmental dyslexia/dysgraphia in both opaque and transparent orthographies.

Short-term Memory in Childhood Dyslexia: Deficient Serial Order in Multiple Modalities.

PubMed

Cowan, Nelson; Hogan, Tiffany P; Alt, Mary; Green, Samuel; Cabbage, Kathryn L; Brinkley, Shara; Gray, Shelley

2017-08-01

In children with dyslexia, deficits in working memory have not been well-specified. We assessed second-grade children with dyslexia, with and without concomitant specific language impairment, and children with typical development. Immediate serial recall of lists of phonological (non-word), lexical (digit), spatial (location) and visual (shape) items were included. For the latter three modalities, we used not only standard span but also running span tasks, in which the list length was unpredictable to limit mnemonic strategies. Non-word repetition tests indicated a phonological memory deficit in children with dyslexia alone compared with those with typical development, but this difference vanished when these groups were matched for non-verbal intelligence and language. Theoretically important deficits in serial order memory in dyslexic children, however, persisted relative to matched typically developing children. The deficits were in recall of (1) spoken digits in both standard and running span tasks and (2) spatial locations, in running span only. Children with dyslexia with versus without language impairment, when matched on non-verbal intelligence, had comparable serial order memory, but differed in phonology. Because serial orderings of verbal and spatial elements occur in reading, the careful examination of order memory may allow a deeper understanding of dyslexia and its relation to language impairment. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Phonological skills, visual attention span, and visual stress in developmental dyslexia.

PubMed

Saksida, Amanda; Iannuzzi, Stéphanie; Bogliotti, Caroline; Chaix, Yves; Démonet, Jean-François; Bricout, Laure; Billard, Catherine; Nguyen-Morel, Marie-Ange; Le Heuzey, Marie-France; Soares-Boucaud, Isabelle; George, Florence; Ziegler, Johannes C; Ramus, Franck

2016-10-01

In this study, we concurrently investigated 3 possible causes of dyslexia-a phonological deficit, visual stress, and a reduced visual attention span-in a large population of 164 dyslexic and 118 control French children, aged between 8 and 13 years old. We found that most dyslexic children showed a phonological deficit, either in terms of response accuracy (92.1% of the sample), speed (84.8%), or both (79.3%). Deficits in visual attention span, as measured by partial report ability, affected 28.1% of dyslexic participants, all of which also showed a phonological deficit. Visual stress, as measured by subjective reports of visual discomfort, affected 5.5% of dyslexic participants, not more than controls (8.5%). Although phonological variables explained a large amount of variance in literacy skills, visual variables did not explain any additional variance. Finally, children with comorbid phonological and visual deficits did not show more severe reading disability than children with a pure phonological deficit. These results (a) confirm the importance of phonological deficits in dyslexia; (b) suggest that visual attention span may play a role, but a minor one, at least in this population; (c) do not support any involvement of visual stress in dyslexia. Among the factors that may explain some differences with previously published studies, the present sample is characterized by very stringent inclusion criteria, in terms of the severity of reading disability and in terms of exclusion of comorbidities. This may exacerbate the role of phonological deficits to the detriment of other factors playing a role in reading acquisition. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Visual memory transformations in dyslexia.

PubMed

Barnes, James; Hinkley, Lisa; Masters, Stuart; Boubert, Laura

2007-06-01

Representational Momentum refers to observers' distortion of recognition memory for pictures that imply motion because of an automatic mental process which extrapolates along the implied trajectory of the picture. Neuroimaging evidence suggests that activity in the magnocellular visual pathway is necessary for representational momentum to occur. It has been proposed that individuals with dyslexia have a magnocellular deficit, so it was hypothesised that these individuals would show reduced or absent representational momentum. In this study, 30 adults with dyslexia and 30 age-matched controls were compared on two tasks, one linear and one rotation, which had previously elicited the representational momentum effect. Analysis indicated significant differences in the performance of the two groups, with the dyslexia group having a reduced susceptibility to representational momentum in both linear and rotational directions. The findings highlight that deficits in temporal spatial processing may contribute to the perceptual profile of dyslexia.

The modality and redundancy effects in multimedia learning in children with dyslexia.

PubMed

Knoop-van Campen, Carolien A N; Segers, Eliane; Verhoeven, Ludo

2018-05-01

The present study aimed to examine the modality and redundancy effects in multimedia learning in children with dyslexia in order to find out whether their learning benefits from written and/or spoken text with pictures. We compared study time and knowledge gain in 26 11-year-old children with dyslexia and 38 typically reading peers in a within-subjects design. All children were presented with a series of user-paced multimedia lessons in 3 conditions: pictorial information presented with (a) written text, (b) audio, or (c) combined text and audio. We also examined whether children's learning outcomes were related to their working memory. With respect to study time, we found modality and reversed redundancy effects. Children with dyslexia spent more time learning in the text condition, compared with the audio condition and the combined text-and-audio condition. Regarding knowledge gain, no modality or redundancy effects were evidenced. Although the groups differed on working memory, it did not influence the modality or redundancy effect on study time or knowledge gain. In multimedia learning, it thus is more efficient to provide children with dyslexia with audio or with auditory support. Copyright © 2018 John Wiley & Sons, Ltd.

Thalamo-Cortical Connectivity: What Can Diffusion Tractography Tell Us About Reading Difficulties in Children?

PubMed Central

Fan, Qiuyun; Davis, Nicole; Anderson, Adam W.

2014-01-01

Abstract Reading is an essential skill in modern society, but many people have deficits in the decoding and word recognition aspects of reading, a difficulty often referred to as dyslexia. The primary focus of neuroimaging studies to date in dyslexia has been on cortical regions; however, subcortical regions may also be important for explaining this disability. Here, we used diffusion tensor imaging to examine the association between thalamo-cortical connectivity and children's reading ability in 20 children with typically developed reading ability (age range 8–17/10–17 years old from two imaging centers) and 19 children with developmental dyslexia (DYS) (age range 9–17/9–16 years old). To measure thalamo-cortical connections, the structural images were segmented into cortical and subcortical anatomical regions that were used as target and seed regions in the probabilistic tractography analysis. Abnormal thalamic connectivity was found in the dyslexic group in the sensorimotor and lateral prefrontal cortices. These results suggest that the thalamus may play a key role in reading behavior by mediating the functions of task-specific cortical regions; such findings lay the foundation for future studies to investigate further neurobiological anomalies in the development of thalamo-cortical connectivity in DYS. PMID:24963547

A Three-Year Longitudinal Study of Reading and Spelling Difficulty in Chinese Developmental Dyslexia: The Matter of Morphological Awareness.

PubMed

Tong, Xiuhong; McBride, Catherine; Lo, Jason Chor Ming; Shu, Hua

2017-11-01

In the present study, we used a three-time point longitudinal design to investigate the associations of morphological awareness to word reading and spelling in a small group of those with and without dyslexia taken from a larger sample of 164 Hong Kong Chinese children who remained in a longitudinal study across ages 6, 7 and 8. Among those 164 children, 15 had been diagnosed as having dyslexia by professional psychologists, and 15 other children manifested average reading ability and had been randomly selected from the sample for comparison. All children were administered a battery of tasks including Chinese character recognition, word dictation, morphological awareness, phonological awareness and rapid automatized naming. Multivariate analysis of variance and predictive discriminate analysis were performed to examine whether the dyslexic children showed differences in the cognitive-linguistic tasks in comparison with controls. Results suggested that the dyslexic groups had poorer performance in morphological awareness and RAN across all 3 years. However, phonological awareness was not stable in distinguishing the groups. Findings suggest that morphological awareness is a relatively strong correlate of spelling difficulties in Chinese, but phonological awareness is not. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Evaluation of the Bangor Dyslexia Test (BDT) for use with Adults.

PubMed

Reynolds, Andrea Elaine; Caravolas, Markéta

2016-02-01

The Bangor Dyslexia Test (BDT) is a short, easy-to-administer screener for use with a broad age range, which has been in use in the UK for over three decades. A distinctive feature of the battery is its focus on skills requiring aspects of verbal and phonological processing without, however, measuring literacy skills per se. Despite its longstanding existence and usage, there has been no evaluation of the psychometric properties of the battery as an adult dyslexia screener. We examined the psychometric properties of the BDT and evaluated its capacity to discriminate between adults with and without dyslexia. A large archival sample of university students with dyslexia (n = 193) and students with no reported literacy difficulties (n = 40) were compared on the BDT as well as on literacy and cognitive measures. Statistical analyses revealed the BDT to be a reliable (α = .72) and valid dyslexia screening tool with the capacity to effectively identify adults at risk of the disorder with an overall classification rate of 94% (sensitivity 96.4% and specificity 82.5%). In addition, higher indices of dyslexia risk on the BDT were associated with lower scores on standardized measures of literacy. Copyright © 2016 John Wiley & Sons, Ltd.

Error Types and Error Positions in Neglect Dyslexia: Comparative Analyses in Neglect Patients and Healthy Controls

ERIC Educational Resources Information Center

Weinzierl, Christiane; Kerkhoff, Georg; van Eimeren, Lucia; Keller, Ingo; Stenneken, Prisca

2012-01-01

Unilateral spatial neglect frequently involves a lateralised reading disorder, neglect dyslexia (ND). Reading of single words in ND is characterised by left-sided omissions and substitutions of letters. However, it is unclear whether the distribution of error types and positions within a word shows a unique pattern of ND when directly compared to…

The Cost-Effectiveness of an Intensive Treatment Protocol for Severe Dyslexia in Children

ERIC Educational Resources Information Center

Hakkaart-van Roijen, Leona; Goettsch, Wim G.; Ekkebus, Michel; Gerretsen, Patty; Stolk, Elly A.

2011-01-01

Studies of interventions for dyslexia have focused entirely on outcomes related to literacy. In this study, we considered a broader picture assessing improved quality of life compared with costs. A model served as a tool to compare costs and effects of treatment according to a new protocol and care as usual. Quality of life was measured and valued…

How do the Spellings of Children with Dyslexia Compare with Those of Nondyslexic Children?

ERIC Educational Resources Information Center

Cassar, Marie; Treiman, Rebecca; Moats, Louisa; Pollo, Tatiana Cury; Kessler, Brett

2005-01-01

Children with dyslexia are believed to have very poor phonological skills for which they compensate, to some extent, through relatively well-developed knowledge of letter patterns. We tested this view in Study 1 by comparing 25 dyslexic children and 25 younger normal children, chosen so that both groups performed, on average, at a second-grade…

Dyslexic brain activation abnormalities in deep and shallow orthographies: A meta‐analysis of 28 functional neuroimaging studies

PubMed Central

Martin, Anna; Kronbichler, Martin

2016-01-01

Abstract We used coordinate‐based meta‐analysis to objectively quantify commonalities and differences of dyslexic functional brain abnormalities between alphabetic languages differing in orthographic depth. Specifically, we compared foci of under‐ and overactivation in dyslexic readers relative to nonimpaired readers reported in 14 studies in deep orthographies (DO: English) and in 14 studies in shallow orthographies (SO: Dutch, German, Italian, Swedish). The separate meta‐analyses of the two sets of studies showed universal reading‐related dyslexic underactivation in the left occipitotemporal cortex (including the visual word form area (VWFA)). The direct statistical comparison revealed higher convergence of underactivation for DO compared with SO in bilateral inferior parietal regions, but this abnormality disappeared when foci resulting from stronger dyslexic task‐negative activation (i.e., deactivation relative to baseline) were excluded. Higher convergence of underactivation for DO compared with SO was further identified in the left inferior frontal gyrus (IFG) pars triangularis, left precuneus, and right superior temporal gyrus, together with higher convergence of overactivation in the left anterior insula. Higher convergence of underactivation for SO compared with DO was found in the left fusiform gyrus, left temporoparietal cortex, left IFG pars orbitalis, and left frontal operculum, together with higher convergence of overactivation in the left precentral gyrus. Taken together, the findings support the notion of a biological unity of dyslexia, with additional orthography‐specific abnormalities and presumably different compensatory mechanisms. The results are discussed in relation to current functional neuroanatomical models of developmental dyslexia. Hum Brain Mapp 37:2676–2699, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. PMID:27061464

Critical periods of vulnerability for the developing nervous system: evidence from humans and animal models.

PubMed Central

Rice, D; Barone, S

2000-01-01

Vulnerable periods during the development of the nervous system are sensitive to environmental insults because they are dependent on the temporal and regional emergence of critical developmental processes (i.e., proliferation, migration, differentiation, synaptogenesis, myelination, and apoptosis). Evidence from numerous sources demonstrates that neural development extends from the embryonic period through adolescence. In general, the sequence of events is comparable among species, although the time scales are considerably different. Developmental exposure of animals or humans to numerous agents (e.g., X-ray irradiation, methylazoxymethanol, ethanol, lead, methyl mercury, or chlorpyrifos) demonstrates that interference with one or more of these developmental processes can lead to developmental neurotoxicity. Different behavioral domains (e.g., sensory, motor, and various cognitive functions) are subserved by different brain areas. Although there are important differences between the rodent and human brain, analogous structures can be identified. Moreover, the ontogeny of specific behaviors can be used to draw inferences regarding the maturation of specific brain structures or neural circuits in rodents and primates, including humans. Furthermore, various clinical disorders in humans (e.g., schizophrenia, dyslexia, epilepsy, and autism) may also be the result of interference with normal ontogeny of developmental processes in the nervous system. Of critical concern is the possibility that developmental exposure to neurotoxicants may result in an acceleration of age-related decline in function. This concern is compounded by the fact that developmental neurotoxicity that results in small effects can have a profound societal impact when amortized across the entire population and across the life span of humans. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 8 Figure 9 Figure 12 Figure 14 Figure 16 Figure 17 PMID:10852851

Inflectional spelling deficits in developmental dyslexia.

PubMed

Egan, Joanne; Tainturier, Marie-Josèphe

2011-01-01

The goal of this study was to examine past-tense spelling deficits in developmental dyslexia and their relationship to phonological abilities, spoken morphological awareness and word specific orthographic memory. Three groups of children (28 9-year-old dyslexic, 28 chronological age-matched and 28 reading/spelling age-matched children) completed a battery of tests including spelling regularly inflected words (e.g., kissed) and matched one-morpheme words (e.g., wrist). They were also assessed on a range of tests of reading and spelling abilities and associated linguistic measures. Dyslexic children were impaired in relation to chronological age-matched controls on all measures. Furthermore, they were significantly poorer than younger reading and spelling age-matched controls at spelling inflected verbs, supporting the existence of a specific deficit in past-tense spelling in dyslexia. In addition to under-using the -ed spelling on inflected verbs, the dyslexic children were less likely to erroneously apply this spelling to one-morpheme words than younger controls. Dyslexics were also poorer than younger controls at using a consistent spelling for stems presented in isolation versus as part of an inflected word, indicating that they make less use of the morphological relations between words to support their spelling. In line with this interpretation, regression analyses revealed another qualitative difference between the spelling and reading age-matched group and the dyslexic group: while both spoken morphological awareness and orthographic word specific memory were significant predictors of the accuracy of past-tense spelling in the former group, only orthographic memory (irregular word reading and spelling) was a significant factor in the dyslexic group. Finally, we identified a subgroup of seven dyslexic children who were severely deficient in past-tense spelling. This subgroup was also significantly worse than other dyslexics and than younger controls on scores of orthographic memory. The implications of our findings for teaching and remediation strategies are discussed. Copyright © 2011 Elsevier Srl. All rights reserved.

Visual processing of multiple elements in the dyslexic brain: evidence for a superior parietal dysfunction

PubMed Central

Lobier, Muriel A.; Peyrin, Carole; Pichat, Cédric; Le Bas, Jean-François; Valdois, Sylviane

2014-01-01

The visual attention (VA) span deficit hypothesis of developmental dyslexia posits that impaired multiple element processing can be responsible for poor reading outcomes. In VA span impaired dyslexic children, poor performance on letter report tasks is associated with reduced parietal activations for multiple letter processing. While this hints towards a non-specific, attention-based dysfunction, it is still unclear whether reduced parietal activity generalizes to other types of stimuli. Furthermore, putative links between reduced parietal activity and reduced ventral occipito-temporal (vOT) in dyslexia have yet to be explored. Using functional magnetic resonance imaging, we measured brain activity in 12 VA span impaired dyslexic adults and 12 adult skilled readers while they carried out a categorization task on single or multiple alphanumeric or non-alphanumeric characters. While healthy readers activated parietal areas more strongly for multiple than single element processing (right-sided for alphanumeric and bilateral for non-alphanumeric), similar stronger multiple element right parietal activations were absent for dyslexic participants. Contrasts between skilled and dyslexic readers revealed significantly reduced right superior parietal lobule (SPL) activity for dyslexic readers regardless of stimuli type. Using a priori anatomically defined regions of interest, we showed that neural activity was reduced for dyslexic participants in both SPL and vOT bilaterally. Finally, we used multiple regressions to test whether SPL activity was related to vOT activity in each group. In the left hemisphere, SPL activity covaried with vOT activity for both normal and dyslexic readers. In contrast, in the right hemisphere, SPL activity covaried with vOT activity only for dyslexic readers. These results bring critical support to the VA interpretation of the VA Span deficit. In addition, they offer a new insight on how deficits in automatic vOT based word recognition could arise in developmental dyslexia. PMID:25071509

Perception of patterns of musical beat distribution in phonological developmental dyslexia: significant longitudinal relations with word reading and reading comprehension.

PubMed

Goswami, Usha; Huss, Martina; Mead, Natasha; Fosker, Tim; Verney, John P

2013-05-01

In a recent study, we reported that the accurate perception of beat structure in music ('perception of musical meter') accounted for over 40% of the variance in single word reading in children with and without dyslexia (Huss et al., 2011). Performance in the musical task was most strongly associated with the auditory processing of rise time, even though beat structure was varied by manipulating the duration of the musical notes. Here we administered the same musical task a year later to 88 children with and without dyslexia, and used new auditory processing measures to provide a more comprehensive picture of the auditory correlates of the beat structure task. We also measured reading comprehension and nonword reading in addition to single word reading. One year later, the children with dyslexia performed more poorly in the musical task than younger children reading at the same level, indicating a severe perceptual deficit for musical beat patterns. They now also had significantly poorer perception of sound rise time than younger children. Longitudinal analyses showed that the musical beat structure task was a significant longitudinal predictor of development in reading, accounting for over half of the variance in reading comprehension along with a linguistic measure of phonological awareness. The non-linguistic musical beat structure task is an important independent longitudinal and concurrent predictor of variance in reading attainment by children. The different longitudinal versus concurrent associations between musical beat perception and auditory processing suggest that individual differences in the perception of rhythmic timing are an important shared neural basis for individual differences in children in linguistic and musical processing. Copyright © 2012 Elsevier Ltd. All rights reserved.

Reading in French-Speaking Adults with Dyslexia

ERIC Educational Resources Information Center

Martin, Jennifer; Cole, Pascale; Leuwers, Christel; Casalis, Severine; Zorman, Michel; Sprenger-Charolles, Liliane

2010-01-01

This study investigated the reading and reading-related skills of 15 French-speaking adults with dyslexia, whose performance was compared with that of chronological-age controls (CA) and reading-level controls (RL). Experiment 1 assessed the efficiency of their phonological reading-related skills (phonemic awareness, phonological short-term…

Syntactic comprehension in reading and listening: a study with French children with dyslexia.

PubMed

Casalis, Séverine; Leuwers, Christel; Hilton, Heather

2013-01-01

This study examined syntactic comprehension in French children with dyslexia in both listening and reading. In the first syntactic comprehension task, a partial version of the Epreuve de Compréhension syntaxico-sémantique (ECOSSE test; French adaptation of Bishop's test for receptive grammar test) children with dyslexia performed at a lower level in the written but not in the spoken modality, compared to reading age-matched children, suggesting a difficulty in handling syntax while reading. In the second task, syntactic processing was further explored through a test of relative clause processing, in which inflectional markers could aid in attributing roles to the elements in a complex syntactic structure. Children with dyslexia were insensitive to inflectional markers in both reading and listening, as was the reading age control group, while only the older normal reader group appeared to make use of the inflectional markers. Overall, the results support the hypothesis that difficulties in comprehension in dyslexia are strongly related to poor reading skills.

E-Readers Are More Effective than Paper for Some with Dyslexia

PubMed Central

Schneps, Matthew H.; Thomson, Jenny M.; Chen, Chen; Sonnert, Gerhard; Pomplun, Marc

2013-01-01

E-readers are fast rivaling print as a dominant method for reading. Because they offer accessibility options that are impossible in print, they are potentially beneficial for those with impairments, such as dyslexia. Yet, little is known about how the use of these devices influences reading in those who struggle. Here, we observe reading comprehension and speed in 103 high school students with dyslexia. Reading on paper was compared with reading on a small handheld e-reader device, formatted to display few words per line. We found that use of the device significantly improved speed and comprehension, when compared with traditional presentations on paper for specific subsets of these individuals: Those who struggled most with phoneme decoding or efficient sight word reading read more rapidly using the device, and those with limited VA Spans gained in comprehension. Prior eye tracking studies demonstrated that short lines facilitate reading in dyslexia, suggesting that it is the use of short lines (and not the device per se) that leads to the observed benefits. We propose that these findings may be understood as a consequence of visual attention deficits, in some with dyslexia, that make it difficult to allocate attention to uncrowded text near fixation, as the gaze advances during reading. Short lines ameliorate this by guiding attention to the uncrowded span. PMID:24058697

Dyslexia and early intervention: what did we learn from the Dutch Dyslexia Programme?

PubMed

van der Leij, Aryan

2013-11-01

Part of the Dutch Dyslexia Programme has been dedicated to early intervention. The question of whether the genetically affected learning mechanism of children who are at familial risk (FR) of developing dyslexia could be influenced by training phoneme awareness and letter-sound associations in the prereading phase was investigated. The rationale was that intervention studies reveal insights about the weaknesses of the learning mechanisms of FR children. In addition, the studies aimed to gather practical insights to be used in the development of a system of early diagnosis and prevention. Focused on the last period of kindergarten before formal reading instruction starts in Grade 1, intervention methods with comparable samples and designs but differences in delivery mode (use of computer or manual), tutor (semi-professional or parent), location (at school or at home), and additional practices (serial rapid naming or simple word reading) have been executed to test the hypothesis that the incidence and degree of dyslexia can be reduced. The present position paper summarizes the Dutch Dyslexia Programme findings and relates them to findings of other studies. It is discussed that the Dutch studies provide evidence on why prevention of dyslexia is hard to accomplish. It is argued that effective intervention should not only start early but also be adapted to the individual and often long-lasting educational needs of children at risk of reading failure. Copyright © 2013 John Wiley & Sons, Ltd.

Genetic analysis of dyslexia candidate genes in the European cross-linguistic NeuroDys cohort.

PubMed

Becker, Jessica; Czamara, Darina; Scerri, Tom S; Ramus, Franck; Csépe, Valéria; Talcott, Joel B; Stein, John; Morris, Andrew; Ludwig, Kerstin U; Hoffmann, Per; Honbolygó, Ferenc; Tóth, Dénes; Fauchereau, Fabien; Bogliotti, Caroline; Iannuzzi, Stéphanie; Chaix, Yves; Valdois, Sylviane; Billard, Catherine; George, Florence; Soares-Boucaud, Isabelle; Gérard, Christophe-Loïc; van der Mark, Sanne; Schulz, Enrico; Vaessen, Anniek; Maurer, Urs; Lohvansuu, Kaisa; Lyytinen, Heikki; Zucchelli, Marco; Brandeis, Daniel; Blomert, Leo; Leppänen, Paavo H T; Bruder, Jennifer; Monaco, Anthony P; Müller-Myhsok, Bertram; Kere, Juha; Landerl, Karin; Nöthen, Markus M; Schulte-Körne, Gerd; Paracchini, Silvia; Peyrard-Janvid, Myriam; Schumacher, Johannes

2014-05-01

Dyslexia is one of the most common childhood disorders with a prevalence of around 5-10% in school-age children. Although an important genetic component is known to have a role in the aetiology of dyslexia, we are far from understanding the molecular mechanisms leading to the disorder. Several candidate genes have been implicated in dyslexia, including DYX1C1, DCDC2, KIAA0319, and the MRPL19/C2ORF3 locus, each with reports of both positive and no replications. We generated a European cross-linguistic sample of school-age children - the NeuroDys cohort - that includes more than 900 individuals with dyslexia, sampled with homogenous inclusion criteria across eight European countries, and a comparable number of controls. Here, we describe association analysis of the dyslexia candidate genes/locus in the NeuroDys cohort. We performed both case-control and quantitative association analyses of single markers and haplotypes previously reported to be dyslexia-associated. Although we observed association signals in samples from single countries, we did not find any marker or haplotype that was significantly associated with either case-control status or quantitative measurements of word-reading or spelling in the meta-analysis of all eight countries combined. Like in other neurocognitive disorders, our findings underline the need for larger sample sizes to validate possibly weak genetic effects.

Children with dyslexia show a reduced processing benefit from bimodal speech information compared to their typically developing peers.

PubMed

Schaadt, Gesa; van der Meer, Elke; Pannekamp, Ann; Oberecker, Regine; Männel, Claudia

2018-01-17

During information processing, individuals benefit from bimodally presented input, as has been demonstrated for speech perception (i.e., printed letters and speech sounds) or the perception of emotional expressions (i.e., facial expression and voice tuning). While typically developing individuals show this bimodal benefit, school children with dyslexia do not. Currently, it is unknown whether the bimodal processing deficit in dyslexia also occurs for visual-auditory speech processing that is independent of reading and spelling acquisition (i.e., no letter-sound knowledge is required). Here, we tested school children with and without spelling problems on their bimodal perception of video-recorded mouth movements pronouncing syllables. We analyzed the event-related potential Mismatch Response (MMR) to visual-auditory speech information and compared this response to the MMR to monomodal speech information (i.e., auditory-only, visual-only). We found a reduced MMR with later onset to visual-auditory speech information in children with spelling problems compared to children without spelling problems. Moreover, when comparing bimodal and monomodal speech perception, we found that children without spelling problems showed significantly larger responses in the visual-auditory experiment compared to the visual-only response, whereas children with spelling problems did not. Our results suggest that children with dyslexia exhibit general difficulties in bimodal speech perception independently of letter-speech sound knowledge, as apparent in altered bimodal speech perception and lacking benefit from bimodal information. This general deficit in children with dyslexia may underlie the previously reported reduced bimodal benefit for letter-speech sound combinations and similar findings in emotion perception. Copyright © 2018 Elsevier Ltd. All rights reserved.

Do students with dyslexia have a different personality profile as measured with the big five?

PubMed

Tops, Wim; Verguts, Ellen; Callens, Maaike; Brysbaert, Marc

2013-01-01

Few studies are available about the personality profile of higher education students with dyslexia and to which extent this could be any different from their non-dyslexic peers. AIMS AND SAMPLES: To obtain empirical evidence, we compared the personality profile of a group of 100 Dutch-speaking students with dyslexia with that of a control group of 100 students without learning disabilities. The NEO-PI-R based on the Big Five in personality research was used. Our study showed no differences in the personality between both groups. This agrees with a recent meta-analysis of English findings (Swanson & Hsieh, 2009), suggesting that students with dyslexia do not perceive themselves differently than their non-dyslexic peers. Practical implications and directions for future research are considered.

Deterioration of dyslexia after non-dominant temporal lobectomy for drug-resistant epilepsy.

PubMed

Haeren, Roel H L; Hendriks, Marc P H; Vlooswijk, Marielle; Verdyck, Lex; van Kranen-Mastenbroek, Vivianne H J M; Wagner, Louis; van Benthum, Sophie; Schijns, Olaf E M G

2016-03-01

We present a patient with drug-resistant right-sided temporal lobe epilepsy, caused by a ganglioglioma of the parahippocampal gyrus. Preoperatively, the patient was also known to have dyslexia. A right-sided anterior temporal lobectomy, including complete lesionectomy, was performed. Several months after the otherwise uncomplicated procedure, the patient complained about visual memory disturbances, accompanied by increased reading and spelling problems. Postoperative neuropsychological examination revealed deterioration of the visual memory functions, compared to the preoperative assessment, and consequently provided a possible explanation for worsening of the pre-existing dyslexia. In this case report, we hypothesize on the cause of this unusual deterioration and present recommendations to be included in the preoperative epilepsy surgery evaluation for patients with verbal or reading disorders such as dyslexia.

Grey Matter Alterations Co-Localize with Functional Abnormalities in Developmental Dyslexia: An ALE Meta-Analysis

PubMed Central

Linkersdörfer, Janosch; Lonnemann, Jan; Lindberg, Sven; Hasselhorn, Marcus; Fiebach, Christian J.

2012-01-01

The neural correlates of developmental dyslexia have been investigated intensively over the last two decades and reliable evidence for a dysfunction of left-hemispheric reading systems in dyslexic readers has been found in functional neuroimaging studies. In addition, structural imaging studies using voxel-based morphometry (VBM) demonstrated grey matter reductions in dyslexics in several brain regions. To objectively assess the consistency of these findings, we performed activation likelihood estimation (ALE) meta-analysis on nine published VBM studies reporting 62 foci of grey matter reduction in dyslexic readers. We found six significant clusters of convergence in bilateral temporo-parietal and left occipito-temporal cortical regions and in the cerebellum bilaterally. To identify possible overlaps between structural and functional deviations in dyslexic readers, we conducted additional ALE meta-analyses of imaging studies reporting functional underactivations (125 foci from 24 studies) or overactivations (95 foci from 11 studies ) in dyslexics. Subsequent conjunction analyses revealed overlaps between the results of the VBM meta-analysis and the meta-analysis of functional underactivations in the fusiform and supramarginal gyri of the left hemisphere. An overlap between VBM results and the meta-analysis of functional overactivations was found in the left cerebellum. The results of our study provide evidence for consistent grey matter variations bilaterally in the dyslexic brain and substantial overlap of these structural variations with functional abnormalities in left hemispheric regions. PMID:22916214

Performance of Children With Developmental Dyslexia on Two Skill Learning Tasks-Serial Reaction Time and Tower of Hanoi Puzzle: A Test of the Specific Procedural Learning Difficulties Theory.

PubMed

Vakil, Eli; Lowe, Michal; Goldfus, Carol

2015-01-01

Among the various theories proposed to explain developmental dyslexia (DD), the theory of specific procedural learning difficulties has gained certain support and is the framework for the current research. This theory claims that an inability to achieve skill automaticity explains the difficulties experienced by individuals with DD. Previous research on automaticity and DD has exhibited methodological issues such as a failure to test a range of skills. The current study broadens previous findings by delineating various reading skills correlated with several aspects of skill acquisition. Furthermore, the study utilizes two nonverbal tasks that reflect distinct types of skills: Serial Reaction Time (SRT) and the Tower of Hanoi Puzzle (TOHP). A total of 53 children aged 11 to 13 participated in the study, of whom 23 were children with DD and 30 were controls. Participants completed a test battery that consisted of reading tests, the SRT, and the TOHP. Results show no differences in learning rate between individuals with or without DD, although individuals with DD performed both tasks at a slower rate. Correlations were identified between a number of reading measures and measures of skill acquisition, expressed primarily in individuals with DD. Implications are examined in the discussion. © Hammill Institute on Disabilities 2013.

Dyslexia and Substance Use in a University Undergraduate Population.

PubMed

Wilcockson, Thomas D W; Pothos, Emmanuel M; Fawcett, Angela J

2016-01-02

A number of cognitive deficits are associated with dyslexia. However, only a limited amount of research has been performed exploring a putative link between dyslexia and substance use. As substance use is thought to involve a cognitive component, it is possible that the pattern of substance use would be different for dyslexic participants, when compared to nondyslexic controls. During the current study, a guiding hypothesis was that people with dyslexia would demonstrate less substance use than nondyslexic controls. Theories of memory activation, automaticity, and attentional bias in substance use suggest that cognitive components of substance use are important in the development and maintenance of continued substance use and it is thought that, at least some of these components, would be impaired in a dyslexic population. If the cognitive deficits displayed by dyslexics somehow impair the development of cognitive components of substance use, substance use for dyslexic participants may be less pronounced. This paper therefore examines this hypothesis by comparing substance use within dyslexic and nondyslexic participants, from an undergraduate population. This was an exploratory questionnaire-based study. Dyslexic participants (n = 35) were compared to control participants (n = 62) on a series of questions designed to measure their substance use history. The results provided preliminary evidence of a difference between dyslexic and nondyslexic substance use. Dyslexics reported a substance use history that was significantly lower than nondyslexic controls. These results are interpreted in terms of cognitive deficits within dyslexia and with reference to the cognitive model of substance use.

Past-Tense Morphology and Phonological Deficits in Children with Dyslexia and Children with Language Impairment

ERIC Educational Resources Information Center

Robertson, Erin K.; Joanisse, Marc F.; Desroches, Amy S.; Terry, Alexandra

2013-01-01

The authors investigated past-tense morphology problems in children with dyslexia compared to those classically observed in children with oral language impairment (LI). Children were tested on a past-tense elicitation task involving regulars ("look-looked"), irregulars ("take-took"), and nonwords ("murn-murned").…

Improving reading skills in students with dyslexia: the efficacy of a sublexical training with rhythmic background

PubMed Central

Bonacina, Silvia; Cancer, Alice; Lanzi, Pier Luca; Lorusso, Maria Luisa; Antonietti, Alessandro

2015-01-01

The core deficit underlying developmental dyslexia (DD) has been identified in difficulties in dynamic and rapidly changing auditory information processing, which contribute to the development of impaired phonological representations for words. It has been argued that enhancing basic musical rhythm perception skills in children with DD may have a positive effect on reading abilities because music and language share common mechanisms and thus transfer effects from the former to the latter are expected to occur. A computer-assisted training, called Rhythmic Reading Training (RRT), was designed in which reading exercises are combined with rhythm background. Fourteen junior high school students with DD took part to 9 biweekly individual sessions of 30 min in which RRT was implemented. Reading improvements after the intervention period were compared with ones of a matched control group of 14 students with DD who received no intervention. Results indicated that RRT had a positive effect on both reading speed and accuracy and significant effects were found on short pseudo-words reading speed, long pseudo-words reading speed, high frequency long words reading accuracy, and text reading accuracy. No difference in rhythm perception between the intervention and control group were found. Findings suggest that rhythm facilitates the development of reading skill because of the temporal structure it imposes to word decoding. PMID:26500581

Increased Response to Altered Auditory Feedback in Dyslexia: A Weaker Sensorimotor Magnet Implied in the Phonological Deficit

PubMed Central

Groen, Margriet A.; Ito, Takayuki; Francisco, Ana A.; Gracco, Vincent L.; Pugh, Ken R.; Verhoeven, Ludo

2017-01-01

Purpose The purpose of this study was to examine whether developmental dyslexia (DD) is characterized by deficiencies in speech sensory and motor feedforward and feedback mechanisms, which are involved in the modulation of phonological representations. Method A total of 42 adult native speakers of Dutch (22 adults with DD; 20 participants who were typically reading controls) were asked to produce /bep/ while the first formant (F1) of the /e/ was not altered (baseline), increased (ramp), held at maximal perturbation (hold), and not altered again (after-effect). The F1 of the produced utterance was measured for each trial and used for statistical analyses. The measured F1s produced during each phase were entered in a linear mixed-effects model. Results Participants with DD adapted more strongly during the ramp phase and returned to baseline to a lesser extent when feedback was back to normal (after-effect phase) when compared with the typically reading group. In this study, a faster deviation from baseline during the ramp phase, a stronger adaptation response during the hold phase, and a slower return to baseline during the after-effect phase were associated with poorer reading and phonological abilities. Conclusion The data of the current study are consistent with the notion that the phonological deficit in DD is associated with a weaker sensorimotor magnet for phonological representations. PMID:28257585

Enhancement of brain event-related potentials to speech sounds is associated with compensated reading skills in dyslexic children with familial risk for dyslexia.

PubMed

Lohvansuu, Kaisa; Hämäläinen, Jarmo A; Tanskanen, Annika; Ervast, Leena; Heikkinen, Elisa; Lyytinen, Heikki; Leppänen, Paavo H T

2014-12-01

Specific reading disability, dyslexia, is a prevalent and heritable disorder impairing reading acquisition characterized by a phonological deficit. However, the underlying mechanism of how the impaired phonological processing mediates resulting dyslexia or reading disabilities remains still unclear. Using ERPs we studied speech sound processing of 30 dyslexic children with familial risk for dyslexia, 51 typically reading children with familial risk for dyslexia, and 58 typically reading control children. We found enhanced brain responses to shortening of a phonemic length in pseudo-words (/at:a/ vs. /ata/) in dyslexic children with familial risk as compared to other groups. The enhanced brain responses were associated with better performance in behavioral phonemic length discrimination task, as well as with better reading and writing accuracy. Source analyses revealed that the brain responses of sub-group of dyslexic children with largest responses originated from a more posterior area of the right temporal cortex as compared to the responses of the other participants. This is the first electrophysiological evidence for a possible compensatory speech perception mechanism in dyslexia. The best readers within the dyslexic group have probably developed alternative strategies which employ compensatory mechanisms substituting their possible earlier deficit in phonological processing and might therefore be able to perform better in phonemic length discrimination and reading and writing accuracy tasks. However, we speculate that for reading fluency compensatory mechanisms are not that easily built and dyslexic children remain slow readers during their adult life. Copyright © 2014 Elsevier B.V. All rights reserved.

Measuring orthographic transparency and morphological-syllabic complexity in alphabetic orthographies: a narrative review.

PubMed

Borleffs, Elisabeth; Maassen, Ben A M; Lyytinen, Heikki; Zwarts, Frans

2017-01-01

This narrative review discusses quantitative indices measuring differences between alphabetic languages that are related to the process of word recognition. The specific orthography that a child is acquiring has been identified as a central element influencing reading acquisition and dyslexia. However, the development of reliable metrics to measure differences between language scripts hasn't received much attention so far. This paper therefore reviews metrics proposed in the literature for quantifying orthographic transparency, syllabic complexity, and morphological complexity of alphabetic languages. The review included searches of Web of Science, PubMed, PsychInfo, Google Scholar, and various online sources. Search terms pertained to orthographic transparency, morphological complexity, and syllabic complexity in relation to reading acquisition, and dyslexia. Although the predictive value of these metrics is promising, more research is needed to validate the value of the metrics discussed and to understand the 'developmental footprint' of orthographic transparency, morphological complexity, and syllabic complexity in the lexical organization and processing strategies.

Children with Specific Language Impairment are not impaired in the acquisition and retention of Pavlovian delay and trace conditioning of the eyeblink response☆

PubMed Central

Hardiman, Mervyn J.; Hsu, Hsin-jen; Bishop, Dorothy V.M.

2013-01-01

Three converging lines of evidence have suggested that cerebellar abnormality is implicated in developmental language and literacy problems. First, some brain imaging studies have linked abnormalities in cerebellar grey matter to dyslexia and specific language impairment (SLI). Second, theoretical accounts of both dyslexia and SLI have postulated impairments of procedural learning and automatisation of skills, functions that are known to be mediated by the cerebellum. Third, motor learning has been shown to be abnormal in some studies of both disorders. We assessed the integrity of face related regions of the cerebellum using Pavlovian eyeblink conditioning in 7–11 year-old children with SLI. We found no relationship between oral language skills or literacy skills with either delay or trace conditioning in the children. We conclude that this elementary form of associative learning is intact in children with impaired language or literacy development. PMID:24139661

[Molecular genetics of functional articulation disorder in children].

PubMed

Zhao, Yun-Jing; Ma, Hong-Wei

2012-04-01

Genetic factors are an important cause of functional articulation disorder in children. This article reviews some genes and chromosome regions associated with a genetic susceptibility to functional articulation disorders. The forkhead box P2 (FOXP2) gene on chromosome 7 is introduced in details including its structure, expression and function. The relationship between the FOXP2 gene and developmental apraxia of speech is discussed. As a transcription factor, FOXP2 gene regulates the expression of many genes. CNTNAP2 as an important target gene of FOXP2 is a key gene influencing language development. Functional articulation disorder may be developed to dyslexia, therefore some candidate regions and genes related to dyslexia, such as 3p12-13, 15q11-21, 6p22 and 1p34-36, are also introduced. ROBO1 gene in 3p12.3, ZNF280D gene, TCF12 gene, EKN1 gene in 15q21, and KIAA0319 gene in 6p22 have been candidate genes for the study of functional articulation disorder.

Beyond ;Deficit-Based; thinking in autism research. Comment on ;Implications of the idea of neurodiversity for understanding the origins of developmental disorders; by Nobuo Masataka

NASA Astrophysics Data System (ADS)

Silberman, Steve

2017-03-01

Nobuo's paper [1] marks a pioneering attempt to reconcile the provocative concept of neurodiversity - the notion that developmental disabilities like autism, dyslexia, and ADHD are not inherently pathological, but reflect natural human variations that deserve societal accommodations equivalent to those afforded to people with physical disabilities - with the ongoing effort to investigate the neurological underpinnings of these conditions. As the framework of neurodiversity rapidly gains social acceptance and influence in education, employment, service provision, and related fields, it is important for researchers to understand this concept and consider how it may inform and shape their work in the coming years. Nobuo's paper provides a useful template for these efforts.

Slowing in reading and picture naming: the effects of aging and developmental dyslexia.

PubMed

De Luca, Maria; Marinelli, Chiara Valeria; Spinelli, Donatella; Zoccolotti, Pierluigi

2017-10-01

We examined the slowing in vocal reaction times shown by dyslexic (compared to control) children with that of older (compared to younger) adults using an approach focusing on the detection of global, non-task-specific components. To address this aim, data were analyzed with reference to the difference engine (DEM) and rate and amount (RAM) models. In Experiment 1, typically developing children, children with dyslexia (both attending sixth grade), younger adults and older adults read words and non-words and named pictures. In Experiment 2, word and picture conditions were presented to dyslexic and control children attending eighth grade. In both experiments, dyslexic children were delayed in reading conditions, while they were unimpaired in naming pictures (a finding which indicates spared access to the phonological lexicon). The reading difficulty was well accounted for by a single multiplicative factor while only the residual effect of length (but not frequency and lexicality) was present after controlling for over-additivity using a linear mixed effects model with random slopes on critical variables. Older adults were slower than younger adults across reading and naming conditions. This deficit was well described by a single multiplicative factor. Thus, while slowing of information processing is limited to orthographic stimuli in dyslexic children, it cuts across verbal tasks in older adults. Overall, speed differences in groups such as dyslexic children and older adults can be effectively described with reference to deficits in domains encompassing a variety of experimental conditions rather than deficits in single specific task/conditions. The DEM and RAM prove effective in teasing out global vs. specific components of performance.