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Hale JB, Chen SA, Tan SC, Poon K, Fitzer KR, Boyd LA. Reconciling individual differences with collective needs: The juxtaposition of sociopolitical and neuroscience perspectives on remediation and compensation of student skill deficits. Trends Neurosci Educ 2016. [DOI: 10.1016/j.tine.2016.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Zoubrinetzky R, Collet G, Serniclaes W, Nguyen-Morel MA, Valdois S. Relationships between Categorical Perception of Phonemes, Phoneme Awareness, and Visual Attention Span in Developmental Dyslexia. PLoS One 2016; 11:e0151015. [PMID: 26950210 PMCID: PMC4780782 DOI: 10.1371/journal.pone.0151015] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 02/23/2016] [Indexed: 11/22/2022] Open
Abstract
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.
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Affiliation(s)
- Rachel Zoubrinetzky
- Centre Référent des Troubles du Langage et des Apprentissages, Pôle Couple-Enfant, Centre Hospitalier Universitaire, Grenoble, France
- Université Grenoble Alpes, LPNC, CS 40700, F-38058, Grenoble, France
- * E-mail:
| | - Gregory Collet
- Unité de Recherche en Neurosciences Cognitives, Centre de Recherches en Cognition et Neurosciences, Université Libre de Bruxelles, Brussels, Belgium
| | - Willy Serniclaes
- Unité de Recherche en Neurosciences Cognitives, Centre de Recherches en Cognition et Neurosciences, Université Libre de Bruxelles, Brussels, Belgium
- Laboratoire Psychologie de la Perception, CNRS, UMR 8242, and Université Paris-Descartes, Paris, France
| | - Marie-Ange Nguyen-Morel
- Centre Référent des Troubles du Langage et des Apprentissages, Pôle Couple-Enfant, Centre Hospitalier Universitaire, Grenoble, France
| | - Sylviane Valdois
- Centre Référent des Troubles du Langage et des Apprentissages, Pôle Couple-Enfant, Centre Hospitalier Universitaire, Grenoble, France
- Laboratoire de Psychologie et NeuroCognition, CNRS, UMR 5105, F-38000, Grenoble, France
- Université Grenoble Alpes, LPNC, CS 40700, F-38058, Grenoble, France
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Awadh FHR, Phénix T, Antzaka A, Lallier M, Carreiras M, Valdois S. Cross-Language Modulation of Visual Attention Span: An Arabic-French-Spanish Comparison in Skilled Adult Readers. Front Psychol 2016; 7:307. [PMID: 27014125 PMCID: PMC4779959 DOI: 10.3389/fpsyg.2016.00307] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 02/17/2016] [Indexed: 11/25/2022] Open
Abstract
In delineating the amount of orthographic information that can be processed in parallel during a single fixation, the visual attention (VA) span acts as a key component of the reading system. Previous studies focused on the contribution of VA span to normal and pathological reading in monolingual and bilingual children from different European languages, without direct cross-language comparison. In the current paper, we explored modulations of VA span abilities in three languages –French, Spanish, and Arabic– that differ in transparency, reading direction and writing systems. The participants were skilled adult readers who were native speakers of French, Spanish or Arabic. They were administered tasks of global and partial letter report, single letter identification and text reading. Their VA span abilities were assessed using tasks that require the processing of briefly presented five consonant strings (e.g., R S H F T). All five consonants had to be reported in global report but a single cued letter in partial report. Results showed that VA span was reduced in Arabic readers as compared to French or Spanish readers who otherwise show a similar high performance in the two report tasks. The analysis of VA span response patterns in global report showed a left-right asymmetry in all three languages. A leftward letter advantage was found in French and Spanish but a rightward advantage in Arabic. The response patterns were symmetric in partial report, regardless of the language. Last, a significant relationship was found between VA span abilities and reading speed but only for French. The overall findings suggest that the size of VA span, the shape of VA span response patterns and the VA Span-reading relationship are modulated by language-specific features.
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Affiliation(s)
- Faris H R Awadh
- Department of Psychology, Faculty of Arts, Al Qadisiya UniversityAl Diwaniyah, Iraq; LPNC, Laboratoire de Psychologie et NeuroCognition, Université de Grenoble-AlpesGrenoble, France
| | - Thierry Phénix
- LPNC, Laboratoire de Psychologie et NeuroCognition, Université de Grenoble-Alpes Grenoble, France
| | - Alexia Antzaka
- BCBL, Basque Center on Cognition, Brain and Language San Sebastian, Spain
| | - Marie Lallier
- BCBL, Basque Center on Cognition, Brain and Language San Sebastian, Spain
| | - Manuel Carreiras
- BCBL, Basque Center on Cognition, Brain and Language San Sebastian, Spain
| | - Sylviane Valdois
- LPNC, Laboratoire de Psychologie et NeuroCognition, Université de Grenoble-AlpesGrenoble, France; Centre National de la Recherche Scientifique, LPNC, UMR 5105Grenoble, France
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54
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Boros M, Anton JL, Pech-Georgel C, Grainger J, Szwed M, Ziegler JC. Orthographic processing deficits in developmental dyslexia: Beyond the ventral visual stream. Neuroimage 2016; 128:316-327. [PMID: 26774610 DOI: 10.1016/j.neuroimage.2016.01.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 10/29/2015] [Accepted: 01/06/2016] [Indexed: 11/24/2022] Open
Abstract
Fast effortless reading has been associated with the Visual Word Form Area (VWFA), a region in the ventral visual stream that specializes in the recognition of letter strings. Several neuroimaging studies of dyslexia revealed an underactivation of this region. However, most of these studies used reading tasks and/or were carried out on adults. Given that fluent reading is severely impaired in dyslexics, any underactivation might simply reflect a well-established reading deficit in impaired readers and could be the consequence rather than the cause of dyslexia. Here, we designed a task that does not rely on reading per se but that tapped early visual orthographic processing that forms the basis of reading. Dyslexic children aged 8-12years and age-matched controls were asked to search for letters, digits, and symbols in 5-element strings (Experiment 1). This novel task was complemented by a classic task known to activate the VWFA, namely the passive viewing of pseudowords and falsefonts (Experiment 2). We found that in addition to significant group differences in the VWFA, dyslexic children showed a significant underactivation of the middle occipital gyrus (MOG) relative to the control group. Several areas in the MOG are known for their engagement in visuospatial processing, and it has been proposed that the MOG is necessary for ordering the symbols in unfamiliar strings. Our results suggest that the VWFA deficit might be secondary to an impairment of visuospatial processing in the MOG. We argue that efficient processing in MOG in the course of reading acquisition is critical for the development of effortless fast visual word recognition in the VWFA.
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Affiliation(s)
- Marianna Boros
- Institute Of Psychology, Jagiellonian University, Kraków, Poland
| | - Jean-Luc Anton
- Centre D'IRM Fonctionnelle Cérébrale - Institut De Neurosciences De La Timone, Aix Marseille University, CNRS, Marseille, France
| | - Catherine Pech-Georgel
- Centre De Références Des Troubles D'Apprentissages, Institut du Développement de l'Enfant et de sa Communication (IDEC), Hôpital Salvator, Marseille, France
| | - Jonathan Grainger
- Laboratoire De Psychologie Cognitive, Brain And Language Research Institute, Aix-Marseille University and CNRS, Marseille, France
| | - Marcin Szwed
- Institute Of Psychology, Jagiellonian University, Kraków, Poland.
| | - Johannes C Ziegler
- Laboratoire De Psychologie Cognitive, Brain And Language Research Institute, Aix-Marseille University and CNRS, Marseille, France.
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55
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Garcia-Zapirain B, Garcia-Chimeno Y, Saralegui I, Fernandez-Ruanova B, Martinez R. Differences in effective connectivity between children with dyslexia, monocular vision and typically developing readers: A DTI study. Biomed Signal Process Control 2016. [DOI: 10.1016/j.bspc.2015.07.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Xia Z, Hoeft F, Zhang L, Shu H. Neuroanatomical anomalies of dyslexia: Disambiguating the effects of disorder, performance, and maturation. Neuropsychologia 2015; 81:68-78. [PMID: 26679527 DOI: 10.1016/j.neuropsychologia.2015.12.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 09/17/2015] [Accepted: 12/06/2015] [Indexed: 12/26/2022]
Abstract
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.
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Affiliation(s)
- Zhichao Xia
- State Key Lab of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China; Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing 100875, China; Division of Child and Adolescent Psychiatry, Department of Psychiatry, UCSF, 401 Parnassus Ave, San Francisco, CA 94143, USA
| | - Fumiko Hoeft
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, UCSF, 401 Parnassus Ave, San Francisco, CA 94143, USA; Haskins Laboratories, 300 George St #900, New Haven, CT 06511, USA; Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi Shinjuku Tokyo, 160-8582, Japan
| | - Linjun Zhang
- College of Chinese Studies, Beijing Language and Culture University, Beijing 100083, China
| | - Hua Shu
- State Key Lab of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China; Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing 100875, China.
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Abstract
The purpose of this theoretical analysis and synthesis is to indicate how left-eye sighting dominance may lead to reading failure through dysfunctional right hemisphere letter encoding. Differing compensatory strategies are postulated to lead to outcomes that include the development of the phonologically impaired and phonologically proficient subtypes of dyslexia as well as specific spelling disability. Evidence is presented indicating that these disorders might be prevented by delaying the introduction of letter writing until the age of 8 years. Early childhood speech categorization in children genetically at-risk of developing dyslexia is also considered from this perspective. Convergent support for this premature writing hypothesis is provided by a comparison with the development of the left-hand inverted writing posture.
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58
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Tamboer P, Scholte HS, Vorst HCM. Dyslexia and voxel-based morphometry: correlations between five behavioural measures of dyslexia and gray and white matter volumes. ANNALS OF DYSLEXIA 2015; 65:121-141. [PMID: 25908528 PMCID: PMC4565889 DOI: 10.1007/s11881-015-0102-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 03/04/2015] [Indexed: 05/29/2023]
Abstract
In voxel-based morphometry studies of dyslexia, the relation between causal theories of dyslexia and gray matter (GM) and white matter (WM) volume alterations is still under debate. Some alterations are consistently reported, but others failed to reach significance. We investigated GM alterations in a large sample of Dutch students (37 dyslexics and 57 non-dyslexics) with two analyses: group differences in local GM and total GM and WM volume and correlations between GM and WM volumes and five behavioural measures. We found no significant group differences after corrections for multiple comparisons although total WM volume was lower in the group of dyslexics when age was partialled out. We presented an overview of uncorrected clusters of voxels (p < 0.05, cluster size k > 200) with reduced or increased GM volume. We found four significant correlations between factors of dyslexia representing various behavioural measures and the clusters found in the first analysis. In the whole sample, a factor related to performances in spelling correlated negatively with GM volume in the left posterior cerebellum. Within the group of dyslexics, a factor related to performances in Dutch-English rhyme words correlated positively with GM volume in the left and right caudate nucleus and negatively with increased total WM volume. Most of our findings were in accordance with previous reports. A relatively new finding was the involvement of the caudate nucleus. We confirmed the multiple cognitive nature of dyslexia and suggested that experience greatly influences anatomical alterations depending on various subtypes of dyslexia, especially in a student sample.
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Affiliation(s)
- Peter Tamboer
- Department of Psychology, Faculty of Social and Behavioural Sciences, University of Amsterdam, Amsterdam, The Netherlands.
- , Weesperplein 4, Room 218, 1018XA, Amsterdam, The Netherlands.
- , Overtoom 247B, 1054HW, Amsterdam, The Netherlands.
| | - H Steven Scholte
- Department of Psychology, Faculty of Social and Behavioural Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Harrie C M Vorst
- Department of Psychology, Faculty of Social and Behavioural Sciences, University of Amsterdam, Amsterdam, The Netherlands
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59
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Saj A, Barisnikov K. Influence of spatial perception abilities on reading in school-age children. COGENT PSYCHOLOGY 2015. [DOI: 10.1080/23311908.2015.1049736] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Affiliation(s)
- Arnaud Saj
- Department of Neurology, University Hospital of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva, Switzerland
- Department of Neurosciences, Laboratory of Neurology and Imaging Cognition, University of Geneva, Geneva, Switzerland
| | - Koviljka Barisnikov
- Child Clinical Neuropsychology Unit, Department of Psychology, University of Geneva, Geneva, Switzerland
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60
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Visual attention span deficits and assessing causality in developmental dyslexia. Nat Rev Neurosci 2015; 16:225. [DOI: 10.1038/nrn3836-c2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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61
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Visual attention deficits in developmental dyslexia cannot be ascribed solely to poor reading experience. Nat Rev Neurosci 2015; 16:225. [PMID: 25790867 DOI: 10.1038/nrn3836-c1] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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62
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Lallier M, Acha J, Carreiras M. Cross-linguistic interactions influence reading development in bilinguals: a comparison between early balanced French-Basque and Spanish-Basque bilingual children. Dev Sci 2015; 19:76-89. [DOI: 10.1111/desc.12290] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 12/18/2014] [Indexed: 12/01/2022]
Affiliation(s)
- Marie Lallier
- Basque Center on Cognition; Brain and Language; San Sebastían Spain
| | - Joana Acha
- Departamento Psicología básica; UPV/EHU; San Sebastían Spain
| | - Manuel Carreiras
- Basque Center on Cognition; Brain and Language; San Sebastían Spain
- Basque Ikerbasque, Basque Foundation for Science; Bilbao Spain
- Departamento Lengua Vasca y Comunicación; UPV/EHU; Bilbao Spain
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63
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Soriano-Ferrer M, Piedra Martínez E. A review of the neurobiological basis of dyslexia in the adult population. Neurologia 2014; 32:50-57. [PMID: 25444408 DOI: 10.1016/j.nrl.2014.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 08/08/2014] [Indexed: 01/18/2023] Open
Abstract
INTRODUCTION Adult dyslexia affects about 4% of the population. However, studies on the neurobiological basis of dyslexia in adulthood are scarce compared to paediatric studies. AIM This review investigates the neurobiological basis of dyslexia in adulthood. DEVELOPMENT 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. CONCLUSION 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.
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Affiliation(s)
- M Soriano-Ferrer
- Departamento de Psicología Evolutiva y de la Educación, Facultad de Psicología, Universidad de Valencia, Valencia, España.
| | - E Piedra Martínez
- Escuela de Educación Especial, Escuela de Psicología Educativa, Facultad de Filosofía, Universidad del Azuay, Cuenca, Ecuador
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64
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Germano GD, Reilhac C, Capellini SA, Valdois S. The phonological and visual basis of developmental dyslexia in Brazilian Portuguese reading children. Front Psychol 2014; 5:1169. [PMID: 25352822 PMCID: PMC4196516 DOI: 10.3389/fpsyg.2014.01169] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 09/26/2014] [Indexed: 11/13/2022] Open
Abstract
Evidence from opaque languages suggests that visual attention processing abilities in addition to phonological skills may act as cognitive underpinnings of developmental dyslexia. We explored the role of these two cognitive abilities on reading fluency in Brazilian Portuguese, a more transparent orthography than French or English. Sixty-six children with developmental dyslexia and normal Brazilian Portuguese children participated. They were administered three tasks of phonological skills (phoneme identification, phoneme, and syllable blending) and three visual tasks (a letter global report task and two non-verbal tasks of visual closure and visual constancy). Results show that Brazilian Portuguese children with developmental dyslexia are impaired not only in phonological processing but further in visual processing. The phonological and visual processing abilities significantly and independently contribute to reading fluency in the whole population. Last, different cognitively homogeneous subtypes can be identified in the Brazilian Portuguese population of children with developmental dyslexia. Two subsets of children with developmental dyslexia were identified as having a single cognitive disorder, phonological or visual; another group exhibited a double deficit and a few children showed no visual or phonological disorder. Thus the current findings extend previous data from more opaque orthographies as French and English, in showing the importance of investigating visual processing skills in addition to phonological skills in children with developmental dyslexia whatever their language orthography transparency.
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Affiliation(s)
- Giseli D Germano
- Investigation Learning Disabilities Laboratory, Department of Speech and Hearing Sciences, São Paulo State University Marília, Brazil
| | - Caroline Reilhac
- Department of Cognitive Science, Johns Hopkins University Baltimore, MD, USA
| | - Simone A Capellini
- Investigation Learning Disabilities Laboratory, Department of Speech and Hearing Sciences, São Paulo State University Marília, Brazil
| | - Sylviane Valdois
- Centre National de la Recherche Scientifique, UMR 5105 Grenoble, France ; Laboratoire de Psychologie and Neurocognition, Université Grenoble Alpes Grenoble, France
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65
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Carreiras M, Quiñones I, Hernández-Cabrera JA, Duñabeitia JA. Orthographic Coding: Brain Activation for Letters, Symbols, and Digits. Cereb Cortex 2014; 25:4748-60. [PMID: 25077489 DOI: 10.1093/cercor/bhu163] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The present experiment investigates the input coding mechanisms of 3 common printed characters: letters, numbers, and symbols. Despite research in this area, it is yet unclear whether the identity of these 3 elements is processed through the same or different brain pathways. In addition, some computational models propose that the position-in-string coding of these elements responds to general flexible mechanisms of the visual system that are not character-specific, whereas others suggest that the position coding of letters responds to specific processes that are different from those that guide the position-in-string assignment of other types of visual objects. Here, in an fMRI study, we manipulated character position and character identity through the transposition or substitution of 2 internal elements within strings of 4 elements. Participants were presented with 2 consecutive visual strings and asked to decide whether they were the same or different. The results showed: 1) that some brain areas responded more to letters than to numbers and vice versa, suggesting that processing may follow different brain pathways; 2) that the left parietal cortex is involved in letter identity, and critically in letter position coding, specifically contributing to the early stages of the reading process; and that 3) a stimulus-specific mechanism for letter position coding is operating during orthographic processing.
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Affiliation(s)
- Manuel Carreiras
- Basque Center of Cognition, Brain and Language (BCBL), Donostia, Spain Ikerbasque, Basque Foundation for Science, Bilbao, Spain Department of Basque Language and Communication, University of the Basque Country EHU/UPV, Bilbao, Spain
| | - Ileana Quiñones
- Basque Center of Cognition, Brain and Language (BCBL), Donostia, Spain
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66
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Lobier MA, Peyrin C, Pichat C, Le Bas JF, Valdois S. Visual processing of multiple elements in the dyslexic brain: evidence for a superior parietal dysfunction. Front Hum Neurosci 2014; 8:479. [PMID: 25071509 PMCID: PMC4083222 DOI: 10.3389/fnhum.2014.00479] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 06/13/2014] [Indexed: 11/13/2022] Open
Abstract
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.
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Affiliation(s)
- Muriel A Lobier
- Laboratoire de Psychologie et NeuroCognition, Université Grenoble Alpes Grenoble, France ; Neuroscience Center, University of Helsinki Helsinki, Finland
| | - Carole Peyrin
- Laboratoire de Psychologie et NeuroCognition, Université Grenoble Alpes Grenoble, France ; CNRS, Laboratoire de Psychologie et NeuroCognition UMR5105, Grenoble, France
| | - Cédric Pichat
- Laboratoire de Psychologie et NeuroCognition, Université Grenoble Alpes Grenoble, France ; CNRS, Laboratoire de Psychologie et NeuroCognition UMR5105, Grenoble, France
| | - Jean-François Le Bas
- INSERM U836/Université Joseph Fourier - Institut des Neurosciences Grenoble, France
| | - Sylviane Valdois
- Laboratoire de Psychologie et NeuroCognition, Université Grenoble Alpes Grenoble, France ; CNRS, Laboratoire de Psychologie et NeuroCognition UMR5105, Grenoble, France
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67
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Zoubrinetzky R, Bielle F, Valdois S. New insights on developmental dyslexia subtypes: heterogeneity of mixed reading profiles. PLoS One 2014; 9:e99337. [PMID: 24918441 PMCID: PMC4053380 DOI: 10.1371/journal.pone.0099337] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Accepted: 05/14/2014] [Indexed: 11/19/2022] Open
Abstract
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.
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Affiliation(s)
- Rachel Zoubrinetzky
- Centre Référent de Diagnostic des Troubles du Langage et des Apprentissages, Pôle Couple-Enfant, Centre Hospitalier Universitaire, Grenoble, France
- Laboratoire de Psychologie et NeuroCognition, CNRS, UMR 5105, Université Grenoble Alpes, Grenoble, France
- * E-mail:
| | - Frédérique Bielle
- Centre Référent de Diagnostic des Troubles du Langage et des Apprentissages, Pôle Couple-Enfant, Centre Hospitalier Universitaire, Grenoble, France
| | - Sylviane Valdois
- Centre Référent de Diagnostic des Troubles du Langage et des Apprentissages, Pôle Couple-Enfant, Centre Hospitalier Universitaire, Grenoble, France
- Laboratoire de Psychologie et NeuroCognition, CNRS, UMR 5105, Université Grenoble Alpes, Grenoble, France
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68
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Heim S, Pape-Neumann J, van Ermingen-Marbach M, Brinkhaus M, Grande M. Shared vs. specific brain activation changes in dyslexia after training of phonology, attention, or reading. Brain Struct Funct 2014; 220:2191-207. [PMID: 24802381 DOI: 10.1007/s00429-014-0784-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 04/17/2014] [Indexed: 11/29/2022]
Abstract
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.
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Affiliation(s)
- Stefan Heim
- Department of Psychiatry, Psychotherapy, and Psychosomatics, Uniklinik RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany,
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69
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Lallier M, Valdois S, Lassus-Sangosse D, Prado C, Kandel S. Impact of orthographic transparency on typical and atypical reading development: evidence in French-Spanish bilingual children. RESEARCH IN DEVELOPMENTAL DISABILITIES 2014; 35:1177-1190. [PMID: 24559885 DOI: 10.1016/j.ridd.2014.01.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 01/17/2014] [Accepted: 01/23/2014] [Indexed: 06/03/2023]
Abstract
The present study aimed to quantify cross-linguistic modulations of the contribution of phonemic awareness skills and visual attention span (VA Span) skills (number of visual elements that can be processed simultaneously) to reading speed and accuracy in 18 Spanish-French balanced bilingual children with and without developmental dyslexia. The children were administered two similar reading batteries in French and Spanish. The deficits of the dyslexic children in reading accuracy were mainly visible in their opaque orthography (French) whereas difficulties indexed by reading speed were observed in both their opaque and transparent orthographies. Dyslexic children did not exhibit any phonemic awareness problems in French or in Spanish, but showed poor VA Span skills compared to their control peers. VA span skills correlated with reading accuracy and speed measures in both Spanish and French, whereas phonemic awareness correlated with reading accuracy only. Overall, the present results show that the VA Span is tightly related to reading speed regardless of orthographic transparency, and that it accounts for differences in reading performance between good and poor readers across languages. The present findings further suggest that VA Span skills may play a particularly important role in building-up specific word knowledge which is critical for lexical reading strategies.
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Affiliation(s)
- Marie Lallier
- Basque Center on Cognition, Brain and Language, San Sebastian, Spain.
| | - Sylviane Valdois
- Université Grenoble Alpes, Laboratoire de Psychologie et NeuroCognition, Grenoble, France; Centre National pour la Recherche Scientifique, France
| | - Delphine Lassus-Sangosse
- Centre de Diagnostic des troubles du langage et des apprentissages, Département de pédiatrie CHU Nord, Grenoble, France
| | - Chloé Prado
- Centre Hospitalier Universitaire de Grenoble, France
| | - Sonia Kandel
- Université Grenoble Alpes, Laboratoire de Psychologie et NeuroCognition, Grenoble, France; GIPSA-Lab, CNRS UMR 5216, Grenoble, France; Institut Universitaire de France, Paris, France
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70
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Dyslexia in a French–Spanish bilingual girl: Behavioural and neural modulations following a visual attention span intervention. Cortex 2014; 53:120-45. [PMID: 24508158 DOI: 10.1016/j.cortex.2013.11.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 11/16/2013] [Accepted: 11/18/2013] [Indexed: 11/20/2022]
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71
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Ihnen SKZ, Petersen SE, Schlaggar BL. Separable roles for attentional control sub-systems in reading tasks: a combined behavioral and fMRI study. ACTA ACUST UNITED AC 2013; 25:1198-218. [PMID: 24275830 PMCID: PMC4397571 DOI: 10.1093/cercor/bht313] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Attentional control is important both for learning to read and for performing difficult reading tasks. A previous study invoked 2 mechanisms to explain reaction time (RT) differences between reading tasks with variable attentional demands. The present study combined behavioral and neuroimaging measures to test the hypotheses that there are 2 mechanisms of interaction between attentional control and reading; that these mechanisms are dissociable both behaviorally and neuro-anatomically; and that the 2 mechanisms involve functionally separable control systems. First, RT evidence was found in support of the 2-mechanism model, corroborating the previous study. Next, 2 sets of brain regions were identified as showing functional magnetic resonance imaging blood oxygen level-dependent activity that maps onto the 2-mechanism distinction. One set included bilateral Cingulo-opercular regions and mostly right-lateralized Dorsal Attention regions (CO/DA+). This CO/DA+ region set showed response properties consistent with a role in reporting which processing pathway (phonological or lexical) was biased for a particular trial. A second set was composed primarily of left-lateralized Frontal-parietal (FP) regions. Its signal properties were consistent with a role in response checking. These results demonstrate how the subcomponents of attentional control interact with subcomponents of reading processes in healthy young adults.
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Affiliation(s)
| | - Steven E Petersen
- Department of Neurology Department of Radiology Department of Anatomy and Neurobiology Department of Neurosurgery and Department of Psychology and Department of Biomedical Engineering, Washington University in St. Louis, 1 Brookings Dr, St Louis, MO 63130, USA
| | - Bradley L Schlaggar
- Department of Neurology Department of Radiology Department of Anatomy and Neurobiology Department of Pediatrics, Washington University in St. Louis School of Medicine, 660 S Euclid Ave, St Louis, MO 63110, USA
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Vieira S, Quercia P, Bonnetblanc F, Michel C. Space representation in children with dyslexia and children without dyslexia: contribution of line bisection and circle centering tasks. RESEARCH IN DEVELOPMENTAL DISABILITIES 2013; 34:3997-4008. [PMID: 24036389 DOI: 10.1016/j.ridd.2013.08.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 08/17/2013] [Accepted: 08/19/2013] [Indexed: 06/02/2023]
Abstract
Line bisection tasks (different space locations and different line lengths) and circle centering tasks (visuo-proprioceptive and proprioceptive explorations, with left or right starting positions) were used to investigate space representation in children with dyslexia and children without dyslexia. In line bisection, children with dyslexia showed a significant rightward bias for central and right-sided locations and a leftward bias for left-sided location. Furthermore, the spatial context processing was asymmetrically more efficient in the left space. In children without dyslexia, no significant bias was observed in central lines but the spatial context processing was symmetrical in both spaces. When the line length varied, no main effect was shown. These results strengthen the 'inverse pseudoneglect' hypothesis in dyslexia. In the lateral dimension of the circle centering tasks, children showed a response bias in the direction of the starting hand location for proprioceptive condition. For radial dimension, the children showed a forward bias in visuo-proprioceptive condition and more backward error in proprioceptive condition. Children with dyslexia showed a forward bias in clockwise exploration and more accurate performance in counterclockwise exploration for left starting position which may be in accordance with leftward asymmetrical spatial context processing in line bisection. These results underline the necessity to use the line bisection task with different locations as an appropriate experimental paradigm to study lateral representational bias in dyslexia. The contribution of the present results in the understanding of space representation in children with dyslexia and children without dyslexia is discussed in terms of attentional processes and neuroanatomical substrate.
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Affiliation(s)
- Stéphanie Vieira
- Université de Bourgogne, Dijon, Campus Universitaire, UFR STAPS, BP 27877, F-21078 Dijon, France; INSERM U1093, Cognition, Action et Plasticité Sensorimotrice, F-21078 Dijon, France
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73
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Fernandes T, Vale AP, Martins B, Morais J, Kolinsky R. The deficit of letter processing in developmental dyslexia: combining evidence from dyslexics, typical readers and illiterate adults. Dev Sci 2013; 17:125-41. [DOI: 10.1111/desc.12102] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 06/10/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Tânia Fernandes
- Faculty of Psychology and Education Sciences; Universidade do Porto; Portugal
| | - Ana P. Vale
- Dyslexia Unit, Department of Education and Psychology; Universidade de Trás-os-Montes e Alto Douro; Portugal
| | - Bruno Martins
- Dyslexia Unit, Department of Education and Psychology; Universidade de Trás-os-Montes e Alto Douro; Portugal
| | - José Morais
- Unité de recherche en Neurosciences Cognitives (UNESCOG); Center for Research in Cognition and Neurosciences (CRCN); Université Libre de Bruxelles; Belgium
| | - Régine Kolinsky
- Unité de recherche en Neurosciences Cognitives (UNESCOG); Center for Research in Cognition and Neurosciences (CRCN); Université Libre de Bruxelles; Belgium
- Fonds de la Recherche Scientifique-FNRS; Belgium
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74
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Lallier M, Donnadieu S, Valdois S. Investigating the role of visual and auditory search in reading and developmental dyslexia. Front Hum Neurosci 2013; 7:597. [PMID: 24093014 PMCID: PMC3782690 DOI: 10.3389/fnhum.2013.00597] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 09/03/2013] [Indexed: 12/02/2022] Open
Abstract
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.
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Affiliation(s)
- Marie Lallier
- Basque Center on Cognition Brain and Language Donostia-San Sebastian, Spain
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75
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Schneps MH, Thomson JM, Chen C, Sonnert G, Pomplun M. E-readers are more effective than paper for some with dyslexia. PLoS One 2013; 8:e75634. [PMID: 24058697 PMCID: PMC3776763 DOI: 10.1371/journal.pone.0075634] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 08/15/2013] [Indexed: 11/19/2022] Open
Abstract
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.
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Affiliation(s)
- Matthew H. Schneps
- Science Education Department, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, United States of America
| | - Jenny M. Thomson
- Harvard Graduate School of Education, Harvard University, Cambridge, Massachusetts, United States of America
| | - Chen Chen
- Science Education Department, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, United States of America
- Harvard Graduate School of Education, Harvard University, Cambridge, Massachusetts, United States of America
| | - Gerhard Sonnert
- Science Education Department, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, United States of America
| | - Marc Pomplun
- Department of Computer Science, University of Massachusetts, Boston, Massachusetts, United States of America
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Advances in experimental psychopatholinguistics: What can we learn from simulation of disorder-like symptoms in human volunteers? Adv Cogn Psychol 2013; 9:102-11. [PMID: 23833697 PMCID: PMC3700744 DOI: 10.2478/v10053-008-0137-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 04/04/2013] [Indexed: 11/21/2022] Open
Abstract
For more than a century, work on patients with acquired or developmental language
disorders has informed psycholinguistic models of normal linguistic processing
in healthy persons. On the other hand, such models of healthy language
processing have been used as blue-prints to gain further insights into the
impairments of patients with language pathologies. Against the exemplary
background of language production, the first part of this paper reflects this
relationship and formulates a desideratum for naturalistic albeit controlled
experimental settings. Two recent examples of behavioural and neurofunctional
research are presented in which aphasia-like speech symptoms were elicited in
healthy control subjects. In the second part, this idea to investigate
disorder-like symptoms which are being experimentally induced for the course of
the study is further pursued in the field of reading and dyslexia research.
Here, it is argued, again on the basis of behavioural and neurofunctional data,
that such an approach is advantageous in at least two respects: 1. It allows a much more stringent control of experimental factors and confounds
than could be potentially achieved in a clinical setting. 2. It allows in-extenso piloting of experiments with healthy volunteers before
actually recruiting selected (and sometimes rare) patients. It will be concluded that the experimental simulation of disorder-like symptoms
in easily accessible healthy volunteers may be a useful approach to understand
novel aspects of a language disorder on the basis of a human neurocognitive
model of this disorder.
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Lallier M, Donnadieu S, Valdois S. Developmental dyslexia: exploring how much phonological and visual attention span disorders are linked to simultaneous auditory processing deficits. ANNALS OF DYSLEXIA 2013; 63:97-116. [PMID: 22829423 DOI: 10.1007/s11881-012-0074-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 06/28/2012] [Indexed: 05/21/2023]
Abstract
The simultaneous auditory processing skills of 17 dyslexic children and 17 skilled readers were measured using a dichotic listening task. Results showed that the dyslexic children exhibited difficulties reporting syllabic material when presented simultaneously. As a measure of simultaneous visual processing, visual attention span skills were assessed in the dyslexic children. We presented the dyslexic children with a phonological short-term memory task and a phonemic awareness task to quantify their phonological skills. Visual attention spans correlated positively with individual scores obtained on the dichotic listening task while phonological skills did not correlate with either dichotic scores or visual attention span measures. Moreover, all the dyslexic children with a dichotic listening deficit showed a simultaneous visual processing deficit, and a substantial number of dyslexic children exhibited phonological processing deficits whether or not they exhibited low dichotic listening scores. These findings suggest that processing simultaneous auditory stimuli may be impaired in dyslexic children regardless of phonological processing difficulties and be linked to similar problems in the visual modality.
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Affiliation(s)
- Marie Lallier
- Basque Center on Cognition, Brain and Language, Paseo Mikeletegi 69, 2nd Floor, 20009 Donostia, Spain.
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78
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Abstract
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.
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Affiliation(s)
- Patrick Quercia
- Department of Ophthalmology, University Hospital, Dijon, France
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Szalkowski CE, Booker AB, Truong DT, Threlkeld SW, Rosen GD, Fitch RH. Knockdown of the candidate dyslexia susceptibility gene homolog dyx1c1 in rodents: effects on auditory processing, visual attention, and cortical and thalamic anatomy. Dev Neurosci 2013; 35:50-68. [PMID: 23594585 DOI: 10.1159/000348431] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 01/23/2013] [Indexed: 12/24/2022] Open
Abstract
The current study investigated the behavioral and neuroanatomical effects of embryonic knockdown of the candidate dyslexia susceptibility gene (CDSG) homolog Dyx1c1 through RNA interference (RNAi) in rats. Specifically, we examined long-term effects on visual attention abilities in male rats, in addition to assessing rapid and complex auditory processing abilities in male and, for the first time, female rats. Our results replicated prior evidence of complex acoustic processing deficits in Dyx1c1 male rats and revealed new evidence of comparable deficits in Dyx1c1 female rats. Moreover, we found new evidence that knocking down Dyx1c1 produced orthogonal impairments in visual attention in the male subgroup. Stereological analyses of male brains from prior RNAi studies revealed that, despite consistent visible evidence of disruptions of neuronal migration (i.e., heterotopia), knockdown of Dyx1c1 did not significantly alter the cortical volume, hippocampal volume, or midsagittal area of the corpus callosum (measured in a separate cohort of like-treated Dyx1c1 male rats). Dyx1c1 transfection did, however, lead to significant changes in medial geniculate nucleus (MGN) anatomy, with a significant shift to smaller MGN neurons in Dyx1c1-transfected animals. Combined results provide important information about the impact of Dyx1c1 on behavioral functions that parallel domains known to be affected in language-impaired populations as well as information about widespread changes to the brain following early disruption of this CDSG.
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Affiliation(s)
- Caitlin E Szalkowski
- Department of Psychology/Behavioral Neuroscience, University of Connecticut, Storrs, Conn. 06269, USA.
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80
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Lallier M, Carreiras M, Tainturier MJ, Savill N, Thierry G. Orthographic transparency modulates the grain size of orthographic processing: Behavioral and ERP evidence from bilingualism. Brain Res 2013; 1505:47-60. [DOI: 10.1016/j.brainres.2013.02.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 02/07/2013] [Accepted: 02/11/2013] [Indexed: 11/30/2022]
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Szalkowski CE, Fiondella CF, Truong DT, Rosen GD, LoTurco JJ, Fitch RH. The effects of Kiaa0319 knockdown on cortical and subcortical anatomy in male rats. Int J Dev Neurosci 2013; 31:116-22. [PMID: 23220223 PMCID: PMC3689304 DOI: 10.1016/j.ijdevneu.2012.11.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 11/20/2012] [Accepted: 11/21/2012] [Indexed: 12/13/2022] Open
Abstract
Developmental dyslexia is a disorder characterized by a specific deficit in reading despite adequate overall intelligence and educational resources. The neurological substrate underlying these significant behavioral impairments is not known. Studies of post mortem brain tissue from male and female dyslexic individuals revealed focal disruptions of neuronal migration concentrated in the left hemisphere, along with aberrant symmetry of the right and left the planum temporale, and changes in cell size distribution within the medial geniculate nucleus of the thalamus (Galaburda et al., 1985; Humphreys et al., 1990). More recent neuroimaging studies have identified several changes in the brains of dyslexic individuals, including regional changes in gray matter, changes in white matter, and changes in patterns of functional activation. In a further effort to elucidate the etiology of dyslexia, epidemiological and genetic studies have identified several candidate dyslexia susceptibility genes. Some recent work has investigated associations between some of these genetic variants and structural changes in the brain. Variants of one candidate dyslexia susceptibility gene, KIAA0319, have been linked to morphological changes in the cerebellum and functional activational changes in the superior temporal sulcus (Jamadar et al., 2011; Pinel et al., 2012). Animal models have been used to create a knockdown of Kiaa0319 (the rodent homolog of the human gene) via in utero RNA interference in order to study the gene's effects on brain development and behavior. Studies using this animal model have demonstrated that knocking down the gene leads to focal disruptions of neuronal migration in the form of ectopias and heterotopias, similar to those observed in the brains of human dyslexics. However, further changes to the structure of the brain have not been studied following this genetic disruption. The current study sought to determine the effects of embryonic Kiaa0319 knockdown on volume of the cortex and hippocampus, as well as midsagittal area of the corpus callosum in male rats. Results demonstrate that Kiaa0319 knockdown did not change the volume of the cortex or hippocampus, but did result in a significant reduction in the midsagittal area of the corpus callosum. Taken in the context of previous reports of behavioral deficits following Kiaa0319 knockdown (Szalkowski et al., 2012), and reports that reductions of corpus callosum size are related to processing deficits in humans (Paul, 2011), these results suggest that Kiaa0319 has a specific involvement in neural systems important for temporal processing.
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Affiliation(s)
- Caitlin E Szalkowski
- Department of Psychology/Behavioral Neuroscience, University of Connecticut, Storrs, 06269, United States.
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Reilhac C, Peyrin C, Démonet JF, Valdois S. Role of the superior parietal lobules in letter-identity processing within strings: FMRI evidence from skilled and dyslexicreaders. Neuropsychologia 2013; 51:601-12. [PMID: 23270676 DOI: 10.1016/j.neuropsychologia.2012.12.010] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Revised: 12/10/2012] [Accepted: 12/17/2012] [Indexed: 10/27/2022]
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83
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Koyama MS, Di Martino A, Kelly C, Jutagir DR, Sunshine J, Schwartz SJ, Castellanos FX, Milham MP. Cortical signatures of dyslexia and remediation: an intrinsic functional connectivity approach. PLoS One 2013; 8:e55454. [PMID: 23408984 PMCID: PMC3569450 DOI: 10.1371/journal.pone.0055454] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 12/28/2012] [Indexed: 02/06/2023] Open
Abstract
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.
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Affiliation(s)
- Maki S. Koyama
- Rutgers University Center for Molecular and Behavioral Neuroscience, Newark, New Jersey, United States of America
- Phyllis Green and Randolph Cowen Institute for Pediatric Neuroscience, New York University Child Study Center, NYU Langone Medical Center, New York, New York, United States of America
- * E-mail:
| | - Adriana Di Martino
- Phyllis Green and Randolph Cowen Institute for Pediatric Neuroscience, New York University Child Study Center, NYU Langone Medical Center, New York, New York, United States of America
| | - Clare Kelly
- Phyllis Green and Randolph Cowen Institute for Pediatric Neuroscience, New York University Child Study Center, NYU Langone Medical Center, New York, New York, United States of America
| | - Devika R. Jutagir
- Phyllis Green and Randolph Cowen Institute for Pediatric Neuroscience, New York University Child Study Center, NYU Langone Medical Center, New York, New York, United States of America
| | - Jessica Sunshine
- Phyllis Green and Randolph Cowen Institute for Pediatric Neuroscience, New York University Child Study Center, NYU Langone Medical Center, New York, New York, United States of America
| | - Susan J. Schwartz
- Center for the Developing Brain, Child Mind Institute, New York, New York, United States of America
| | - Francisco X. Castellanos
- Phyllis Green and Randolph Cowen Institute for Pediatric Neuroscience, New York University Child Study Center, NYU Langone Medical Center, New York, New York, United States of America
- Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, United States of America
| | - Michael P. Milham
- Center for the Developing Brain, Child Mind Institute, New York, New York, United States of America
- Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, United States of America
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84
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On the importance of considering individual profiles when investigating the role of auditory sequential deficits in developmental dyslexia. Cognition 2013; 126:121-7. [PMID: 23040058 DOI: 10.1016/j.cognition.2012.09.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Revised: 09/10/2012] [Accepted: 09/10/2012] [Indexed: 11/22/2022]
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85
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Reilhac C, Jucla M, Iannuzzi S, Valdois S, Démonet JF. Effect of orthographic processes on letter identity and letter-position encoding in dyslexic children. Front Psychol 2012; 3:154. [PMID: 22661961 PMCID: PMC3356879 DOI: 10.3389/fpsyg.2012.00154] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Accepted: 04/27/2012] [Indexed: 11/23/2022] Open
Abstract
The ability to identify letters and encode their position is a crucial step of the word recognition process. However and despite their word identification problem, the ability of dyslexic children to encode letter identity and letter-position within strings was not systematically investigated. This study aimed at filling this gap and further explored how letter identity and letter-position encoding is modulated by letter context in developmental dyslexia. For this purpose, a letter-string comparison task was administered to French dyslexic children and two chronological age (CA) and reading age (RA)-matched control groups. Children had to judge whether two successively and briefly presented four-letter strings were identical or different. Letter-position and letter identity were manipulated through the transposition (e.g., RTGM vs. RMGT) or substitution of two letters (e.g., TSHF vs. TGHD). Non-words, pseudo-words, and words were used as stimuli to investigate sub-lexical and lexical effects on letter encoding. Dyslexic children showed both substitution and transposition detection problems relative to CA-controls. A substitution advantage over transpositions was only found for words in dyslexic children whereas it extended to pseudo-words in RA-controls and to all type of items in CA-controls. Letters were better identified in the dyslexic group when belonging to orthographically familiar strings. Letter-position encoding was very impaired in dyslexic children who did not show any word context effect in contrast to CA-controls. Overall, the current findings point to a strong letter identity and letter-position encoding disorder in developmental dyslexia.
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Affiliation(s)
- Caroline Reilhac
- Imagerie Cérébrale et Handicaps Neurologiques, INSERM, UMRS 825, Université Toulouse III Paul SabatierToulouse, France
| | - Mélanie Jucla
- EA Octogone – Laboratoire Jacques-Lordat (EA 4156), Université Toulouse II Le MirailToulouse, France
| | - Stéphanie Iannuzzi
- Imagerie Cérébrale et Handicaps Neurologiques, INSERM, UMRS 825, Université Toulouse III Paul SabatierToulouse, France
| | - Sylviane Valdois
- Laboratoire de Psychologie et Neuro-Cognition, CNRS, UMR 5105, Université Pierre Mendès FranceGrenoble, France
| | - Jean-François Démonet
- Imagerie Cérébrale et Handicaps Neurologiques, INSERM, UMRS 825, Université Toulouse III Paul SabatierToulouse, France
- Leenaards Memory Center, CHUV and University of LausanneLausanne, Switzerland
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