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Panahi R, Akbari M, Jarollahi F, Haghani H, Kazemnezhad Leyli E, Zia M. Atypical function of auditory sensory gating in children with developmental dyslexia: Investigating its relationship with cognitive abilities. DYSLEXIA (CHICHESTER, ENGLAND) 2023; 29:426-440. [PMID: 37779260 DOI: 10.1002/dys.1754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 06/24/2023] [Accepted: 09/12/2023] [Indexed: 10/03/2023]
Abstract
Impairments of auditory processing are among frequent findings in dyslexia. However, it is unclear how auditory signals are gated from brainstem to higher central processing stages in these individuals. The present study was done to investigate auditory sensory gating in children with developmental dyslexia (DD), and to determine whether sensory gating correlates with performance on behavioural tasks. Auditory sensory gating at P50, N1 and P2 waves was evaluated in two groups including 20 children with DD and 19 children with typical reading development (TRD). Behavioural tests were used to evaluate phonological working memory (PWM) and selective attention abilities. Sensory gating in children with DD was significantly less efficient than their peers at P50, N1 and P2 waves. Lower auditory evoked potential (AEP) amplitudes were found in the DD group. The children with TRD scored better in all the behavioural tests. Relationships were reported between sensory gating at P50, N1, P2 and behavioural performance in the two groups. Children with dyslexia had deficient sensory gating in comparison with controls. In addition, children with dyslexia experienced problems with PWM and selective attention tasks. The function of sensory gating was associated with attentional and PWM performances in this group.
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Affiliation(s)
- Rasool Panahi
- Otorhinolaryngology Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
- Department of Audiology, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Mehdi Akbari
- Department of Audiology, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Farnoush Jarollahi
- Department of Audiology, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Hamid Haghani
- Department of Biostatistics, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Ehsan Kazemnezhad Leyli
- Department of Biostatistics, Guilan Road Trauma Research Center, Guilan University of Medical Sciences, Rasht, Iran
| | - Maryam Zia
- Otorhinolaryngology Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
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2
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Pellegrino M, Ben-Soussan TD, Paoletti P. A Scoping Review on Movement, Neurobiology and Functional Deficits in Dyslexia: Suggestions for a Three-Fold Integrated Perspective. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:3315. [PMID: 36834011 PMCID: PMC9966639 DOI: 10.3390/ijerph20043315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/08/2023] [Accepted: 02/12/2023] [Indexed: 06/18/2023]
Abstract
Developmental dyslexia is a common complex neurodevelopmental disorder. Many theories and models tried to explain its symptomatology and find ways to improve poor reading abilities. The aim of this scoping review is to summarize current findings and several approaches and theories, focusing on the interconnectedness between motion, emotion and cognition and their connection to dyslexia. Consequently, we present first a brief overview of the main theories and models regarding dyslexia and its proposed neural correlates, with a particular focus on cerebellar regions and their involvement in this disorder. After examining different types of intervention programs and remedial training, we highlight the effects of a specific structured sensorimotor intervention named Quadrato Motor Training (QMT). QMT utilizes several cognitive and motor functions known to be relevant in developmental dyslexia. We introduce its potential beneficial effects on reading skills, including working memory, coordination and attention. We sum its effects ranging from behavioral to functional, structural and neuroplastic, especially in relation to dyslexia. We report several recent studies that employed this training technique with dyslexic participants, discussing the specific features that distinguish it from other training within the specific framework of the Sphere Model of Consciousness. Finally, we advocate for a new perspective on developmental dyslexia integrating motion, emotion and cognition to fully encompass this complex disorder.
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Affiliation(s)
- Michele Pellegrino
- Research Institute for Neuroscience, Education and Didactics, Patrizio Paoletti Foundation for Development and Communication, 06081 Assisi, Italy
| | - Tal Dotan Ben-Soussan
- Research Institute for Neuroscience, Education and Didactics, Patrizio Paoletti Foundation for Development and Communication, 06081 Assisi, Italy
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3
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Cheviet A, Bonnefond A, Bertrand F, Maumy-Bertrand M, Doignon-Camus N. How visual attention span and phonological skills contribute to N170 print tuning: An EEG study in French dyslexic students. BRAIN AND LANGUAGE 2022; 234:105176. [PMID: 36063725 DOI: 10.1016/j.bandl.2022.105176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 08/17/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
Developmental dyslexia is a disorder characterized by a sustainable learning deficit in reading. Based on ERP-driven approaches focusing on the visual word form area, electrophysiological studies have pointed a lack of visual expertise for written word recognition in dyslexic readers by contrasting the left-lateralized N170 amplitudes elicited by alphabetic versus non-alphabetic stimuli. Here, we investigated in 22 dyslexic participants and 22 age-matched control subjects how two behavioural abilities potentially affected in dyslexic readers (phonological and visual attention skills) contributed to the N170 expertise during a word detection task. Consistent with literature, dyslexic participants exhibited poorer performance in these both abilities as compared to healthy subjects. At the brain level, we observed (1) an unexpected preservation of the N170 expertise in the dyslexic group suggesting a possible compensatory mechanism and (2) a modulation of this expertise only by phonological skills, providing evidence for the phonological mapping deficit hypothesis.
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Affiliation(s)
- Alexis Cheviet
- Department of Psychology, Durham University, South Road, Durham DH1 3LE, United Kingdom.
| | - Anne Bonnefond
- Department of Psychiatry, University of Strasbourg, INSERM U1114, Strasbourg, France
| | - Frédéric Bertrand
- LIST3N, Université de Technologie de Troyes, Troyes, France; Institut de Recherche Mathématique Avancée, CNRS UMR 7501, Labex IRMIA, Université de Strasbourg, Strasbourg, France
| | - Myriam Maumy-Bertrand
- LIST3N, Université de Technologie de Troyes, Troyes, France; Institut de Recherche Mathématique Avancée, CNRS UMR 7501, Labex IRMIA, Université de Strasbourg, Strasbourg, France
| | - Nadège Doignon-Camus
- LISEC UR 2310, University of Strasbourg, University of Haute-Alsace, University of Lorraine, Strasbourg, France
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4
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Siegelman N, van den Bunt MR, Lo JCM, Rueckl JG, Pugh KR. Theory-driven classification of reading difficulties from fMRI data using Bayesian latent-mixture models. Neuroimage 2021; 242:118476. [PMID: 34416399 PMCID: PMC8494078 DOI: 10.1016/j.neuroimage.2021.118476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 07/19/2021] [Accepted: 08/13/2021] [Indexed: 11/29/2022] Open
Abstract
Decades of research have led to several competing theories regarding the neural contributors to impaired reading. But how can we know which theory (or theories) identifies the types of markers that indeed differentiate between individuals with reading disabilities (RD) and their typically developing (TD) peers? To answer this question, we propose a new analytical tool for theory evaluation and comparison, grounded in the Bayesian latent-mixture modeling framework. We start by constructing a series of latent-mixture classification models, each reflecting one existing theoretical claim regarding the neurofunctional markers of RD (highlighting network-level differences in either mean activation, inter-subject heterogeneity, inter-region variability, or connectivity). Then, we run each model on fMRI data alone (i.e., while models are blind to participants' behavioral status), which enables us to interpret the fit between a model's classification of participants and their behavioral (known) RD/TD status as an estimate of its explanatory power. Results from n=127 adolescents and young adults (RD: n=59; TD: n=68) show that models based on network-level differences in mean activation and heterogeneity failed to differentiate between TD and RD individuals. In contrast, classifications based on variability and connectivity were significantly associated with participants' behavioral status. These findings suggest that differences in inter-region variability and connectivity may be better network-level markers of RD than mean activation or heterogeneity (at least in some populations and tasks). More broadly, the results demonstrate the promise of latent-mixture modeling as a theory-driven tool for evaluating different theoretical claims regarding neural contributors to language disorders and other cognitive traits.
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Affiliation(s)
| | | | | | - Jay G Rueckl
- Haskins Laboratories, USA; University of Connecticut, USA
| | - Kenneth R Pugh
- Haskins Laboratories, USA; University of Connecticut, USA; Yale University, USA
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5
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Fraenz C, Schlüter C, Friedrich P, Jung RE, Güntürkün O, Genç E. Interindividual differences in matrix reasoning are linked to functional connectivity between brain regions nominated by Parieto-Frontal Integration Theory. INTELLIGENCE 2021. [DOI: 10.1016/j.intell.2021.101545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
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Li H, Booth JR, Feng X, Wei N, Zhang M, Zhang J, Zhong H, Lu C, Liu L, Ding G, Meng X. Functional parcellation of the right cerebellar lobule VI in children with normal or impaired reading. Neuropsychologia 2020; 148:107630. [PMID: 32976851 DOI: 10.1016/j.neuropsychologia.2020.107630] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 09/06/2020] [Accepted: 09/14/2020] [Indexed: 12/27/2022]
Abstract
Neuroimaging studies have reported that the right cerebellar lobule VI is engaged in reading, but its role is unclear. The goal of our study was to identify functionally-dissociable subregions in the right lobule VI and how these subregions contribute to reading in children with normal or impaired reading. In Experiment I, typically developing children performed an orthographic task and a phonological task during functional magnetic resonance imaging (fMRI). We classified the voxels in the right lobule VI into seven zones based on the patterns of functional connectivity with the cerebrum across both tasks. In Experiment II, we compared the brain activation and cerebro-cerebellar connectivities of each subregion between children readers with different reading levels. We did not find significant group differences in cerebellar activation. However, we found that impaired readers had considerably higher functional connectivity between R1 and the right angular gyrus and the right precuneus compared to the control group in the phonological task. These findings show that the right cerebellar lobule VI is functionally parceled and its subregions might be differentially connected with the cerebrum between children with normal reading abilities and those with impaired reading.
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Affiliation(s)
- Hehui Li
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China
| | - James R Booth
- Department of Psychology and Human Development, Vanderbilt University, Nashville, TN, 37203-5721, USA
| | - Xiaoxia Feng
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China
| | - Na Wei
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China
| | - Manli Zhang
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, 100871, China
| | - Jia Zhang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China
| | - Hejing Zhong
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China
| | - Chunming Lu
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China
| | - Li Liu
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China
| | - Guosheng Ding
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China.
| | - Xiangzhi Meng
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, 100871, China; PekingU-PolyU Center for Child Development and Learning, Peking University, Beijing, 100871, China.
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7
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Bosch-Bayard J, Girini K, Biscay RJ, Valdes-Sosa P, Evans AC, Chiarenza GA. Resting EEG effective connectivity at the sources in developmental dysphonetic dyslexia. Differences with non-specific reading delay. Int J Psychophysiol 2020; 153:135-147. [DOI: 10.1016/j.ijpsycho.2020.04.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 04/21/2020] [Accepted: 04/24/2020] [Indexed: 02/07/2023]
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8
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Cummine J, Villarena M, Onysyk T, Devlin JT. A Study of Null Effects for the Use of Transcranial Direct Current Stimulation (tDCS) in Adults With and Without Reading Impairment. NEUROBIOLOGY OF LANGUAGE (CAMBRIDGE, MASS.) 2020; 1:434-451. [PMID: 36793290 PMCID: PMC9923690 DOI: 10.1162/nol_a_00020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 07/19/2020] [Indexed: 05/09/2023]
Abstract
UNLABELLED There is evidence to support the hypothesis that the delivery of anodal transcranial direct current stimulation (tDCS) to the left temporoparietal junction can enhance performance on reading speed and reading accuracy (Costanzo et al., 2016b; Heth & Lavidor, 2015). Here, we explored whether we could demonstrate similar effects in adults with and without reading impairments. METHOD Adults with (N = 33) and without (N = 29) reading impairment were randomly assigned to anodal or sham stimulation conditions. All individuals underwent a battery of reading assessments pre and post stimulation. The stimulation session involved 15 min of anodal/sham stimulation over the left temporoparietal junction while concurrently completing a computerized nonword segmentation task known to activate the temporoparietal junction. RESULTS There were no conclusive findings that anodal stimulation impacted reading performance for skilled or impaired readers. CONCLUSIONS While tDCS may provide useful gains on reading performance in the paediatric population, much more work is needed to establish the parameters under which such findings would transfer to adult populations. The documentation, reporting, and interpreting of null effects of tDCS are immensely important to a field that is growing exponentially with much uncertainty.
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Affiliation(s)
| | - Miya Villarena
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - Taylor Onysyk
- Communication Sciences and Disorders, University of Alberta, Edmonton, Canada
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9
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Riccio CA, Hynd GW. Contributions of Neuropsychology to Our Understanding of Developmental Reading Problems. SCHOOL PSYCHOLOGY REVIEW 2019. [DOI: 10.1080/02796015.1995.12085778] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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10
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Zhou A, Duan B, Wen M, Wu W, Li M, Ma X, Tan Y. Self-Referential Processing Can Modulate Visual Spatial Attention Deficits in Children With Dyslexia. Front Psychol 2019; 10:2270. [PMID: 31636595 PMCID: PMC6788299 DOI: 10.3389/fpsyg.2019.02270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 09/23/2019] [Indexed: 11/13/2022] Open
Abstract
Considerable research has shown that children with dyslexia have deficits in visual spatial attention orientation. Additionally, self-referential processing makes self-related information play a unique role in the individual visual spatial attention orientation. However, it is unclear whether such self-referential processing impacts the visual spatial attention orientation of children with dyslexia. Therefore, we manipulated the reference task systematically in the cue-target paradigm and investigated the modulation effect of self-referential processing on visual spatial attention of children with dyslexia. In the self-referential processing condition, we observed that children with dyslexia demonstrated stable cue effects in the visual spatial attention orientation tasks when the Stimulus Onset Asynchronies (SOAs) were set to 100 ms, while other-referential processing weakened the cue effects of the visual spatial attention orientation of children with dyslexia. With cue effect as the index, we also observed that the self-referential processing had a significant larger regulatory effect at the early stage of visual spatial attention orientation, as compared with other-referential processing. These differences have a high-ranked consistency between children with dyslexia and typically developing reader. The results suggested that self-referential processing can regulate the visual spatial attention deficits of children with dyslexia.
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Affiliation(s)
- Aibao Zhou
- School of Psychology, Northwest Normal University, Lanzhou, China.,Key Laboratory of Behavioral and Mental Health, Lanzhou, China
| | - Baojun Duan
- School of Psychology, Northwest Normal University, Lanzhou, China.,School of Teacher Education, Hexi University, Zhangye, China
| | - Menglin Wen
- School of Psychology, Northwest Normal University, Lanzhou, China
| | - Wenyi Wu
- School of Psychology, Northwest Normal University, Lanzhou, China
| | - Mei Li
- School of Psychology, Northwest Normal University, Lanzhou, China.,School of Education, Lanzhou City University, Lanzhou, China
| | - Xiaofeng Ma
- School of Psychology, Northwest Normal University, Lanzhou, China
| | - Yanggang Tan
- School of Psychology, Northwest Normal University, Lanzhou, China
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11
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Moreau D, Stonyer JE, McKay NS, Waldie KE. No evidence for systematic white matter correlates of dyslexia: An Activation Likelihood Estimation meta-analysis. Brain Res 2019; 1683:36-47. [PMID: 29456133 DOI: 10.1016/j.brainres.2018.01.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 01/11/2018] [Accepted: 01/12/2018] [Indexed: 01/18/2023]
Abstract
Dyslexia is a prevalent neurodevelopmental disorder, characterized by reading and spelling difficulties. Beyond the behavioral and functional correlates of this condition, a growing number of studies have explored structural differences between individuals with dyslexia and typically developing individuals. To date, findings remain disparate - some studies suggest differences in fractional anisotropy (FA), an indirect measure of white matter integrity, whereas others do not identify significant disparities. Here, we synthesized the existing literature on this topic by conducting a meta-analysis of Diffusion Tensor Imaging (DTI) studies investigating white matter correlates of dyslexia via voxel-based analyses (VBA) of FA. Our results showed no reliable clusters underlying differences between dyslexics and typical individuals, after correcting for multiple comparisons (false discovery rate correction). Because group comparisons might be too coarse to yield subtle differences, we further explored differences in FA as a function of reading ability, measured on a continuous scale. Consistent with our initial findings, reading ability was not associated with reliable differences in white matter integrity. These findings nuance the current view of profound, structural differences underlying reading ability and its associated disorders, and suggest that their neural correlates might be more subtle than previously thought.
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Affiliation(s)
- David Moreau
- Centre for Brain Research, School of Psychology, University of Auckland, New Zealand.
| | - Josephine E Stonyer
- Centre for Brain Research, School of Psychology, University of Auckland, New Zealand
| | - Nicole S McKay
- Centre for Brain Research, School of Psychology, University of Auckland, New Zealand
| | - Karen E Waldie
- Centre for Brain Research, School of Psychology, University of Auckland, New Zealand
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12
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Menashe S. Spatial selective attention and asynchrony of cognitive systems in adult dyslexic readers: an ERPs and behavioral study. ANNALS OF DYSLEXIA 2018; 68:145-164. [PMID: 29931552 DOI: 10.1007/s11881-018-0160-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 06/05/2018] [Indexed: 06/08/2023]
Abstract
The aim of this study was to gain additional knowledge about the asynchrony phenomenon in developmental dyslexia, especially when spatial selective attention is manipulated. Adults with developmental dyslexia and non-impaired readers underwent two experimental tasks, one including alphabetic stimuli (pre-lexical consonant-vowel syllables) and the other containing non-alphabetic stimuli (pictures and sounds of animals). Participants were instructed to attend to the right or left hemifields and to respond to all stimuli on that hemifield. Behavioral parameters and event-related potentials were recorded. The main finding was that the dyslexic readers demonstrated asynchrony between the auditory and visual modalities when alphabetic stimuli were presented on the right hemifield. These results suggest that intact reading is linked to a synchronized auditory and visual speed of processing even when spatial selective attention is manipulated. The findings of the current study are discussed in terms of asynchrony between modalities as a neurocognitive marker in developmental dyslexia.
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Affiliation(s)
- Shay Menashe
- The Edmond J. Safra Brain Research Center for the Study of Learning Disabilities, Faculty of Education, University of Haifa, 31905, Mt. Carmel, Haifa, Israel.
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13
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Handler SM, Fierson WM. Reading difficulties and the pediatric ophthalmologist. J AAPOS 2017; 21:436-442. [PMID: 28939535 DOI: 10.1016/j.jaapos.2017.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 09/14/2017] [Indexed: 11/15/2022]
Abstract
Approximately 20% of children have dyslexia, a language-based reading disability. A variation in language processing in the brain leads to a deficit in phonological (auditory) processing, which leads to problems in learning to read, write, and spell. Myths continue to exist regarding dyslexia and vision, and although eye and vision problems may coexist with dyslexia, they are not more prevalent than in the general population. Rarely vision problems may make reading at near very difficult and may masquerade as a learning problem or attention deficit disorder/attention deficit hyperactivity disorder. The pediatric ophthalmologist can play a valuable role in determining whether any eye or vision problems exist that might interfere with learning or reading. Treatments to improve these eye conditions may help make reading more comfortable, but they are not a therapy for coexisting dyslexia. The use of vision therapy has never been shown scientifically to be effective and may prevent the application of effective interventions during the critical period of development when reading disorders can best be remediated. The pediatric ophthalmologist should educate parents about reading and dyslexia and provide prompt referral to professionals who have expertise in evaluating and treating learning disabilities.
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14
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Diagnosis of developmental learning and attention disorders in adults: A review of clinical modalities. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.npbr.2016.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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15
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Shaywitz BA, Shaywitz SE, Pugh KR, Skudlarski P, Fulbright RK, Constable R, Fletcher JM, Liberman AM, Shankweiler DP, Katz L, Bronen RA, Marchione KE, Lacadie C, Gore JC. The Functional Organization of Brain for Reading and Reading Disability (Dyslexia. Neuroscientist 2016. [DOI: 10.1177/107385849600200413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Converging evidence from many lines of investigation now indicates that dyslexia (reading disability) represents a disorder affecting linguistic systems in brain. Furthermore, these studies point to deficits in one particular component of the language system—phonological processing—as the most severe, robust, and consistent findings in children and adults with dyslexia (the "phonological deficit" hypothesis). Until recently, the cerebral localization of those processes related to reading have been elusive, in no small measure because as uniquely human activities, language and reading can be studied only in humans. Within the last year, it has become possible to use functional magnetic resonance imaging (fMRI) to localize the component processes used in reading: orthography, phonology, and lexical-semantic processing. We found that in men phonological processing was lateralized to the left inferior frontal gyrus (IFG, Broca's area); in contrast, in women performance of a phonological task produced bilateral activation of this region. These findings provide the first clear evidence of sex differences in the functional organization of the brain for language and indicate that these differences exist at the level of phonological processing. Not only do these findings support and extend a long-held hypothesis suggesting that language functions are more likely to be highly lateralized in males, but, of particular relevance to the scientific study of reading and reading disability, these data suggest that the activation of the IFG region during the performance of a rhyming task may provide a neural "signature" for phonological processing, the core cognitive component in reading and reading disability. NEUROSCIENTIST 2:245-255, 1996
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Affiliation(s)
| | | | - Kenneth R. Pugh
- Department of Pediatrics, Haskins Laboratories, Department of Diagnostic Radiology (PS, RKF, RTC, RAB,
CL, JCG); Yale Umversity School of Medicine
| | - Pawel Skudlarski
- Haskins Laboratories, Department of Diagnostic Radiology (PS, RKF, RTC, RAB,
CL, JCG); Yale Umversity School of Medicine
| | - Robert K. Fulbright
- Haskins Laboratories, Department of Diagnostic Radiology (PS, RKF, RTC, RAB,
CL, JCG); Yale Umversity School of Medicine
| | - R.Todd Constable
- Haskins Laboratories, Department of Diagnostic Radiology (PS, RKF, RTC, RAB,
CL, JCG); Yale Umversity School of Medicine
| | - Jack M. Fletcher
- Department of Diagnostic Radiology (PS, RKF, RTC, RAB,
CL, JCG); Yale Umversity School of Medicine, Department of Pediatrics, University of Texas Medical
School-Houston
| | - Alvin M. Liberman
- Department of Diagnostic Radiology (PS, RKF, RTC, RAB,
CL, JCG); Yale Umversity School of Medicine
| | - Donald P. Shankweiler
- Department of Diagnostic Radiology (PS, RKF, RTC, RAB,
CL, JCG); Yale Umversity School of Medicine
| | - Leonard Katz
- Department of Diagnostic Radiology (PS, RKF, RTC, RAB,
CL, JCG); Yale Umversity School of Medicine
| | - Richard A. Bronen
- Haskins Laboratories, Department of Diagnostic Radiology (PS, RKF, RTC, RAB,
CL, JCG); Yale Umversity School of Medicine
| | | | - Cheryl Lacadie
- Haskins Laboratories, Department of Diagnostic Radiology (PS, RKF, RTC, RAB,
CL, JCG); Yale Umversity School of Medicine
| | - John C. Gore
- Haskins Laboratories, Department of Diagnostic Radiology (PS, RKF, RTC, RAB,
CL, JCG); Yale Umversity School of Medicine, Department of Applied Physics, Yale University
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16
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Gabay Y, Shamay-Tsoory SG, Goldfarb L. Cognitive and emotional empathy in typical and impaired readers and its relationship to reading competence. J Clin Exp Neuropsychol 2016; 38:1131-43. [DOI: 10.1080/13803395.2016.1199663] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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17
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Fitch RH, Tallal P. Neural Mechanisms of Language-Based Learning Impairments: Insights from Human Populations and Animal Models. ACTA ACUST UNITED AC 2016; 2:155-78. [PMID: 15006291 DOI: 10.1177/1534582303258736] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The acquisition of speech perception and consequent expression of language represent fundamental aspects of human functioning. Yet roughly 7% to 8% of children who are otherwise healthy and of normal intelligence exhibit unexplained delays and impairments in acquiring these skills. Ongoing research has revealed several key features of language disability that may pro-vide more direct insight into underlying anomalous neural functioning. For example, evidence supports a strong association between basic defects in processing rapidly changing acoustic information and emergent disruptions in speech perception, as well as cascading effects on other forms of language development (including reading). Considerable neurobiological research has thus focused on developmental factors that might deleteriously influence rapid sensory processing. Additional research focuses on mechanisms of neural plasticity, including how such brains might be “retrained” for improved processing of language. These and related findings from human clinical studies, electrophysiological studies, neuroimaging studies, and animal models are reviewed.
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Papagiannopoulou EA, Lagopoulos J. Resting State EEG Hemispheric Power Asymmetry in Children with Dyslexia. Front Pediatr 2016; 4:11. [PMID: 26942169 PMCID: PMC4764697 DOI: 10.3389/fped.2016.00011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 02/10/2016] [Indexed: 11/13/2022] Open
Abstract
Dyslexia is a neurodevelopmental disorder estimated to affect between 4 and 7% of the population. It is often referred to as a learning disability and is characterized by deficits in the linguistic system. To better understand the neural underpinnings of dyslexia, we examined the electroencephalography (EEG) power spectra between pre-adolescents with dyslexia and neurotypical control children during eyes closed state. We reported the differences in spontaneous oscillatory activity of each major EEG band (delta, theta, alpha, and beta) adopting a global as well as in a region-by-region and hemispheric approach to elucidate whether there are changes in asymmetry in children with dyslexia compared to controls. We also examined the relationship between EEG power spectra and clinical variables. The findings of our study confirm the presence of an atypical linguistic network, evident in children with dyslexia. This abnormal network hallmarked by a dominance of theta activity suggests that these abnormalities are present prior to these children learning to read, thus implicating delayed maturation and abnormal hypoarousal mechanisms.
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Affiliation(s)
| | - Jim Lagopoulos
- Brain and Mind Research Institute, University of Sydney, Camperdown, NSW, Australia; Sunshine Coast Mind and Neuroscience - Thompson Institute, University of the Sunshine Coast, Birtinya, QLD, Australia
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Hurschler MA, Liem F, Oechslin M, Stämpfli P, Meyer M. fMRI reveals lateralized pattern of brain activity modulated by the metrics of stimuli during auditory rhyme processing. BRAIN AND LANGUAGE 2015; 147:41-50. [PMID: 26025759 DOI: 10.1016/j.bandl.2015.05.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 03/09/2015] [Accepted: 05/04/2015] [Indexed: 06/04/2023]
Abstract
Our fMRI study investigates auditory rhyme processing in spoken language to further elucidate the topic of functional lateralization of language processing. During scanning, 14 subjects listened to four different types of versed word strings and subsequently performed either a rhyme or a meter detection task. Our results show lateralization to auditory-related temporal regions in the right hemisphere irrespective of task. As for the left hemisphere we report responses in the supramarginal gyrus as well as in the opercular part of the inferior frontal gyrus modulated by the presence of regular meter and rhyme. The interaction of rhyme and meter was associated with increased involvement of the superior temporal sulcus and the putamen of the right hemisphere. Overall, these findings support the notion of right-hemispheric specialization for suprasegmental analyses during processing of spoken sentences and provide neuroimaging evidence for the influence of metrics on auditory rhyme processing.
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Affiliation(s)
- Martina A Hurschler
- Univ Zurich, Inst Psychol, Neuroplasticity and Learning in the Healthy Aging Brain (HAB LAB), Zurich, Switzerland.
| | - Franziskus Liem
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Univ Zurich, International Normal Aging and Plasticity Imaging Center, Zurich, Switzerland
| | - Mathias Oechslin
- Univ Zurich, International Normal Aging and Plasticity Imaging Center, Zurich, Switzerland
| | - Philipp Stämpfli
- Univ Zurich, MR-Center of the Psychiatric University Hospital and the Department of Child and Adolescent Psychiatry, Zurich, Switzerland; Univ Zurich, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, Zurich, Switzerland
| | - Martin Meyer
- Univ Zurich, Inst Psychol, Neuroplasticity and Learning in the Healthy Aging Brain (HAB LAB), Zurich, Switzerland; Univ Zurich, International Normal Aging and Plasticity Imaging Center, Zurich, Switzerland; University Research Priority Program "Dynamics of Healthy Aging", University of Zurich, Switzerland; Univ Klagenfurt, Inst Psychol, Div Cognitive Neuroscience, Klagenfurt, Austria
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20
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Thomson JM, Doruk D, Mascio B, Fregni F, Cerruti C. Transcranial direct current stimulation modulates efficiency of reading processes. Front Hum Neurosci 2015; 9:114. [PMID: 25852513 PMCID: PMC4360704 DOI: 10.3389/fnhum.2015.00114] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 02/16/2015] [Indexed: 11/18/2022] Open
Abstract
Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that offers promise as an investigative method for understanding complex cognitive operations such as reading. This study explores the ability of a single session of tDCS to modulate reading efficiency and phonological processing performance within a group of healthy adults. Half the group received anodal or cathodal stimulation, on two separate days, of the left temporo-parietal junction while the other half received anodal or cathodal stimulation of the right homologue area. Pre- and post-stimulation assessment of reading efficiency and phonological processing was carried out. A larger pre-post difference in reading efficiency was found for participants who received right anodal stimulation compared to participants who received left anodal stimulation. Further, there was a significant post-stimulation increase in phonological processing speed following right hemisphere anodal stimulation. Implications for models of reading and reading impairment are discussed.
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Affiliation(s)
| | - Deniz Doruk
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School Boston, MA, USA
| | - Bryan Mascio
- Harvard Graduate School of Education Cambridge, MA, USA
| | - Felipe Fregni
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School Boston, MA, USA
| | - Carlo Cerruti
- Harvard Graduate School of Education Cambridge, MA, USA
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21
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Pollack C, Luk G, Christodoulou JA. A meta-analysis of functional reading systems in typically developing and struggling readers across different alphabetic languages. Front Psychol 2015; 6:191. [PMID: 25806009 PMCID: PMC4354279 DOI: 10.3389/fpsyg.2015.00191] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 02/05/2015] [Indexed: 11/26/2022] Open
Abstract
Functional neuroimaging research has identified multiple brain regions supporting reading-related activity in typical and atypical readers across different alphabetic languages. Previous meta-analyses performed on these functional magnetic resonance imaging findings typically report significant between-group contrasts comparing typical readers and readers with reading difficulty or a clinical diagnosis of developmental dyslexia. In order to advance our understanding of cross-linguistic convergence of reading-related brain activations for these reader groups, analyses using activation likelihood estimation were carried out separately for typical and atypical readers who ranged from children to adults. Contrasts were analyzed for tasks involving rhyming or reading of letter or word stimuli presented visually in English, Dutch, Italian, German, French, or Norwegian. Typical readers showed reliable activation in only left lateralized regions, including the inferior frontal area, precentral area and middle temporal gyrus. Atypical readers also showed activation in the left inferior frontal area and precentral region, in addition to significant activations in the right hemisphere, including the superior, medial and inferior frontal regions, lingual gyrus and the inferior occipital area. These results distinguish between typical and atypical reader group activations, showing common and distinct regions of activation when engaged in reading-related activities, extending previous meta-analyses on identifying brain regions relevant to reading to include cross-linguistic analyses for alphabetic scripts. Results support the universality of a signature pattern of brain activation in developmental dyslexia across alphabetic languages.
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Affiliation(s)
| | - Gigi Luk
- Harvard Graduate School of Education Cambridge, MA, USA
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22
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Ma Y, Koyama MS, Milham MP, Castellanos FX, Quinn BT, Pardoe H, Wang X, Kuzniecky R, Devinsky O, Thesen T, Blackmon K. Cortical thickness abnormalities associated with dyslexia, independent of remediation status. Neuroimage Clin 2014; 7:177-86. [PMID: 25610779 PMCID: PMC4300011 DOI: 10.1016/j.nicl.2014.11.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Revised: 10/18/2014] [Accepted: 11/11/2014] [Indexed: 11/11/2022]
Abstract
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.
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Affiliation(s)
- Yizhou Ma
- Department of Neurology, Comprehensive Epilepsy Center, School of Medicine, New York University, New York, NY, USA
- Department of Psychology, New York University, New York, NY, USA
| | - Maki S. Koyama
- Child Mind Institute, New York, NY, USA
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Michael P. Milham
- Child Mind Institute, New York, NY, USA
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - F. Xavier Castellanos
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA
- Child Study Center at NYU Langone Medical Center, New York, NY, USA
- Department of Radiology, School of Medicine, New York University, New York, NY, USA
| | - Brian T. Quinn
- Department of Neurology, Comprehensive Epilepsy Center, School of Medicine, New York University, New York, NY, USA
| | - Heath Pardoe
- Department of Neurology, Comprehensive Epilepsy Center, School of Medicine, New York University, New York, NY, USA
| | - Xiuyuan Wang
- Department of Neurology, Comprehensive Epilepsy Center, School of Medicine, New York University, New York, NY, USA
| | - Ruben Kuzniecky
- Department of Neurology, Comprehensive Epilepsy Center, School of Medicine, New York University, New York, NY, USA
| | - Orrin Devinsky
- Department of Neurology, Comprehensive Epilepsy Center, School of Medicine, New York University, New York, NY, USA
| | - Thomas Thesen
- Department of Neurology, Comprehensive Epilepsy Center, School of Medicine, New York University, New York, NY, USA
- Department of Radiology, School of Medicine, New York University, New York, NY, USA
| | - Karen Blackmon
- Department of Neurology, Comprehensive Epilepsy Center, School of Medicine, New York University, New York, NY, USA
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Paulesu E, Danelli L, Berlingeri M. Reading the dyslexic brain: multiple dysfunctional routes revealed by a new meta-analysis of PET and fMRI activation studies. Front Hum Neurosci 2014; 8:830. [PMID: 25426043 PMCID: PMC4227573 DOI: 10.3389/fnhum.2014.00830] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 09/29/2014] [Indexed: 02/01/2023] Open
Abstract
Developmental dyslexia has been the focus of much functional anatomical research. The main trust of this work is that typical developmental dyslexics have a dysfunction of the phonological and orthography to phonology conversion systems, in which the left occipito-temporal cortex has a crucial role. It remains to be seen whether there is a systematic co-occurrence of dysfunctional patterns of different functional systems perhaps converging on the same brain regions associated with the reading deficit. Such evidence would be relevant for theories like, for example, the magnocellular/attentional or the motor/cerebellar ones, which postulate a more basic and anatomically distributed disorder in dyslexia. We addressed this issue with a meta-analysis of all the imaging literature published until September 2013 using a combination of hierarchical clustering and activation likelihood estimation methods. The clustering analysis on 2360 peaks identified 193 clusters, 92 of which proved spatially significant. Following binomial tests on the clusters, we found left hemispheric network specific for normal controls (i.e., of reduced involvement in dyslexics) including the left inferior frontal, premotor, supramarginal cortices and the left infero-temporal and fusiform regions: these were preferentially associated with reading and the visual-to-phonology processes. There was also a more dorsal left fronto-parietal network: these clusters included peaks from tasks involving phonological manipulation, but also motoric or visuo-spatial perception/attention. No cluster was identified in area V5 for no task, nor cerebellar clusters showed a reduced association with dyslexics. We conclude that the examined literature demonstrates a specific lack of activation of the left occipito-temporal cortex in dyslexia particularly for reading and reading-like behaviors and for visuo-phonological tasks. Additional deficits of motor and attentional systems relevant for reading may be associated with altered functionality of dorsal left fronto-parietal cortex.
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Affiliation(s)
- Eraldo Paulesu
- Department of Psychology, University of Milano-Bicocca Milan, Italy ; NEUROMI- Milan Center for Neuroscience, University of Milano-Bicocca Milan, Italy ; fMRI - Unit, Istituto di Ricovero e Cura a Carattere Scientifico Galeazzi Milan, Italy
| | - Laura Danelli
- Department of Psychology, University of Milano-Bicocca Milan, Italy ; NEUROMI- Milan Center for Neuroscience, University of Milano-Bicocca Milan, Italy
| | - Manuela Berlingeri
- Department of Psychology, University of Milano-Bicocca Milan, Italy ; NEUROMI- Milan Center for Neuroscience, University of Milano-Bicocca Milan, Italy
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24
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Elmer S, Jäncke L. Intracerebral functional connectivity-guided neurofeedback as a putative rehabilitative intervention for ameliorating auditory-related dysfunctions. Front Psychol 2014; 5:1227. [PMID: 25400606 PMCID: PMC4212614 DOI: 10.3389/fpsyg.2014.01227] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 10/09/2014] [Indexed: 01/25/2023] Open
Abstract
Electroencephalography (EEG) constitutes one of the most eligible candidates for neurofeedback applications, principally due to its excellent temporal resolution best reflecting the natural dynamics of brain processes. In addition, EEG is easy to use and provides the opportunity for mobile applications. In the present opinion article, we pinpoint the advantages of using intracerebral functional connectivity (IFC) instead of quantitative scalp EEG for interventional applications. In fact, due to the convergence of multiple signals originating from different spatial locations and electrophysiological interactions, miscellaneous scalp signals are too unspecific for therapeutic neurofeedback applications. Otherwise, IFC opens novel perspectives for influencing brain activity in specific dysfunctional small- and large-scale neuronal networks with a reasonable spatial resolution. In the present article, we propose concrete interventional IFC applications that may be used to ameliorate auditory-related dysfunctions such as developmental dyslexia.
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Affiliation(s)
- Stefan Elmer
- Division Neuropsychology, Institute of Psychology, University of ZurichZurich, Switzerland
| | - Lutz Jäncke
- Division Neuropsychology, Institute of Psychology, University of ZurichZurich, Switzerland
- Center for Integrative Human PhysiologyZurich, Switzerland
- International Normal Aging and Plasticity Imaging CenterZurich, Switzerland
- Research Unit for Plasticity and Learning of the Healthy Aging Brain, University of ZurichZurich, Switzerland
- Dynamic of Healthy Aging, University Research Priority Program University of ZurichSwitzerland
- Department of Special Education, King Abdulaziz UniversityJeddah, Saudi Arabia
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25
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Tailby C, Weintrob DL, Saling MM, Fitzgerald C, Jackson GD. Reading difficulty is associated with failure to lateralize temporooccipital function. Epilepsia 2014; 55:746-753. [PMID: 24725071 DOI: 10.1111/epi.12607] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2014] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Studies of focal epilepsy have revealed abnormalities of language organization; however, little attention has been paid to disorders of reading in this group. We hypothesized that language functional magnetic resonance imaging (fMRI) would reveal differences in language organization between focal epilepsy patients with and without reading difficulties. METHODS We conducted language fMRI studies of 10 focal epilepsy patients with reading difficulties, 34 focal epilepsy patients without reading difficulties, and 42 healthy controls. RESULTS We defined regions of interests on the basis of activation patterns on an orthographic lexical retrieval task. Comparison of activations within these ROIs on a second Noun-Verb task revealed epilepsy-related effects (relative to healthy controls: reduced activation in left inferior frontal cortex), as well as greater activation in the right temporooccipital cortex specific to the reading difficulty group. SIGNIFICANCE These findings identify a focal epilepsy effect in the left frontal region (present in patients with and without reading difficulties), and a functional abnormality specific to the reading difficulty group localized to right temporooccipital cortex-a region implicated in lexicosemantic processing. Our observations suggest a failure of left hemisphere specialization among focal epilepsy patients with reading difficulties.
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Affiliation(s)
- Chris Tailby
- The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia; School of Psychological Sciences, University of Melbourne, Victoria, Australia
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26
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Eicher JD, Gruen JR. Imaging-genetics in dyslexia: connecting risk genetic variants to brain neuroimaging and ultimately to reading impairments. Mol Genet Metab 2013; 110:201-12. [PMID: 23916419 PMCID: PMC3800223 DOI: 10.1016/j.ymgme.2013.07.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 07/02/2013] [Accepted: 07/02/2013] [Indexed: 12/19/2022]
Abstract
Dyslexia is a common pediatric disorder that affects 5-17% of schoolchildren in the United States. It is marked by unexpected difficulties in fluent reading despite adequate intelligence, opportunity, and instruction. Classically, neuropsychologists have studied dyslexia using a variety of neurocognitive batteries to gain insight into the specific deficits and impairments in affected children. Since dyslexia is a complex genetic trait with high heritability, analyses conditioned on performance on these neurocognitive batteries have been used to try to identify associated genes. This has led to some successes in identifying contributing genes, although much of the heritability remains unexplained. Additionally, the lack of relevant human brain tissue for analysis and the challenges of modeling a uniquely human trait in animals are barriers to advancing our knowledge of the underlying pathophysiology. In vivo imaging technologies, however, present new opportunities to examine dyslexia and reading skills in a clearly relevant context in human subjects. Recent investigations have started to integrate these imaging data with genetic data in attempts to gain a more complete and complex understanding of reading processes. In addition to bridging the gap from genetic risk variant to a discernible neuroimaging phenotype and ultimately to the clinical impairments in reading performance, the use of neuroimaging phenotypes will reveal novel risk genes and variants. In this article, we briefly discuss the genetic and imaging investigations and take an in-depth look at the recent imaging-genetics investigations of dyslexia.
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Affiliation(s)
- John D. Eicher
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520
| | - Jeffrey R. Gruen
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520
- Departments of Pediatrics and Investigative Medicine, Yale University School of Medicine, New Haven, CT 06520
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Hernandez N, Andersson F, Edjlali M, Hommet C, Cottier JP, Destrieux C, Bonnet-Brilhault F. Cerebral functional asymmetry and phonological performance in dyslexic adults. Psychophysiology 2013; 50:1226-38. [PMID: 24117474 DOI: 10.1111/psyp.12141] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 07/23/2013] [Indexed: 11/27/2022]
Abstract
Developmental dyslexia is a frequent language-based learning disorder characterized by difficulty in reading. The predominant etiologic view postulates that reading impairment is related to phonological and orthographic dysfunction. The aim of this fMRI study was to evaluate the neural bases of phonological processing impairment in remediated dyslexic adults (DD). We used a rhyming words judgment task contrasted with an unreadable fonts font-matching judgment task to compare patterns of activation and functional asymmetry in DD and normal-reading young adults. We found evidence of a link between asymmetry in inferior frontal gyrus and performance during the phonological processing. We also observed that DD recruit a network including regions involved in articulatory control in order to achieve rhyme judgment suggesting that, due to a lack of hemispheric specialization, DD recruit the latter network to achieve rhyme judgment.
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Affiliation(s)
- N Hernandez
- U930 INSERM, Tours, France; Team 1 Autism-UMR930 Imaging, Brain University François-Rabelais of Tours, Tours, France
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28
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Danelli L, Berlingeri M, Bottini G, Ferri F, Vacchi L, Sberna M, Paulesu E. Neural intersections of the phonological, visual magnocellular and motor/cerebellar systems in normal readers: implications for imaging studies on dyslexia. Hum Brain Mapp 2013; 34:2669-87. [PMID: 22736513 PMCID: PMC6870382 DOI: 10.1002/hbm.22098] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 03/14/2012] [Accepted: 03/15/2012] [Indexed: 01/27/2023] Open
Abstract
We used fMRI to explore the extent of the anatomical overlap of three neural systems that the literature on developmental dyslexia associates with reading: the auditory phonological, the visual magnocellular, and the motor/cerebellar systems. Twenty-eight normal subjects performed four tasks during fMRI scans: word and pseudoword reading, auditory rhyming for letter names, visual motion perception, and a motor sequence learning task. We found that the left occipitotemporal cortex (OTC), which previous studies reported to be dysfunctional in dyslexia, can be fractionated into different functional areas: an anterior and lateral area that was activated by both reading and auditory rhyming tasks; a posterior area that was commonly activated by both the reading and the motion perception task and a medial/intermediate area, including the so-called Visual Word Form Area, which was specifically activated by the reading task. These results show that the left OTC is an area of segregated convergence of different functional systems. We compared our results with the hypoactivation pattern reported for reading in a previous cross-cultural PET study on 36 dyslexic subjects from three countries. The region of decreased activation in dyslexia overlapped with regions that are specific for reading and those activated during both the auditory rhyming task and the single word and pseudoword reading task described in the present fMRI study. No overlap was found with the activation patterns for the visual motion perception task or for the motor sequence learning task. These observations challenge current theories of dyslexia.
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Affiliation(s)
- Laura Danelli
- Psychology Department, University of Milano-Bicocca, Milan, Italy
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29
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Reading the wrong way with the right hemisphere. Brain Sci 2013; 3:1060-75. [PMID: 24961521 PMCID: PMC4061874 DOI: 10.3390/brainsci3031060] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 06/04/2013] [Accepted: 07/08/2013] [Indexed: 11/20/2022] Open
Abstract
Reading is a complex process, drawing on a variety of brain functions in order to link symbols to words and concepts. The three major brain areas linked to reading and phonological analysis include the left temporoparietal region, the left occipitotemporal region and the inferior frontal gyrus. Decreased activation of the left posterior language system in dyslexia is well documented but there is relatively limited attention given to the role of the right hemisphere. The current study investigated differences in right and left hemisphere activation between individuals with dyslexia and non-impaired readers in lexical decision tasks (regular words, irregular words, pseudowords) during functional Magnetic Resonance Imaging (fMRI). Results revealed the expected hypo-activation in the left posterior areas in those with dyslexia but also areas of overactivation in the right hemisphere. During pseudoword decisions, for example, adults with dyslexia showed more right inferior occipital gyrus activation than controls. In general the increased activation of left-hemisphere language areas found in response to both regular and pseudowords was absent in dyslexics. Laterality indices showed that while controls showed left lateralised activation of the temporal lobe during lexical decision making, dyslexic readers showed right activation. Findings will inform theories of reading and will have implications for the design of reading interventions.
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30
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Liu L, You W, Wang W, Guo X, Peng D, Booth J. Altered brain structure in Chinese dyslexic children. Neuropsychologia 2013; 51:1169-76. [PMID: 23542499 DOI: 10.1016/j.neuropsychologia.2013.03.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 02/27/2013] [Accepted: 03/19/2013] [Indexed: 01/08/2023]
Abstract
Due to the logographic nature of the writing system, learning to read Chinese places heavy demands on encoding of orthographic forms through rote memorization. Moreover, phonology has to often be retrieved from memory during reading because of the inconsistent mapping between characters and their pronunciations. Using optimized voxel-based morphometry, we examined differences in volumetrics between children with reading disability (RD, 10-12 years old) and age-matched typically developing (TD) children. Our study shows reduced gray matter volume (GMV) for RD in right inferior occipital gyrus and left inferior frontal gyrus, consistent with previous studies suggesting that Chinese dyslexics have deficits in orthographic and phonological processing. The deficit in phonological processing was further supported by reductions in white matter volumes (WMV) in left precentral gyrus. Greater deficits in ortho-phonological processing may be associated with semantic compensation, as lower skill RD children showed greater GMV in anterior temporal cortex, even though as a group they showed less GMV in this region compared to TD. Perhaps most interestingly, we showed reduced GMV in bilateral ventromedial prefrontal cortices (vmPFC) and this was correlated with reductions in WMV within vmPFC, suggesting that RD have deficits in memory retrieval. Moreover, these GMV alterations in vmPFC for the RD were correlated with alterations in right parahippocampal gyrus, which also showed a reduced GMV, suggesting that RD have a correlated deficit in memory encoding. Our results are consistent with previous studies suggesting that Chinese dyslexics have deficits in visuo-orthographic and phonological processing, but our study importantly suggests deficits in memory encoding and retrieval, perhaps due to the unique demands of the Chinese writing system.
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Affiliation(s)
- Li Liu
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China.
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Centanni TM, Booker AB, Sloan AM, Chen F, Maher BJ, Carraway RS, Khodaparast N, Rennaker R, LoTurco JJ, Kilgard MP. Knockdown of the dyslexia-associated gene Kiaa0319 impairs temporal responses to speech stimuli in rat primary auditory cortex. Cereb Cortex 2013; 24:1753-66. [PMID: 23395846 DOI: 10.1093/cercor/bht028] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
One in 15 school age children have dyslexia, which is characterized by phoneme-processing problems and difficulty learning to read. Dyslexia is associated with mutations in the gene KIAA0319. It is not known whether reduced expression of KIAA0319 can degrade the brain's ability to process phonemes. In the current study, we used RNA interference (RNAi) to reduce expression of Kiaa0319 (the rat homolog of the human gene KIAA0319) and evaluate the effect in a rat model of phoneme discrimination. Speech discrimination thresholds in normal rats are nearly identical to human thresholds. We recorded multiunit neural responses to isolated speech sounds in primary auditory cortex (A1) of rats that received in utero RNAi of Kiaa0319. Reduced expression of Kiaa0319 increased the trial-by-trial variability of speech responses and reduced the neural discrimination ability of speech sounds. Intracellular recordings from affected neurons revealed that reduced expression of Kiaa0319 increased neural excitability and input resistance. These results provide the first evidence that decreased expression of the dyslexia-associated gene Kiaa0319 can alter cortical responses and impair phoneme processing in auditory cortex.
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Affiliation(s)
- T M Centanni
- School of Behavioral and Brain Sciences, University of Texas at Dallas
| | | | - A M Sloan
- School of Behavioral and Brain Sciences, University of Texas at Dallas
| | - F Chen
- University of Connecticut
| | | | - R S Carraway
- School of Behavioral and Brain Sciences, University of Texas at Dallas
| | - N Khodaparast
- School of Behavioral and Brain Sciences, University of Texas at Dallas
| | - R Rennaker
- School of Behavioral and Brain Sciences, University of Texas at Dallas
| | | | - M P Kilgard
- School of Behavioral and Brain Sciences, University of Texas at Dallas
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Cope N, Eicher JD, Meng H, Gibson CJ, Hager K, Lacadie C, Fulbright RK, Constable RT, Page GP, Gruen JR. Variants in the DYX2 locus are associated with altered brain activation in reading-related brain regions in subjects with reading disability. Neuroimage 2012; 63:148-56. [PMID: 22750057 DOI: 10.1016/j.neuroimage.2012.06.037] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 05/25/2012] [Accepted: 06/19/2012] [Indexed: 10/28/2022] Open
Abstract
Reading disability (RD) is a complex genetic disorder with unknown etiology. Genes on chromosome 6p22, including DCDC2, KIAA0319, and TTRAP, have been identified as RD associated genes. Imaging studies have shown both functional and structural differences between brains of individuals with and without RD. There are limited association studies performed between RD genes, specifically genes on 6p22, and regional brain activation during reading tasks. Using fourteen variants in DCDC2, KIAA0319, and TTRAP and exhaustive reading measures, we first tested for association with reading performance in 82 parent-offspring families (326 individuals). Next, we determined the association of these variants with activation of sixteen brain regions of interest during four functional magnetic resonance imaging-reading tasks. We nominally replicated associations between reading performance and variants of DCDC2 and KIAA0319. Furthermore, we observed a number of associations with brain activation patterns during imaging-reading tasks with all three genes. The strongest association occurred between activation of the left anterior inferior parietal lobe and complex tandem repeat BV677278 in DCDC2 (uncorrected p=0.00003, q=0.0442). Our results show that activation patterns across regions of interest in the brain are influenced by variants in the DYX2 locus. The combination of genetic and functional imaging data show a link between genes and brain functioning during reading tasks in subjects with RD. This study highlights the many advantages of imaging data as an endophenotype for discerning genetic risk factors for RD and other communication disorders and underscores the importance of integrating neurocognitive, imaging, and genetic data in future investigations.
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Affiliation(s)
- Natalie Cope
- Yale Child Health Research Center, Yale University School of Medicine, New Haven, CT 06520, USA
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Abstract
The brain's ability to bind incoming auditory and visual stimuli depends critically on the temporal structure of this information. Specifically, there exists a temporal window of audiovisual integration within which stimuli are highly likely to be perceived as part of the same environmental event. Several studies have described the temporal bounds of this window, but few have investigated its malleability. Recently, our laboratory has demonstrated that a perceptual training paradigm is capable of eliciting a 40% narrowing in the width of this window that is stable for at least 1 week after cessation of training. In the current study, we sought to reveal the neural substrates of these changes. Eleven human subjects completed an audiovisual simultaneity judgment training paradigm, immediately before and after which they performed the same task during an event-related 3T fMRI session. The posterior superior temporal sulcus (pSTS) and areas of auditory and visual cortex exhibited robust BOLD decreases following training, and resting state and effective connectivity analyses revealed significant increases in coupling among these cortices after training. These results provide the first evidence of the neural correlates underlying changes in multisensory temporal binding likely representing the substrate for a multisensory temporal binding window.
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Abstract
The brain's ability to bind incoming auditory and visual stimuli depends critically on the temporal structure of this information. Specifically, there exists a temporal window of audiovisual integration within which stimuli are highly likely to be perceived as part of the same environmental event. Several studies have described the temporal bounds of this window, but few have investigated its malleability. Recently, our laboratory has demonstrated that a perceptual training paradigm is capable of eliciting a 40% narrowing in the width of this window that is stable for at least 1 week after cessation of training. In the current study, we sought to reveal the neural substrates of these changes. Eleven human subjects completed an audiovisual simultaneity judgment training paradigm, immediately before and after which they performed the same task during an event-related 3T fMRI session. The posterior superior temporal sulcus (pSTS) and areas of auditory and visual cortex exhibited robust BOLD decreases following training, and resting state and effective connectivity analyses revealed significant increases in coupling among these cortices after training. These results provide the first evidence of the neural correlates underlying changes in multisensory temporal binding likely representing the substrate for a multisensory temporal binding window.
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Monzalvo K, Fluss J, Billard C, Dehaene S, Dehaene-Lambertz G. Cortical networks for vision and language in dyslexic and normal children of variable socio-economic status. Neuroimage 2012; 61:258-74. [PMID: 22387166 DOI: 10.1016/j.neuroimage.2012.02.035] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 01/02/2012] [Accepted: 02/14/2012] [Indexed: 11/15/2022] Open
Affiliation(s)
- Karla Monzalvo
- INSERM, Cognitive Neuroimaging Unit, Gif sur Yvette, 91191 France
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36
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Peyrin C, Lallier M, Démonet JF, Pernet C, Baciu M, Le Bas JF, Valdois S. Neural dissociation of phonological and visual attention span disorders in developmental dyslexia: FMRI evidence from two case reports. BRAIN AND LANGUAGE 2012; 120:381-394. [PMID: 22285025 DOI: 10.1016/j.bandl.2011.12.015] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 09/23/2011] [Accepted: 12/24/2011] [Indexed: 05/31/2023]
Abstract
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.
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Affiliation(s)
- C Peyrin
- CNRS UMR 5105, 38040 Grenoble, France.
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Rezaie R, Simos PG, Fletcher JM, Cirino PT, Vaughn S, Papanicolaou AC. Engagement of temporal lobe regions predicts response to educational interventions in adolescent struggling readers. Dev Neuropsychol 2012; 36:869-88. [PMID: 21978010 DOI: 10.1080/87565641.2011.606404] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Brain activation profiles obtained using magnetoencephalography were compared between middle-school students experiencing reading difficulties and non-reading-impaired students during performance of a continuous printed word recognition task. Struggling readers underwent small-group remedial instruction, and students who showed significant gains in word reading efficiency at a one-year follow-up assessment were classified as Adequate Responders whereas those not demonstrating such gains as Inadequate Responders. At baseline, compared to Inadequate Responders, the activation profiles of Adequate Responders featured increased activity in the left middle, superior temporal, and ventral occipitotemporal regions, as well as in the right mesial temporal cortex. The degree of activity in these regions was a significant predictor of improvement in word reading efficiency beyond the prediction afforded by baseline reading accuracy or fluency measures. The engagement of brain areas that typically serve as key components of the brain circuit for reading may be an important factor in predicting response to intervention in older students who experience reading difficulties.
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Affiliation(s)
- Roozbeh Rezaie
- Department of Pediatrics, Children's Learning Institute, University of Texas Health Science Center, Houston, Texas 77030, USA.
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38
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Hämäläinen JA, Rupp A, Soltész F, Szücs D, Goswami U. Reduced phase locking to slow amplitude modulation in adults with dyslexia: An MEG study. Neuroimage 2012; 59:2952-61. [DOI: 10.1016/j.neuroimage.2011.09.075] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 09/15/2011] [Accepted: 09/29/2011] [Indexed: 11/29/2022] Open
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Davis N, Barquero L, Compton DL, Fuchs LS, Fuchs D, Gore JC, Anderson AW. Functional correlates of children's responsiveness to intervention. Dev Neuropsychol 2011; 36:288-301. [PMID: 21462008 DOI: 10.1080/87565641.2010.549875] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Functional imaging research has yielded evidence of changes in poor readers after instructional intervention. Although it is well established that within the group of children with poor reading there are differences in behavioral response to intervention, little is know about the functional correlates of responsiveness. Therefore, we acquired functional magnetic resonance imaging (MRI) data from children identified as "at risk for reading disability" who responded differently to a reading intervention (5 responders; 5 nonresponders; 4 controls). Groups differed in activation level of the left hemisphere posterior superior temporal and the middle temporal gyri, suggesting that future imaging studies should consider responders and nonresponders separately.
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Affiliation(s)
- Nicole Davis
- Vanderbilt University Institute of Imaging Science, Nashville, Tennessee 37203-5721, USA.
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The homophone effect during visual word recognition in children: an fMRI study. PSYCHOLOGICAL RESEARCH 2011; 76:280-91. [PMID: 21660483 DOI: 10.1007/s00426-011-0347-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Accepted: 05/23/2011] [Indexed: 10/18/2022]
Abstract
Functional magnetic resonance imaging was used to investigate the role of phonology in visual word recognition (VWR). A group of children between the ages of 7 and 13 participated in a lexical decision task in which lexical frequency and homophony were manipulated. A significant homophone effect was observed for the high-frequency condition, indicating that phonology does indeed play a significant role in VWR. The brain activation patterns also support this idea in that regions that have been linked to phonological processing, the inferior frontal gyrus and the inferior parietal lobe, also revealed a homophone effect. Additionally, the posterior superior temporal cortex showed a homophone effect; however, this activation is argued to be related to lexical competition generated by the high-frequency homophone via the activation of multiple semantic representations.
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41
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Grande M, Meffert E, Huber W, Amunts K, Heim S. Word frequency effects in the left IFG in dyslexic and normally reading children during picture naming and reading. Neuroimage 2011; 57:1212-20. [PMID: 21609767 DOI: 10.1016/j.neuroimage.2011.05.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 05/06/2011] [Accepted: 05/10/2011] [Indexed: 01/18/2023] Open
Abstract
Word frequency effects have been reported in numerous neuroimaging studies with typically reading adults, emphasising the role of the left inferior frontal gyrus (LIFG). Within LIFG, different cytoarchitectonic modules (areas 44 and 45) have been related to phonological vs. lexico-semantic processing, respectively. This fMRI study investigated the differential impact of word frequency on LIFG activation in reading and picture naming in primary school children with and without developmental dyslexia. All children showed the typical LIFG frequency effect in both tasks. The effect was comparable in a fronto-orbital region anterior-inferior adjacent to area 45. During reading but not picture naming, a second effect was observed in area 44. Here, the fMRI effect for lexical frequency was stronger for the dyslexic than the normal readers. These findings demonstrate the neural underpinnings of a selective deficit in dyslexic children in the graphemic input lexicon, whereas abstract lexical representations appear to be processed equally well in dyslexic and normally reading children. To conclude, the present fMRI study demonstrated differential impact of word frequency on LIFG activation in primary school children during reading but not picture naming. Apart from extending previous knowledge from studies with adults to childhood, the study sheds further light on a potential neural mechanism for deficient grapheme-to-phoneme conversion in dyslexic children.
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Affiliation(s)
- Marion Grande
- Section Neurological Cognition Research, Department of Neurology, Medical School, RWTH Aachen University, Aachen, Germany
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42
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Abstract
Individuals with developmental dyslexia vary in their ability to improve reading skills, but the brain basis for improvement remains largely unknown. We performed a prospective, longitudinal study over 2.5 y in children with dyslexia (n = 25) or without dyslexia (n = 20) to discover whether initial behavioral or brain measures, including functional MRI (fMRI) and diffusion tensor imaging (DTI), can predict future long-term reading gains in dyslexia. No behavioral measure, including widely used and standardized reading and language tests, reliably predicted future reading gains in dyslexia. Greater right prefrontal activation during a reading task that demanded phonological awareness and right superior longitudinal fasciculus (including arcuate fasciculus) white-matter organization significantly predicted future reading gains in dyslexia. Multivariate pattern analysis (MVPA) of these two brain measures, using linear support vector machine (SVM) and cross-validation, predicted significantly above chance (72% accuracy) which particular child would or would not improve reading skills (behavioral measures were at chance). MVPA of whole-brain activation pattern during phonological processing predicted which children with dyslexia would improve reading skills 2.5 y later with >90% accuracy. These findings identify right prefrontal brain mechanisms that may be critical for reading improvement in dyslexia and that may differ from typical reading development. Brain measures that predict future behavioral outcomes (neuroprognosis) may be more accurate, in some cases, than available behavioral measures.
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44
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Yamada Y, Stevens C, Dow M, Harn BA, Chard DJ, Neville HJ. Emergence of the neural network for reading in five-year-old beginning readers of different levels of pre-literacy abilities: an fMRI study. Neuroimage 2010; 57:704-13. [PMID: 20977940 DOI: 10.1016/j.neuroimage.2010.10.057] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 10/08/2010] [Accepted: 10/15/2010] [Indexed: 10/18/2022] Open
Abstract
The present study traced the emergence of the neural circuits for reading in five-year-old children of diverse pre-literacy ability. In the fall and winter of kindergarten, children performed a one-back task with letter versus false font stimuli during fMRI scanning. At the start of kindergarten, children with on-track pre-literacy skills (OT) recruited bilateral temporo-parietal regions for the letter > false font comparison. In contrast, children at-risk for reading difficulty (AR) showed no differential activation in this region. Following 3 months of kindergarten and, for AR children, supplemental reading instruction, OT children showed left-lateralized activation in the temporo-parietal region, whereas AR children showed bilateral activation and recruitment of frontal regions including the anterior cingulate cortex. These data suggest that typical reading development is associated with initial recruitment and subsequent disengagement of right hemisphere homologous regions while atypical reading development may be associated with compensatory recruitment of frontal regions.
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Affiliation(s)
- Yoshiko Yamada
- Brain Development Laboratory, Department of Psychology, 1227 University of Oregon, Eugene, Oregon 97403, USA.
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45
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Guttorm TK, Leppänen PHT, Hämäläinen JA, Eklund KM, Lyytinen HJ. Newborn event-related potentials predict poorer pre-reading skills in children at risk for dyslexia. JOURNAL OF LEARNING DISABILITIES 2010; 43:391-401. [PMID: 19890075 DOI: 10.1177/0022219409345005] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Earlier results from the Jyväskylä Longitudinal Study of Dyslexia showed that newborn event-related potentials (ERPs) of children with and without familial risk for dyslexia were associated with receptive language and verbal memory skills between 2.5 and 5 years of age. We further examined whether these ERPs (responses to synthetic consonant-vowel syllables /ba/, /da/, /ga/; presented equiprobably with 3,910-7,285 ms interstimulus intervals) predict later pre-reading skills measured before the onset of school (6.5 years of age). In line with our earlier results, the at-risk children (N = 11) with atypical speech processing in the right hemisphere (a slower shift in polarity from positivity to negativity in responses to /ga/ at 540-630 ms) scored significantly lower in phonological skills, rapid naming, and letter knowledge than the control children (N = 10) without enhanced right hemispheric speech processing. These results further extend our earlier findings of newborn ERPs in predicting poorer language skills. These consistent differences in ERPs to speech sounds may have applications in the future for the early identification of children at risk for developmental language problems. This would facilitate well-directed intervention even before reading problems are typically diagnosed.
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Affiliation(s)
- Tomi K Guttorm
- Department of Psychology, University of Jyväskylä, Finland.
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46
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Trauzettel-Klosinski S, Koitzsch AM, Dürrwächter U, Sokolov AN, Reinhard J, Klosinski G. Eye movements in German-speaking children with and without dyslexia when reading aloud. Acta Ophthalmol 2010; 88:681-91. [PMID: 19508458 DOI: 10.1111/j.1755-3768.2009.01523.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE The phonological difficulty and orthographic regularity of a language influence reading strategies. Only a few studies have been conducted in readers of German, which has a high grapheme-phoneme correspondence. The aim of this study was to investigate, firstly, the influence of different levels of phonological difficulty of reading material in German on reading in children and, secondly, to compare the reading strategies of German children with findings in English-speaking readers. METHODS Eye movements in 16 German children with dyslexia and 16 age-matched control children (mean age 9.5±0.35years) in the third and fourth grades of school were recorded by scanning laser ophthalmoscope while they read aloud two texts of differing levels of difficulty. RESULTS In the dyslexia group, reading speed was slowed, and the number of saccades and regressions was raised markedly, although the percentage of regressions only slightly. The number of eye movements increased in both groups with increasing text difficulty, although much more in the dyslexia group than in the control group, whereas fixation duration was not influenced. CONCLUSIONS Phonological difficulty influences reading speed and eye movement pattern: children with dyslexia markedly increase their number of eye movements and analyse the text in smaller units per fixation, but keep fixation duration constant. This strategy reflects their favouring of the indirect, sublexical route of grapheme-phoneme conversion, whereas readers of English-language texts are more likely to prefer the whole-word approach, i.e. the direct, lexical route that is associated with orthographic memory.
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47
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Landi N, Mencl WE, Frost SJ, Sandak R, Pugh KR. An fMRI study of multimodal semantic and phonological processing in reading disabled adolescents. ANNALS OF DYSLEXIA 2010; 60:102-21. [PMID: 20049657 PMCID: PMC3148012 DOI: 10.1007/s11881-009-0029-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Accepted: 09/11/2009] [Indexed: 05/23/2023]
Abstract
Using functional magnetic resonance imaging, we investigated multimodal (visual and auditory) semantic and unimodal (visual only) phonological processing in reading disabled (RD) adolescents and non-impaired (NI) control participants. We found reduced activation for RD relative to NI in a number of left-hemisphere reading-related areas across all processing tasks regardless of task type (semantic vs. phonological) or modality (auditory vs. visual modality). Moreover, activation differences in these regions, which included the inferior frontal gyrus, the superior temporal gyrus, and the occipitotemporal region, were largely independent of in-scanner performance in our auditory semantic task. That is, although RD participants and NI participants differed in performance in visually presented conditions, they did not differ significantly in the auditory condition, yet similar patterns of reduced activation were observed in these regions across conditions. These findings indicate a neurobiological marker in RD that is independent of task, modality, or performance. These findings are discussed in the context of current neurobiological models of RD.
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Affiliation(s)
- Nicole Landi
- Child Study Center, Yale University School of Medicine, 230 S. Frontage, New Haven, CT 06520, USA.
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48
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Sun YF, Lee JS, Kirby R. Brain imaging findings in dyslexia. Pediatr Neonatol 2010; 51:89-96. [PMID: 20417459 DOI: 10.1016/s1875-9572(10)60017-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Revised: 07/07/2009] [Accepted: 07/28/2009] [Indexed: 01/18/2023] Open
Abstract
Dyslexia is a brain-based disorder that has been intensively studied in the Western world for more than a century because of its social burden. However, affected individuals in Chinese communities are neither recognized nor formally diagnosed. Previous studies have concentrated on the disadvantages of reading deficits, and few have addressed non-linguistic skills, which are included in the symptoms. In addition, certain dyslexics possess visual spatial talents that have usually been ignored. In this review, we discuss the available information regarding brain imaging studies of dyslexia based on studies in Caucasian subjects. Gray matter deficits have been demonstrated in dyslexics using structural magnetic resonance imaging. Reduced neural activities in the left temporal and left parietal cortices, and diffuse widespread activation patterns in the cerebellum could be detected using functional magnetic resonance imaging. Changes in lactate levels, N-acetylaspartate/choline-containing compounds and N-acetylaspartate/creatine ratios, and phosphomonoester peak area were detected in magnetic resonance spectroscopy studies. Lower fractional anisotropy values in bilateral white matter tracts have been demonstrated by diffusion tensor imaging. Abnormal Broca's area activation was found using positron emission tomography imaging. Increased activities in the right frontal and temporal brain regions were detected using electroencephalography. Reduced hemispheric asymmetry and increased left inferior frontal activation were reported following magnetoencephalography. Although these imaging modalities are not currently diagnostic or prognostic, they are able to provide information on the causes of dyslexia beyond what was previously provided by behavioral or cognition studies.
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Affiliation(s)
- Ying-Fang Sun
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan.
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49
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Carter M, Rastatter MP, Walker MM, O’Brien K. The effects of frequency altered feedback on the reading processes of adults with reading disorders. Neurosci Lett 2009; 461:69-73. [DOI: 10.1016/j.neulet.2009.06.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 06/04/2009] [Accepted: 06/11/2009] [Indexed: 11/16/2022]
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50
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Kumar A, Chugani HT. PET in the Assessment of Pediatric Brain Development and Developmental Disorders. PET Clin 2009; 3:487-515. [PMID: 27156816 DOI: 10.1016/j.cpet.2009.04.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This article discusses and reviews the role and contribution of PET in understanding the structural and functional changes that occur during brain development, and how these changes relate to behavioral and cognitive development in the infant and child. Data regarding various aspects of brain development, such as glucose metabolism, protein synthesis, and maturation and development of neurotransmitter systems will help in understanding the pathogenesis and neurologic basis of various developmental and neurologic disorders. This may help in following disease evolution and progression, planning and development of various therapeutic interventions, timing these interventions and monitoring their responses, and rendering long-term prognostication.
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Affiliation(s)
- Ajay Kumar
- Departments of Pediatrics and Neurology, School of Medicine, Wayne State University, Children's Hospital of Michigan, 3901 Beaubien Boulevard, Detroit, MI 48201, USA
| | - Harry T Chugani
- Departments of Pediatrics and Neurology, School of Medicine, Wayne State University, Children's Hospital of Michigan, 3901 Beaubien Boulevard, Detroit, MI 48201, USA; Division of Pediatric Neurology, Children's Hospital of Michigan, 3901 Beaubien Boulevard, Detroit, MI, USA; PET Center, Children's Hospital of Michigan, Detroit, MI 48201, USA.
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