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Electrophysiological Evidence against the Magnocellular Deficit Theory in Developmental Dyslexia

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DOI: 10.4236/jbbs.2013.32025    3,442 Downloads   5,655 Views   Citations

ABSTRACT

Over the last two decades, the hypothesis of a magnocellular deficit in dyslexia has raised considerable interest and controversy. Using an electrophysiological procedure (visual evoked potentials, VEP), we compared magnocellular and parvocellular contrast and spatial frequency-response functions between phonological dyslexics (n = 16) and a typical reading group (n = 12) matched for age and socioeconomic background. No significant differences were found between the two groups in the amplitude of the VEP components associated with either magnocellular or parvocellular responses. However, topographic analyses revealed a group difference in the distribution of amplitude in the right frontal and left temporal regions, which appeared to be underactivated in dyslexics. These results suggest a deficit in the higher-level cortical regions involved in phonological and/or linguistic processing, and calls into question the notion of a magnocellular involvement in dyslexia.

Conflicts of Interest

The authors declare no conflicts of interest.

Cite this paper

M. Sayeur, R. Béland, D. Ellemberg, C. Perchet, M. McKerral, M. Lassonde and K. Lavoie, "Electrophysiological Evidence against the Magnocellular Deficit Theory in Developmental Dyslexia," Journal of Behavioral and Brain Science, Vol. 3 No. 2, 2013, pp. 239-251. doi: 10.4236/jbbs.2013.32025.

References

[1] American Psychiatric Association, “Diagnostic and Statistical Manual of Mental Disorders: DSM-IV-TR,” 4th Editon, American Psychiatic and Association, Washington DC, 2000.
[2] S. E. Shaywitz, B. A. Shaywitz, K. R. Pugh, R. K. Fulbright, R. T. Constable, W. E. Mencl, D. P. Shankweiler, A. M. Liberman, P. Skudlarski, J. M. Fletcher, L. Katz, K. E. Marchione, C. Lacadie, C. Gatenby, and J. C. Gore, “Functional Disruption in the Organization of the Brain for Reading in Dyslexia,” Proceedings of the National Academy of Sciences, Vol. 95, No. 5, 1998, pp. 2636-2641. doi:10.1073/pnas.95.5.2636
[3] C. Boden and D. Giaschi, “M-Stream Deficits and Reading-Related Visual Processes in Developmental Dyslexia,” Psychological Bulletin, Vol. 133, No. 2, 2007, pp. 346-366. doi:10.1037/0033-2909.133.2.346
[4] K. Nandakumar and S. J. Leat, “Dyslexia: A Review of Two Theories,” Clinical and Experimental Optometry, Vol. 91, No. 4, 2008, pp. 333-340. doi:10.1111/j.1444-0938.2008.00277.x
[5] K. R. Pugh, W. E. Mencl, A. R. Jenner, L. Katz, S. J. Frost, J. R. Lee, S. E. Shaywitz and B. A. Shaywitz, “Functional Neuroimaging Studies of Reading and Reading Disability (Developmental Dyslexia),” Mental Retardation and Developmental Disabilities Research Reviews, Vol. 6, No. 3, 2000, pp. 207-213. doi:10.1002/1098-2779(2000)6:3<207::AID-MRDD8>3.0.CO;2-P
[6] J. I. Breier, P. G. Simos, J. M. Fletcher, E. M. Castillo, W. Zhang and A. C. Papanicolaou, “Abnormal Activation of Temporoparietal Language Areas during Phonetic Analysis in Children with Dyslexia,” Neuropsychology, Vol. 17, No. 4, 2003, pp. 610-621. doi:10.1037/0894-4105.17.4.610
[7] F. Hoeft, A. Meyler, A. Hernandez, C. Juel, H. TaylorHill, J. L. Martindale, G. McMillon, G. Kolchugina, J. M. Black, A. Faizi, G. K. Deutsch, W. T. Siok, A. L. Reiss, S. Whitfield-Gabrieli and J. D. E. Gabrieli, “Functional and Morphometric Brain Dissociation between Dyslexia and Reading Ability,” Proceedings of the National Academy of Sciences, Vol. 104, No. 10, 2007, pp. 4234-4239. doi:10.1073/pnas.0609399104
[8] T. Fagerheim, P. Raeymaekers, F. E. Tønnessen, M. Pedersen, L. Tranebjærg and H. A. Lubs, “A New Gene (DYX3) for Dyslexia Is Located on Chromosome 2,” Journal of Medical Genetics, Vol. 36, No. 9, 1999, pp. 664-669.
[9] L. Bradley and P. E. Bryant, “Categorizing Sounds and Learning to Read: A Causal Connexion,” Nature, Vol. 301, 1983, pp. 419-421. doi:10.1038/301419a0
[10] G. Schulte-Körne and J. Bruder, “Clinical Neurophysiology of Visual and Auditory Processing in Dyslexia: A Review,” Clinical Neurophysiology, Vol. 121, No. 11, 2010, pp. 1794-1809. doi:10.1016/j.clinph.2010.04.028
[11] D. Perin, “Phonemic Segmentation and Spelling,” British Journal of Psychology, Vol. 74, No. 1, 1983, pp. 129-144. doi:10.1111/j.2044-8295.1983.tb01849.x
[12] I. Y. Liberman, H. Rubin, S. Duques and J. Carlisle, “Linguistic Abilities and Spelling Proficiency in Kindergarten and Adult Poor Spellers,” In: D. Gray and J. Kavanagh, Eds., Biobehavioral Measures of Dyslexia, York Press, Parkton, 1985, pp. 163-176.
[13] G. W. MacDonald and A. Cornwall, “The Relationship between Phonological Awareness and Reading and Spelling Achievement Eleven Years Later,” Journal of Learning Disabilities, Vol. 28, No. 8, 1995, pp. 523-527. doi:10.1177/002221949502800807
[14] I. Lundberg and T. Hoien, “Initial Enabling Knowledge and Skills in Reading Acquisition: Print Awareness and Phonological Segmentation,” In: D. Sawyer and B. Fox, Eds., Phonological Awareness in Reading—The Evolution of Current Perspectives, Springer-Verlag, New York, 1991, pp. 73-96.
[15] M.-C. St-Pierre and R. Beland, “Reproduction of Inflectional Markers in French-Speaking Children with Reading Impairment,” Journal of Speech Lang Hear Research, Vol. 53, No. 2, 2010, pp. 469-489. doi:10.1044/1092-4388(2009/07-0251)
[16] M. Habib, “The Neurological Basis of Developmental Dyslexia: An Overview and Working Hypothesis,” Brain, Vol. 123, No. 12, 2000, pp. 2373-2399. doi:10.1093/brain/123.12.2373
[17] W. Lovegrove, A. Bowling, D. Badcock and M. Blackwood, “Specific Reading Disability: Differences in Contrast Sensitivity as a Function of Spatial Frequency,” Science, Vol. 210, No. 4468, 1980, pp. 439-440. doi:10.1126/science.7433985
[18] W. J. Lovegrove, M. Heddle and W. Slaghuis, “Reading Disability: Spatial Frequency Specific Deficits in Visual Information Store,” Neuropsychologia, Vol. 18, No. 1, 1980, pp. 111-115. doi:10.1016/0028-3932(80)90093-7
[19] A. J. Sperling, Z.-L. Lu, F. R. Manis and M. S. Seidenberg, “Selective Magnocellular Deficits in Dyslexia: A ‘Phantom Contour’ Study,” Neuropsychologia, Vol. 41, No. 10, 2003, pp. 1422-1429. doi:10.1016/S0028-3932(03)00044-7
[20] J. Stein, “The Magnocellular Theory of Developmental Dyslexia,” Dyslexia: The Journal of the British Dyslexia Association, Vol. 7, No. 7, 2001, pp. 12-36.
[21] P. Lennie, “Parallel Visual Pathways: A Review,” Vision Research, Vol. 20, No. 7, 1980, pp. 561-594. doi:10.1016/0042-6989(80)90115-7
[22] W. Merigan, A. Freeman and S. P. Meyers, “Parallel Processing Streams in Human Visual Cortex,” Neuroreport, Vol. 8, No. 18, 1997, pp. 3985-3991. doi:10.1097/00001756-199712220-00027
[23] P. Rezaie and A. Dean, “Periventricular Leukomalacia, Inflammation and White Matter Lesions within the Developing Nervous System,” Neuropathology, Vol. 22, No. 3, 2002, pp. 106-132. doi:10.1046/j.1440-1789.2002.00438.x
[24] E. R. Kandel, J. H. Schwartz and T. M. Jessel, “Principles of Neural Science,” Elsevier, New York, 2000.
[25] L. J. Croner and E. Kaplan, “Receptive Fields of P and M Ganglion Cells across the Primate Retina,” Vision Research, Vol. 35, No. 1, 1995, pp. 7-24. doi:10.1016/0042-6989(94)E0066-T
[26] M. Livingstone and D. Hubel, “Psychophysical Evidence for Separate Channels for the Perception of Form, Color, Movement, and Depth,” Journal of Neuroscience, Vol. 7, No. 11, 1987, pp. 3416-3468.
[27] W. H. Merigan and J. H. Maunsell, “How Parallel Are the Primate Visual Pathways?” Annals of Review Neuroscience, Vol. 16, No. 18, 1993, pp. 369-402. doi:10.1146/annurev.ne.16.030193.002101
[28] B. Hammarrenger, F. Lepore, S. Lippe, M. Labrosse, J.-P. Guillemot and M.-S. Roy, “Magnocellular and Parvocellular Developmental Course in Infants during the First Year of Life,” Documenta Ophthalmologica, Vol. 107, No. 3, 2003, pp. 225-233. doi:10.1023/B:DOOP.0000005331.66114.05
[29] B. Hammarrenger, M.-S. Roy, D. Ellemberg, M. Labrosse, J. Orquin, S. Lippe and F. Lepore, “Developmental Delay and Magnocellular Visual Pathway Function in VeryLow-Birthweight Preterm Infants,” Developmental Medicine & Child Neurology, Vol. 49, No. 1, 2007, pp. 28-33. doi:10.1017/S0012162207000084.x
[30] M. Livingstone and D. Hubel, “Segregation of Form, Color, Movement, and Depth: Anatomy, Physiology, and Perception,” Science, Vol. 240, No. 4853, 1988, pp. 740749. doi:10.1126/science.3283936
[31] R. Shapley, “Visual Sensitivity and Parallel Retinocortical Channels,” Annual Review of Psychology, Vol. 41, No. 1, 1990, pp. 635-658. doi:10.1146/annurev.ps.41.020190.003223
[32] B. G. Breitmeyer, “Unmasking Visual Masking: A Look at the ‘Why’ behind the Veil of the ‘How’,” Psychological Review, Vol. 87, No. 1, 1980, pp. 52-69. doi:10.1037/0033-295X.87.1.52
[33] W. Singer and N. Bedworth, “Inhibitory Interaction between X and Y Units in the Cat Lateral Geniculate Nucleus,” Brain Research, Vol. 49, No. 2, 1973, pp. 291-307. doi:10.1016/0006-8993(73)90424-1
[34] B. G. Breitmeyer, “Visual Masking: An Integrative Approach,” Oxford University Press, Oxford, 1984.
[35] B. G. Breitmeyer, “Reality and Relevance of Sustained and Transient Channels in Reading and Reading Disability,” In: R. Schmid and D. Zambarbieri, Eds., Oculomotor Control and Cognitive Processes, North Holland, Amsterdam, 1991, pp. 473-483.
[36] P. L. Cornelissen, P. C. Hansen, I. Gilchrist, F. Cormack, J. Essex and C. Frankish, “Coherent Motion Detection and Letter Position Encoding,” Vision Research, Vol. 38, No. 14, 1998, pp. 2181-2191. doi:10.1016/S0042-6989(98)00016-9
[37] P. L. Cornelissen, P. C. Hansen, J. L. Hutton, V. Evangelinou and J. F. Stein, “Magnocellular Visual Function and Children’s Single Word Reading,” Vision Research, Vol. 38, No. 3, 1998, pp. 471-482. doi:10.1016/S0042-6989(97)00199-5
[38] J. Stein and V. Walsh, “To See but Not to Read: The Magnocellular Theory of Dyslexia,” Trends in Neurosciences, Vol. 20, No. 20, 1997, pp. 147-152. doi:10.1016/S0166-2236(96)01005-3
[39] M. S. Livingstone, G. D. Rosen, F. W. Drislane and A. M. Galaburda, “Physiological and Anatomical Evidence for a Magnocellular Defect in Developmental Dyslexia,” Proceedings of the National Academy of Sciences of the United States of America, Vol. 88, No. 18, 1991, pp. 7943-7947. doi:10.1073/pnas.88.18.7943
[40] W. J. Lovegrove, “Is the Question of the Role of Visual Deficits as a Cause of Reading Disabilities a Closed One? Comments on Hulme,” Cognitive Neuropsychology, Vol. 8, No. 6, 1991, pp. 435-441. doi:10.1080/02643299108253381
[41] B. C. Skottun, “The Magnocellular Deficit Theory of Dyslexia: The Evidence from Contrast Sensitivity,” Vision Research, Vol. 40, No. 1, 2000, pp. 111-127. doi:10.1016/S0042-6989(99)00170-4
[42] B. C. Skottun and J. Skoyles, “Dyslexia, Direction Selectivity and Magnocellular Sensitivity,” Vision Research, Vol. 47, No. 14, 2007, pp. 1974-1975. doi:10.1016/j.visres.2006.10.027
[43] B. C. Skottun and J. R. Skoyles, “Coherent Motion, Magnocellular Sensitivity and the Causation of Dyslexia,” International Journal of Neuroscience, Vol. 118, No. 1, 2008, pp. 185-190.
[44] J. Skoyles and B. C. Skottun, “On the Prevalence of Magnocellular Deficits in the Visual System of Non-Dyslexic Individuals,” Brain and Language, Vol. 88, No. 1, 2004, pp. 79-82. doi:10.1016/S0093-934X(03)00162-7
[45] E. Borsting, W. H. Ridder Iii, K. Dudeck, C. Kelley, L. Matsui and J. Motoyama, “The Presence of a Magnocellular Defect Depends on the Type of Dyslexia,” Vision Research, Vol. 36, No. 7, 1996, pp. 1047-1053. doi:10.1016/0042-6989(95)00199-9
[46] A. M. Galaburda, “Neuroanatomic Basis of Developmental Dyslexia,” Neurologic Clinics, Vol. 11, No. 1, 1993, pp. 161-173.
[47] A. M. Galaburda, “Neurology of Developmental Dyslexia,” Current Opinion in Neurobiology, Vol. 3, No. 2, 1993, pp. 237-242. doi:10.1016/0959-4388(93)90216-L
[48] J. B. Demb, G. M. Boynton and D. J. Heeger, “Brain Activity in Visual Cortex Predicts Individual Differences in Reading?Performance,” Proceedings of the National Academy of Sciences of the United States of America, Vol. 94, No. 24, 1997, pp. 13363-13366. doi:10.1073/pnas.94.24.13363
[49] J. B. Demb, G. M. Boynton and D. J. Heeger, “Functional Magnetic Resonance Imaging of Early Visual Pathways in Dyslexia,” The Journal of Neuroscience, Vol. 18, No. 17, 1998, pp. 6939-6951.
[50] G. F. Eden, J. W. VanMeter, J. M. Rumsey, J. M. Maisog, R. P. Woods and T. A. Zeffiro, “Abnormal Processing of visual Motion in Dyslexia Revealed by Functional Brain imaging,” Nature, Vol. 382, No. 6586, 1996, pp. 66-69. doi:10.1038/382066a0
[51] F. Martin and W. Lovegrove, “The Effects of Field Size and Luminance on Contrast Sensitivity Differences between Specifically Reading Disabled and Normal Children,” Neuropsychologia, Vol. 22, No. 1, 1984, pp. 73-77. doi:10.1016/0028-3932(84)90009-5
[52] F. Martin and W. J. Lovegrove, “Uniform-Field Flicker Masking in Control and Specifically-Disabled Readers,” Perception, Vol. 17, No. 2, 1988, pp. 203-214. doi:10.1068/p170203
[53] A. Galaburda and M. Livingstone, “Evidence for a Magnocellular Defect in Developmental Dyslexia,” Annals of the New York Academy of Sciences, Vol. 682, 1993, pp. 70-82. doi:10.1111/j.1749-6632.1993.tb22960.x
[54] Z. Kubová, M. Kuba, H. Spekreijse and C. Blakemore, “Contrast Dependence of Motion-Onset and Pattern-Reversal Evoked Potentials,” Vision Research, Vol. 35, No. 2, 1995, pp. 197-205. doi:10.1016/0042-6989(94)00138-C
[55] S. Lehmkuhle, R. P. Garzia, L. Turner, T. Hash and J. A. Baro, “A Defective Visual Pathway in Children with Reading Disability,” New England Journal of Medicine, Vol. 328, No. 14, 1993, pp. 989-996. doi:10.1056/NEJM199304083281402
[56] J. G. May, W. P. Dunlap and W. J. Lovegrove, “Factor Scores Derived from Visual Evoked Potentials Latencies Differentiate Good and Poor Readers,” Clinical Vision Sciences, Vol. 7, 1992, pp. 67-70.
[57] J. G. May, W. J. Lovegrove, F. Martain, and P. Nelson, “Pattern-Elicited Visual Evoked Potentials in Good and Poor Readers,” Clinical Vision Sciences, Vol. 6, 1991, pp. 131-136.
[58] G. Schulte-Korne, J. Bartling, W. Deimel and H. Remschmidt, “Motion-Onset VEPs in Dyslexia. Evidence for Visual Perceptual Deficit,” Neuroreport, Vol. 15, No. 6, 2004, pp. 1075-1078. doi:10.1097/00001756-200404290-00029
[59] J. Brecelj, M. Strucl and V. Raic, “Do Visual Neurophysiological Tests Reflect Magnocellular Deficit in Dyslexic Children?” Pflügers Archiv-European Journal of Physiology, Vol. 431, No. 6, 1996, pp. R299-R300. doi:10.1007/BF02346387
[60] L. Mecacci, E. Sechi and G. Levi, “Abnormalities of Visual Evoked Potentials by Checker-boards in Children with Specific Reading Disability,” Brain and Cognition, Vol. 2, No. 2, 1983, pp. 135-143. doi:10.1016/0278-2626(83)90004-0
[61] H. A. Solan, V. G. Sujita, A. P. Ficarra and S. A. Wurst, “Binocular Advantage and Visual Processing in Dyslexic and Control Children as Measured by Visual Evoked Potentials,” Optometry & Vision Science, Vol. 67, No. 2, 1990, pp. 105-110. doi:10.1097/00006324-199002000-00008
[62] Z. Kubovà, M. Kuba, J. Peregrin and V. Nonakova, “Visual Evoked Potential Evidence for Magnocellular System Deficit in Dyslexia,” Physiological Research, Vol. 45, No. 1, 1996, pp. 87-89.
[63] D. Ellemberg, B. Hammarrenger, F. Lepore, M. S. Roy and J. P. Guillemot, “Contrast Dependency of VEPs as a Function of Spatial Frequency: The Parvocellular and Magnocellular Contributions to Human VEPs,” Spatial Vision, Vol. 15, No. 1, 2001, pp. 99-111. doi:10.1163/15685680152692042
[64] G. F. Harding, J. V. Odom, W. Spileers and H. Spekreijse, “Standard for Visual Evoked Potentials 1995. The International Society for Clinical Electrophysiology of Vision,” Vision Research, Vol. 36, No. 21, 1996, pp. 3567-3572. doi:10.1016/0042-6989(96)00125-3
[65] M. Bach and D. Ullrich, “Contrast Dependency of Motion-Onset and Pattern-Reversal VEPs: Interaction of Stimulus Type, Recording Site and Response Component,” Vision Research, Vol. 37, No. 13, 1997, pp. 1845-1849. doi:10.1016/S0042-6989(96)00317-3
[66] A. Vassilev, V. Stomonyakov and V. Manahilov, “Spatial-Frequency Specific Contrast Gain and Flicker Masking of Human Transient VEP*,” Vision Research, Vol. 34, No. 7, 1994, pp. 863-872. doi:10.1016/0042-6989(94)90036-1
[67] M. Kronbichler, F. Hutzler and H. Wimmer, “Dyslexia: Verbal Impairments in the Absence of Magnocellular Impairments,” Neuroreport, Vol. 13, No. 5, 2002, pp. 617620. doi:10.1097/00001756-200204160-00016
[68] J. D. Victor, M. M. Conte, L. Burton and R. D. Nass, “Visual Evoked Potentials in Dyslexics and Normals: Failure to Find a Difference in Transient or Steady-State Responses,” Visual Neuroscience, Vol. 10, No. 5, 1993, pp. 939-946. doi:10.1017/S0952523800006155
[69] S. Johannes, C. L. Kussmaul, T. F. Münte and G. R. Mangun, “Developmental Dyslexia: Passive Visual Stimulation Provides No Evidence for a Magnocellular Processing Defect,” Neuropsychologia, Vol. 34, No. 11, 1996, pp. 1123-1127. doi:10.1016/0028-3932(96)00026-7
[70] S. Amitay, G. Ben-Yehudah, K. Banai and M. Ahissar, “Disabled Readers Suffer from Visual and Auditory Impairments but Not from a Specific Magnocellular Deficit,” Brain, Vol. 125, No. 10, 2002, pp. 2272-2285. doi:10.1093/brain/awf231
[71] G. Ben-Yehudah, E. Sackett, L. Malchi-Ginzberg and M. Ahissar, “Impaired Temporal Contrast Sensitivity in Dyslexics Is Specific to Retain-and-Compare Paradigms,” Brain, Vol. 124, No. 7, 2001, pp. 1381-1395. doi:10.1093/brain/124.7.1381
[72] F. Ramus, “Developmental Dyslexia: Specific Phonological Deficit or General Sensorimotor Dysfunction?” Current Opinion in Neurobiology, Vol. 13, No. 2, 2003, pp. 212-218. doi:10.1016/S0959-4388(03)00035-7
[73] M. J. Williams, G. W. Stuart, A. Castles and K. I. McAnally, “Contrast Sensitivity in Subgroups of Developmental Dyslexia,” Vision Research, Vol. 43, No. 4, 2003, pp. 467-477. doi:10.1016/S0042-6989(02)00573-4
[74] J. Stevenson, K. Langley, H. Pay, A. Payton, J. Worthington, W. Ollier and A. Thapar, “Attention Deficit Hyperactivity Disorder with Reading Disabilities: Preliminary Genetic Findings on the Involvement of the ADRA2A Gene,” Journal of Child Psychology and Psy-chiatry and Allied Disciplines, Vol. 46, No. 10, 2005, pp. 1081-1088. doi:10.1111/j.1469-7610.2005.01533.x
[75] J. M. Carroll and J. E. Iles, “An Assessment of Anxiety levels in Dyslexic Students in Higher Education,” British Journal of Educational Psychology, Vol. 76, No. 3, 2006, pp. 651-662. doi:10.1348/000709905X66233
[76] E. G. Willcutt and B. F. Pennington, “Psychiatric Comorbidity in Children and Adolescents with Reading Disability,” The Journal of Child Psychology and Psychiatry and Allied Disciplines, Vol. 41, No. 8, 2000, pp. 1039-1048. doi:10.1111/1469-7610.00691
[77] E. Peli and M. A. García-Pérez, “Contrast Sensitivity in Dyslexia: Deficit or Artifact?” Optometry & Vision Science, Vol. 74, No. 12, 1997, pp. 986-987. doi:10.1097/00006324-199712000-00017
[78] C. C. Duncan, J. M. Rumsey, S. M. Wilkniss, M. B. Denckla, S. D. Hamburger and M. Odou-Potkin, “Developmental Dyslexia and Attention Dysfunction in Adults: Brain Potential Indices of Information Processing,” Psychophysiology, Vol. 31, No. 4, 1994, pp. 386401. doi:10.1111/j.1469-8986.1994.tb02447.x
[79] F. Ramus, “Neurobiology of Dyslexia: A Reinterpretation of the Data,” Trends in Neurosciences, Vol. 27, No. 12, 2004, pp. 720-726. doi:10.1016/j.tins.2004.10.004
[80] W. Lovegrove, “Weakness in the Transient Visual System: A Causal Factor in Dyslexia?” Annals of the New York Academy of Sciences, Vol. 682, No. , 1993, pp. 57-69. doi:10.1111/j.1749-6632.1993.tb22959.x
[81] B. A. Shaywitz, S. E. Shaywitz, K. R. Pugh, W. E. Mencl, R. K. Fulbright, P. Skudlarski, R. T. Constable, K. E. Marchione, J. M. Fletcher, G. R. Lyon and J. C. Gore, “Disruption of Posterior Brain Systems for Reading in Children with Developmental Dyslexia,” Biological Psychiatry, Vol. 52, No. 2, 2002, pp. 101-110. doi:10.1016/S0006-3223(02)01365-3
[82] A. Meyler, T. A. Keller, V. L. Cherkassky, D. Lee, F. Hoeft, S. Whitfield-Gabrieli, J. D. E. Gabrieli and M. A. Just, “Brain Activation during Sentence Comprehension among Good and Poor Readers,” Cerebral Cortex, 2007, Vol. 17, No. 12, pp. 2780-2787. doi:10.1093/cercor/bhm006
[83] F. Cao, T. Bitan, T.-L. Chou, D. D. Burman and J. R. Booth, “Deficient Orthographic and Phonological Representations in Children with Dyslexia Revealed by Brain Activation Patterns,” Journal of Child Psychology and Psychiatry, Vol. 47, No. 10, 2006, pp. 1041-1050. doi:10.1111/j.1469-7610.2006.01684.x
[84] N. Brunswick, E. McCrory, C. J. Price, C. D. Frith and U. Frith, “Explicit and Implicit Processing of Words and Pseudowords by Adult Developmental Dyslexics,” Brain, Vol. 122, No. 10, 1999, pp. 1901-1917. doi:10.1093/brain/122.10.1901
[85] P. Helenius, R. Salmelin, E. Service and J. F. Connolly, “Semantic Cortical Activation in Dyslexic Readers,” Journal of Cognitive Neuroscience, Vol. 11, No. 5, 1999, pp. 535-550. doi:10.1162/089892999563599
[86] E. Temple, R. A. Poldrack, A. Protopapas, S. Nagarajan, T. Salz, P. Tallal, M. M. Merzenich and J. D. E. Gabrieli, “Disruption of the Neural Response to Rapid Acoustic stimuli in Dyslexia: Evidence from Functional MRI,” Proceedings of the National Academy of Sciences of the United States of America, Vol. 97, No. 25, 2000, pp. 13907-13912. doi:10.1073/pnas.240461697

  
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