Impaired tuning of a fast occipito-temporal response for print in dyslexic children learning to read.

Developmental dyslexia is defined as a disorder of learning to read. It is thus critical to examine the neural processes that impair learning to read during the early phase of reading acquisition, before compensatory mechanisms are adapted by older readers with dyslexia. Using electroencephalography-based event-related imaging, we investigated how tuning of visual activity for print advances in the same children before and after initial reading training in school. The focus was on a fast, coarse form of visual tuning for print, measured as an increase of the occipito-temporal N1 response at 150-270 ms in the event-related potential (ERP) to words compared to symbol strings. The results demonstrate that the initial development of reading skills and visual tuning for print progressed more slowly in those children who became dyslexic than in their control peers. Print-specific tuning in 2nd grade strongly distinguished dyslexic children from controls. It was maximal in the inferior occipito-temporal cortex, left-lateralized in controls, and reduced in dyslexic children. The results suggest that delayed initial visual tuning for print critically contributes to the development of dyslexia.

[1]  J D Watson,et al.  Nonparametric Analysis of Statistic Images from Functional Mapping Experiments , 1996, Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism.

[2]  W. Slaghuis,et al.  Visual and Language Processing Disorders are Concurrent in Dyslexia and Continue into Adulthood , 1996, Cortex.

[3]  Daniel Brandeis,et al.  Coarse neural tuning for print peaks when children learn to read , 2006, NeuroImage.

[4]  U. Frith,et al.  Explicit and implicit processing of words and pseudowords by adult developmental dyslexics: A search for Wernicke's Wortschatz? , 1999, Brain : a journal of neurology.

[5]  Bruce D. McCandliss,et al.  The development of reading impairment: a cognitive neuroscience model. , 2003, Mental retardation and developmental disabilities research reviews.

[6]  Daniel Brandeis,et al.  Altered responses to tone and phoneme mismatch in kindergartners at familial dyslexia risk , 2003, Neuroreport.

[7]  Daniel Brandeis,et al.  Neurophysiological signs of rapidly emerging visual expertise for symbol strings , 2005, Neuroreport.

[8]  Daniel Brandeis,et al.  Evidence for developmental changes in the visual word processing network beyond adolescence , 2006, NeuroImage.

[9]  D. Perani,et al.  Neuropsychological deficits and neural dysfunction in familial dyslexia , 2006, Brain Research.

[10]  E. Halgren,et al.  Dynamic Statistical Parametric Mapping Combining fMRI and MEG for High-Resolution Imaging of Cortical Activity , 2000, Neuron.

[11]  Christian Gaser,et al.  Phonological processing in dyslexic children: a study combining functional imaging and event related potentials , 2002, Neuroscience Letters.

[12]  J. Pernier,et al.  ERP Manifestations of Processing Printed Words at Different Psycholinguistic Levels: Time Course and Scalp Distribution , 1999, Journal of Cognitive Neuroscience.

[13]  D Brandeis,et al.  Mapping brain electric micro-states in dyslexic children during reading. , 1994, Acta paedopsychiatrica.

[14]  Riitta Salmelin,et al.  Cortical Sequence of Word Perception in Beginning Readers , 2006, The Journal of Neuroscience.

[15]  B. Shaywitz,et al.  Dyslexia (Specific Reading Disability) , 2005, Biological Psychiatry.

[16]  R. Salmelin,et al.  Dynamics of letter string perception in the human occipitotemporal cortex. , 1999, Brain : a journal of neurology.

[17]  H. Wimmer,et al.  Evidence for a dysfunction of left posterior reading areas in German dyslexic readers , 2006, Neuropsychologia.

[18]  P. Bryant,et al.  Categorizing sounds and learning to read—a causal connection , 1983, Nature.

[19]  K. Eklund,et al.  Brain Event-Related Potentials (ERPs) Measured at Birth Predict Later Language Development in Children with and Without Familial Risk for Dyslexia , 2005, Cortex.

[20]  D. Lehmann,et al.  Low resolution electromagnetic tomography: a new method for localizing electrical activity in the brain. , 1994, International journal of psychophysiology : official journal of the International Organization of Psychophysiology.

[21]  Urs Maurer,et al.  The development of visual expertise for words: The contribution of electrophysiology , 2007 .

[22]  R. C. Oldfield The assessment and analysis of handedness: the Edinburgh inventory. , 1971, Neuropsychologia.

[23]  J. G. Snodgrass,et al.  A standardized set of 260 pictures: norms for name agreement, image agreement, familiarity, and visual complexity. , 1980, Journal of experimental psychology. Human learning and memory.

[24]  M. Posner,et al.  Influencing brain networks: implications for education , 2005, Trends in Cognitive Sciences.

[25]  P Berg,et al.  A multiple source approach to the correction of eye artifacts. , 1994, Electroencephalography and clinical neurophysiology.

[26]  S. A. Wurst,et al.  Binocular advantage and visual processing in dyslexic and control children as measured by visual evoked potentials. , 1990, Optometry and vision science : official publication of the American Academy of Optometry.

[27]  A. Liberman,et al.  Functional disruption in the organization of the brain for reading in dyslexia. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[28]  F. Ramus,et al.  Theories of developmental dyslexia: insights from a multiple case study of dyslexic adults. , 2003, Brain : a journal of neurology.

[29]  A. Chan,et al.  A breakdown of event schemas in patients with schizophrenia: an examination of their script for dining at restaurants , 1999, Psychiatry Research.

[30]  P. Skudlarski,et al.  Disruption of posterior brain systems for reading in children with developmental dyslexia , 2002, Biological Psychiatry.

[31]  J. Fletcher,et al.  Cerebral mechanisms involved in word reading in dyslexic children: a magnetic source imaging approach. , 2000, Cerebral cortex.

[32]  T. Koenig,et al.  Low resolution brain electromagnetic tomography (LORETA) functional imaging in acute, neuroleptic-naive, first-episode, productive schizophrenia , 1999, Psychiatry Research: Neuroimaging.

[33]  U. Frith,et al.  Precursors of literacy delay among children at genetic risk of dyslexia. , 2000, Journal of child psychology and psychiatry, and allied disciplines.

[34]  R. Poldrack,et al.  Disrupted neural responses to phonological and orthographic processing in dyslexic children: an fMRI study , 2001, Neuroreport.

[35]  B. Pennington,et al.  Early reading development in children at family risk for dyslexia. , 2001, Child development.

[36]  F. Fazio,et al.  Dyslexia: Cultural Diversity and Biological Unity , 2001, Science.

[37]  R. Salmelin,et al.  Dissociation of normal feature analysis and deficient processing of letter-strings in dyslexic adults. , 1999, Cerebral cortex.

[38]  D. Lehmann,et al.  Reference-free identification of components of checkerboard-evoked multichannel potential fields. , 1980, Electroencephalography and clinical neurophysiology.

[39]  F. Ramus Neurobiology of dyslexia: a reinterpretation of the data. , 2004, Trends in neurosciences.

[40]  J. Maisog,et al.  A positron emission tomographic study of impaired word recognition and phonological processing in dyslexic men. , 1997, Archives of neurology.

[41]  Carolyn A. Denton,et al.  Early development of neurophysiological processes involved in normal reading and reading disability: a magnetic source imaging study. , 2005, Neuropsychology.

[42]  Daniel Brandeis,et al.  Emerging Neurophysiological Specialization for Letter Strings , 2005, Journal of Cognitive Neuroscience.

[43]  S Lehéricy,et al.  The visual word form area: spatial and temporal characterization of an initial stage of reading in normal subjects and posterior split-brain patients. , 2000, Brain : a journal of neurology.