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Mihaylova MS, Bocheva NB, Stefanova MD, Genova BZ, Totev TT, Racheva KI, Shtereva KA, Staykova SN. Visual noise effect on reading in three developmental disorders: ASD, ADHD, and DD. AUTISM & DEVELOPMENTAL LANGUAGE IMPAIRMENTS 2022; 7:23969415221106119. [PMID: 36382080 PMCID: PMC9620686 DOI: 10.1177/23969415221106119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Background and aims Developmental disorders such as Autism Spectrum Disorder (ASD), Attention Deficit Hyperactivity Disorder (ADHD), and Developmental Dyslexia (DD) are reported to have more visual problems, oral language difficulties, and diminished reading skills in addition to their different diagnostic features. Moreover, these conditions also have increased internal noise and probably an impaired ability of external noise filtering. The aim of the present study was to compare the reading performance of these groups in the presence of external visual noise which disrupts the automatic reading processes through the degradation of letters. Methods Sixty-four children and adolescents in four groups, ASD, ADHD, DD, and TD, participated in the study. Two types of stimuli were used - unrelated words and pseudowords. The noise was generated by exchanging a fixed number of pixels between the black symbols and the white background distorting the letters. The task of the participants was to read aloud the words or pseudowords. The reading time for a single letter string, word or pseudoword, was calculated, and the proportion of errors was assessed in order to describe the reading performance. Results The results obtained showed that the reading of unrelated words and pseudowords differs in the separate groups of participants and is affected differently by the added visual noise. In the no-noise condition, the group with TD had the shortest time for reading words and short pseudowords, followed by the group with ASD, while their reading of long pseudowords was slightly slower than that of the ASD group. The noise increase evoked variations in the reading of groups with ASD and ADHD, which differed from the no-noise condition and the control group with TD. The lowest proportion of errors was observed in readers with TD. The reading performance of the DD group was the worst at all noise levels, with the most prolonged reading time and the highest proportion of errors. At the highest noise level, the participants from all groups read the words and pseudowords with similar reading speed and accuracy. Conclusions In reading words and pseudowords, the ASD, ADHD, and DD groups show difficulties specific for each disorder revealed in a prolonged reading time and a higher proportion of errors. The dissimilarity in reading abilities of the groups with different development is most evident when the accuracy and reading speed are linked together. Implications The use of noise that degrades the letter structure in the present study allowed us to separate the groups with ASD, ADHD, and DD and disclose specifics in the reading process of each disorder. Error type analysis may provide a basis to improve the educational strategies by appropriately structuring the learning process of children with TD, ASD, ADHD, and DD.
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Affiliation(s)
- Milena Slavcheva Mihaylova
- Milena Slavcheva Mihaylova, Institute of
Neurobiology, Bulgarian Academy of Sciences, 23 Academic Georgi Bonchev Street,
Sofia 1113, Bulgaria.
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Varga V, Tóth D, Amora KK, Czikora D, Csépe V. ERP Correlates of Altered Orthographic-Phonological Processing in Dyslexia. Front Psychol 2021; 12:723404. [PMID: 34721182 PMCID: PMC8548581 DOI: 10.3389/fpsyg.2021.723404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 09/15/2021] [Indexed: 11/13/2022] Open
Abstract
Automatic visual word recognition requires not only well-established phonological and orthographic representations but also efficient audio-visual integration of these representations. One possibility is that in developmental dyslexia, inefficient orthographic processing might underlie poor reading. Alternatively, reading deficit could be due to inefficient phonological processing or inefficient integration of orthographic and phonological information. In this event-related potential study, participants with dyslexia (N = 25) and control readers (N = 27) were presented with pairs of words and pseudowords in an implicit same-different task. The reference-target pairs could be identical, or different in the identity or the position of the letters. To test the orthographic-phonological processing, target stimuli were presented in visual-only and audiovisual conditions. Participants with and without dyslexia processed the reference stimuli similarly; however, group differences emerged in the processing of target stimuli, especially in the audiovisual condition where control readers showed greater N1 responses for words than for pseudowords, but readers with dyslexia did not show such difference. Moreover, after 300 ms lexicality effect exhibited a more focused frontal topographic distribution in readers with dyslexia. Our results suggest that in developmental dyslexia, phonological processing and audiovisual processing deficits are more pronounced than orthographic processing deficits.
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Affiliation(s)
- Vera Varga
- Brain Imaging Centre, Research Centre for Natural Sciences, Budapest, Hungary.,Department of Cognitive Science, Budapest University of Technology and Economics, Budapest, Hungary
| | - Dénes Tóth
- Brain Imaging Centre, Research Centre for Natural Sciences, Budapest, Hungary
| | - Kathleen Kay Amora
- Brain Imaging Centre, Research Centre for Natural Sciences, Budapest, Hungary.,Multilingualism Doctoral School, Faculty of Modern Philology and Social Sciences, University of Pannonia, Veszprém, Hungary
| | - Dávid Czikora
- Brain Imaging Centre, Research Centre for Natural Sciences, Budapest, Hungary
| | - Valéria Csépe
- Brain Imaging Centre, Research Centre for Natural Sciences, Budapest, Hungary.,Institute for Hungarian and Applied Linguistics, Pannon University, Veszprém, Hungary
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Taroyan NA, Butnicu B, Ypsilanti A, Overton PG. Individual Differences in Performance Speed Are Associated With a Positivity/Negativity Bias. An ERP and Behavioral Study. Front Behav Neurosci 2020; 14:7. [PMID: 32082128 PMCID: PMC7005202 DOI: 10.3389/fnbeh.2020.00007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 01/15/2020] [Indexed: 11/16/2022] Open
Abstract
There is a current dispute over the origins, incidence, and development of Positivity Bias, i.e., preferential processing of positive relative to negative information. We addressed this question using a multi-method technique of behavioral, psychometric and event-related potential (ERP) measures in a lexical decision task (LDT). Twenty-four university students (11 female) participated (age range 18–26), but four were omitted owing to data issues. Participants were classified as Positivity Biased (PB) if their LDT responses to positive words were faster than negative words, and vice versa for those classified as Negativity Biased (NB), leading to a group of 11 PB participants and a group of 9 NB participants. Interestingly, the PB group was significantly faster overall than the NB group and had significantly shorter P2 component ERP latencies in the left occipital region. Furthermore, the PB group had significantly higher scores for expressive suppression (ES), together with higher scores for Crystallized Knowledge and for cognitive reappraisal (CR). These results suggest that around 55% of the students had Positivity Bias, and these were more efficient in processing information and had better emotion regulation abilities than those with a Negativity Bias.
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Affiliation(s)
- Naira A. Taroyan
- Heart of the Campus, Collegiate Crescent Campus, Sheffield Hallam University, Sheffield, United Kingdom
- *Correspondence: Naira A. Taroyan
| | - Beatrice Butnicu
- Heart of the Campus, Collegiate Crescent Campus, Sheffield Hallam University, Sheffield, United Kingdom
| | - Antonia Ypsilanti
- Heart of the Campus, Collegiate Crescent Campus, Sheffield Hallam University, Sheffield, United Kingdom
| | - Paul G. Overton
- Department of Psychology, The University of Sheffield, Sheffield, United Kingdom
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4
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Abstract
Impaired print tuning in dyslexia has been shown in alphabetic languages; whether we can observe the same in a nonalphabetic language such as Chinese is still questionable. The present study investigated the N170 component in response to Chinese words versus nonword pseudo-words in 10-year-old children with developmental dyslexia (DD) when they were asked to performed a lexical decision task. The N170 was enhanced for DD group than control group, regardless of Chinese words or pseudo-words. The group effect of N170 amplitudes was more robust for Chinese words over pseudo-words. Although the N170 did not show the word advantage in the control group, larger N170 for Chinese words versus pseudo-words was found in the DD group. These findings suggest that there was a dysfunction/inefficient processing in the early stage of processing Chinese words in patients with DD.
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Perdue MV, Mascheretti S, Kornilov SA, Jasińska KK, Ryherd K, Einar Mencl W, Frost SJ, Grigorenko EL, Pugh KR, Landi N. Common variation within the SETBP1 gene is associated with reading-related skills and patterns of functional neural activation. Neuropsychologia 2018; 130:44-51. [PMID: 30009840 DOI: 10.1016/j.neuropsychologia.2018.07.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 05/09/2018] [Accepted: 07/12/2018] [Indexed: 11/25/2022]
Abstract
Epidemiological population studies highlight the presence of substantial individual variability in reading skill, with approximately 5-10% of individuals characterized as having specific reading disability (SRD). Despite reported substantial heritability, typical for a complex trait, the specifics of the connections between reading and the genome are not understood. Recently, the SETBP1 gene has been implicated in several complex neurodevelopmental syndromes and disorders that impact language. Here, we examined the relationship between common polymorphisms in this gene, reading, and reading associated behaviors using data from an ongoing project on the genetic basis of SRD (n = 135). In addition, an exploratory analysis was conducted to examine the relationship between SETBP1 and brain activation using functional magnetic resonance imaging (fMRI; n = 73). Gene-based analyses revealed a significant association between SETBP1 and phonological working memory, with rs7230525 as the strongest associated single nucleotide polymorphism (SNP). fMRI analysis revealed that the rs7230525-T allele is associated with functional neural activation during reading and listening to words and pseudowords in the right inferior parietal lobule (IPL). These findings suggest that common genetic variation within SETBP1 is associated with reading behavior and reading-related brain activation patterns in the general population.
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Affiliation(s)
- Meaghan V Perdue
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, USA; Haskins Laboratories, New Haven, CT, USA
| | - Sara Mascheretti
- Child Psychopathology Unit, Scientific Institute, IRCCS E. Medea, Bosisio Parini, LC, Italy
| | - Sergey A Kornilov
- Texas Institute for Measurement, Evaluation, and Statistics, University of Houston, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Kaja K Jasińska
- Haskins Laboratories, New Haven, CT, USA; Department of Linguistics and Cognitive Science, University of Delaware, Newark, DE, USA
| | - Kayleigh Ryherd
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, USA; Haskins Laboratories, New Haven, CT, USA
| | | | | | - Elena L Grigorenko
- Haskins Laboratories, New Haven, CT, USA; Texas Institute for Measurement, Evaluation, and Statistics, University of Houston, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; St. Petersburg State University, Russia
| | - Kenneth R Pugh
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, USA; Haskins Laboratories, New Haven, CT, USA
| | - Nicole Landi
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, USA; Haskins Laboratories, New Haven, CT, USA.
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Basagni B, Patané I, Ferrari V, Bruno N. Impaired reading not due to visual field loss in a patient with a right-hemipsheric lesion. Neurocase 2014; 20:510-23. [PMID: 23984952 DOI: 10.1080/13554794.2013.826684] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We describe a right-handed patient (M.B.), who developed left hemianopsia and a severe reading impairment after right occipital-parietal hemorrhage. The pattern of his reading deficit was very similar to that of pure alexia (alexia-without-agraphia): extremely slow reading times with frequent grapheme substitutions and omissions. A test of letter reading while controlling for saccadic eye movements and hemifield of presentation ruled out hemianoptic alexia. Although there have already been reports of reading impairments in right handers following right- hemispheric lesions, ours is, to the best of our knowledge, the first where visual field loss can be definitely excluded as the main cause. Based on a standard neuropsychological assessment and on additional behavioral tests, we argue that M.B.'s difficulties are unlikely to be due to right-hemisphere dominance for language. After considering several candidate explanations, we suggest that M.B.'s symptoms may be related to an impairment in attentional processes related to reading.
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Affiliation(s)
- Benedetta Basagni
- a Centro S. Maria ai Servi, Fondazione Don Carlo Gnocchi , Parma , Italy
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7
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Mahé G, Doignon-Camus N, Dufour A, Bonnefond A. Conflict control processing in adults with developmental dyslexia: An event related potentials study. Clin Neurophysiol 2014; 125:69-76. [DOI: 10.1016/j.clinph.2013.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 06/10/2013] [Accepted: 06/11/2013] [Indexed: 10/26/2022]
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Savill NJ, Thierry G. Electrophysiological evidence for impaired attentional engagement with phonologically acceptable misspellings in developmental dyslexia. Front Psychol 2011; 2:139. [PMID: 21734903 PMCID: PMC3124829 DOI: 10.3389/fpsyg.2011.00139] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 06/09/2011] [Indexed: 11/13/2022] Open
Abstract
Event-related potential (ERP) studies of word recognition have provided fundamental insights into the time-course and stages of visual and auditory word form processing in reading. Here, we used ERPs to track the time-course of phonological processing in dyslexic adults and matched controls. Participants engaged in semantic judgments of visually presented high-cloze probability sentences ending either with (a) their best completion word, (b) a homophone of the best completion, (c) a pseudohomophone of the best completion, or (d) an unrelated word, to examine the interplay of phonological and orthographic processing in reading and the stage(s) of processing affected in developmental dyslexia. Early ERP peaks (N1, P2, N2) were modulated in amplitude similarly in the two groups of participants. However, dyslexic readers failed to show the P3a modulation seen in control participants for unexpected homophones and pseudohomophones (i.e., sentence completions that are acceptable phonologically but are misspelt). Furthermore, P3a amplitudes significantly correlated with reaction times in each experimental condition. Our results showed no sign of a deficit in accessing phonological representations during reading, since sentence primes yielded phonological priming effects that did not differ between participant groups in the early phases of processing. On the other hand, we report new evidence for a deficient attentional engagement with orthographically unexpected but phonologically expected words in dyslexia, irrespective of task focus on orthography or phonology. In our view, this result is consistent with deficiency in reading occurring from the point at which attention is oriented to phonological analysis, which may underlie broader difficulties in sublexical decoding.
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Affiliation(s)
| | - Guillaume Thierry
- School of Psychology, Bangor UniversityBangor, UK
- Economic and Social Research Council Centre for Research on Bilingualism in Theory and Practice, Bangor UniversityBangor, UK
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9
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Savill NJ, Thierry G. Reading for sound with dyslexia: Evidence for early orthographic and late phonological integration deficits. Brain Res 2011; 1385:192-205. [DOI: 10.1016/j.brainres.2011.02.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2010] [Revised: 01/26/2011] [Accepted: 02/03/2011] [Indexed: 11/30/2022]
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10
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Behavioral performances in participants with phonological dyslexia and different patterns on the N170 component. Brain Cogn 2011; 75:91-100. [PMID: 21094575 DOI: 10.1016/j.bandc.2010.10.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 09/09/2010] [Accepted: 10/20/2010] [Indexed: 10/18/2022]
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11
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Kast M, Elmer S, Jancke L, Meyer M. ERP differences of pre-lexical processing between dyslexic and non-dyslexic children. Int J Psychophysiol 2010; 77:59-69. [DOI: 10.1016/j.ijpsycho.2010.04.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Revised: 04/15/2010] [Accepted: 04/16/2010] [Indexed: 11/30/2022]
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12
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Reading words and pseudowords in dyslexia: ERP and behavioural tests in English-speaking adolescents. Int J Psychophysiol 2009; 74:199-208. [DOI: 10.1016/j.ijpsycho.2009.09.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2008] [Revised: 08/14/2009] [Accepted: 09/02/2009] [Indexed: 11/23/2022]
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13
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[Assessment of central auditory processes in Spanish in children with dyslexia and controls. Binaural Fusion Test and Filtered Word Test]. ACTA OTORRINOLARINGOLOGICA ESPANOLA 2009; 60:415-21. [PMID: 19909717 DOI: 10.1016/j.otorri.2009.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Accepted: 06/15/2009] [Indexed: 11/18/2022]
Abstract
OBJECTIVES The aim is to assess the ability to discriminate words, using two psychoacoustic verbal tests of central auditory processes in Spanish: Binaural Fusion Test (BFT in its Spanish version) and Filtered Word Test (FWT in its Spanish version) in children with dyslexia and controls. METHODS One group of 40 dyslexic children was receiving therapy for dyslexia at the time of the tests. 40 children without dyslexia were selected as controls, out of 298 children who attended a public school. RESULTS The rate of males to females was 2/1 in the dyslexic group. The average correct answers for the BFT were 65-66% in dyslexic group and 75-80% in the control group. For the FWT they were 50-54% in the dyslexic group and 67-71% in the control group (student t <0.05). CONCLUSIONS These results contribute to make evident disorders in central auditory processing in children with dyslexia. We suggest using the tests with each patient in order to elaborate a rehabilitation plan.
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Peñaloza-López YR, del Rosario Olivares García M, de la Sancha SJ, García-Pedroza F, Perez Ruiz SJ. Assessment of central auditory processes in evaluated in Spanish in children with dyslexia and controls. Binaural Fusion Test and Filtered Word Test. ACTA OTORRINOLARINGOLOGICA ESPANOLA 2009. [DOI: 10.1016/s2173-5735(09)70168-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Meng X, Tian X, Jian J, Zhou X. Orthographic and phonological processing in Chinese dyslexic children: An ERP study on sentence reading. Brain Res 2007; 1179:119-30. [PMID: 17904537 DOI: 10.1016/j.brainres.2007.08.046] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Revised: 08/15/2007] [Accepted: 08/17/2007] [Indexed: 11/16/2022]
Abstract
An event-related potential (ERP) experiment was conducted to explore the differences between Chinese-speaking dyslexic children and normal school children in orthographic and phonological processing during Chinese sentence reading. Participants were visually presented with sentences, word-by-word and were asked to judge whether the sentences were semantically acceptable. The crucial manipulation was on the sentence-final two-character compound words, which were either correct or incorrect. For the incorrect compounds, the second characters of the base words were replaced by homophonic or orthographically similar characters. It was found that, for the normal controls, the orthographic and phonological mismatches elicited more negative ERP responses, relative to the baseline, over a relatively long time course (including the time windows for P200 and N400) at the central-posterior scalp regions. In contrast, the dyslexic children in general showed no differences between experimental conditions for P200 and N400, although the more detailed time course analyses did reveal some weak effects for the N400 component between experimental conditions. In addition, the mean amplitude of N400 in the homophonic condition was less negative-going for the dyslexics than for the controls. These findings suggest that Chinese dyslexic children have deficits in processing orthographic and phonological information conveyed by characters and, compared with normal children, they rely more on phonological information to access lexical semantics in sentence reading.
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Affiliation(s)
- Xiangzhi Meng
- Department of Psychology, Peking University, Beijing 100871, China
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Taroyan NA, Nicolson RI, Fawcett AJ. Behavioural and neurophysiological correlates of dyslexia in the continuous performance task. Clin Neurophysiol 2007; 118:845-55. [PMID: 17317301 DOI: 10.1016/j.clinph.2006.11.273] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2005] [Revised: 10/25/2006] [Accepted: 11/21/2006] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To investigate whether attentional difficulties are a "core" feature of developmental Dyslexia. METHODS Behavioural indices and event related potentials (ERPs) were recorded from 10 dyslexic participants (ages 15.5-17.4) and 10 control participants (ages 14.4-18.3) in the Continuous Performance Task (CPT), an established test of attentional performance. Participants were screened to ensure that none was diagnosable as attention deficit (ADHD). RESULTS There were no significant differences in mean reaction time, error rate or sustained attention between the groups. By contrast, the P3 amplitude was significantly smaller and its latency significantly longer for the dyslexic group. This component was significantly lateralised in controls, whereas in dyslexics it was symmetrical. CONCLUSIONS Under the relatively light workload conditions of the CPT, "pure" dyslexic participants showed no behavioural signs of attentional difficulties. The attenuated, delayed and symmetrical ERPs in our dyslexic group may reflect abnormal information processing in the right parietal lobe and abnormal interhemispheric asymmetry in Dyslexia. SIGNIFICANCE The behavioural data suggest that abnormal attentional performance is not a "core" feature of developmental Dyslexia, and highlight the importance of distinguishing between dyslexic participants with and without ADHD symptoms. The presence of electrophysiological markers of Dyslexia in CPT revealed the atypical brain organisation that characterises "pure" Dyslexia.
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Affiliation(s)
- N A Taroyan
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, UK.
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Wunderlich JL, Cone-Wesson BK, Shepherd R. Maturation of the cortical auditory evoked potential in infants and young children. Hear Res 2006; 212:185-202. [PMID: 16459037 DOI: 10.1016/j.heares.2005.11.010] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2005] [Revised: 11/25/2005] [Accepted: 11/28/2005] [Indexed: 10/25/2022]
Abstract
The aim of this study was to evaluate the maturation of the cortical auditory evoked potential (CAEP) in humans. The participants in this experiment were 10 newborns (<7 days), 19 toddlers (13-41 months), 20 children (4-6 years) and 9 adults (18-45 years). CAEPs were obtained in response to low (400 Hz) and high (3000 Hz) tones and to the word token /baed/, all presented at 60 dB HL, at a rate of 0.22 Hz. Latency and amplitude measures were made for CAEP components P1, N1, P2 and N2 as a function of participant age, stimulus type and electrode montage. CAEP component latencies were relatively stable from birth to 6 years, but adults demonstrated significantly shorter latencies compared to infants and children. Components P1 and N2 decreased in amplitude, while components N1 and P2 increased in amplitude from birth to adulthood. Words evoked significantly larger CAEPs in newborns compared to responses evoked by tones, but in other age groups the effects of stimulus type on component amplitudes and latencies were less consistent. There was evidence of immature tonotopic organisation of the generators of N1 when responses from infants and young children were compared to those of adults. The scalp distribution of components N1 and P2 was clearly different in newborns and toddlers compared to children and adults. In the younger groups, both N1 and P2 were uniformly distributed across the scalp but in children and adults these components showed more focal distributions, with evidence of response laterality increasing with maturity. The results of the present study describe, for the first time, CAEPs recorded from multiple scalp electrodes, for tones and speech stimuli, in infants and children from birth to 6 years of age. Frequency-related differences in component amplitude were apparent at all ages reflecting development of tonotopic organisation of the CAEP neural generators.
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Affiliation(s)
- Julia Louise Wunderlich
- Department of Otolaryngology, The University of Melbourne, 384-388 Albert Street, East Melbourne, 3002 Vic., Australia.
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Abstract
This article examines the importance of developmental designs in dyslexia research using a neuroconstructivist framework. According to neuroconstructivism, the lowest level of impairment should be identified as early as possible, and developmental effects on higher-level cognition examined longitudinally. A number of recent studies proposing candidate low-level impairments have not used such developmental designs. The role of normal variation in postulated causal factors on development is ignored, inadequate control groups are used, and the nature and timing of environmental inputs are not measured, even though reading is taught systematically and both reading acquisition and dyslexia vary with orthography. It is suggested here that only a phonological deficit arising from low-level auditory processing problems meets the criteria for a neuroconstructivist approach.
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Affiliation(s)
- Usha Goswami
- Faculty of Education, University of Cambridge, Shaftesbury Road, Cambridge, CB2 2BX, UK.
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Csépe V, Szücs D, Honbolygó F. Number-word reading as challenging task in dyslexia? An ERP study. Int J Psychophysiol 2003; 51:69-83. [PMID: 14629924 DOI: 10.1016/s0167-8760(03)00154-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The aim of the present study was to evaluate processes of lexical access, selection and early semantic access in young native Hungarian students as well as in dyslexics compensating successfully for their reading problems of developmental origin. The present study made use of the well-known lexical decision paradigm in which event-related potentials (ERPs) elicited by words, number-words and pseudowords were measured. Subjects had to judge whether the letter strings seen were meaningful or meaningless. Our results suggest that in good readers additional activity occurs in the sensory or selection stage of lexical access when words of low sight frequency, e.g. number-words are read. Significant processing differences for words vs. number-words were found in the later stage of processing. Based on our ERP data we do not suggest number-words for judging general features of lexical processing, especially when developmental dyslexia is the focus of study. Our results show that young adults may develop a particular compensation strategy for reading words of different frequency. We found that: (1) Lexical access is fast and accurate in good readers and the early components elicited by words and number-words do not differ. (2) Attentional effort is reflected by enhanced early components to number-words. (3) Dyslexics may compensate for the weakness of sight word vocabulary, characteristic for frequent words as well, during lexical selection and at a later stage of processing. (4) Dyslexic adults, who compensate well for reading difficulties, differ significantly in this later stage when words have to be read. (5) The late positive component of ERPs reflects additional activation allocated to word reading when low frequency words such as number-words are read. Good readers show this effect as well, therefore, the largest difference found between dyslexics and controls is found for frequent words. (6) The early semantic access is absent in dyslexics when pseudowords are read and this process may be one of the strategies used by dyslexics in a transparent orthography.
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Affiliation(s)
- Valéria Csépe
- Institute for Psychology of the Hungarian Academy of Sciences, Research Group of Developmental Psychophysiology, Szondi utca 83-85, Budapest H-1394, Hungary.
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