ABSTRACT
Acute carbon monoxide (CO) intoxication may result in delayed neurological sequelae, which can include amnesia, ataxia, aphasia, emotional lability, disorientation, dysphagia, and other manifestations. A 27-year-old man reported symptoms of aphasia with agraphia and alexia in a review after CO intoxication. The patient received outpatient speech therapy, as well as repeated sessions of hyperbaric oxygen for 15 days, interspersing speech therapy with hyperbaric oxygen therapy for two months. After this period of combined treatment the aphasic symptomatology remitted, and oral and written language was normal. The complete disappearance of aphasia with agraphia and alexia confirms the efficacy of the combined intervention. More data from large clinical studies are needed to assess the outcomes of hyperbaric oxygen treatment in patients with delayed neurological sequelae after CO intoxication, but this case suggests it may be a good therapeutic option in combination with specific speech therapy.
Subject(s)
Agraphia , Aphasia , Carbon Monoxide Poisoning , Dyslexia , Hyperbaric Oxygenation , Male , Humans , Adult , Carbon Monoxide , Agraphia/complications , Agraphia/therapy , Speech Therapy , Aphasia/complications , Aphasia/therapy , Carbon Monoxide Poisoning/complications , Dyslexia/complications , Dyslexia/therapyABSTRACT
In this work, two different studies are examined to evaluate the effectiveness of a novel intervention program for the improvement of reading ability in children with dyslexia, known as repeated reading with vocal music masking (RVM). The proposed remedial approach is inspired by Breznitz's original work. The studies assess a 5-week program of intensive RVM training in a pre-post-test clinical paradigm, as well as a longitudinal paradigm where it is compared to 8 months of the standard remediation program (SRP). The results of both studies support the efficacy of the newly proposed RVM method. Notably in the longitudinal study, the reading speed of children, as well as related phonological, visuo-attentional, and cognitive skills, and attitudes toward reading, were measured regularly. Significant improvements in reading efficiency and related skills were observed, as well as greater motivation to read after RVM training. A modeling of the data specifically linked executive and processing speed skills to be involved in RVM training, suggesting that RVM may help rebalance the phonological and orthographic coding procedures necessary for efficient reading. The short, intensive, and focused nature of RVM training makes it a viable and attractive intervention for clinical practice. As preliminary results are promising, RVM training may prove to be a valuable tool that clinicians can call upon to effectively treat reading fluency disorders, especially when standard programs do not provide results.
Subject(s)
Dyslexia/psychology , Dyslexia/therapy , Music Therapy/methods , Reading , Remedial Teaching/methods , Attention/physiology , Child , Dyslexia/epidemiology , Early Intervention, Educational/methods , Humans , Longitudinal Studies , Male , Pilot Projects , Random Allocation , Treatment OutcomeABSTRACT
BACKGROUND: About 10% of the western population suffers from a specific disability in the acquisition of reading and writing skills, known as developmental dyslexia (DD). Even though DD starts in childhood it frequently continuous throughout lifetime. Impaired processing of acoustic features at the phonematic scale based on dysfunctional auditory temporal resolution is considered as one core deficit underlying DD. Recently, the efficacy of transcranial electrical stimulation (tES) to modulate auditory temporal resolution and phoneme processing in healthy individuals has been demonstrated. OBJECTIVE: The present work aims to investigate online effects of tES on phoneme processing in individuals with DD. METHOD: Using an established phoneme-categorization task, we assessed the immediate behavioral and electrophysiological effects of transcranial alternating current stimulation (tACS) and transcranial random noise stimulation (tRNS) over bilateral auditory cortex in children and adolescents with DD (study 1) and adults with DD (study 2) on auditory phoneme processing acuity. RESULTS: Our data revealed that tACS improved phoneme categorization in children and adolescents with DD, an effect that was paralleled by an increase in evoked brain response patterns representing low-level sensory processing. In the adult sample we replicated these findings and additionally showed a more pronounced impact of tRNS on phoneme-categorization acuity. CONCLUSION: These results provide compelling evidence for the potential of both tACS and tRNS to increase temporal precision of the auditory system in DD and suggest transcranial electrical stimulation as potential intervention in DD to foster the effect of standard phonology-based training.
Subject(s)
Acoustic Stimulation/methods , Auditory Cortex/physiology , Dyslexia/psychology , Dyslexia/therapy , Phonetics , Transcranial Direct Current Stimulation/methods , Adolescent , Auditory Perception/physiology , Child , Dyslexia/diagnosis , Female , Humans , Male , Random AllocationABSTRACT
Dyslexia is a common developmental learning difficulty, which persists throughout life. It is highly likely that those working in primary care will know, or even work with someone who has dyslexia. Dyslexia can impact on performance in postgraduate training and exams. The stereotypical characteristics of dyslexia, such as literacy difficulties, are often not obvious in adult learners. Instead, recognition requires a holistic approach to evaluating personal strengths and difficulties, in the context of a supportive relationship. Strategies to support dyslexic learners should consider recommendations made in formal diagnostic reports, and aim to address self-awareness and coping skills.
Subject(s)
Dyslexia/psychology , General Practice/education , Physicians, Primary Care/education , Students, Medical/psychology , Adaptation, Psychological , Dyslexia/diagnosis , Dyslexia/therapy , Education, Medical, Graduate , Humans , Physicians, Primary Care/psychologyABSTRACT
INTRODUCTION: ADHD occurs in 3% of school-age children (and in 70% of them in adulthood) and represents an important medical and social problem. It is characterized by attention deficits, hyperactivity and impulsiveness. Neurofeedback therapy (EEG biofeedback, NF) is carried out based on the analysis of EEG. OBJECTIVE: To investigate the effect of NF therapy on clinical status and parameters of the EEG in ADHD. MATERIALS AND METHODS: In the years 2007-2014, 287 children (191 boys), aged 6-17 years were included into the study. Some children with ADHD had other coexisting disorders like: tics, dyslexia, emotional or behavior disorders. Visual analysis of EEG was made and 7 selected parameters of bioelectrical activity were assessed. EEG tracing before and after NF therapy were compared. NF therapy lasted from 9 months to 3 years (mean 1.5 years). 60-240 NF training sessions were performed with the use of NF device, video-games and 16-channel Elmiko devices. Statistical analysis of the results was made. RESULTS: Children with ADHD additionally presented low self-esteem, anxiety and sleep disorders. The baseline theta/beta ratio in children with ADHD and ADHD with cooccurring dyslexia was >4.0 and in children with ADHD and coexisting tics 3.0-3.8, with coexisting behavioral disorders 3.7-4.0 and emotional disorders 3.3-3.7. After therapy, this ratio decreased significantly in all groups, but most significantly in ADHD and ADHD with dyslexia group. In the group with dyslexia theta and alpha activity in the left fronto-temporo-parietal region (the speech centers) has been increased. In children with ADHD and behavior disorders right-sided paroxysmal changes in the form of slow and sharp waves in the temporo-centro-parietal regions were found. In emotionally disturbed children increased fast beta activity in the right hemisphere (anxiety, fear) was observed. Initially NF therapy reduced hyperactivity and impulsivity of children, subsequently improvement of attention was observed and eventually reduction of emotional and behavior disturbances was noticed. Noticeable improvement in the self-esteem was observed as well. The therapy had a positive impact on the spatial organization of EEG in each group. It proved to be particularly useful in children with ADHD and dyslexia. CONCLUSIONS: Neurofeedback therapy is a valuable tool with beneficial impact on children with ADHD and accompanying disorders. Characteristics of brain bioelectric activity provides a reliable basis to establish individual EEG bio-feedback protocols of therapy in children and monitor the effectiveness of treatment. In the last 4 years the number of children with ADHD and cooccurring tics who applied for neurofeedback therapy has increased significantly.
Subject(s)
Attention Deficit Disorder with Hyperactivity/complications , Dyslexia/complications , Neurofeedback , Adolescent , Attention Deficit Disorder with Hyperactivity/psychology , Attention Deficit Disorder with Hyperactivity/therapy , Behavioral Symptoms/complications , Behavioral Symptoms/therapy , Child , Dyslexia/therapy , Electroencephalography , Female , Humans , Male , Tics/complications , Tics/therapy , Treatment OutcomeABSTRACT
En este informe se revisa la investigación que respalda distintas intervenciones para el tratamiento de la dislexia, concretamente los trabajos de síntesis, en especial síntesis de las mejores evidencias, revisiones sistemáticas o metaanálisis publicados sobre cada tipo de intervención. En los casos en que no se ha publicado ningún trabajo de síntesis o estos trabajos son antiguos, se hace una revisión de la investigación primaria. Los trabajos localizados indican que los métodos fonológicos de intervención en la dislexia, es decir, aquellos en los que se combina el entrenamiento en habilidades fonológicas con el conocimiento de las letras y la práctica de la lectura, están ampliamente respaldados por la investigación. En cambio, la investigación sobre otros sistemas es sumamente escasa, ofrece resultados contradictorios o indica que se trata de sistemas ineficaces. Las intervenciones que están en estas situaciones son: la integración auditiva, el entrenamiento auditivo con soporte informático, la terapia visual, las lentes tintadas, el entrenamiento perceptivo-motor, las técnicas quiroprácticas, la integración sensorial, el método Davis, el neurofeedback, la musicoterapia y la educación musical o las dietas y suplementos alimenticios. A partir de esta revisión se realizan las siguientes recomendaciones: promocionar las intervenciones de tipo fonológico para el tratamiento de la dislexia, no utilizar o recomendar intervenciones que no estén respaldadas por la investigación científica, que los métodos de intervención que no hayan probado su eficacia no reciban el nombre de «terapia» o «tratamiento», y la creación y difusión de una guía sobre intervención en dislexia basada en evidencias científicas (AU)
In this report the research that supports various interventions for the treatment of dyslexia is revised, specifically the works of synthesis, especially synthesis of best evidence, systematic reviews or meta-analyses published about each type of intervention. A review of primary research is made in cases in which no synthesis work has been published or where these works are old. Localised works indicate that the phonological methods of intervention in dyslexia, i.e. those in which training in phonological skills is combined with knowledge of letters and the practice of reading, are widely supported by research. However, research on other methods is either extremely scarce or it offers conflicting results or it leads to the conclusion that they are inefficient methods. Interventions in this situation are: the auditory integration, the auditory training with computer support, visual therapy, the tinted lenses, motor-perceptual training, chiropractic techniques, sensory integration, the Davis method, neurofeedback, music therapy and music education or diets and dietary supplements. Promotion of phonological interventions is recommended; it is necessary to avoid recommendations of intervention methods for dyslexia which are not supported by scientific research; methods of intervention that have not proven their effectiveness may not be presented as therapies or treatments; and the creation and distribution of a guide on intervention in dyslexia based on scientific evidence is recommended (AU)
Subject(s)
Humans , Male , Female , Dyslexia/epidemiology , Dyslexia/therapy , Speech, Language and Hearing Sciences/instrumentation , Speech, Language and Hearing Sciences/methods , Auditory Perceptual Disorders/rehabilitation , Auditory Perceptual Disorders/therapy , Hearing , Hearing Disorders/therapy , Dichotic Listening Tests/instrumentation , Dichotic Listening Tests/methods , Bone Diseases/complications , Chiropractic/methods , Evaluation of Results of Therapeutic Interventions/methods , Evaluation of the Efficacy-Effectiveness of InterventionsABSTRACT
We report a rare case of a patient unable to read (alexic) and write (agraphic) after a mild head injury. He had preserved speech and comprehension, could spell aloud, identify words spelt aloud and copy letter features. He was unable to visualise letters but showed no problems with digits. Neuropsychological testing revealed general visual memory, processing speed and imaging deficits. Imaging data revealed an 8 mm colloid cyst of the third ventricle that splayed the fornix. Little is known about functions mediated by fornical connectivity, but this region is thought to contribute to memory recall. Other regions thought to mediate letter recognition and letter imagery, visual word form area and visual pathways were intact. We remediated reading and writing by multimodal letter retraining. The study raises issues about the neural substrates of reading, role of fornical tracts to selective memory in the absence of other pathology, and effective remediation strategies for selective functional deficits.
Subject(s)
Colloid Cysts/complications , Dyslexia/etiology , Pattern Recognition, Visual , Adolescent , Attention , Brain/pathology , Colloid Cysts/diagnosis , Colloid Cysts/surgery , Dyslexia/therapy , Humans , Magnetic Resonance Imaging , Male , Memory , Neuroimaging , Neuropsychological Tests , Reading , Wechsler Scales , WritingABSTRACT
Neurofeedback training (NFT) is an effective intervention in regulating electroencephalogram (EEG) abnormalities leading to improvements in behavioral deficits, which exist in children with reading disabilities. This single-subject study explores our evaluation of the improvements in the reading ability and phonological awareness deficit, as well as the changes in the EEG in children with reading disabilities as a result of NFT. Participants were 6 children, aged between 8 and 10 years, who completed twenty 30-minute sessions of NFT and follow-up measurement sessions 2 months subsequent to the completion of the training sessions. The results showed significant improvement in reading and phonological awareness skills. Furthermore, EEG analysis did not show notable changes in the power of the targeted bands (delta, theta, and beta), rather there was normalization of coherence of the theta band at T3-T4, delta band at Cz-Fz, and beta band at Cz-Fz, Cz-Pz, and Cz-C4. These significant changes in coherence possibly indicate integration of sensory and motor areas that explains the improvements in reading skills and phonological awareness.
Subject(s)
Dyslexia/physiopathology , Dyslexia/therapy , Electroencephalography/methods , Neurofeedback/methods , Reading , Child , Humans , Male , Neuropsychological Tests , Parietal Lobe/physiology , Phonetics , Psychoacoustics , Speech Perception/physiology , Temporal Lobe/physiology , Treatment OutcomeABSTRACT
Auditory-based communication skills are developed at a young age and are maintained throughout our lives. However, some individuals - both young and old - encounter difficulties in achieving or maintaining communication proficiency. Biological signals arising from hearing sounds relate to real-life communication skills such as listening to speech in noisy environments and reading, pointing to an intersection between hearing and cognition. Musical experience, amplification, and software-based training can improve these biological signals. These findings of biological plasticity, in a variety of subject populations, relate to attention and auditory memory, and represent an integrated auditory system influenced by both sensation and cognition.
Subject(s)
Auditory Perception/physiology , Brain Stem/physiopathology , Computer-Assisted Instruction , Evoked Potentials, Auditory, Brain Stem/physiology , Hearing Aids , Music Therapy/methods , Perceptual Masking/physiology , Reading , Software , Speech Perception/physiology , Attention/physiology , Auditory Pathways/physiopathology , Cerebral Cortex/physiopathology , Child , Child Development Disorders, Pervasive/physiopathology , Child Development Disorders, Pervasive/therapy , Dyslexia/physiopathology , Dyslexia/therapy , Humans , Learning Disabilities/physiopathology , Learning Disabilities/therapy , Memory, Short-Term/physiology , Phonetics , Prosthesis Design , Sound SpectrographyABSTRACT
OBJECTIVE: To analyze the effect of nonverbal auditory training on reading and phonological awareness tasks in children with dyslexia and the effect of age in relation to post-training learning considering the ages from 7 to 14. METHODS: In experiment 1, one group with dyslexia (total = 12) was trained and compared with a group of untrained dyslexic subjects (total = 28). In experiment 2, the performance of the trained dyslexic group (total = 18) was compared at three different moments: 2 months before, at the beginning, and at the end of training. Training was carried out for 2 months using a computer program responsible for training discrimination skills. RESULTS: The group receiving nonverbal auditory training demonstrated significant improvements (mainly for the group from 7 to 10 years old), not only in the nonverbal auditory skills trained (p < 0.001), but also in phonological awareness syllable tasks (synthesis, segmentation, manipulation and syllable transposition) in experiment 1 (p < 0.003), and phonemic tasks (p < 0.001) and text reading (p < 0.001) in experiment 2. CONCLUSION: The results suggest a link between verbal and nonverbal skills, in addition to corroborating studies regarding the existence of a critical learning period.
Subject(s)
Auditory Perception , Auditory Perceptual Disorders/therapy , Computer-Assisted Instruction , Critical Period, Psychological , Discrimination, Psychological , Dyslexia/therapy , Reading , Acoustic Stimulation , Adolescent , Age Factors , Auditory Perceptual Disorders/complications , Child , Comprehension , Dyslexia/etiology , Female , Humans , Male , Models, Neurological , Models, Psychological , Phonetics , Play and Playthings , Treatment OutcomeABSTRACT
Studies in children and adults with the reading disability developmental dyslexia have shown behavioral improvements after reading intervention. In another line of work, it has been shown that intensive training in a variety of cognitive and sensorimotor skills can result in changes in gray matter volume (GMV). This study examined changes in GMV following intensive reading intervention in children with dyslexia using voxel-based morphometry (VBM). Eleven dyslexic children underwent an eight week training focused on mental imagery, articulation and tracing of letters, groups of letters and words, which resulted in significant gains in reading skills. This was followed by an eight week null period (control) where no intervention was administered and no further significant gains in reading were observed. Structural scans were obtained before the intervention, after the intervention and after the null period. GMV increases between the first two time points were found in the left anterior fusiform gyrus/hippocampus, left precuneus, right hippocampus and right anterior cerebellum. However these areas did not change between time points two and three (control period), suggesting that the changes were specific to the intervention period. These results demonstrate for the first time that (1) training-induced changes in GMV can be observed in a pediatric sample and (2) reading improvements induced by intervention are accompanied by GMV changes.
Subject(s)
Brain/pathology , Dyslexia/therapy , Reading , Remedial Teaching/methods , Child , Female , Humans , Image Interpretation, Computer-Assisted , Magnetic Resonance Imaging , MaleABSTRACT
Numerous methods based on very different concepts are available to treat children with dyslexia. Basically, symptomatic and causal principles can be distinguished. Among the symptomatic methods are systematic programmes based on learning theory, in which reading and spelling or precursors of these abilities are directly trained. Causal methods promise pronounced and persistent improvement of reading and spelling abilities through elimination of the postulated reason underlying the learning disabilities. Among the causal methods are treatment programmes that train low-level functions. Such training is based on the assumption that deficits of auditory, visual or kinesthetic perception, of motor skills or of the coordination of cerebral functional areas are at the bottom of specific learning disabilities. Concepts of other causal methods act on the assumption that learning processes are blocked or that abnormal medical conditions or psychiatric disorders constitute the background of dyslexia. Reviewed in the article are treatment concepts for children with dyslexia in the German-speaking countries and the methods of treatment derived from the different concepts. Results of evaluation studies are summarized and characteristics of effective treatment methods are listed. It is stressed that efficacy is proven only for symptomatic training programmes but not for causal methods.
Subject(s)
Dyslexia/therapy , Adolescent , Causality , Child , Complementary Therapies , Dyslexia/diagnosis , Dyslexia/epidemiology , Dyslexia/psychology , Education, Special , Humans , Reading , Remedial Teaching , Risk Factors , Treatment Outcome , Verbal LearningABSTRACT
This article reviews the evidence for computer-based auditory training (CBAT) in children with language, reading, and related learning difficulties, and evaluates the extent it can benefit children with auditory processing disorder (APD). Searches were confined to studies published between 2000 and 2008, and they are rated according to the level of evidence hierarchy proposed by the American Speech-Language Hearing Association (ASHA) in 2004. We identified 16 studies of two commercially available CBAT programs (13 studies of Fast ForWord (FFW) and three studies of Earobics) and five further outcome studies of other non-speech and simple speech sounds training, available for children with language, learning, and reading difficulties. The results suggest that, apart from the phonological awareness skills, the FFW and Earobics programs seem to have little effect on the language, spelling, and reading skills of children. Non-speech and simple speech sounds training may be effective in improving children's reading skills, but only if it is delivered by an audio-visual method. There is some initial evidence to suggest that CBAT may be of benefit for children with APD. Further research is necessary, however, to substantiate these preliminary findings.
Subject(s)
Acoustic Stimulation/methods , Dyslexia/therapy , Language Development Disorders/therapy , Learning Disabilities/epidemiology , Learning Disabilities/therapy , Teaching/methods , Therapy, Computer-Assisted/instrumentation , Child , Comorbidity , Dyslexia/epidemiology , Humans , Language Development Disorders/epidemiology , Phonetics , Speech Discrimination Tests , Speech PerceptionABSTRACT
Phonological theories of dyslexia assume a specific deficit in representation, storage and recall of phonemes. Various brain imaging techniques, including qEEG, point to the importance of a range of areas, predominantly the left hemispheric temporal areas. This study attempted to reduce reading and spelling deficits in children who are dyslexic by means of neurofeedback training based on neurophysiological differences between the participants and gender and age matched controls. Nineteen children were randomized into an experimental group receiving qEEG based neurofeedback (n = 10) and a control group (n = 9). Both groups also received remedial teaching. The experimental group improved considerably in spelling (Cohen's d = 3). No improvement was found in reading. An indepth study of the changes in the qEEG power and coherence protocols evidenced no fronto-central changes, which is in line with the absence of reading improvements. A significant increase of alpha coherence was found, which may be an indication that attentional processes account for the improvement in spelling. Consideration of subtypes of dyslexia may refine the results of future studies.
Subject(s)
Biofeedback, Psychology/methods , Dyslexia/psychology , Dyslexia/therapy , Electroencephalography/methods , Reading , Adolescent , Child , Data Interpretation, Statistical , Female , Humans , Language Tests , Male , Neuropsychological Tests , Treatment OutcomeABSTRACT
OBJECTIVE: This study presents a case series of 157 children with developmental delay syndromes, including the conditions such as dyspraxia, dyslexia, attention-deficit hyperactivity disorder, and learning disabilities who received chiropractic care. CLINICAL FEATURES: A consecutive sample of 157 children aged 6 to 13 years (86 boys and 71 girls) with difficulties in reading, learning, social interaction, and school performance who met these inclusion criteria were included. INTERVENTION AND OUTCOMES: Each patient received a multimodal chiropractic treatment protocol, applied kinesiology chiropractic technique. The outcome measures were a series of 8 standardized psychometric tests given to the children by a certified speech therapist pre- and posttreatment, which evaluate 20 separate areas of cognitive function, including patient- or parent-reported improvements in school performance, social interaction, and sporting activities. Individual and group data showed that at the end of treatment, the 157 children showed improvements in the 8 psychometric tests and 20 areas of cognitive function compared with their values before treatment. Their ability to concentrate, maintain focus and attention, and control impulsivity and their performance at home and school improved. CONCLUSIONS: This report suggests that a multimodal chiropractic method that assesses and treats motor dysfunction reduced symptoms and enhanced the cognitive performance in this group of children.
Subject(s)
Child Welfare/statistics & numerical data , Developmental Disabilities/therapy , Disability Evaluation , Manipulation, Chiropractic/methods , Adolescent , Apraxias/therapy , Attention Deficit Disorder with Hyperactivity/therapy , Child , Child Behavior Disorders/therapy , Dyslexia/therapy , Female , Follow-Up Studies , Humans , Learning Disabilities/therapy , Male , Outcome Assessment, Health Care , Psychometrics , Quality of Life , Severity of Illness Index , Surveys and Questionnaires , Syndrome , Treatment OutcomeABSTRACT
BACKGROUND: Dyslexia is a common learning difficulty affecting up to 10% of British children that is associated with a wide range of cognitive, emotional and physical symptoms. In the absence of effective conventional treatment, it is likely that parents will seek complementary and alternative medicine (CAM) to try and help their children. However, little is known about the level of CAM use or the type of CAM used by dyslexic children. AIMS: This study assessed: (1) the lifetime use of CAM by dyslexic children, (2) the role of socio-demographic factors in CAM use by dyslexic children, (3) parental attitudes towards CAM use in the treatment of dyslexia, and (4) how parents' understanding of dyslexia affects CAM use. METHODS & PROCEDURES: A semi-structured questionnaire-based survey of parents of 148 dyslexic school children was undertaken. The children had been recruited to a university research programme investigating the effectiveness of a complementary therapy for the treatment of learning difficulties. OUTCOMES & RESULTS: Lifetime use of CAM was 55.4% (82 children). The most popular CAM approaches were nutritional supplements/special diets (63 children) followed by homeopathy (29 children) and osteopathy/chiropractic manipulation (29 children). Socio-demographic factors did not predict CAM use. In total, parents of 101 dyslexic children reported that an interest in CAM for the treatment of dyslexia was based on their preference for CAM for their families more generally. Parents who thought that dyslexia was a 'medical/health' disorder were more likely to have used CAM with their children (p<0.01) than other parents in this survey. CONCLUSIONS & IMPLICATIONS: Educational and health professionals should be aware that many dyslexic children use CAM. Parents of dyslexic children should be provided with evidence-based advice to help them make informed therapeutic choices.
Subject(s)
Complementary Therapies/methods , Dyslexia/therapy , Health Knowledge, Attitudes, Practice , Parents/psychology , Adolescent , Child , Female , Humans , Male , Socioeconomic Factors , Surveys and Questionnaires , United KingdomABSTRACT
Children without dyslexia (n=10) received nonphonological treatment, and those with dyslexia received phonological (n=11) or nonphonological (n=9) treatment. Before and after treatment they performed aural repeat, visual decode, and aural match pseudoword tasks during functional MRI scanning that separated stimulus input from response production. Group map analysis indicated that children with dyslexia overactivated compared with good readers during the aural-repeat/aural-match contrast in bilateral frontal (Brodmann's area [BA] 3, 4, 5, 6, 9), left parietal (BA 2, 3), left temporal (BA 38), and right temporal (BA 20, 21, 37) regions (stimulus input) and underactivated in right frontal (BA 24, 32) and right insula (BA 48) regions (response production); they underactivated in BA 19/V5 during the visual-decode/aural-match contrast (response production). Individual brain analysis for children with dyslexia revealed that during the aural-repeat/aural-match contrast (stimulus input), phonological treatment decreased and normalized activation in left supramarginal gyrus and postcentral gyrus. Nonphonological treatment increased and normalized activation during the visual-decode/aural-match contrast (response production) in BA19/V5 and changed activation in the same direction as good readers during aural-repeat/aural-match contrast (stimulus input) in left postcentral gyrus. The significance of the findings for competing theories of dyslexia is discussed.
Subject(s)
Behavior Therapy/methods , Brain Mapping , Cerebral Cortex , Dyslexia/therapy , Magnetic Resonance Imaging , Phonetics , Acoustic Stimulation/methods , Adolescent , Cerebral Cortex/blood supply , Cerebral Cortex/pathology , Cerebral Cortex/physiopathology , Child , Dyslexia/physiopathology , Female , Humans , Image Processing, Computer-Assisted/methods , Language Tests , Male , Oxygen/blood , Photic Stimulation/methods , Time FactorsABSTRACT
Reading disability is associated with phonological problems which might originate in auditory processing disorders. The aim of the present study was 2-fold: first, the perceptual skills of average-reading children and children with dyslexia were compared in a categorical perception task assessing the processing of a phonemic contrast based on voice onset time (VOT). The medial olivocochlear (MOC) system, an inhibitory pathway functioning under central control, was also explored. Secondly, we investigated whether audiovisual training focusing on voicing contrast could modify VOT sensitivity and, in parallel, induce MOC system plasticity. The results showed an altered voicing sensitivity in some children with dyslexia, and that the most severely impaired children presented the most severe reading difficulties. These deficits in VOT perception were sometimes accompanied by MOC function abnormalities, in particular a reduction in or even absence of the asymmetry in favour of the right ear found in average-reading children. Audiovisual training significantly improved reading and shifted the categorical perception curve of certain children with dyslexia towards the average-reading children's pattern of voicing sensitivity. Likewise, in certain children MOC functioning showed increased asymmetry in favour of the right ear following audiovisual training. The training-related improvements in reading score were greatest in children presenting the greatest changes in MOC lateralization. Taken together, these results confirm the notion that some auditory system processing mechanisms are impaired in children with dyslexia and that audiovisual training can diminish these deficits.