Phonological, temporal and spectral processing in vowel length discrimination is impaired in German primary school children with developmental dyslexia

Evaluation of p300 and spectral resolution in children with attention deficit hyperactivity disorder and specific learning disorder

This study aims to examine auditory processing, P300 values and functional impairment levels among children with Attention Deficit and Hyperactivity Disorder (ADHD), Specific Learning Disorder (SLD), ADHD+SLD and healthy controls. Children with ADHD (n = 17), SLD (n = 15), ADHD+SLD (n = 15), and healthy controls (n = 15) between the ages of 7-12 were evaluated with K-SADS, Weiss Functional Impairment Rating Scale, Turgay DSM-IV Disruptive Behavior Disorders Rating Scale, The Mathematics, Reading, Writing Assessment Scale and Children's Auditory Performance Scale (CHAPS). Auditory P300 event-related potentials and Spectral-Temporally Modulated Ripple Test (SMRT) were applied. Three patient groups were found to be riskier than healthy controls according to the CHAPS. There was no significant difference between the groups in the SMRT. In post-hoc analyses of P300 parietal amplitudes, ADHD, SLD, and ADHD+SLD were found to be significantly lower than the control group. The amplitudes of the ADHD+SLD were by far the lowest. It has been shown that auditory performance skills and p300 amplitudes are lower in children diagnosed with only ADHD or SLD compared to the control group, with the lowest values observed in ADHD+SLD. This study suggests that the difficulties with attention and cognitive functions in the ADHD+SLD are more severe than ADHD and/or SLD without comorbidity.

The multiple-level framework of developmental dyslexia: the long trace from a neurodevelopmental deficit to an impaired cultural technique

Developmental dyslexia is a neurodevelopmental disorder characterized by an unexpected impairment in literacy acquisition leading to specific poor academic achievement and possible secondary symptoms. The multi-level framework of developmental dyslexia considers five levels of a causal pathway on which a given genotype is expressed and hierarchically transmitted from one level to the next under the increasing influence of individual learning-relevant traits and environmental factors moderated by cultural conditions. These levels are the neurobiological, the information processing and the skill level (prerequisites and acquisition of literacy skills), the academic achievement level and the level of secondary effects. Various risk factors are present at each level within the assumed causal pathway and can increase the likelihood of exhibiting developmental dyslexia. Transition from one level to the next is neither unidirectional nor inevitable. This fact has direct implications for prevention and intervention which can mitigate transitions from one level to the next. In this paper, various evidence-based theories and findings regarding deficits at different levels are placed in the proposed framework. In addition, the moderating effect of cultural impact at and between information processing and skill levels are further elaborated based on a review of findings regarding influences of different writing systems and orthographies. These differences impose culture-specific demands for literacy-specific cognitive procedures, influencing both literacy acquisition and the manifestation of developmental dyslexia.

Rhythm but not melody processing helps reading via phonological awareness and phonological memory

Despite abundant evidence that music skills relate to enhanced reading performance, the mechanisms subtending this relation are still under discussion. The Temporal Sampling Framework (TSF) provides a well-defined explanation for the music-reading link: musical rhythm perception would relate to reading because it helps to encode speech units, which, in turn, is fundamental to reading. However, in spite of this clear mediation-based prediction (effect of music skills mediated by the encoding of speech units), the tests made to it so far remain inconclusive, either due to the use of hybrid measures (rhythm perception and production, musical and non-musical rhythm) or to underspecified mediation results (unclear presence of partial mediation). In the present study, we addressed these potential weaknesses of previous studies and investigated whether phonological memory and phonological awareness (proxies of speech encoding abilities) mediate the effects of rhythm perception abilities on reading in late first-graders. To test for the specificity of musical rhythm in this relation, we examined the same hypothesis for melody perception. Results showed full mediation for effects of musical rhythm perception, while melody perception did not even relate to reading. Our findings support the predictions embedded in the TSF and highlight the potential of rhythm-based interventions in early stimulation.

[Effects of the Computer-Based Grapho-Phonological Training Lautarium in Children with Developmental Dyslexia]

Effects of the Computer-Based Grapho-Phonological Training Lautarium in Children with Developmental Dyslexia The effects of the computer-based training program Lautarium on phonological awareness and literacy skills were investigated in 41 third-grade children with developmental dyslexia who attended special dyslexia classes in a primary school in Saxony, Germany. Based on the proven efficacy of phonics-based instruction, Lautarium combines training of phoneme perception and phonological awareness with training of grapheme-phoneme-relationships and reading and spelling of transparent words. In addition, rapid access from written words to meaning is included. The children of the training group (N = 27) worked through the program during school lessons, 5 times per week for 30 minutes, for a period of 7 weeks. During the training period, the controls (N = 14) received traditional remedial reading instruction, 2-3 times per week, in small groups. Children's performance in phonological awareness, reading, and spelling was assessed at three time points (pretest, immediate posttest, and follow-up after 9 weeks). Pretest scores did not differ between groups. For spelling and subtests of phonological awareness, group comparisons of raw scores at posttest and follow-up including the respective pretest score as covariate confirmed stronger improvements in the training group when compared to the controls. Effect sizes were medium to strong. For reading, improvements did not differ between groups. In both groups, standard scores (T-scores) for reading and spelling increased significantly and substantially across the study period (from pretest to follow-up). The results confirm the efficacy of computer-based training with Lautarium in children with dyslexia, and the efficacy of school-based remedial instruction provided in the dyslexia classes.

Functional illiteracy and developmental dyslexia: looking for common roots. A systematic review

A considerable amount of the population in more economically developed countries are functionally illiterate (i.e., low literate). Despite some years of schooling and basic reading skills, these individuals cannot properly read and write and, as a consequence have problems to understand even short texts. An often-discussed approach (Greenberg et al. 1997) assumes weak phonological processing skills coupled with untreated developmental dyslexia as possible causes of functional illiteracy. Although there is some data suggesting commonalities between low literacy and developmental dyslexia, it is still not clear, whether these reflect shared consequences (i.e., cognitive and behavioral profile) or shared causes. The present systematic review aims at exploring the similarities and differences identified in empirical studies investigating both functional illiterate and developmental dyslexic samples. Nine electronic databases were searched in order to identify all quantitative studies published in English or German. Although a broad search strategy and few limitations were applied, only 5 studies have been identified adequate from the resulting 9269 references. The results point to the lack of studies directly comparing functional illiterate with developmental dyslexic samples. Moreover, a huge variance has been identified between the studies in how they approached the concept of functional illiteracy, particularly when it came to critical categories such the applied definition, terminology, criteria for inclusion in the sample, research focus, and outcome measures. The available data highlight the need for more direct comparisons in order to understand what extent functional illiteracy and dyslexia share common characteristics.

Effects of computerized grapho-phonological training on literacy acquisition and vocabulary knowledge in children with an immigrant background learning German as L2

As a consequence of globalization and migration, the number of children receiving literacy instruction in their second language (L2) is high and still increasing. Therefore, teachers need instruction methods that are effective in both L1 and L2 learners. Here, we investigate the effectiveness of a computerized training program combining phoneme perception, phonological awareness, and systematic phonics, in a sample of second-graders (N = 26) instructed in German as L2. Based on prior evidence concerning (1) literacy acquisition in L2 and (2) effects of literacy development on oral language abilities, we expected significant training effects on children’s literacy skills and vocabulary knowledge. The children of the training group worked through the program during school lessons, 20 min per day, for a period of 8 weeks. The controls continued to receive standard classroom instruction. German tests of phonological awareness, reading, spelling, and vocabulary were performed at three time points (pretest, immediate posttest, and follow-up after 9 weeks). Analyses confirmed that improvements in phonological awareness, spelling, and vocabulary between pretest and posttest were stronger in the training group when compared to the controls. For spelling and vocabulary, these effects were still significant at follow-up. Effect sizes were medium to high. For the reading measures, no group differences were found. In sum, the results yield further evidence for the effectiveness of phonics-based literacy instruction in L2 learners, and for the beneficial effects of basic literacy skills on novel word learning.

The emergence of dyslexia in the developing brain

Developmental dyslexia, a severe deficit in literacy learning, is a neurodevelopmental learning disorder. Yet, it is not clear whether existing neurobiological accounts of dyslexia capture potential predispositions of the deficit or consequences of reduced reading experience. Here, we longitudinally followed 32 children from preliterate to school age using functional and structural magnetic resonance imaging techniques. Based on standardised and age-normed reading and spelling tests administered at school age, children were classified as 16 dyslexic participants and 16 controls. This longitudinal design allowed us to disentangle possible neurobiological predispositions for developing dyslexia from effects of individual differences in literacy experience. In our sample, the disorder can be predicted already before literacy learning from auditory cortex gyrification and aberrant downstream connectivity within the speech processing system. These results provide evidence for the notion that dyslexia may originate from an atypical maturation of the speech network that precedes literacy instruction.

Another Temporal Processing Deficit in Individuals With Developmental Dyslexia: The Case of Normalization for Speaking Rate

Purpose Developmental dyslexia (DD) has mostly been attributed to arise from phonological impairments; however, several theories indicate a temporal processing deficit as the underlying cause of DD. So far, research examined the influence of temporal cues on concurrent speech sound categorization in DD, but effects of temporal information from a context (e.g., speaking rate) on the perception of subsequent sounds (i.e., "rate normalization") have not been considered. This study examined whether individuals with DD are capable of implicitly extracting temporal information embedded in context and use it for phoneme categorization to the same extent as healthy readers. Method Fifteen individuals diagnosed with DD and 16 healthy readers, all native speakers of Hebrew, listened to context sentences followed by target words. They had to indicate whether the target word sounded more like taam ("taste"; a long-vowel response) or tam ("naïve"; a short-vowel response). Temporal information of the context was manipulated (slow vs. fast speaking rate sentences) as well as the vowel duration of the target in a 5-step continuum. Results Listeners with DD did use the rate context to inform their decisions but to a significantly lesser extent than healthy listeners. In addition, their categorization of the vowel duration continuum was somewhat less distinct than that of the control group. Conclusions Individuals with DD are impaired not only in tasks involving direct temporal processing, as shown in previous studies but also in the use of temporal information of a context that impacts the perception of subsequent target words. This inability to fully utilize rate normalization processes may influence the formation of abstract phonological representations in individuals with DD.

Phonemes, words, and phrases: Tracking phonological processing in pre-schoolers developing dyslexia

OBJECTIVES

Individuals with dyslexia often suffer from deficient segmental phonology, but the status of suprasegmental phonology (prosody) is still discussed.

METHODS

In three passive-listening event-related brain potential (ERP) studies, we examined prosodic processing in literacy-impaired children for various prosodic units by contrasting the processing of word-level and phrase-level prosody, alongside segmental phonology. We retrospectively analysed school children's ERPs at preschool age for discrimination of vowel length (phoneme processing), discrimination of stress pattern (word-level prosody), and processing of prosodic boundaries (phrase-level prosody).

RESULTS

We found differences between pre-schoolers with and without later literacy difficulties for phoneme and stress pattern discrimination, but not for prosodic boundary perception.

CONCLUSION

Our findings complement the picture of phonological processing in dyslexia by confirming difficulties in segmental phonology and showing that prosodic processing is affected for the smaller word level, but not the larger phrase level.

SIGNIFICANCE

These findings might have implications for early interventions, considering both phonemic awareness and stress pattern training.

Are Temporal and Tonal Musical Skills Related to Phonological Awareness and Literacy Skills? - Evidence From Two Cross-Sectional Studies With Children From Different Age Groups

Temporal and spectral auditory processing abilities are required for efficient and unimpaired processing of speech and might thus be associated with the development of phonological and literacy skills in children. Indeed, studies with unselected children have found links between these basic auditory processing abilities and the development of phonological awareness, reading, and spelling. Additionally, associations between the processing of temporal or spectral/tonal information in music and phonological awareness/literacy have been reported, but findings concerning relations between music processing and spelling are rather sparse. To gain more insights into the specific, potentially age-dependent relevance of various temporal (e.g., rhythm, tempo) and tonal (e.g., pitch, melody) musical subdomains for phonological awareness and literacy, we adapted five music-processing tasks (three temporal, two tonal) for use with tablet computers and used them in two cross-sectional studies with German children from two age groups: Study 1 was conducted with preschool children (about 5 years of age; without formal reading and spelling instruction) and focused on associations between music processing and phonological awareness. In Study 2, third-graders (about 8 years of age) were investigated concerning relations between music processing, phonological awareness, reading comprehension, and spelling. In both studies, rhythm reproduction and pitch perception turned out to be significant predictors of phonological awareness in stepwise regression analyses. Although various associations between music processing and literacy were found for third-graders in Study 2, after phonological awareness was accounted for, only rhythm reproduction made a unique contribution to literacy skills, namely, to alphabetic spelling skills. Hence, both studies indicate that temporal (i.e., rhythm reproduction) and spectral/tonal (i.e., pitch perception) musical skills are distinctly and uniquely related to phonological awareness in children from different age groups (preschool vs. Grade 3). The finding that rhythm reproduction, an auditory temporal processing skill integrating perceptual and motor aspects of rhythm processing, was especially tightly linked to phonological awareness and literacy corroborates other findings on associations between rhythm processing and literacy development and is of interest from the viewpoint of current theories of developmental dyslexia. The potential relevance of our results for applied research concerning early diagnosis and training of literacy-related skills is discussed.

Cognitive Profiles of Developmental Dysgraphia

Developmental dysgraphia is a disorder of writing/spelling skills, closely related to developmental dyslexia. For developmental dyslexia, profiles with a focus on phonological, attentional, visual or auditory deficits have recently been established. Unlike for developmental dyslexia, however, there are only few studies about dysgraphia, in particular about the variability of its causes. Research has demonstrated high similarity between developmental dyslexia and dysgraphia. Thus, the aim of the study was to investigate cognitive deficits as potential predictors of dysgraphia, analogously to those for dyslexia, in order to identify dysgraphia profiles, depending on the particular underlying disorder. Different tests were carried out with 3rd and 4th grade school children to assess their spelling abilities, tapping into phonological processing, auditory sound discrimination, visual attention and visual magnocellular functions as well as reading. A group of 45 children with developmental dysgraphia was compared to a control group. The results showed that besides phonological processing abilities, auditory skills and visual magnocellular functions affected spelling ability, too. Consequently, by means of a two-step cluster analysis, the group of dysgraphic children could be split into two distinct clusters, one with auditory deficits and the other with deficits in visual magnocellular functions. Visual attention was also related to spelling disabilities, but had no characteristic distinguishing effect for the two clusters. Together, these findings demonstrate that a more fine-grained diagnostic view on developmental dysgraphia, which takes the underlying cognitive profiles into account, might be advantageous for optimizing the outcome of individuum-centered intervention programs.

Neural correlates of phonological processing: Disrupted in children with dyslexia and enhanced in musically trained children

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First fMRI investigation of phonological processing in musically trained children.

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Greater bilateral activation with music training in regions disrupted in dyslexia.

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Implications for music training to support compensatory neural network in dyslexia.

Phonological processing has been postulated as a core area of deficit among children with dyslexia. Reduced brain activation during phonological processing in children with dyslexia has been observed in left-hemispheric temporoparietal regions. Musical training has shown positive associations with phonological processing abilities, but the neural mechanisms underlying this relationship remain unspecified. The present research aims to distinguish neural correlates of phonological processing in school-age typically developing musically trained children, musically untrained children, and musically untrained children with dyslexia utilizing fMRI. A whole-brain ANCOVA, accounting for gender and nonverbal cognitive abilities, identified a main effect of group in bilateral temporoparietal regions. Subsequent region-of-interest analyses replicated temporoparietal hypoactivation in children with dyslexia relative to typically developing children. By contrast, musically trained children showed greater bilateral activation in temporoparietal regions when compared to each musically untrained group. Therefore, musical training shows associations with enhanced bilateral activation of left-hemispheric regions known to be important for reading. Findings suggest that engagement of these regions through musical training may underlie the putative positive effects of music on reading development. This supports the hypothesis that musical training may facilitate the development of a bilateral compensatory neural network, which aids children with atypical function in left-hemispheric temporoparietal regions.

Revisiting the "enigma" of musicians with dyslexia: Auditory sequencing and speech abilities

Previous research has suggested a link between musical training and auditory processing skills. Musicians have shown enhanced perception of auditory features critical to both music and speech, suggesting that this link extends beyond basic auditory processing. It remains unclear to what extent musicians who also have dyslexia show these specialized abilities, considering often-observed persistent deficits that coincide with reading impairments. The present study evaluated auditory sequencing and speech discrimination in 52 adults comprised of musicians with dyslexia, nonmusicians with dyslexia, and typical musicians. An auditory sequencing task measuring perceptual acuity for tone sequences of increasing length was administered. Furthermore, subjects were asked to discriminate synthesized syllable continua varying in acoustic components of speech necessary for intraphonemic discrimination, which included spectral (formant frequency) and temporal (voice onset time [VOT] and amplitude envelope) features. Results indicate that musicians with dyslexia did not significantly differ from typical musicians and performed better than nonmusicians with dyslexia for auditory sequencing as well as discrimination of spectral and VOT cues within syllable continua. However, typical musicians demonstrated superior performance relative to both groups with dyslexia for discrimination of syllables varying in amplitude information. These findings suggest a distinct profile of speech processing abilities in musicians with dyslexia, with specific weaknesses in discerning amplitude cues within speech. Because these difficulties seem to remain persistent in adults with dyslexia despite musical training, this study only partly supports the potential for musical training to enhance the auditory processing skills known to be crucial for literacy in individuals with dyslexia. (PsycINFO Database Record

Phonological abilities in literacy-impaired children: Brain potentials reveal deficient phoneme discrimination, but intact prosodic processing

Intact phonological processing is crucial for successful literacy acquisition. While individuals with difficulties in reading and spelling (i.e., developmental dyslexia) are known to experience deficient phoneme discrimination (i.e., segmental phonology), findings concerning their prosodic processing (i.e., suprasegmental phonology) are controversial. Because there are no behavior-independent studies on the underlying neural correlates of prosodic processing in dyslexia, these controversial findings might be explained by different task demands. To provide an objective behavior-independent picture of segmental and suprasegmental phonological processing in impaired literacy acquisition, we investigated event-related brain potentials during passive listening in typically and poor-spelling German school children. For segmental phonology, we analyzed the Mismatch Negativity (MMN) during vowel length discrimination, capturing automatic auditory deviancy detection in repetitive contexts. For suprasegmental phonology, we analyzed the Closure Positive Shift (CPS) that automatically occurs in response to prosodic boundaries. Our results revealed spelling group differences for the MMN, but not for the CPS, indicating deficient segmental, but intact suprasegmental phonological processing in poor spellers. The present findings point towards a differential role of segmental and suprasegmental phonology in literacy disorders and call for interventions that invigorate impaired literacy by utilizing intact prosody in addition to training deficient phonemic awareness.

Developmental Dyslexia and Dysgraphia: What can We Learn from the One About the Other?

Up to 17% of German school children suffer from reading and writing disabilities. Unlike developmental dyslexia, only few studies have addressed dysgraphia. Presenting a comprehensive overview of the current state of the art in developmental dyslexia and dysgraphia, this paper aims to determine how far existing knowledge about the causes of developmental dyslexia also apply to developmental dysgraphia. To promote understanding of developmental dysgraphia, the paper discusses relevant aspects such as predictors, causes and comorbidities, models of acquisition as well as existing deficit models. A comparison of definitions in the DSM-V and ICD-10 complemented by an overview of the most recent German guideline ought to give the reader deeper insight into this topic. The current issue of growing up bilingually and the connection between reading and writing deficits are also discussed. In conclusion, this paper presents a critical survey of theoretical and practical implications for the diagnostics and treatment of developmental dysgraphia.

Evidence for a general auditory processing deficit in developmental dyslexia from a discrimination paradigm using speech versus nonspeech sounds matched in complexity

PURPOSE

It is unknown whether phonological deficits are the primary cause of developmental dyslexia or whether they represent a secondary symptom resulting from impairments in processing basic acoustic parameters of speech. This might be due, in part, to methodological difficulties. Our aim was to overcome two of these difficulties: the comparability of stimulus material and task in speech versus nonspeech conditions.

METHOD

In this study, the authors (a) assessed auditory processing of German vowel center stimuli, spectrally rotated versions of these stimuli, and bands of formants; (b) used the same task for linguistic and nonlinguistic conditions; and (c) varied systematically temporal and spectral parameters inherent in the German vowel system. Forty-two adolescents and adults with and without reading disabilities participated.

RESULTS

Group differences were found for all linguistic and nonlinguistic conditions for both temporal and spectral parameters. Auditory deficits were identified in most but not all participants with dyslexia. These deficits were not restricted to speech stimuli-they were also found for nonspeech stimuli with equal and lower complexity compared with the vowel stimuli. Temporal deficits were not observed in isolation.

CONCLUSION

These results support the existence of a general auditory processing impairment in developmental dyslexia.

Differences in sensory processing of German vowels and physically matched non-speech sounds as revealed by the mismatch negativity (MMN) of the human event-related brain potential (ERP)

We compared processing of speech and non-speech by means of the mismatch negativity (MMN). For this purpose, the MMN elicited by vowels was compared to those elicited by two non-speech stimulus types: spectrally rotated vowels, having the same stimulus complexity as the speech stimuli, and sounds based on the bands of formants of the vowels, representing non-speech stimuli of lower complexity as compared to the other stimulus types. This design allows controlling for effects of stimulus complexity when comparing neural correlates of processing speech to non-speech. Deviants within a modified multi-feature design differed either in duration or spectral property. Moreover, the difficulty to discriminate between the standard and the two deviants was controlled for each stimulus type by means of an additional active discrimination task. Vowels elicited a larger MMN compared to both non-speech stimulus types, supporting the concept of language-specific phoneme representations and the role of the participants' prior experience.