Picture naming deficits in developmental dyslexia: the phonological representations hypothesis

Phonological deficits in dyslexia impede lexical processing of spoken words: Linking behavioural and MEG data

Phonological difficulties have been identified as a core deficit in developmental dyslexia, yet everyday speech comprehension, which relies on phonological processing, is seemingly unaffected. This raises the question as to how dyslexic readers process spoken words to achieve normal word comprehension. Here we establish a link between neural correlates of lexical and sublexical processing in auditory words and behaviourally measured phonological deficits using magnetoencephalography (MEG). Spatiotemporally resolved cortical responses to phonological and lexico-semantic information were computed with the event-related regression technique (Hauk et al., 2009) and correlated with dyslexic and non-dyslexic subjects' phonological skills. We found that phonological deficits reduced cortical responses to both phonological and lexico-semantic information (phonological neighbours and word frequency). Individuals with lower phonological skills - independent of dyslexia diagnosis - showed weaker neural responses to phonological neighbourhood information in both hemispheres 200-500 ms after word onset and reduced sensitivity to written and spoken word frequency between 200 and 650 ms. Dyslexic readers showed weaker responses to written word frequency in particular compared to the control group, pointing towards an additional effect of print exposure on auditory word processing. Source space analysis localised phonological and lexico-semantic effect peaks to the left superior temporal gyrus, a key area that has been related to core deficits in dyslexia across a range of neuroimaging studies. The results provide comprehensive evidence that phonological deficits impact both sublexical and lexical stages of spoken word processing and that these deficits cannot be fully compensated through neural re-organization of lexical-distributional information at the single word level. Theoretical and practical implications for typical readers, dyslexic readers, and readers with developmental language disorder are discussed.

Atypical speech production of multisyllabic words and phrases by children with developmental dyslexia

The prevalent "core phonological deficit" model of dyslexia proposes that the reading and spelling difficulties characterizing affected children stem from prior developmental difficulties in processing speech sound structure, for example, perceiving and identifying syllable stress patterns, syllables, rhymes and phonemes. Yet spoken word production appears normal. This suggests an unexpected disconnect between speech input and speech output processes. Here we investigated the output side of this disconnect from a speech rhythm perspective by measuring the speech amplitude envelope (AE) of multisyllabic spoken phrases. The speech AE contains crucial information regarding stress patterns, speech rate, tonal contrasts and intonational information. We created a novel computerized speech copying task in which participants copied aloud familiar spoken targets like "Aladdin." Seventy-five children with and without dyslexia were tested, some of whom were also receiving an oral intervention designed to enhance multi-syllabic processing. Similarity of the child's productions to the target AE was computed using correlation and mutual information metrics. Similarity of pitch contour, another acoustic cue to speech rhythm, was used for control analyses. Children with dyslexia were significantly worse at producing the multi-syllabic targets as indexed by both similarity metrics for computing the AE. However, children with dyslexia were not different from control children in producing pitch contours. Accordingly, the spoken production of multisyllabic phrases by children with dyslexia is atypical regarding the AE. Children with dyslexia may not appear to listeners to exhibit speech production difficulties because their pitch contours are intact. RESEARCH HIGHLIGHTS: Speech production of syllable stress patterns is atypical in children with dyslexia. Children with dyslexia are significantly worse at producing the amplitude envelope of multi-syllabic targets compared to both age-matched and reading-level-matched control children. No group differences were found for pitch contour production between children with dyslexia and age-matched control children. It may be difficult to detect speech output problems in dyslexia as pitch contours are relatively accurate.

Effects of a developmental dyslexia remediation protocol based on the training of audio-phonological cognitive processes in dyslexic children with high intellectual potential: study protocol for a multiple-baseline single-case experimental design

BACKGROUND

The significant prevalence of children with high intellectual potential (HIP) in the school-age population and the high rate of comorbidity with learning disabilities such as dyslexia has increased the demand for speech and language therapy and made it more complex. However, the management of dyslexic patients with high intellectual potential (HIP-DD) is poorly referenced in the literature. A large majority of studies on HIP-DD children focus on the screening and diagnosis of developmental dyslexia, but only a few address remediation. Developmental dyslexia is a severe and persistent disorder that affects the acquisition of reading and implies the impairment of several underlying cognitive processes. These include deficits in Categorical Perception, Rapid Automatized Naming, and phonological awareness, particularly phonemic awareness. Some authors claim that HIP-DD children's underlying deficits mainly concern rapid automatized naming and phonological awareness. Thus, the purpose of this study is to present a remediation protocol for developmental dyslexia in HIP-DD children. This protocol proposes to compare the effects on reading skills of an intensive intervention targeting categorical perception, rapid automatized naming, and phonemic analysis versus standard speech therapy remediation in HIP-DD children.

METHODS

A multiple-baseline single-case experimental design (A1BCA2) will be proposed to 4 French HIP-DD patients for a period of 30 weeks. Intervention phases B and C correspond to categorical perception training and rapid automatized naming training. During phases B and C, each training session will be associated with phonemic analysis training and a reading and writing task. At inclusion, a speech and language, psychological, and neuropsychological assessment will be performed to define the four patients' profiles. Patients will be assigned to the different baseline lengths using a simple computerized randomization procedure. The duration of the phases will be counterbalanced. The study will be double blinded. A weekly measurement of phonological and reading skills will be performed for the full duration of the study.

DISCUSSION

The purpose of this protocol is to observe the evolution of reading skills with each type of intervention. From this observation, hypotheses concerning the remediation of developmental dyslexia in HIP-DD children can be tested. The strengths and limitations of the study are discussed.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04028310 . Registered on July 18, 2019. Version identifier is no. ID RCB 2019-A01453-54, 19-HPNCL-02, 07/18/2019.

Proportional Reasoning Deficit in Dyslexia

Dyslexia has been linked to an altered perception of metrical structures in language, but no study to date has explored the link between reading impairments and other forms of metrical thinking (e.g., proportional reasoning). In the present study, we assessed proportional reasoning in 16 dyslexic children and 16 age-matched controls from 7 to 10 years of age in order to investigate whether dyslexia might be also linked to an altered form of metrical thinking. We found that dyslexic children are less accurate in performing judgments about proportionality compared to typical peers and that reading accuracy correlates with proportional reasoning abilities for 7-8-year-old children. Overall, these findings suggest that a link exists between reading and proportional reasoning abilities. We might speculate that fostering reasoning based on the meter can facilitate reading because it permits the segmentation of words in syllables and that dyslexia can be identified early with alternative non-reading tasks such as the proportional reasoning task used in this work.

Is learning a logographic script easier than reading an alphabetic script for German children with dyslexia?

PURPOSE

Developmental dyslexia in alphabetic languages (DD) is characterized by a phonological deficit. Since logographic scripts rely predominantly on visual and morphological processing, reading performance in DD can be assumed to be less impaired when reading logographic scripts.

METHODS

40 German-speaking children (18 with DD, 22 not reading-impaired-group C; 9-11 years) received Chinese lessons. Eye movements (EM) were recorded during naming single alphabetic words, pictures (confrontational) and Chinese characters to be named in German and Chinese. The main outcome variables were: Articulation latency, numbers and durations of fixations. Quality of life (QoL) was assessed by questionnaires.

RESULTS

While reading alphabetic words, articulation latencies and numbers of fixations were significantly higher for group DD than for group C (AL-DD = 1.13, AL-C = 0.84, p< .001; FN-DD = 3.50; FN-C = 2.00, p< .001). For naming pictures and Chinese characters in German and in Chinese, no significant group differences were found for any of the EM variables. The percentage of correct answers was high for German naming (DD = 86.67%, C = 95.24%; p = .015) and lower for Chinese naming in both groups, but significantly lower in group DD, especially for Chinese naming (DD = 56.67%, C: 83.77%; p = .003). QoL differed between groups from the children's perspective only at posttest. Parents of group DD perceived their children`s QoL to be lower compared with parents of group C at pre- and posttest.

CONCLUSIONS

Children with dyslexia performed as well as group C during naming Chinese characters in German and in Chinese regarding their EM variables, presumably because they processed Chinese characters by the visuo-spatial pathway with direct access to the semantic system. However, the significantly lower percentage of correct answers especially during Chinese naming showed that group DD had more difficulties naming Chinese characters than group C, which could be attributed to their phonological deficit, among other factors.

TRIAL REGISTRATION

German clinical trials register (DRKS00015697).

Success Is Not the Entire Story for a Scientific Theory: The Case of the Phonological Deficit Theory of Dyslexia

In a recent paper, Share discussed four different “Common Misconceptions about the Phonological Deficit Theory of Dyslexia” and described this theory as “a model of true scientific progress” and a clear “success story”. In this note, I argue that at least part of the success of this theory is due to the lack of explicit predictions which make it very difficult (if possible) to test its predictions, and, possibly, falsify the theory. Some areas of pertinent research, including categorical phoneme perception, picture naming, and phonological awareness are summarized. Furthermore, two lines of research in which groups of researchers have attempted to formulate more explicit predictions are briefly outlined. It is concluded that, although much research has variously referred to the phonological deficit theory of dyslexia, the resulting large body of evidence presents a complex pattern of results which, in the absence of an explicit formulation of the theory, is extremely difficult to frame within a unitary interpretation. Overall, what seems needed is a theoretical formulation that, on the one hand, can account for the complex pattern of available evidence and, on the other hand, provide testable predictions for future research.

Remediation of a phonological representation deficit in Chinese children with dyslexia: A comparison between metalinguistic training and working memory training

A form-preparation task in the language production field was adopted to examine output phonological representations in Chinese dyslexia and their susceptibility to training. Forty-one Chinese children with dyslexia (7-11 years old) and 36 chronological age controls completed this task. The controls demonstrated a marginally significant syllable facilitation effect (d = -0.13), indicating their use of syllable-sized phonological representations during speech production, while the group with dyslexia showed a significantly different pattern (d = 0.04), opposite to the direction of a facilitation effect. The children with dyslexia were then randomly assigned to either metalinguistic training (N = 22) or working memory training (N = 19). Only the metalinguistic training subgroup demonstrated a significant syllable facilitation effect afterward (metalinguistic: d = -0.13; working memory: d = -0.01). The results suggest the presence of a phonological representation deficit at the syllable level in Chinese dyslexia and its possible remediation by metalinguistic training. Such a phonological deficit in readers of a logographic script strongly supports the impaired phonological representation view of developmental dyslexia. A video abstract of this article can be viewed at https://youtu.be/zT2Be0xMkh0.

Timing anticipation in adults and children with Developmental Dyslexia: evidence of an inefficient mechanism

Developmental Dyslexia (DD) is a learning disorder characterized by specific difficulties in learning to read accurately and fluently, which has been generally explained in terms of phonological deficits. Recent research has shown that individuals with DD experience timing difficulties in the domains of language, music perception and motor control, probably due to impaired rhythmic perception, suggesting that timing deficit might be a key underlying factor to explain such a variety of difficulties. The present work presents two experiments aimed at assessing the anticipatory ability on a given rhythm of 9-year old Italian children and Italian adults with and without DD. Both adults and children with DD displayed a greater timing error and were more variable than controls in high predictable stimuli. No difference between participants with and without DD was found in the control condition, in which the uncertain timing of the beat did not permit the extraction of regularities. These results suggest that both children and adults with DD are unable to exploit temporal regularities to efficiently anticipate the next sensory event whereas control participants easily are. By showing that the anticipatory timing system of individuals with Developmental Dyslexia appears affected, this study adds another piece of evidence to the multifaceted reality of Developmental Dyslexia.

Delayed development of phonological constancy in toddlers at family risk for dyslexia

Phonological constancy refers to infants' ability to disregard variations in the phonetic realisation of speech sounds that do not indicate lexical contrast, e.g., when listening to accented speech. In typically-developing infants, this ability develops between 15- and 19-months of age, coinciding with the consolidation of infants' native phonological competence and vocabulary growth. Here we investigated the developmental time course of phonological constancy in infants at family risk for developmental dyslexia, using a longitudinal design. Developmental dyslexia is a disorder affecting the acquisition of reading and spelling skills, and it also affects early auditory processing, speech perception, and lexical acquisition. Infants at-risk and not at-risk for dyslexia, based on a family history of dyslexia, participated when they were 15-, 19-, and 26-months of age. Phonological constancy was indexed by comparing at-risk and not at-risk infants' ability to recognise familiar words in two preferential looking tasks: (1) a task using words presented in their native accent, and (2) a task using words presented in a non-native accent. We expected a delay in phonological constancy for the at-risk infants. As predicted, in the non-native accent task, not at-risk infants recognised familiar words by 19 months, but at-risk infants did not. The control infants thus exhibited phonological constancy. By 26 months, at-risk toddlers did show successful word recognition in the native accent task. However, for the non-native accent task at 26 months, neither at-risk nor control infants showed familiar word recognition. These findings are discussed in terms of the impact of family risk for dyslexia on toddlers' consolidation of early phonological and lexical skills.

Visual Input and Orthographic Knowledge in Word Reading of Children with Low Vision

This study investigated whether the difficulties with reading of children with low vision are a matter of reduced visual input or also a consequence of a lack of orthographic knowledge because of less reading experience. The results indicated that reduced visual input is the only cause of these children's lower reading performance.

Does phonological distance impact quality of phonological representations? Evidence from Arabic diglossia

The study tested the impact of the phonological distance between Spoken Arabic (SpA) and Standard Arabic (StA) on quality of phonological representations among kindergarten, first-, second-, and sixth-grade Arabic-speaking children (N = 120). A pronunciation accuracy judgment task targeted three types of StA words that varied in extent of phonological distance from their form in SpA: (a) identical words, with an identical lexical-phonological form in StA and SpA; (b) cognate words, with partially overlapping phonological forms; items in this category varied in degree of phonological distance too; and (c) unique words with entirely different lexical-phonological forms. Multilevel Regression analysis showed that phonological distance had a significant impact on quality of phonological representations across all grades. Growth in quality of phonological representations was mainly noted between the three younger groups and the sixth-graders. Implications for the impact of phonological distance on phonological representations and on language and literacy development are discussed.

Beyond the phonological deficit: Semantics contributes indirectly to decoding efficiency in children with dyslexia

The present study explored the direct and indirect contribution of semantic abilities to the levels of phonological and orthographic abilities in children with dyslexia. The semantic abilities of fifty‐five 9‐year‐old Dutch children diagnosed with dyslexia were associated with their phonological abilities (phonological awareness, rapid naming, and verbal working memory) and their word decoding and pseudoword decoding efficiency scores. It was found that children's semantic abilities predicted both word decoding efficiency and pseudoword decoding efficiency indirectly via phonological awareness and rapid naming. These results can be explained in terms of a lexical restructuring account of early reading development; strong semantic abilities provide children with dyslexia with a boost to strengthen their phonological skills and naming skills, which indirectly facilitate their reading development.

Enhanced semantic involvement during word recognition in children with dyslexia

We investigated whether children with dyslexia show enhanced semantic involvement as compensation for deficient phonological processing during reading. Phonological and semantic processing during reading and moderating effects of word frequency and word length in children with and without dyslexia were examined using a picture-word priming paradigm. Participants were 61 children with dyslexia and 50 typical readers in Grade 6 of primary school. Primes were either semantically or phonologically (shared onset and rime) related or unrelated to their target word. Results showed that priming effects were stronger in children with dyslexia than in typical readers in the semantic condition but did not differ between groups in the phonological condition. Overall, word length and word frequency effects were stronger for children with dyslexia than for typical readers, but word length and word frequency did not affect priming effects differently for the two groups. In both groups, only semantic priming effects were stronger for low-frequency longer words. Finally, individual word and pseudoword reading efficiency correlated with priming effects only in the semantic condition and only in children with dyslexia. It can be concluded that children with dyslexia, compared with typical readers, rely more on semantic information in word reading but do not show deficient phonological activation during reading compared with typical readers.

Speech Recognition in Noise by Children with and without Dyslexia: How is it Related to Reading?

PURPOSE

Developmental dyslexia is commonly viewed as a phonological deficit that makes it difficult to decode written language. But children with dyslexia typically exhibit other problems, as well, including poor speech recognition in noise. The purpose of this study was to examine whether the speech-in-noise problems of children with dyslexia are related to their reading problems, and if so, if a common underlying factor might explain both. The specific hypothesis examined was that a spectral processing disorder results in these children receiving smeared signals, which could explain both the diminished sensitivity to phonological structure - leading to reading problems - and the speech recognition in noise difficulties. The alternative hypothesis tested in this study was that children with dyslexia simply have broadly based language deficits.

PARTICIPANTS

Ninety-seven children between the ages of 7 years; 10 months and 12 years; 9 months participated: 46 with dyslexia and 51 without dyslexia.

METHODS

Children were tested on two dependent measures: word reading and recognition in noise with two types of sentence materials: as unprocessed (UP) signals, and as spectrally smeared (SM) signals. Data were collected for four predictor variables: phonological awareness, vocabulary, grammatical knowledge, and digit span.

RESULTS

Children with dyslexia showed deficits on both dependent and all predictor variables. Their scores for speech recognition in noise were poorer than those of children without dyslexia for both the UP and SM signals, but by equivalent amounts across signal conditions indicating that they were not disproportionately hindered by spectral distortion. Correlation analyses on scores from children with dyslexia showed that reading ability and speech-in-noise recognition were only mildly correlated, and each skill was related to different underlying abilities.

CONCLUSIONS

No substantial evidence was found to support the suggestion that the reading and speech recognition in noise problems of children with dyslexia arise from a single factor that could be defined as a spectral processing disorder. The reading and speech recognition in noise deficits of these children appeared to be largely independent.

A cognitive psychometric model for assessment of picture naming abilities in aphasia

Picture naming impairments are a typical feature of stroke-induced aphasia. Overall accuracy and rates of different error types are used to make inferences about the severity and nature of damage to the brain's language network. Currently available assessment tools for picture naming accuracy treat it as a unidimensional measure, while assessment tools for error types treat items homogenously, contrary to findings from psycholinguistic investigations of word production. We created and tested a new cognitive psychometric model for assessment of picture naming responses, using cognitive theory to specify latent processing decisions during the production of a naming attempt, and using item response theory to separate the effects of item difficulty and participant ability on these internal processing decisions. The model enables multidimensional assessment of latent picture naming abilities on a common scale, with a relatively large cohort for normative reference. We present the results of 4 experiments testing our interpretation of the model's parameters, as they apply to picture naming predictions, lexical properties of the items, statistical properties of the lexicon, and participants' scores on other tests. We also created a website for researchers and clinicians to analyze item-level data using our model, providing estimates of latent abilities and percentile scores, as well as credible intervals to help gauge the reliability of the estimated model parameters and identify meaningful changes. To the extent that the model is successful, the estimated parameter values may aid in treatment decisions and progress monitoring, or they may help elucidate the functional properties of brain networks. (PsycINFO Database Record

Inhibition and Updating, but Not Switching, Predict Developmental Dyslexia and Individual Variation in Reading Ability

To elucidate the core executive function profile (strengths and weaknesses in inhibition, updating, and switching) associated with dyslexia, this study explored executive function in 27 children with dyslexia and 29 age matched controls using sensitive z-mean measures of each ability and controlled for individual differences in processing speed. This study found that developmental dyslexia is associated with inhibition and updating, but not switching impairments, at the error z-mean composite level, whilst controlling for processing speed. Inhibition and updating (but not switching) error composites predicted both dyslexia likelihood and reading ability across the full range of variation from typical to atypical. The predictive relationships were such that those with poorer performance on inhibition and updating measures were significantly more likely to have a diagnosis of developmental dyslexia and also demonstrate poorer reading ability. These findings suggest that inhibition and updating abilities are associated with developmental dyslexia and predict reading ability. Future studies should explore executive function training as an intervention for children with dyslexia as core executive functions appear to be modifiable with training and may transfer to improved reading ability.

How many deficits in the same dyslexic brains? A behavioural and fMRI assessment of comorbidity in adult dyslexics

Dyslexia can have different manifestations: this has motivated different theories on its nature, on its underlying brain bases and enduring controversies on how to best treat it. The relative weight of the different manifestations has never been evaluated using both behavioural and fMRI measures, a challenge taken here to assess the major systems called into play in dyslexia by different theories. We found that adult well-compensated dyslexics were systematically impaired only in reading and in visuo-phonological tasks, while deficits for other systems (e.g., motor/cerebellar, visual magnocellular/motion perception) were only very occasional. In line with these findings, fMRI showed a reliable hypoactivation only for the task of reading, in the left occipito-temporal cortex (l-OTC). The l-OTC, normally a crossroad between the reading system and other systems, did not show the same level of intersection in dyslexics; yet, it was not totally silent because it responded, in segregated parts, during auditory phonological and visual motion perception tasks. This minimal behavioural and functional anatomical comorbidity demonstrates that a specific deficit of reading is the best description for developmental dyslexia, at least for adult well-compensated cases, with clear implications for rehabilitation strategies. The reduced intersection of multiple systems in the l-OTC suggests that dyslexics suffer from a coarser connectivity, leading to disconnection between the multiple domains that normally interact during reading.

Slowing in reading and picture naming: the effects of aging and developmental dyslexia

We examined the slowing in vocal reaction times shown by dyslexic (compared to control) children with that of older (compared to younger) adults using an approach focusing on the detection of global, non-task-specific components. To address this aim, data were analyzed with reference to the difference engine (DEM) and rate and amount (RAM) models. In Experiment 1, typically developing children, children with dyslexia (both attending sixth grade), younger adults and older adults read words and non-words and named pictures. In Experiment 2, word and picture conditions were presented to dyslexic and control children attending eighth grade. In both experiments, dyslexic children were delayed in reading conditions, while they were unimpaired in naming pictures (a finding which indicates spared access to the phonological lexicon). The reading difficulty was well accounted for by a single multiplicative factor while only the residual effect of length (but not frequency and lexicality) was present after controlling for over-additivity using a linear mixed effects model with random slopes on critical variables. Older adults were slower than younger adults across reading and naming conditions. This deficit was well described by a single multiplicative factor. Thus, while slowing of information processing is limited to orthographic stimuli in dyslexic children, it cuts across verbal tasks in older adults. Overall, speed differences in groups such as dyslexic children and older adults can be effectively described with reference to deficits in domains encompassing a variety of experimental conditions rather than deficits in single specific task/conditions. The DEM and RAM prove effective in teasing out global vs. specific components of performance.

Morphology and spelling in French students with dyslexia: the case of silent final letters

Spelling is a challenge for individuals with dyslexia. Phoneme-to-grapheme correspondence rules are highly inconsistent in French, which make them very difficult to master, in particular for dyslexics. One recurrent manifestation of this inconsistency is the presence of silent letters at the end of words. Many of these silent letters perform a morphological function. The current study examined whether students with dyslexia (aged between 10 and 15 years) benefit from the morphological status of silent final letters when spelling. We compared, their ability to spell words with silent final letters that are either morphologically justified (e.g., tricot, "knit," where the final "t" is pronounced in morphologically related words such as tricoter, "to knit" and tricoteur "knitter") or not morphologically justified (e.g., effort, "effort") to that of a group of younger children matched for reading and spelling level. Results indicated that the dyslexic students' spelling of silent final letters was impaired in comparison to the control group. Interestingly, morphological status helped the dyslexics improve the accuracy of their choice of final letters, contrary to the control group. This finding provides new evidence of morphological processing in dyslexia during spelling.

Prosodic Similarity Effects in Short-Term Memory in Developmental Dyslexia

Children with developmental dyslexia are characterized by phonological difficulties across languages. Classically, this 'phonological deficit' in dyslexia has been investigated with tasks using single-syllable words. Recently, however, several studies have demonstrated difficulties in prosodic awareness in dyslexia. Potential prosodic effects in short-term memory have not yet been investigated. Here we create a new instrument based on three-syllable words that vary in stress patterns, to investigate whether prosodic similarity (the same prosodic pattern of stressed and unstressed syllables) exerts systematic effects on short-term memory. We study participants with dyslexia and age-matched and younger reading-level-matched typically developing controls. We find that all participants, including dyslexic participants, show prosodic similarity effects in short-term memory. All participants exhibited better retention of words that differed in prosodic structure, although participants with dyslexia recalled fewer words accurately overall compared to age-matched controls. Individual differences in prosodic memory were predicted by earlier vocabulary abilities, by earlier sensitivity to syllable stress and by earlier phonological awareness. To our knowledge, this is the first demonstration of prosodic similarity effects in short-term memory. The implications of a prosodic similarity effect for theories of lexical representation and of dyslexia are discussed. © 2016 The Authors. Dyslexia published by John Wiley & Sons Ltd.

Polysyllable productions in preschool children with speech sound disorders: Error categories and the Framework of Polysyllable Maturity

PURPOSE

Children with speech sound disorders (SSD) find polysyllables difficult; however, routine sampling and measurement of speech accuracy are insufficient to describe polysyllable accuracy and maturity. This study had two aims: (1) compare two speech production tasks and (2) describe polysyllable errors within the Framework of Polysyllable Maturity.

METHOD

Ninety-three preschool children with SSD from the Sound Start Study (4;0-5;5 years) completed the Polysyllable Preschool Test (POP) and the Diagnostic Evaluation of Articulation and Phonology (DEAP-Phonology).

RESULT

Vowel accuracy was significantly different between the POP and the DEAP-Phonology. Polysyllables were analysed using the seven Word-level Analysis of Polysyllables (WAP) error categories: (1) substitution of consonants or vowels (97.8% of children demonstrated common use), (2) deletion of syllables, consonants or vowels (65.6%), (3) distortion of consonants or vowels (0.0%), (4) addition of consonants or vowels (0.0%), (5) alteration of phonotactics (77.4%), (6) alteration of timing (63.4%) and (7) assimilation or alteration of sequence (0.0%). The Framework of Polysyllable Maturity described five levels of maturity based on children's errors.

CONCLUSIONS

Polysyllable productions of preschool children with SSD can be analysed and categorised using the WAP and interpreted using the Framework of Polysyllable Maturity.

Spelling Errors of Dyslexic Children in Bosnian Language With Transparent Orthography

The purpose of this study was to explore the nature of spelling errors made by children with dyslexia in Bosnian language with transparent orthography. Three main error categories were distinguished: phonological, orthographic, and grammatical errors. An analysis of error type showed 86% of phonological errors,10% of orthographic errors, and 4% of grammatical errors. Furthermore, the majority errors were the omissions and substitutions, followed by the insertions, omission of rules of assimilation by voicing, and errors with utilization of suffix. We can conclude that phonological errors were dominant in children with dyslexia at all grade levels.

Poor readers' retrieval mechanism: efficient access is not dependent on reading skill

A substantial body of evidence points to a cue-based direct-access retrieval mechanism as a crucial component of skilled adult reading. We report two experiments aimed at examining whether poor readers are able to make use of the same retrieval mechanism. This is significant in light of findings that poor readers have difficulty retrieving linguistic information (e.g., Perfetti, 1985). Our experiments are based on a previous demonstration of direct-access retrieval in language processing, presented in McElree et al. (2003). Experiment 1 replicates the original result using an auditory implementation of the Speed-Accuracy Tradeoff (SAT) method. This finding represents a significant methodological advance, as it opens up the possibility of exploring retrieval speeds in non-reading populations. Experiment 2 provides evidence that poor readers do use a direct-access retrieval mechanism during listening comprehension, despite overall poorer accuracy and slower retrieval speeds relative to skilled readers. The findings are discussed with respect to hypotheses about the source of poor reading comprehension.

Confrontation Naming and Reading Abilities at Primary School: A Longitudinal Study

Background. Confrontation naming tasks are useful in the assessment of children with learning and language disorders. Objectives. The aims of this study were (1) providing longitudinal data on confrontation naming; (2) investigating the role of socioeconomic status (SES), intelligence, age, and gender in confrontation naming; (3) identifying relationship between confrontation naming and reading abilities (fluency, accuracy, and comprehension). Method. A five-year longitudinal investigation of confrontation naming (i.e., the Boston Naming Test (BNT)) in a nonclinical sample of Italian primary school children was conducted (n = 126), testing them at the end of each school year, to assess nonverbal intelligence, confrontation naming, and reading abilities. Results. Performance on the BNT emerged as a function of IQ and SES. Significant correlations between confrontation naming and reading abilities, especially comprehension, were found; BNT scores correlated better with reading fluency than with reading accuracy. Conclusions. The longitudinal data obtained in this study are discussed with regard to reading abilities, intelligence, age, gender, and socioeconomic status.

A compensatory role for declarative memory in neurodevelopmental disorders

Most research on neurodevelopmental disorders has focused on their abnormalities. However, what remains intact may also be important. Increasing evidence suggests that declarative memory, a critical learning and memory system in the brain, remains largely functional in a number of neurodevelopmental disorders. Because declarative memory remains functional in these disorders, and because it can learn and retain numerous types of information, functions, and tasks, this system should be able to play compensatory roles for multiple types of impairments across the disorders. Here, we examine this hypothesis for specific language impairment, dyslexia, autism spectrum disorder, Tourette syndrome, and obsessive-compulsive disorder. We lay out specific predictions for the hypothesis and review existing behavioral, electrophysiological, and neuroimaging evidence. Overall, the evidence suggests that declarative memory indeed plays compensatory roles for a range of impairments across all five disorders. Finally, we discuss diagnostic, therapeutic and other implications.

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.

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

It is still unclear whether phonological processing deficits are the underlying cause of developmental dyslexia, or rather a consequence of basic auditory processing impairments. To avoid methodological confounds, in the current study the same task and stimuli of comparable complexity were used to investigate both phonological and basic auditory (temporal and spectral) processing in dyslexia. German dyslexic children (Grades 3 and 4) were compared to age- and grade-matched controls in a vowel length discrimination task with three experimental conditions: In a phonological condition, natural vowels were used, differing both with respect to temporal and spectral information (in German, vowel length is phonemic, and vowel length differences are characterized by both temporal and spectral information). In a temporal condition, spectral information differentiating between the two vowels of a pair was eliminated, whereas in a spectral condition, temporal differences were removed. As performance measure, the sensitivity index d' was computed. At the group level, dyslexic children's performance was inferior to that of controls for phonological as well as temporal and spectral vowel length discrimination. At an individual level, nearly half of the dyslexic sample was characterized by deficits in all three conditions, but there were also some children showing no deficits at all. These results reveal on the one hand that phonological processing deficits in dyslexia may stem from impairments in processing temporal and spectral information in the speech signal. On the other hand they indicate, however, that not all dyslexic children might be characterized by phonological or auditory processing deficits.

The contribution of discrete-trial naming and visual recognition to rapid automatized naming deficits of dyslexic children with and without a history of language delay

Children with Developmental Dyslexia (DD) are impaired in Rapid Automatized Naming (RAN) tasks, where subjects are asked to name arrays of high frequency items as quickly as possible. However the reasons why RAN speed discriminates DD from typical readers are not yet fully understood. Our study was aimed to identify some of the cognitive mechanisms underlying RAN-reading relationship by comparing one group of 32 children with DD with an age-matched control group of typical readers on a naming and a visual recognition task both using a discrete-trial methodology, in addition to a serial RAN task, all using the same stimuli (digits and colors). Results showed a significant slowness of DD children in both serial and discrete-trial naming (DN) tasks regardless of type of stimulus, but no difference between the two groups on the discrete-trial recognition task. Significant differences between DD and control participants in the RAN task disappeared when performance in the DN task was partialled out by covariance analysis for colors, but not for digits. The same pattern held in a subgroup of DD subjects with a history of early language delay (LD). By contrast, in a subsample of DD children without LD the RAN deficit was specific for digits and disappeared after slowness in DN was partialled out. Slowness in DN was more evident for LD than for noLD DD children. Overall, our results confirm previous evidence indicating a name-retrieval deficit as a cognitive impairment underlying RAN slowness in DD children. This deficit seems to be more marked in DD children with previous LD. Moreover, additional cognitive deficits specifically associated with serial RAN tasks have to be taken into account when explaining deficient RAN speed of these latter children. We suggest that partially different cognitive dysfunctions underpin superficially similar RAN impairments in different subgroups of DD subjects.

Short-term memory for order but not for item information is impaired in developmental dyslexia

Recent findings suggest that people with dyslexia experience difficulties with the learning of serial order information during the transition from short- to long-term memory (Szmalec et al. Journal of Experimental Psychology: Learning, Memory, & Cognition 37(5): 1270-1279, 2011). At the same time, models of short-term memory increasingly incorporate a distinction of order and item processing (Majerus et al. Cognition 107: 395-419, 2008). The current study is aimed to investigate whether serial order processing deficiencies in dyslexia can be traced back to a selective impairment of short-term memory for serial order and whether this impairment also affects processing beyond the verbal domain. A sample of 26 adults with dyslexia and a group of age and IQ-matched controls participated in a 2 × 2 × 2 experiment in which we assessed short-term recognition performance for order and item information, using both verbal and nonverbal material. Our findings indicate that, irrespective of the type of material, participants with dyslexia recalled the individual items with the same accuracy as the matched control group, whereas the ability to recognize the serial order in which those items were presented appeared to be affected in the dyslexia group. We conclude that dyslexia is characterized by a selective impairment of short-term memory for serial order, but not for item information, and discuss the integration of these findings into current theoretical views on dyslexia and its associated dysfunctions.

Naming abilities in low-proficiency second language learners

Difficulties in second language (L2) learning are often associated with recognizable learning difficulties in native language (L1), such as in dyslexia. However, some individuals have low L2 proficiency but intact L1 reading skills. These L2 learners experience frequent tip-of-the-tongue states while naming in L1, which indicates that they have a weakness in retrieval of phonological codes of words. The authors hypothesized that if naming ability is shared across languages, this difficulty would reemerge in L2 naming, which was tested using the tip-of-the-tongue experimental paradigm. Consistent with this hypothesis, low-proficiency L2 learners (n = 15) reported more tip-of-the-tongue states, more frequently mispronounced correctly retrieved words, and benefited less from phonological cuing compared to high-proficiency L2 learners (n = 23). It is notable that low-proficiency L2 learners performed worse than individuals with dyslexia (n = 16) on some of these measures, despite the same level of L2 proficiency. These results indicate that L2 naming difficulties of low-proficiency L2 learners are a manifestation not merely of their low L2 proficiency but rather of a general weakness in phonological word form retrieval, which is shared across languages. More broadly, the study provides further evidence for the existence of a distinct profile of cognitive weaknesses characteristic of the behavioral phenotype of low-proficiency L2 learners.

Project DyAdd: implicit learning in adult dyslexia and ADHD

In this study of the project DyAdd, implicit learning was investigated through two paradigms in adults (18-55 years) with dyslexia (n = 36) or with attention deficit/hyperactivity disorder (ADHD, n = 22) and in controls (n = 35). In the serial reaction time (SRT) task, there were no group differences in learning. However, those with ADHD exhibited faster RTs compared to other groups. In the artificial grammar learning (AGL) task, the groups did not differ from each other in their learning (i.e., grammaticality accuracy or similarity choices). Further, all three groups were sensitive to fragment overlap between learning and test-phase items (i.e., similarity choices were above chance). Grammaticality performance of control participants was above chance, but that of participants with dyslexia and participants with ADHD failed to differ from chance, indicating impaired grammaticality learning in these groups. While the main indices of AGL performance, grammaticality accuracy and similarity choices did not correlate with the neuropsychological variables that reflected dyslexia-related (phonological processing, reading, spelling, arithmetic) or ADHD-related characteristics (executive functions, attention), or intelligence, the explicit knowledge for the AGL grammar (i.e., ability to freely generate grammatical strings) correlated positively with the variables of phonological processing and reading. Further, SRT reaction times correlated positively with full scale intelligence quotient (FIQ). We conclude that, in AGL, learning difficulties of the underlying rule structure (as measured by grammaticality) are associated with dyslexia and ADHD. However, learning in AGL is not related to the defining neuropsychological features of dyslexia or ADHD. Instead, the resulting explicit knowledge relates to characteristics of dyslexia.

Individual differences in crossmodal brain activity predict arcuate fasciculus connectivity in developing readers

Crossmodal integration of auditory and visual information, such as phonemes and graphemes, is a critical skill for fluent reading. Previous work has demonstrated that white matter connectivity along the arcuate fasciculus (AF) is predicted by reading skill and that crossmodal processing particularly activates the posterior STS (pSTS). However, the relationship between this crossmodal activation and white matter integrity has not been previously reported. We investigated the interrelationship of crossmodal integration, both in terms of behavioral performance and pSTS activity, with AF tract coherence using a rhyme judgment task in a group of 47 children with a range of reading abilities. We demonstrate that both response accuracy and pSTS activity for crossmodal (auditory-visual) rhyme judgments was predictive of fractional anisotropy along the left AF. Unimodal (auditory-only or visual-only) pSTS activity was not significantly related to AF connectivity. Furthermore, activity in other reading-related ROIs did not show the same AV-only AF coherence relationship, and AV pSTS activity was not related to connectivity along other language-related tracts. This study is the first to directly show that crossmodal brain activity is specifically related to connectivity in the AF, supporting its role in phoneme-grapheme integration ability. More generally, this study helps to define an interdependent neural network for reading-related integration.

Evidence for a preserved sensitivity to orthographic redundancy and an impaired access to phonological syllables in French developmental dyslexics

To evaluate the orthographic and phonological processing skills of developmental dyslexics, we (a) examined their abilities to exploit properties of orthographic redundancy and (b) tested whether their phonological deficit extends to spelling-to-sound connections for large-grain size units such as syllables. To assess the processing skills in dyslexics, we utilized the illusory conjunction paradigm to investigate the nature of reading units in French dyslexic and control children matched in reading age. In control children, reading units were defined by both orthographic redundancy and phonological syllable information. In dyslexics, however, reading units were defined only by orthographic redundancy. Therefore, despite their impairment in reading acquisition, developmental dyslexics have the ability to encode and exploit letter frequency co-occurrences. In contrast, their access to phonological syllables from letters was impaired, suggesting that their phonological deficit extends to large grain-size phonological units.

Neural correlates of temporal auditory processing in developmental dyslexia during German vowel length discrimination: an fMRI study

This fMRI study investigated phonological vs. auditory temporal processing in developmental dyslexia by means of a German vowel length discrimination paradigm (Groth, Lachmann, Riecker, Muthmann, & Steinbrink, 2011). Behavioral and fMRI data were collected from dyslexics and controls while performing same-different judgments of vowel duration in two experimental conditions. In the temporal, but not in the phonological condition, hemodynamic brain activation was observed bilaterally within the anterior insular cortices in both groups and within the left inferior frontal gyrus (IFG) in controls, indicating that the left IFG and the anterior insular cortices are part of a neural network involved in temporal auditory processing. Group subtraction analyses did not demonstrate significant effects. However, in a subgroup analysis, participants performing low in the temporal condition (all dyslexic) showed decreased activation of the insular cortices and the left IFG, suggesting that this processing network might form the neural basis of temporal auditory processing deficits in dyslexia.

Are French dyslexic children sensitive to consonant sonority in segmentation strategies? Preliminary evidence from a letter detection task

This paper aims to investigate whether--and how--consonant sonority (obstruent vs. sonorant) and status (coda vs. onset) within syllable boundaries modulate the syllable-based segmentation strategies. Here, it is questioned whether French dyslexic children, who experience acoustic-phonetic (i.e., voicing) and phonological impairments, are sensitive to an optimal 'sonorant coda-obstruent onset' sonority profile as a cue for a syllable-based segmentation. To examine these questions, we used a modified version of the illusory conjunction paradigm with French dyslexic children compared with both chronological age-matched and reading level-matched controls. Our results first showed that the syllable-based segmentation is developmentally constrained in visual identification: in normally reading children, it appears to progressively increase as reading skills increase. However, surprisingly, our results also showed that dyslexic children were able to use syllable-sized units. Then, data highlighted that a syllable-based segmentation in visual identification basically relies on an optimal 'sonorant coda-obstruent onset' sonority profile rather than on phonological and orthographic statistical properties in normally reading children as well as, surprisingly, in dyslexic children. Our results are discussed to support a sonority-modulated prelexical role of syllable-sized units in visual identification in French, even in dyslexic children who exhibited a developmentally delayed profile. We argue that dyslexic children have deficits in online phonetic-phonological processing rather than degraded or underspecified phonetic-phonological representations.

Separating global and specific factors in developmental dyslexia

The general goal of the study was to identify global and specific components in developmental dyslexia using various manipulations based on the rapid automatization paradigm (RAN). In two experiments, we used both factor analysis and the Rate-and-Amount Model to verify if one (or more) global factor(s) and a variety of specific effects contribute to the naming (and visual search) deficits in children with dyslexia. Results of Experiment 1 indicated the presence of three global components: pictorial naming, detailed orthographic analysis, and visual search. Pictorial naming is predicated by typical RAN tasks (such as naming colors or objects), independent of set size, but also from a variety of other tasks including Stroop interference conditions. The detailed orthographic analysis factor accounts for naming of orthographic stimuli at high set size. Visual search marked tasks requiring the scanning of visual targets. Results of Experiment 2 confirmed the separation between the pictorial naming and detailed orthographic analysis factors both in the original sample and in a new group of children. Furthermore, specific effects of frequency, lexicality, and length were shown to contribute to the reading deficit. Overall, it is proposed that focusing on the profile of both global and specific effects provides a more effective and, at the same time, simpler account of the dyslexics' impairment.

Brain stimulation over Broca's area differentially modulates naming skills in neurotypical adults and individuals with Asperger's syndrome

In the present study we tested the hypothesis that, in subjects with Asperger's syndrome (ASP), the dynamics of language-related regions might be abnormal, so that repetitive transcranial magnetic stimulation (rTMS) over Broca's area leads to differential behavioral effects as seen in neurotypical controls. We conducted a five-stimulation-site, double-blind, multiple crossover, pseudo-randomized, sham-controlled study in 10 individuals with ASP and 10 age- and gender-matched healthy subjects. Object naming was assessed before and after low-frequency rTMS of the left pars opercularis, left pars triangularis, right pars opercularis and right pars triangularis, and sham stimulation, as guided stereotaxically by each individual's brain magnetic resonance imaging. In ASP participants, naming improved after rTMS of the left pars triangularis as compared with sham stimulation, whereas rTMS of the adjacent left opercularis lengthened naming latency. In healthy subjects, stimulation of parts of Broca's area did not lead to significant changes in naming skills, consistent with published data. Overall, these findings support our hypothesis of abnormal language neural network dynamics in individuals with ASP. From a methodological point of view, this work illustrates the use of rTMS to study the dynamics of brain-behavior relations by revealing the differential behavioral impact of non-invasive brain stimulation in a neuropsychiatric disorder.

Is developmental dyslexia modality specific? A visual-auditory comparison of Italian dyslexics

Although developmental dyslexia is often referred to as a cross-modal disturbance, tests of different modalities using the same stimuli are lacking. We compared the performance of 23 children with dyslexia and 42 chronologically matched control readers on reading versus repetition tasks and visual versus auditory lexical decision using the same stimuli. With respect to control readers, children with dyslexia were impaired only on stimuli in the visual modality; they had no deficit on the repetition and auditory lexical decision tasks. By applying the rate-amount model (Faust et al., 1999), we showed that performance of children with dyslexia on visual (but not auditory) tasks was associated with that of control readers by a linear relationship (with a 1.78 slope), suggesting that a global factor accounts for visual (but not auditory) task performance. We conclude that the processing of linguistic stimuli in the visual and auditory modalities is carried out by independent processes and that dyslexic children have a selective deficit in the visual modality.

The Linguistic Affiliation Constraint and phoneme recognition in diglossic Arabic

This study tested the effect of the phoneme's linguistic affiliation (Standard Arabic versus Spoken Arabic) on phoneme recognition among five-year-old Arabic native speaking kindergarteners (N=60). Using a picture selection task of words beginning with the same phoneme, and through careful manipulation of the phonological properties of target phonemes and distractors, the study showed that children's recognition of Standard phonemes was poorer than that of Spoken phonemes. This finding was interpreted as indicating a deficiency in the phonological representations of Standard words. Next, the study tested two hypotheses regarding the specific consequences of under-specified phonological representations: phonological encoding versus phonological processing. These hypotheses were addressed through an analysis of the relative power of distractors. The findings revealed that children's difficulty in accessing Standard Arabic phonemes was due to a difficulty in the phonological encoding of Standard words. We discuss the implications of the findings for language and literacy development in diglossic Arabic.

Semantic abilities in children with pragmatic language impairment: the case of picture naming skills

PURPOSE

The semantic abilities of children with pragmatic language impairment (PLI) are subject to debate. The authors investigated picture naming and definition skills in 5-year-olds with PLI in comparison to typically developing children.

METHOD

84 children with PLI and 80 age-matched typically developing children completed receptive vocabulary, picture naming, and definition tasks.

RESULTS

The PLI group scored lower on the receptive vocabulary and picture naming tasks. Word length and frequency affected naming accuracy in both groups. Children with PLI showed higher numbers of semantic errors, nonrelated errors, and omissions and circumlocutions. The error-type distribution differed between groups: PLI children showed disproportionate levels of nonrelated errors. In the definition task, PLI children showed lower information accuracy for accurately named pictures and comparable accuracy for incorrectly named pictures. Qualitative analysis suggested a high incidence of pragmatically inappropriate definitions for the PLI group. Naming accuracy for both groups improved equally after giving semantic cues.

CONCLUSIONS

These findings suggest a deficit in object identification and/or naming selection. It might be premature to conclude that children with PLI show normal semantic abilities. The results are largely consistent with a general language delay; however, there is also some evidence of a qualitative difference between both groups.

The nature of the phonological processing in French dyslexic children: evidence for the phonological syllable and linguistic features' role in silent reading and speech discrimination

This study investigated the status of phonological representations in French dyslexic children (DY) compared with reading level- (RL) and chronological age-matched (CA) controls. We focused on the syllable's role and on the impact of French linguistic features. In Experiment 1, we assessed oral discrimination abilities of pairs of syllables that varied as a function of voicing, mode or place of articulation, or syllable structure. Results suggest that DY children underperform controls with a 'speed-accuracy' deficit. However, DY children exhibit some similar processing than those highlighted in controls. As in CA and RL controls, DY children have difficulties in processing two sounds that only differ in voicing, and preferentially process obstruent rather than fricative sounds, and more efficiently process CV than CCV syllables. In Experiment 2, we used a modified version of the Colé, Magnan, and Grainger's (Applied Psycholinguistics 20:507-532, 1999) paradigm. Results show that DY children underperform CA controls but outperform RL controls. However, as in CA and RL controls, data reveal that DY children are able to use phonological procedures influenced by initial syllable frequency. Thus, DY children process syllabically high-frequency syllables but phonemically process low-frequency syllables. They also exhibit lexical and syllable frequency effects. Consequently, results provide evidence that DY children performances can be accounted for by laborious phonological syllable-based procedures and also degraded phonological representations.

A short report: Word-level phonological and lexical characteristics interact to influence phoneme awareness

In this study, we examined the influence of word-level phonological and lexical characteristics on early phoneme awareness. Typically developing children, ages 61 to 78 months, completed a phoneme-based, odd-one-out task that included consonant-vowel-consonant word sets (e.g., "chair-chain-ship") that varied orthogonally by a phonological characteristic, sound contrast similarity (similar vs. dissimilar), and a lexical characteristic, neighborhood density (dense vs. sparse). In a subsample of the participants-those with the highest vocabularies-results were in line with a predicted interactive effect of phonological and lexical characteristics on phoneme awareness performance: word sets contrasting similar sounds were less likely to yield correct responses in words from sparse neighborhoods than words from dense neighborhoods. Word sets contrasting dissimilar sounds were most likely to yield correct responses regardless of the words' neighborhood density. Based on these findings, theories of early phoneme awareness should consider both word-level and child-level influences on performance. Attention to these influences is predicted to result in more sensitive and specific measures of reading risk.