Phonological Deficits Research Articles

EEG based functional brain networks analysis in dyslexic children during arithmetic task.

Developmental Dyslexia is a neuro-developmental disorder that often refers to a phonological processing deficit regardless of average IQ. The present study investigated the distinct functional changes in brain networks of dyslexic children during arithmetic task performance using an electroencephalogram. Fifteen dyslexic children and fifteen normally developing children (NDC) were recruited and performed an arithmetic task. Brain functional network measures such as node strength, clustering coefficient, characteristic pathlength and small-world were calculated using graph theory methods for both groups. Task performance showed significantly less performance accuracy in dyslexics against NDC. The neural findings showed increased connectivity in the delta band and reduced connectivity in theta, alpha, and beta band at temporoparietal, and prefrontal regions in dyslexic group while performing the task. The node strengths were found to be significantly high in delta band (T3, O1, F8 regions) and low in theta (T5, P3, Pz regions), beta (Pz) and gamma band (T4 and prefrontal regions) during the task in dyslexics compared to the NDC. The clustering coefficient was found to be significantly low in the dyslexic group (theta and alpha band) and characteristic pathlength was found to be significantly high in the dyslexic group (theta and alpha band) compared to the NDC group while performing task. In conclusion, the present study shows evidence for poor fact-retrieval mechanism and altered network topology in dyslexic brain networks during arithmetic task performance.

Reduced Theta Sampling in Infants at Risk for Dyslexia across the Sensitive Period of Native Phoneme Learning.

Research on children and adults with developmental dyslexia—a specific difficulty in learning to read and spell—suggests that phonological deficits in dyslexia are linked to basic auditory deficits in temporal sampling. However, it remains undetermined whether such deficits are already present in infancy, especially during the sensitive period when the auditory system specializes in native phoneme perception. Because dyslexia is strongly hereditary, it is possible to examine infants for early predictors of the condition before detectable symptoms emerge. This study examines low-level auditory temporal sampling in infants at risk for dyslexia across the sensitive period of native phoneme learning. Using magnetoencephalography (MEG), we found deficient auditory sampling at theta in at-risk infants at both 6 and 12 months, indicating atypical auditory sampling at the syllabic rate in those infants across the sensitive period for native-language phoneme learning. This interpretation is supported by our additional finding that auditory sampling at theta predicted later vocabulary comprehension, nonlinguistic communication and the ability to combine words. Our results indicate a possible early marker of risk for dyslexia.

Is phonological deficit a necessary or sufficient condition for Chinese reading disability?

While phonological skills have been found to be correlated with reading across different writing systems, recent findings have shown that developmental dyslexia in Chinese individuals has multiple deficits, and no single factor has ever been identified as crucial for learning this writing system. To examine whether a deficit in the phonological or another cognitive domain is a necessary or sufficient condition for Chinese reading disability, this study examined the cognitive profiles of 521 good readers and 502 dyslexic readers in Chinese primary schools using a battery of behavioral measures covering phonological, visual, orthographic, visual-motor coordination and working memory skills. The results showed that among all cognitive measures, phonological skills correlated more strongly with character reading performance but that poor phonological skills did not necessarily or sufficiently lead to poor reading performance in Chinese.

A sensorimotor representation impairment in dyslexic adults: A specific profile of comorbidity

Sensorimotor disorders have been frequently reported in children and adults with dyslexia over the past 30 years. The present study aimed to determine the impact of sensorimotor comorbidity risks in dyslexia by investigating the functional links between phonological and sensorimotor representations in young dyslexic adults. Using 52 dyslexic participants and 58 normo-readers, we investigated whether the underlying phonological deficit, which is reported in the literature, was associated with a general impairment of sensorimotor representations of articulatory and bodily actions. Internal action representations were explored through motor imagery tasks, consisting of measuring and comparing the durations of performed or imagined actions chosen from their current repertoire of daily life activities. To detect sensorimotor deficits, all participants completed the extended version of the M-ABC 2, as a reference test. We found sensorimotor impairments in 27% of the young adult dyslexics, then considered as sensorimotor comorbid, as opposed to much less in the normo-reader group (5%). While motor slowdown, reflecting motor difficulty, was present in all dyslexic adults, motor imagery performance was impacted only in the specific dyslexic subgroup with sensorimotor impairments. Moreover, in contrast with slowness, only the comorbid subgroup showed an increased variability in execution durations. The present study highlights the importance of the quality of perception-action coupling, questions the relevance of investigating sensorimotor impairment profiles beyond phonological deficits and provides new arguments supporting the perspective of multiple deficits approaches in dyslexia.

Phonological characteristics of novel gesture production in children with developmental language disorder: Longitudinal findings

Children with developmental language disorder (DLD; aka specific language impairment) are characterized based on deficits in language, especially morphosyntax, in the absence of other explanatory conditions. However, deficits in speech production, as well as fine and gross motor skill, have also been observed, implicating both the linguistic and motor systems. Situated at the intersection of these domains, and providing insight into both, is manual gesture. In the current work, we asked whether children with DLD showed phonological deficits in the production of novel gestures and whether gesture production at 4 years of age is related to language and motor outcomes two years later. Twenty-eight children (14 with DLD) participated in a two-year longitudinal novel gesture production study. At the first and final time points, language and fine motor skills were measured and gestures were analyzed for phonological feature accuracy, including handshape, path, and orientation. Results indicated that, while early deficits in phonological accuracy did not persist for children with DLD, all children struggled with orientation while handshape was the most accurate. Early handshape and orientation accuracy were also predictive of later language skill, but only for the children with DLD. Theoretical and clinical implications of these findings are discussed.

‘Moderate global aphasia’: A generalized decline of language processing caused by glioma surgery but not stroke

Unlike stroke, neurosurgical removal of left-hemisphere gliomas acts upon a reorganized language network and involves brain areas rarely damaged by stroke. We addressed whether this causes the profiles of neurosurgery- and stroke-induced language impairments to be distinct. K-means clustering of language assessment data (neurosurgery cohort: N = 88, stroke cohort: N = 95) identified similar profiles in both cohorts. But critically, a cluster of individuals with specific phonological deficits was only evident in the stroke but not in the neurosurgery cohort. Thus, phonological deficits are less clearly distinguished from other language deficits after glioma surgery compared to stroke. Furthermore, the correlations between language production and comprehension scores at different linguistic levels were more extensive in the neurosurgery than in the stroke cohort. Our findings suggest that neurosurgery-induced language impairments do not correspond to those caused by stroke, but rather manifest as a ‘moderate global aphasia’ – a generalized decline of language processing abilities.

Common Misconceptions about the Phonological Deficit Theory of Dyslexia.

In this discussion paper, I review a number of common misconceptions about the phonological deficit theory (PDH) of dyslexia. These include the common but mistaken idea that the PDH is simply about phonemic awareness (PA), and, consequently, is a circular “pseudo”-explanation or epiphenomenon of reading difficulties. I argue that PA is only the “tip of the phonological iceberg” and that “deeper” spoken-language phonological impairments among dyslexics appear well before the onset of reading and even at birth. Furthermore, not even reading-specific expressions of phonological deficits—PA or pseudoword naming, can be considered circular if we clearly distinguish between reading proper—real meaning-bearing words, or real text, and the mechanisms (subskills) of reading development (such as phonological recoding). I also explain why an understanding of what constitutes an efficient writing system explains why phonology is necessarily a major source of variability in reading ability and hence a core deficit (or at least one core deficit) among struggling readers whether dyslexic or non-dyslexic. I also address the misguided notion that the PDH has now fallen out of favor because most dyslexia researchers have (largely) ceased studying phonological processing. I emphasize that acceptance of the PDH does not imply repudiation of other non-phonological hypotheses because the PDH does not claim to account for all the variance in reading ability/disability. Finally, I ask where neurobiology enters the picture and suggest that researchers need to exercise more caution in drawing their conclusions.

What about lexical competition? Exploring the locus of lexical retrieval deficits in adults with developmental dyslexia.

Individuals with dyslexia do not only show deficits with reading but are also less accurate in naming pictures. This has mainly been linked to prevalent phonological deficits. However, deficits in lexical retrieval of picture names could also be due to increased lexical-semantic competition. The present study tested whether adults with dyslexia (AwDs) are more affected by a competitive lexical-semantic context than control participants. Twenty-seven AwD and 34 control participants completed the blocked-cyclic picture-naming paradigm and the Hayling sentence completion task. In the blocked-cyclic naming task, AwDs showed a larger semantic interference effect than controls in terms of errors, especially producing competitor errors. In the Hayling sentence completion task, AwDs made more errors than controls when asked to complete sentences with semantically unrelated words, that is, in the competitive condition. They especially produced semantically related words or antonyms to target words. We found that AwDs experience difficulties with resolving lexical competition that go beyond their phonological deficits. Future studies will need to establish the mechanisms behind the increased lexical competition that AwDs exhibit. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Morphological Processing in Children with Developmental Dyslexia: A Visual Masked Priming Study

AbstractThis study examined the processing of derivational morphology and its association with early phonological skills of 24 Dutch‐speaking children with dyslexia and 46 controls matched for age. A masked priming experiment was conducted where the semantic overlap between morphologically related pairs was manipulated as part of a lexical decision task. Results suggest that morphological processing is intact in children with dyslexia when compared to age‐matched controls. Significant priming effects were found in each group. Children with dyslexia were found to solely benefit from the morpho‐semantic information, while the morpho‐orthographic form the properties of morphemes‐influenced controls. Due to the longitudinal nature of the data set, an examination of early phonological awareness’s role in the later development of morphological processing skills was possible. In line with the psycholinguistic grain‐size theory, fifth‐grade morphological processing in children with dyslexia was found to be negatively correlated to earlier second‐grade PA skills. A similar relation was not found among the controls. Results indicate a potential shift in the cognitive processes involved during reading to compensate for the observed phonological deficits of children with dyslexia.

Words as Visual Objects: Neural and Behavioral Evidence for High-Level Visual Impairments in Dyslexia.

Developmental dyslexia is defined by reading impairments that are disproportionate to intelligence, motivation, and the educational opportunities considered necessary for reading. Its cause has traditionally been considered to be a phonological deficit, where people have difficulties with differentiating the sounds of spoken language. However, reading is a multidimensional skill and relies on various cognitive abilities. These may include high-level vision—the processes that support visual recognition despite innumerable image variations, such as in viewpoint, position, or size. According to our high-level visual dysfunction hypothesis, reading problems of some people with dyslexia can be a salient manifestation of a more general deficit of high-level vision. This paper provides a perspective on how such non-phonological impairments could, in some cases, cause dyslexia. To argue in favor of this hypothesis, we will discuss work on functional neuroimaging, structural imaging, electrophysiology, and behavior that provides evidence for a link between high-level visual impairment and dyslexia.

Featural and configural processing of faces and houses in matched dyslexic and typical readers

While dyslexia is typically described as a phonological deficit, recent evidence suggests that ventral stream regions, important for visual categorization and object recognition, are hypoactive in dyslexic readers who might accordingly show visual recognition deficits. By manipulating featural and configural information of faces and houses, we investigated whether dyslexic readers are disadvantaged at recognizing certain object classes or using particular visual processing mechanisms. Dyslexic readers found it harder to recognize objects (houses), suggesting that visual problems in dyslexia are not completely domain-specific. Face recognition accuracy was equivalent in the two groups. Lower recognition accuracy for houses was also related to reading difficulties even when accuracy for faces was kept constant, which could indicate a specific relationship between visual word processing and visual processing of non-face objects. Representational similarity analyses (RSA) revealed that featural and configural processes were clearly separable in typical readers, which was not the case for dyslexic readers who appear to rely on a single process. This was not restricted to particular visual categories, occurring for both faces and houses. We speculate that reading deficits in some dyslexic readers reflect their reliance on a single process for object recognition.

Assistive Technology for Dyslexia Students in Elementary School

Technological advances require collaboration in classroom learning practices by providing accessibility to optimize student learning. Classroom learning should be able to accommodate all student learning needs, including students with dyslexia. The purpose of this study was to analyze the need for assistive technology for learning innovation in one of the students who experienced dyslexia in elementary school. This research is qualitative research, using case study method. Data was collected by using interview, observation, and documentation methods. The instruments used in collecting data include: interview guidelines, observation sheets, and documentation guidelines. Data analysis was carried out in a qualitative descriptive manner. The results showed that one of the dyslexic students who is currently in fifth grade elementary school has a phonological deficit and needs learning media to help him practice increasing phonological awareness. Therefore, assistive technology-based learning media is needed to improve the quality of education for dyslexic students, especially in the training process to increase their phonological awareness.

Cognitive Intervention Strategies Directed to Speech and Language Deficits in Primary Progressive Aphasia: Practice-Based Evidence from 18 Cases.

Background: Practice-based evidence can inform and support clinical decision making. Case-report series about the implementation of programs in real-world clinical settings may contribute to verifying the effectiveness of interventions for treating PPA in specific contexts, as well as illustrating challenges that need to be overcome. Objective: To describe and provide practice-based evidence on the effectiveness of four cognitive rehabilitation programs designed for individuals with PPA and directed to speech and language impairments, which were implemented in a specialized outpatient clinic. Methods: Multiple single-case study. Eighteen individuals with different subtypes of PPA were each assigned to one out of four training programs based on comprehensive speech and language assessments. The treatments targeted naming deficits, sentence production, speech apraxia, and phonological deficits. Pre- and post-treatment assessments were undertaken to compare trained and untrained items. Gains were generalized to a different task in the first two types of intervention (naming and sentence production). A follow-up assessment was conducted 1–8 months after treatment among 7 participants. Results: All individuals presented better performance in the trained items at the post-test for each rehabilitation program accomplished, demonstrating that learning of the trained strategies was achieved during the active phase of treatment. For 13 individuals, statistical significance was reached; while for five, the results were maintained. Results about untrained items, generalization to other tasks, and follow-up assessments are presented. Conclusions: The positive results found in our sample bring some practice-based evidence for the benefits of speech and language treatment strategies for clinical management of individuals with PPA.

Factors Explaining Deficits in Reading Acquisition: The Case of Williams Syndrome.

Purpose Multiple factors impact reading acquisition in individuals with reading disability, including genetic disorders such as Williams syndrome (WS). Despite a relative strength in oral language, individuals with WS usually have an intellectual disability and tend to display deficits in areas associated with reading. There is substantial variability in their reading skills. While some authors have postulated that phonological deficits are at the source of their reading deficits, others have suggested that they can be attributed to visuospatial deficits. This study was the first to undertake an in-depth exploration of reading skills among French-speaking children and adults with WS. We tested the assumption that some factors influence performance on single-word identification among individuals with WS, with a focus on the roles of phonological awareness and visuospatial skills. Method Participants were 29 French-speaking adults with WS and 192 controls matched for nonverbal mental age and reading level. We administered tests assessing reading (decoding and word recognition), vocabulary (expressive and receptive), and phonological and visuospatial skills. We also controlled for chronological age and nonverbal reasoning. Results Phonemic awareness was the most predictive factor of single-word identification in the WS group. Visuospatial skills also contributed, but not more or beyond other factors. More broadly, reasoning skills may also have accounted for the variability in single-word identification in WS, but this was not the case for either chronological age or vocabulary. Conclusions There is considerable heterogeneity among adults with WS, who may be either readers or prereaders. Similar profiles identified among individuals with other specific learning disabilities suggest that high reading variability is not specific to the neuropsychological profile of WS. We discuss a multidimensional approach to the factors involved in reading deficits in WS.

The cognitive basis of dyslexia in school-aged children: A multiple case study in a transparent orthography.

This study focuses on the role of numerous cognitive skills such as phonological awareness (PA), rapid automatized naming (RAN), visual and selective attention, auditory skills, and implicit learning in developmental dyslexia. We examined the (co)existence of cognitive deficits in dyslexia and assessed cognitive skills’ predictive value for reading. First, we compared school‐aged children with severe reading impairment (n = 51) to typical readers (n = 71) to explore the individual patterns of deficits in dyslexia. Children with dyslexia, as a group, presented low PA and RAN scores, as well as limited implicit learning skills. However, we found no differences in the other domains. We found a phonological deficit in 51% and a RAN deficit in 26% of children with dyslexia. These deficits coexisted in 14% of the children. Deficits in other cognitive domains were uncommon and most often coexisted with phonological or RAN deficits. Despite having a severe reading impairment, 26% of children with dyslexia did not present any of the tested deficits. Second, in a group of children presenting a wide range of reading abilities (N = 211), we analysed the relationship between cognitive skills and reading level. PA and RAN were independently related to reading abilities. Other skills did not explain any additional variance. The impact of PA and RAN on reading skills differed. While RAN was a consistent predictor of reading, PA predicted reading abilities particularly well in average and good readers with a smaller impact in poorer readers.

Phonological Awareness Deficits in Children With Dyslexia: The Impact of Working Memory as a Function of Modality of Test Administration

This study examined whether the phonological awareness (PA) deficit in Arabic speaking dyslexic children could be impacted by the presence vs. absence of verbal working memory (WM) as function of the sensory modality of administration (auditory vs. visual) of the phonological tests. Three phonological awareness (PA) tasks, i.e., phoneme manipulation, phoneme deletion, and spoonerism task, were administered in two sensory modalities: auditory and visual supported, along with verbal working memory tasks. Results showed that subjects with dyslexia (n = 19) performed significantly lower than typical readers (n = 30) in both PA modalities and working memory tasks. Differences were mainly found between the auditory and visual supported modalities in phoneme deletion and spoonerism for both groups. These results indicate that the PA deficit in children with dyslexia is not specific to the auditory modality and suggest that phonological representations are likely to be impaired in children with dyslexia. Findings shed further light on the issue of whether dyslexia is characterized by poor phonological representations or reduced access to these representations.

The Critical Role of Semantic Working Memory in Language Comprehension and Production

Although research on the role of verbal working memory (WM) in language processing has focused on phonological maintenance, considerable evidence indicates that the maintenance of semantic information plays a more critical role. This article reviews studies of brain-damaged and healthy individuals demonstrating the contribution of semantic WM to language processing. On the sentence-comprehension side, semantic WM supports the retention of individual word meanings prior to their integration. It also serves to maintain semantic information in an activated state such that semantic interference between sentence constituents can be resolved. Phonological WM does not appear to support either of these functions, though it contributes to verbatim sentence recall. On the production side, evidence points to the phrase as the minimal scope of advance planning in sentence formulation, and to semantic WM as supporting the representation of the meanings of the content words within a phrase. Planning at the phonological level appears to have a very limited scope, making few demands on phonological WM. These findings imply that treatment of semantic but not phonological WM deficits should lead to improved sentence comprehension and production, and preliminary findings support that view.

The role of phonological processing in children from a national-type Chinese primary school in Malaysia: implications for dyslexia assessment

ABSTRACT The Malay language writing system is alphabetic and orthographically transparent. This study aimed to determine whether phonological processing skills predict Malay word-level literacy acquisition in Chinese children from a national-type Chinese primary school in Malaysia. A correlational study among 113 Year 1 Chinese children who are non-native speakers of Malay found that phonological awareness was the only significant predictor of Malay word-level literacy acquisition. The prominent role of phonological awareness among the non-native speakers further supports phonological processing deficit as an etiology of word-level literacy difficulties across languages. We conclude that since the non-native speakers rely exclusively on phonological decoding for word-level acquisition, the effect of a phonological deficit would be detrimental. Therefore, the Malay reading-related assessment battery in this study, now validated for both native and non-native speakers can be adapted as a universal early screening tool for detecting Malaysian children at-risk of dyslexia.

Visual attention span and phonological skills in Chinese developmental dyslexia

BackgroundIt has been debated whether visual attention span deficit was independent from phonological deficit in alphabetic developmental dyslexia. Yet, this issue has never been examined in Chinese developmental dyslexia. AimThe aim of the present study was to concurrently investigate visual attention span deficit and phonological deficit in Chinese developmental dyslexia, and examine the relationship between them. MethodsA total of 45 Chinese dyslexic and 43 control children aged between 8 and 11 years old participated in this study. A visual one-back paradigm with both verbal stimuli (character and digit strings) and nonverbal stimuli (color dots and symbols) was employed for measuring visual attention span. Phonological skills were measured by three dimensions: phonological awareness, rapid automatized naming, and verbal short-term memory. ResultsChinese dyslexic children showed deficits in verbal visual attention span and all three dimensions of phonological skills, but not in nonverbal visual attention span. Phonological skills significantly contributed to explaining variance of reading skills and classifying dyslexic and control memberships. Almost all Chinese dyslexic participants who showed a deficit in visual attention span also showed a phonological deficit. ConclusionThe study suggests that visual attention span deficit is not independent from phonological deficit in Chinese developmental dyslexia.

Severe speech impairment is a distinguishing feature of FOXP1-related disorder.

To delineate the speech and language phenotype of a cohort of individuals with FOXP1-related disorder. We administered a standardized test battery to examine speech and oral motor function, receptive and expressive language, non-verbal cognition, and adaptive behaviour. Clinical history and cognitive assessments were analysed together with speech and language findings. Twenty-nine patients (17 females, 12 males; mean age 9y 6mo; median age 8y [range 2y 7mo-33y]; SD 6y 5mo) with pathogenic FOXP1 variants (14 truncating, three missense, three splice site, one in-frame deletion, eight cytogenic deletions; 28 out of 29 were de novo variants) were studied. All had atypical speech, with 21 being verbal and eight minimally verbal. All verbal patients had dysarthric and apraxic features, with phonological deficits in most (14 out of 16). Language scores were low overall. In the 21 individuals who carried truncating or splice site variants and small deletions, expressive abilities were relatively preserved compared with comprehension. FOXP1-related disorder is characterized by a complex speech and language phenotype with prominent dysarthria, broader motor planning and programming deficits, and linguistic-based phonological errors. Diagnosis of the speech phenotype associated with FOXP1-related dysfunction will inform early targeted therapy. What this paper adds Individuals with FOXP1-related disorder have a complex speech and language phenotype. Dysarthria, which impairs intelligibility, is the dominant feature of the speech profile. No participants were receiving speech therapy for dysarthria, but were good candidates for therapy Features of speech apraxia occur alongside persistent phonological errors. Language abilities are low overall; however, expressive language is a relative strength.