Phonological Processing Deficits Research Articles

Developing a Dyslexia Diagnostic Team: A Feasibility Project

Purpose: Dyslexia, a neurobiological phonological processing deficit, can be identified early; however, there is a substantial variation between and within states regarding who makes this diagnosis and when. Dyslexia evaluations are often challenging to obtain and very expensive for families who need to seek them outside of the school setting. The purpose of this study was to determine the feasibility of developing a free dyslexia diagnostic team within our university speech and hearing clinic. Method: We developed a team of academic and clinical faculty and students at the doctoral, master's, and undergraduate levels. We developed a 6-hr (1 day) testing battery and recruited families via social media. Children needed to be between the ages of 8 and 11 years and reported to have classroom difficulty related to word reading and/or spelling. Results: We were able to create a strong and successful team, testing battery, and recruitment plan. Master's students were interested in the opportunity and families drove between 246 and 453 miles to participate. We allocated enough time in our summer schedule for all parties. However, we have concerns about the sustainability of this program, especially during the academic year. Conclusions: Broadly, this dyslexia diagnostic team is a feasible endeavor. There was internal and external community interest. We identified small and solvable barriers related to debriefing and test interpretation. We also identified larger issues related to funding, faculty availability, and student support.

Through the Lens of Struggle: An Inquiry into the Reading Difficulties of Secondary High School Learners

This research, adopting a Phenomenological approach, focuses on understanding the challenges students encounter in comprehending, decoding, and processing written information. Grounded in G. Reid Lyon's Phonological Processing Deficit Theory, introduced in the 1990s, the study aims to uncover the struggles of secondary high school learners facing reading difficulties. Data were gathered through In-Depth Interview and Focused-group Discussion among secondary teachers. Content thematic analysis was used to craft the main themes. Lived experiences on the struggles of secondary high school learners with reading difficulties were: reading difficulties in secondary learners, weak vocabulary and language skills, comprehension issues, learning disabilities, lacking reading motivations, difficulty with reading instruction, and technology distractions. Coping mechanisms were coined to the following themes: time management, active reading strategies, and multimodal learning resources. And finally, educational Insights that can be drawn to Mitigate reading difficulties of secondary learners: teaching approach and recognition of diverse learners, and effective encouragement through access to books and empowering tools. In the future, DepEd plans a comprehensive policy for reading difficulties, prioritizing tailored teacher training, diverse resources, and continuous support for an inclusive environment, while research informs policy and innovative education approaches.

Do we really need a new definition of dyslexia? A commentary.

We provide a commentary on current debates about the definition of dyslexia. We agree with others that dyslexia is best thought of as a dimensional disorder with the best established causal risk factor being a deficit in phonological processing. Dyslexia is particularly common in children from families with a history of dyslexia and in children with preschool language difficulties. We argue that definitions may differ depending upon their purpose. Traditional discrepancy definitions may be useful for research purposes, but when considering the provision of educational services discrepancy definitions are not useful since all children with reading difficulties require reading intervention regardless of their level of IQ.

Developmental dyslexia: Convergence of all theories towards a multifactional model, and the role of ICTs

Dyslexia is a neurodevelopmental disorder that is characterised by slow and inaccurate word recognition. This article intends to summarize the current understanding of developmental dyslexia's etiology, brain bases, neuropsychology, and social context. In this article are discussed the progress has been made the last years in domains involving definition and classification, neuropsychological correlates, neurobiological factors, and intervention of dyslexia. It is also referred to the neuropsychological approaches to dyslexia have evolved and the importance of an interdisciplinary perspective for understanding dyslexia. Dyslexia is caused by multiple genetic and environmental risk factors as well as their interplay. Several candidate genes have been identified in the past decade. At the brain level, dyslexia is associated with aberrant structure and function, particularly in left hemisphere reading/language networks. The neurocognitive influences on dyslexia are also multifactorial and involve phonological processing deficits as well as weaknesses in other oral language skills and processing speed. Contextual issues such as the correlation of dyslexia with an individual’s IQ or age, the manifestation of dyslexia across languages and social classes as well as what treatments are best supported are being examined. This article is aimed at highlighting the exciting new research that cuts across levels of analysis. Such work promises eventually to provide a comprehensive explanation of the disorder as well as its prevention and remediation. In this recent contribution to the field of Dyslexia, we will be mentioned to some historical information, as well as we will be faced with significant issues in the Phonological Theory of Dyslexia. The single versus will multiple deficit accounts. In the field of the etiology of Dyslexia, we will be mentioned to the Behavioural Genetics, to the Molecular Genetics and to Environmental Influences. Individuals with dyslexia show functional abnormalities in both posterior and anterior language networks. This approach is intended to promote scientific knowledge and draws attention to the complexity of the developmental dyslexia (DD).

Lost in Translation: A Preliminary Examination of Phonological Processing, Language, and Reading in Childhood Epilepsy

ABSTRACTChildren with epilepsy are at increased risk for language and reading difficulties. Phonological processing and language underlie reading success, yet their association with reading achievement in children with epilepsy is unknown. We assessed phonological processing, oral language, and reading in children (ages 6 to 12) with epilepsy (EP; n = 6), language problems (LP; n = 14), and typical development (TD; n = 15). The EP and LP group had lower scores on all measures compared with the TD group, with the EP group scoring the lowest on reading comprehension. Phonological processing followed by epilepsy diagnosis predicted reading decoding. Language followed by epilepsy diagnosis predicted reading comprehension. Thus, reading problems in children with epilepsy are not fully explained by their phonological processing or language deficits. Further research that considers other cognitive processes important for reading (e.g., executive function) in this population may help inform our understanding of their reading success.

Predicting Confrontation Naming in the Logopenic Variant of Primary Progressive Aphasia

ABSTRACT Background Naming difficulties are prominent and pervasive in the logopenic variant of primary progressive aphasia (lvPPA) and may reflect its underlying deficits in phonological processing. Importantly, some words appear to be more vulnerable to deterioration than others. We hypothesize that these differences can be explained, in part, by the unique psycholinguistic properties of words. Aims Our study investigated the role of psycholinguistic properties of words, along with their underlying psycholinguistic factors, in predicting confrontation naming performance in individuals with lvPPA. Methods & Procedures Naming accuracy data were collected from 14 individuals with lvPPA using the Boston Naming Test (BNT). For each test item, values were extracted for frequency, age of acquisition (AoA), familiarity, word length, phonological neighborhood density (PND), semantic neighborhood density (SND), arousal, and valence. We examined the effects of these psycholinguistic properties on naming accuracy using logistic regression analyses at the individual level and multiple linear regression analysis at the group level. Further, we performed mediation analyses to examine the mediating contributions of related psycholinguistic properties on naming accuracy. Finally, principal component analysis (PCA) was performed to extract fundamental factors of the psycholinguistic properties. These factor scores were entered into regression analyses to investigate their relative contribution to naming accuracy in lvPPA. Outcomes & Results Age of acquisition emerged as the strongest psycholinguistic predictor of naming accuracy in lvPPA at both the individual and group levels. The influence of AoA on naming accuracy was only partially mediated by frequency. Three principal psycholinguistic factors were extracted from the PCA. These were interpreted as “lexical-semantic usage”, “phonological complexity”, and “emotional intensity”. Results indicated that “lexical-semantic usage” and “emotional intensity” predicted naming performance at both the individual and group levels. Conclusions Age of acquisition has been associated with the phonological level in models of word naming. The observed psycholinguistic effects on naming accuracy are discussed in the context of phonological deficits in lvPPA and models of word naming.

Cognitive subtyping of university students with dyslexia in a semi-transparent orthography: what can weaknesses and strengths tell us about compensation?

Developmental dyslexia is characterized by a profile of reading- and writing-related difficulties which stands out as a core deficit in phonological processing. Although these difficulties seem to persist into adulthood, it is still an open question to what extent they are immune, or not, to the extensive training resulting from extended schooling. The main objective of this study was to explore the heterogeneity of the cognitive profile of European Portuguese highly literate adults with dyslexia. Thirty-one university students diagnosed with dyslexia during childhood and their matched skilled adult control readers were assessed through a battery of reading and cognitive tests. A cluster analysis of data obtained from participants with dyslexia identified two profile groups. While Cluster 1 grouped participants with clear phonological deficits and concomitant reading difficulties, Cluster 2 showed better performance on most of the core skills associated with reading and also better general cognitive abilities, suggesting that these dyslexic readers have partially resolved their phonological constraints along the development, probably due to the systematic exposure to reading and writing. As Cluster 2 matched typical readers in general cognitive abilities, it might also be the case that cognitive strengths associated with general intelligence worked as protective factors, helping students to strategically compensate for their reading difficulties. Overall, these results suggest that both mechanisms–partial remediation of the core phonological deficit and adoption of compensatory strategies supported by general cognitive skills–might contribute together to improving the reading performance of highly literate adults with dyslexia.

Dyslexia and dyscalculia: which neuropsychological processes distinguish the two developmental disorders?

ABSTRACT This study analyses the specific neuropsychological profiles of children with dyslexia and/or dyscalculia, in particular concerning phonological awareness, lexical access, working memory and numerical processing. Four groups were selected, through a screening process that used strict criteria, from 1568 7-10-year-old children: 90 with typical development, 61 with dyslexia, 13 with dyscalculia, and 14 with dyslexia + dyscalculia. Children with dyslexia show a deficit in phonological processing, lexical access, and verbal working memory, especially with alphabetic stimuli. Children with developmental dyscalculia show a deficit of phonological processing, verbal working memory with digits and visual-spatial working memory. They also show an impairment in spatial representation of numbers and in the automatic access to numerical semantics to a greater extent than those with double disturbance. Children with dyslexia + dyscalculia show a profile generally characterized by the summation of the deficits of the two disorders, although they have a lower deficit in access to numerical semantics and mental representation of numbers.

Phonological Processing Skills of Children with Phonological Delay and Phonological Disorder

Objectives: The purpose of this study was to examine the phonological processing skills between children with phonological delay and phonological disorder compared to those of typically developing children. This study aimed to explore whether children with phonological delay and phonological disorder show general or specific weakness on phonological processing skills and if the phonological processing skills can differentiate children with phonological delay from children with phonological disorder. Methods: The participants were 27 children with speech sound disorders (SSDs) and 20 typically developing children. Children with SSDs consisted of 10 children with phonological delay and 17 children with phonological disorder. The tasks for phonological processing skills involved phonological awareness at the levels of word, syllable, body-coda, and phoneme; phonological memory tests including nonword repetition and sentence repetition; and phonological retrieval through rapid automatized number naming test. Results: Children with phonological disorder showed significantly lower phonological awareness at word level than typically developing children and they also exhibited significantly lower nonword repetition than children with phonological delay as well as typically developing children. Both children with phonological delay and disorder performed less well on rapid automatized naming than typically developing children. Conclusion: This study suggests that children with phonological disorder are at higher risk for deficits in phonological processing, and their weakness in nonword repetition which taps phonological memory is more prominent than in children with normal speech or phonological delay.

VERBAL SHORT-TERM IMPAIRMENT IN DYSLEXIA

Verbal short-term memory impairment is one of the most consistently associated deficits observed indevelopmental reading disorders such as dyslexia. The mechanisms involved in the short-term retention ofinformation for serial tasks may be shared across domains of short-term memory, such as verbal and visuospatialshort-term memory. Few studies have addressed the nature of verbal short-term impairment, particularly with regardto the possibility of temporary serial storage of information. A short-term memory serial order impairment appearsto occur for the retention of verbal and visuospatial sequence information. Impairment in the serial ordering of shorttermmemory is not a characteristic of every individual dyslexic subject and is not specific to dyslexia. Futurestudies should determine whether verbal short-term serial order memory impairment is a risk factor that, inassociation with a deficit in phonological processing, may lead to dyslexia or whether verbal short-term serial ordermemory impairment reflects related deficits unrelated to dyslexia. The purpose of this article is to consider theimplications for dyslexia of one aspect of short-term memory, memory for serialization

The association of prenatal cocaine exposure with expressive and receptive language skills, phonological processing and reading ability at age 17

ObjectivePrenatal cocaine exposure (PCE) has been associated with small but significant effects on language development in childhood and early adolescence. This study examined whether this association persists into later adolescence and what relationship language skills may have with reading proficiency in this population. MethodsEnrolled were 338 (167 with PCE, 171 with NCE or no cocaine exposure) 17-year-olds recruited at birth who, together with their current caregiver, were seen as part of a 17-year follow-up. Participants were given assessments of reading achievement (WIAT-III), receptive and expressive language (CELF-IV), and phonological processing (CTOPP). Relationships between PCE status and language outcomes were modeled using multiple linear regression controlling for environmental and caregiver factors, and other prenatal substance exposures. ResultsAdolescents with PCE scored lower in areas of phonological processing and reading related skills compared to adolescents with NCE. PCE by sex interactions were identified on language, memory and spoken language comprehension, with lower scores for girls with PCE compared to girls with NCE. ConclusionThese findings suggest the persistence of PCE's relationship with phonological awareness well into adolescence. PCE was also associated with lower scores on measures of skills related to reading ability, which may be a manifestation of the observed deficits in phonological processing.

Recent Advances in Chinese Developmental Dyslexia

Chinese developmental dyslexia (DD) research provides important insights into the language-universal and language-specific mechanisms underlying dyslexia. In this article, we review recent advances in Chinese DD. Converging behavioral evidence suggests that, while phonological and rapid automatized naming deficits are language universal, orthographic and morphological deficits are specific to the linguistic properties of Chinese. At the neural level, hypoactivation in the left superior temporal/inferior frontal regions in dyslexic children across Chinese and alphabetic languages may indicate a shared phonological processing deficit, whereas hyperactivation in the right inferior occipital/middle temporal regions and atypical activation in the left frontal areas in Chinese dyslexic children may indicate a language-specific compensatory strategy for impaired visual-spatial analysis and a morphological deficit in Chinese DD, respectively. The findings call for further theoretical endeavors to understand the language-universal and Chinese-specific neurobiological mechanisms underlying dyslexia and to design more effective and efficient intervention programs.

Social (pragmatic) communication disorder: Has it proven to be a useful diagnostic category?

At the last revision of the DSM‐5, social (pragmatic) communication disorder was included as a new psychiatric disorder under the broader category of communication disorders (APA, 2013). Symptoms are designated as deficits in social aspects of communication, examples of which are greeting and sharing information, changing communication to meet the needs of the listener, using verbal and nonverbal abilities when interacting with others, and understanding implicit language. Symptoms must cause functional impairment and have their origins in the developmental period. The specification of this disorder was meant to differentiate it from typical specific language impairments such as phonological processing deficits and/or fluency disorders.

Probabilistic Decision-Making in Children With Dyslexia.

BackgroundNeurocognitive mechanisms underlying developmental dyslexia (dD) remain poorly characterized apart from phonological and/or visual processing deficits. Assuming such deficits, the process of learning complex tasks like reading requires the learner to make decisions (i.e., word pronunciation) based on uncertain information (e.g., aberrant phonological percepts)—a cognitive process known as probabilistic decision making, which has been linked to the striatum. We investigate (1) the relationship between dD and probabilistic decision-making and (2) the association between the volume of striatal structures and probabilistic decision-making in dD and typical readers.MethodsTwenty four children diagnosed with dD underwent a comprehensive evaluation and MRI scanning (3T). Children with dD were compared to age-matched typical readers (n = 11) on a probabilistic, risk/reward fishing task that utilized a Bayesian cognitive model with game parameters of risk propensity (γ+) and behavioral consistency (β), as well as an overall adjusted score (average number of casts, excluding forced-fail trials). Volumes of striatal structures (caudate, putamen, and nucleus accumbens) were analyzed between groups and associated with game parameters.ResultsdD was associated with greater risk propensity and decreased behavioral consistency estimates compared to typical readers. Cognitive model parameters associated with timed pseudoword reading across groups. Risk propensity related to caudate volumes, particularly in the dD group.ConclusionDecision-making processes differentiate dD, associate with the caudate, and may impact learning mechanisms. This study suggests the need for further research into domain-general probabilistic decision-making in dD, neurocognitive mechanisms, and targeted interventions in dD.

On the cusp of predictability: Disruption in the typical association between letter and word identification at critical thresholds of RAN and phonological skills

Early identification is important for improving reading outcomes for children at risk for reading difficulties, but current methods tend to perform sub-optimally in identifying true risk. One possible reason is that whereas most prediction models assume linear relationships among risk and reading outcome measures, qualitatively different patterns of association may exist among the measures at different skill levels. We implemented dynamic non-linear modeling to test this possibility in two distinct samples of children: 1) 225 pre-kindergarten and kindergarten with concurrent data and 2) 104 children with longitudinal (pre-)kindergarten and second-grade reading scores. Cusp catastrophe modeling was used to evaluate the moderating effects of rapid automatized naming (RAN) and phonological processing, two foundational pre-reading skills, on the concurrent and longitudinal relationship between letter identification and word reading. We further tested whether RAN and phonological processing have independent non-linear effects on the letter-word reading relationship above and beyond that of a single skill. Deficits in RAN and phonological processing beyond a critical level were associated with non-linear changes in the prediction of word reading from letter knowledge, both concurrently and longitudinally, fully supporting the cusp model over the competing models. These findings demonstrate the importance of implementing non-linear models for predicting risk for reading difficulties. There was no evidence for the interactive effects of RAN and phonological processing on reading. Instead, in accordance with the basic tenants of the double-deficit hypothesis, current results suggest that the constructs represent two salient but separable causes of reading impairment, even at the earliest stages of reading ability. These findings suggest that models predicting which at-risk children will develop poor reading must diverge from assumptions of relationships observed in typical reading.

Reading Impairment in Adolescents with Fetal Alcohol Spectrum Disorders

ABSTRACT Purpose To date, research on effects of prenatal alcohol exposure (PAE) has focused on a broad range of cognitive impairments, but relatively few studies have examined effects of PAE on development of reading skills. Although PAE has been linked to poorer reading comprehension, it remains unclear whether this impairment is attributable to deficits in phonological processing, word reading, oral language skills, and/or executive functioning. Methods A comprehensive reading battery was administered to 10 adolescents with fetal alcohol syndrome (FAS); 16 with partial FAS; 30 nonsyndromal heavily exposed; 49 controls. Results PAE was related to poorer reading comprehension but not to single-word reading or phonological processing, suggesting that the mechanics of reading are intact in adolescents with fetal alcohol spectrum disorders at this age. PAE-related impairment in reading comprehension was mediated, in part, by deficits in mastery of oral language skills, including vocabulary, language structure, and verbal fluency. Conclusions These results are consistent with research showing that reading comprehension in adolescence relies increasingly on linguistic comprehension abilities, especially once word reading becomes automatic and text complexity increases. Our findings suggest that reading-impaired adolescents with PAE will benefit from intervention programs targeting vocabulary knowledge, language structure, verbal fluency, and reading comprehension skills.

The Content Validation of Malaysian Dyslexia Accommodating Screening Test (MYDAST) Through the Application of Fuzzy Delphi Method (FDM)

This study aims to examine the content validity of malaysian dyslexia accommodating screening test (mydast) which was developed for english language teachers to identify dyslexia symptoms among their pupils. Fuzzy delphi method by Murray, Pipino, & Gigch (1985) was applied in the process of validation. This study used the survey design with a printed questionnaire distributed to 15 experts in related field selected through purposive sampling technique. Eight of them were professional experts at public universities and another seven were lay experts from various related professions such as clinical psychologist, english language teachers, and teachers of pupils with dyslexia. 230 items from 15 constructs were validated based on phonological processing deficit hypothesis (Snowling, 1998). The findings show that expert consensus on the items in all the constructs are at a good level except for the ‘rhyming’, ‘digit span’ and ‘reverse digit span’ constructs together with 45 items that must be omitted from mydast. Also, it was found that 24 items must be revised. The overall findings of the experts’ consensus agreement exceed 75%, the overall value of the threshold (d) < 0.2 and ?-cut value exceeds 0.5. This suggests that mydast could be promoted as a psychometric test to identify dyslexia symptoms among pupils by english language teachers.

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.

Psychologists’ diagnostic assessments of adults with dyslexia: an Australian-based survey study

ABSTRACT Objective This study explored how psychologists in Australia assess and diagnose adults with dyslexia. Psychologists’ understandings about dyslexia were recorded alongside the tools used for diagnosing adults with dyslexia (and how these differ from practices with young people). Training experiences and influential factors on diagnostic decision-making in assessing adults for dyslexia were identified. Method An online survey, based on the study aims, was distributed to various professional associations. Participants were 32 registered psychologists in Australia who had assessed adults for dyslexia. Survey responses were analysed using descriptive statistics and non-parametric analyses. Results Most participants reported: (1) that dyslexia is attributable to deficits in phonological processing and rapid automatized naming, (2) assessing adults for dyslexia involves the administration of Wechsler cognitive and achievement tests, (3) familiarity with test tools, diagnostic criteria, and clinical judgement informed adult-focused dyslexia assessment practices, (4) adults and children are assessed for dyslexia in similar ways, and (5) there is little post-registration training specific to assessing adults for dyslexia. Conclusions Psychologists extrapolated child-focused dyslexia assessment practices to adults. This may result in a missed dyslexia diagnosis and/or expending unnecessary resources on assessment. There is a need for increased training in developmentally-sensitive methods for assessing adults for dyslexia.

ERP Correlates of Altered Orthographic-Phonological Processing in Dyslexia.

Automatic visual word recognition requires not only well-established phonological and orthographic representations but also efficient audio-visual integration of these representations. One possibility is that in developmental dyslexia, inefficient orthographic processing might underlie poor reading. Alternatively, reading deficit could be due to inefficient phonological processing or inefficient integration of orthographic and phonological information. In this event-related potential study, participants with dyslexia (N = 25) and control readers (N = 27) were presented with pairs of words and pseudowords in an implicit same-different task. The reference-target pairs could be identical, or different in the identity or the position of the letters. To test the orthographic-phonological processing, target stimuli were presented in visual-only and audiovisual conditions. Participants with and without dyslexia processed the reference stimuli similarly; however, group differences emerged in the processing of target stimuli, especially in the audiovisual condition where control readers showed greater N1 responses for words than for pseudowords, but readers with dyslexia did not show such difference. Moreover, after 300 ms lexicality effect exhibited a more focused frontal topographic distribution in readers with dyslexia. Our results suggest that in developmental dyslexia, phonological processing and audiovisual processing deficits are more pronounced than orthographic processing deficits.