Dyslexic Readers Research Articles

Identifying students with dyslexia: exploration of current assessment methods.

Early identification plays a crucial role in providing timely support to students with learning disabilities, such as dyslexia, in order to overcome their reading difficulties. However, there is significant variability in the methods used for identifying dyslexia. This study aimed to explore and understand the practices of dyslexia identification in the UK. A survey was conducted among 274 dyslexia professionals, including educational psychologists and dyslexia specialists, to investigate the types of assessments they employ, their approach to utilizing assessment data, their decision-making processes, and their conceptualization of dyslexia. Additionally, the study examined whether these professionals held any misconceptions or myths associated with dyslexia. Analysis of the survey data revealed substantial variability in how professionals conceptualize dyslexia, as well as variations in assessment methods. Furthermore, a significant proportion of the survey respondents subscribed to one or more misconceptions regarding dyslexia; the most common misconception identified among professionals was the belief that children with dyslexia read letters in reverse order. The findings highlight the need for standardized approaches to dyslexia identification and debunking prevailing misconceptions. The implications of these findings are discussed, emphasizing the importance of informed policy and practice in supporting students with dyslexia. Recommendations are provided to enhance consistency and accuracy in dyslexia identification, with the aim of facilitating early intervention and support for affected students.

The perceptual span in dyslexic reading and visual search.

Many studies have attempted to identify the root cause of dyslexia. Different theories of dyslexia have proposed either a phonological, attentional, or visual deficit. While research has used eye-tracking to study dyslexia, only two previous studies have used the moving-window paradigm to explore the perceptual span in dyslexic reading, and none have done so in visual search. The present study analysed the perceptual span using both reading and visual search tasks to identify language-independent attentional impairments in dyslexics. We found equivocal evidence that the perceptual span was impaired in dyslexic reading and no evidence of impairment in visual search. However, dyslexic participants did show deficits in the visual search task, with lower search accuracy and shorter saccades compared with controls. These results lend support for a visual, rather than attentional or phonological, account of dyslexia.

Perceptual Adaptation to Noise-Vocoded Speech by Lip-Read Information: No Difference between Dyslexic and Typical Readers.

Auditory speech can be difficult to understand but seeing the articulatory movements of a speaker can drastically improve spoken-word recognition and, on the longer-term, it helps listeners to adapt to acoustically distorted speech. Given that individuals with developmental dyslexia (DD) have sometimes been reported to rely less on lip-read speech than typical readers, we examined lip-read-driven adaptation to distorted speech in a group of adults with DD ( N = 29) and a comparison group of typical readers ( N = 29). Participants were presented with acoustically distorted Dutch words (six-channel noise-vocoded speech, NVS) in audiovisual training blocks (where the speaker could be seen) interspersed with audio-only test blocks. Results showed that words were more accurately recognized if the speaker could be seen (a lip-read advantage), and that performance steadily improved across subsequent auditory-only test blocks (adaptation). There were no group differences, suggesting that perceptual adaptation to disrupted spoken words is comparable for dyslexic and typical readers. These data open up a research avenue to investigate the degree to which lip-read-driven speech adaptation generalizes across different types of auditory degradation, and across dyslexic readers with decoding versus comprehension difficulties.

Informing the Design of an Accessible Arabic Typeface: A Visual Analysis to Identify Letterform Features of Dyslexia-Friendly Typefaces

Dyslexia-friendly typefaces for the Latin script have been proliferating during the past decade. The typefaces are designed to tackle the challenges faced in a dyslexic reading experience by manipulating their letter forms and typographic attributes; several studies reported a positive effect on the reading experience. To this date, no working dyslexia-friendly Arabic typefaces are available for the public. The present study is part of a larger practice-based research, where a novel dyslexia-friendly Arabic typeface is designed using a user-centred design approach. The current visual analysis marks the developmental phase, identifying the letterform features of dyslexia-friendly Latin typefaces that can be mapped to the Arabic script. This article explores the typographic features of dyslexia-friendly Latin typefaces by conducting a qualitative visual analysis; a proposed modified version of Leeuwen’s Typographic Distinctive Features Framework is employed. The results are discussed considering the Arabic script’s visual implications in a dyslexic reading experience. The findings of this study are used to create a list of design considerations for a dyslexia-friendly Arabic typeface.

Error-monitoring: A predictor of future reading skills? A 3-year longitudinal study in children

Investigation of the factors explaining individual differences in the acquisition of expert reading skills has become of particular interest these last decades. Non-verbal abilities, such as visual attention and executive functions play an important role in reading acquisition. Among those non-verbal factors, error-monitoring, which allows one to detect one's own errors and to avoid repeating them in the future, has been reported to be impaired in dyslexic readers. The present three-year longitudinal study aims at determining whether error-monitoring efficiency evaluated before and during reading instruction could improve the explanation of reading skills. To do so, 85 children will be followed from the last year of kindergarten to the second grade. The classic predictors of reading will be assessed at each grade level. Error-monitoring indices in domain-general and reading-related contexts will be derived from EMG data recorded during a Simon task in kindergarten and during both a Simon and a lexical decision tasks in the first and second grades. Findings concerning the role of error-monitoring on reading skills are expected to have an important impact on reading instruction to prevent reading difficulties in at-risk children and improve remediation to help children with reading difficulties.

Atypical hemispheric re-organization of the reading network in high-functioning adults with dyslexia: Evidence from representational similarity analysis

Abstract It has been argued that university students with dyslexia compensate for their reading deficits by a neural re-organization of the typical reading network, where the lexical representations of words are (re-)structured according to semantic rather than orthographic information. To investigate the re-organization of neural word representations more directly, we used multivariate representational similarity analyses (RSA) to find out which brain regions of the reading network respond to orthographic and semantic similarity between 544 pairs of words and whether there were any differences between typical and dyslexic readers. In accordance with the re-organization hypothesis, we predicted greater similarity (i.e., correlation of neural dissimilarity matrices) in adult dyslexic than in typical readers in regions associated with semantic processing and weaker similarity in regions associated with orthographic processing. Our results did not confirm these predictions. First, we found sensitivity to semantic similarity in all three subparts of the fusiform gyrus (FG1, FG2, and FG3) bilaterally. Adults with dyslexia showed less (rather than more) sensitivity to semantic similarity in the posterior subpart of fusiform gyrus (FG1) in the left hemisphere. Second, in typical readers, sensitivity to orthographic information was not only found in the left fusiform gyrus (FG1, FG2, and FG3) but also in left inferior frontal gyrus (IFG). Adults with dyslexia, in contrast, did not show sensitivity to orthographic information in left IFG. However, they showed increased sensitivity to orthographic information in the right hemisphere FG1. Together, the results show abnormal orthographic processing in left IFG and right FG1 and reduced semantic information in left FG1. While we found evidence for compensatory re-organization in adult dyslexia, the present results do not support the hypothesis according to which adults with dyslexia rely more heavily on semantic information. Instead, they revealed atypical hemispheric organization of the reading network that is not restricted to the typical left language hemisphere.

Validation of a Web App Enabling Children with Dyslexia to Identify Personalized Visual and Auditory Parameters Facilitating Online Text Reading

Previous research has shown the importance of font type, size, and spacing to facilitate text reading in dyslexia. Great heterogeneity in the population of readers with specific learning disorders suggests that personalized parameters should be preferable compared to one-fits-all ones. A special automatized procedure was designed to select the most favorable parameters for both text visualization and text-to-speech conversion. A total of 78 primary and middle school students (29 typical readers, 49 children with atypical reading skills, either diagnosed as specific reading disorder or as special learning needs) took part in this study, which included the application of the procedure and a validation of its outcomes through a systematic comparison of the use of the personalized versus standard fonts and voices in reading and writing tests. The results show a significant advantage for the personalized parameters. Moreover, in the case of text-to-speech personalization, the advantage is significantly larger for dyslexic readers than for typical readers. These results confirm the usefulness of a personalization approach in providing support to facilitate learning in dyslexic students.

Early reading at first grade predicts adult reading at age 42 in typical and dyslexic readers

Research indicates that the achievement gap in reading between typical and dyslexic readers is already evident in first grade and persists through adolescence. However, it is not known whether this reading gap persists into adult life. In this report we use an epidemiologic sample of 312 children (typical readers = 246; dyslexic readers = 66), followed longitudinally from age 5 through adulthood and examine two fundamental questions: 1) Is reading level in 1st grade predictive of reading proficiency in adulthood in typical and dyslexic readers? and 2) Are the trajectories of reading development from 1st through 5th grade predictive of reading proficiency in adulthood in typical and dyslexic readers? Our findings indicate that early reading levels in 1st grade as well as the trajectory of reading development through the first five years of school were associated with reading scores in adulthood. This association was stronger for dyslexic than for typical readers, especially the latter factor. These findings indicate that the achievement gap between typical and dyslexic readers persists far beyond adolescence, in fact, into adult life.

Characterization of Cortical and Subcortical Structural Brain Asymmetry in Adults with and without Dyslexia.

Multiple cortical (planum temporale, supramarginal gyrus, fusiform gyrus) and subcortical (caudate, putamen, and thalamus) regions have shown different functional lateralization patterns for skilled vs. dyslexic readers. The extent to which skilled and dyslexic adult readers show differential structural lateralization remains to be seen. Method: Participants included 72 adults (N = 41 skilled; N = 31 dyslexic) who underwent a high-resolution MRI brain scan. The grey matter volume of the cortical and subcortical structures was extracted. Results: While there were clear behavioral differences between the groups, there were no differences in any of the isolated structures (i.e., either total size or asymmetry index) and limited evidence for any brain-behavior relationships. We did find a significant cortical-cortical relationship (p = 0.006) and a subcortical-subcortical relationship (p = 0.008), but not cross-over relationships. Overall, this work provides unique information on neural structures as they relate to reading in skilled and dyslexic readers.

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.

Hebbian Control of Fixations in a Dyslexic Reader: A Case Report.

When reading, dyslexic readers exhibit more and longer fixations than normal readers. However, there is no significant difference when dyslexic and control readers perform only visual tasks on a string of letters, showing the importance of cognitive processes in reading. This linguistic and cognitive processing requirement in reading is often perturbed for dyslexic readers by perceived additional letters and word mirror images superposed on the primary images on the primary cortex, inducing internal visual crowding. Here, we show that while for a normal reader, the number and the duration of fixations remain invariant whatever the nature of the lighting, the excess of fixations and total duration of reading can be controlled for a dyslexic reader using the Hebbian mechanisms to erase extra images in optimized pulse-width lighting. In this case, the number of fixations can then be reduced by a factor of about 1.8, recovering the normal reading experiment.

Fluent contextual reading is associated with greater synchronization of the visual and auditory networks, fluent reading and better speed of processing in children with dyslexia

The asynchrony theory of dyslexia postulates weaker visual (orthographical processing) and auditory (phonological processing) network synchrony in dyslexic readers. The weaker visual-auditory network synchronization is suggested to contribute to slow processing speed, which supports cognitive control, contributing to single-word reading difficulty and lower reading fluency. The current study aims to determine the neurobiological signature for this theory and to examine if prompting enhanced reading speed through deleted text is associated with a greater synchronization of functional connectivity of the visual and auditory networks in children with dyslexia and typical readers (TRs). We further aimed to determine if the change in visual-auditory connectivity prompted by deleted text is associated with reading fluency and processing speed abilities. Nineteen children with dyslexia and 21 typical readers ages 8–12 years old participated in a fMRI under two types of reading conditions: a still text condition and deleted text condition, in which letters was sequentially deleted from the screen. Effects of diagnostic group and condition on functional connectivity (FC) of visual and auditory networks were examined. Results revealed a significant overall effect of condition with a marginally significant Group × Condition interaction, such that as compared with TRs, children with dyslexia showed a significantly greater increase in visual-auditory FC between the still and deleted text conditions. Additionally, for children with dyslexia, this FC increase was significantly correlated with better reading fluency and verbal/nonverbal processing speed.These results support a relationship between the synchronization of the visual and auditory networks, fluent reading and increased speed of processing abilities in children with dyslexia, which can help guide fluency-based intervention strategies.

Impaired extraction and consolidation of morphological regularities in developmental dyslexia: A domain general deficit?

The current study examined whether adults with Developmental Dyslexia are impaired in learning linguistic regularities in a novel language, and whether this may be explained by a domain general deficit in the effect of sleep on consolidation. We compared online learning and offline consolidation of morphological regularities in individuals with Developmental Dyslexia (N = 40) and typical readers (N = 38). Participants learned to apply plural inflections to novel words based on morpho-phonological rules embedded in the input and learned to execute a finger motor sequence task. To test the effects of time and sleep on consolidation, participants were assigned into one of two sleep-schedule groups, trained in the evening or in the morning and tested 12 and 24 h later. Unlike typical readers, Dyslexic readers did not extract the morpho-phonological regularities during training and as a group they did not show offline gains in inflecting trained items 24 h after training, suggesting that the deficit in extraction of regularities during training may be related to the deficit in consolidation. The offline gains in dyslexic readers, were correlated with their prior phonological abilities, and were less affected by sleep than those of typical readers. Although no deficit was found in the consolidation of the motor task, dyslexic readers were again less successful in generating an abstract representation of the motor sequence, reflected in a difficulty to generalize the motor sequence knowledge acquired using one hand to the untrained hand. The results suggest that individuals with Developmental Dyslexia have a domain general deficit in extracting statistical regularities from an input. Within the language domain this deficit is reflected in reduced benefits of consolidation, particularly during sleep, perhaps due to reduced prior phonological abilities, which may impede the individual's ability to extract the linguistic regularities during and after training and thus constrain the consolidation process.

Attentional and lexical factors underlying word-centred neglect dyslexia errors in healthy readers

Word-centred neglect dyslexia is most commonly conceptualised as a deficit caused by attentional biases within spatially coded internal representations of words. However, recent research has suggested that at least some cases of word-centred neglect dyslexia are unrelated to visuospatial neglect and may instead be modulated by self-inhibition and lexical factors. Here, we set out to provide novel insight into potential underlying mechanisms modulating the occurrence of word-centred lateralised reading errors in healthy participants. A sample of 47 healthy readers completed a novel attentional cueing paradigm in which they sequentially identified lateral cues and read presented words under limited exposure conditions. Reading responses were analysed to determine whether word-centred neglect dyslexia could be simulated in healthy readers, to compare the strengths of induced biases, and to identify systematic differences in lexical characteristics between target words and neglect dyslexia reading errors. Healthy participants produced frequent lateralised reading errors in both horizontal and vertical reading stimuli with > 50% of errors classed as neglect dyslexic. Cues appended to word beginnings elicited significantly more reading errors than cues at word ends, illustrating the interaction between existing reading spatial attentional biases and cue-induced biases. Neglect dyslexia reading errors were found to contain significantly more letters per word and had higher concreteness ratings than target words. These findings demonstrate that word-centred neglect dyslexia can be simulated using attentional cues in healthy readers. These results provide important insight into the mechanisms underlying word-centred neglect dyslexia and further fundamental understanding of this syndrome.

EFEKTIFITAS METODE MULTISENSORI DALAM MENINGKATKAN KETERAMPILAN MEMBACA SISWA DISLEKSIA DI SEKOLAH DASAR

Reading skill is an important ability for elementary school students to help understand the subject matter, communicate skills and solve problems that involve understanding, analyzing, and introducing concepts. The aim of the research is to provide an understanding for teachers in diagnosing dyslexic students, namely students who have difficulty reading so that their reading ability can be maximized through multisensory methods. The research was conducted on second-grade students at Margaluyu Public Elementary School, Serang City, involving four dyslexic students and one teacher. The research method uses descriptive qualitative data analysis techniques using the Huberman and Milles model through the stages of data collection, data reduction, data presentation, and conclusion or verification at the end. Data collection instruments used interview sheets, field notes, literature review, and analysis of treatment results documents. Based on the results of the study it was found that the multisensory method has effectively improved dyslexic reading skills in a systematic, direct, and explicit instructional manner by utilizing sensory functions related to visual, auditory, kinesthetic, and tactile. The increase in ability is evidenced in the results of the screening value which increased by 60% after the multisensory method was implemented. The multi-sensory method is very helpful in developing reading skills for dyslexic students, especially for students who have difficulty pronouncing certain letters

The Role of Visual Factors in Dyslexia.

What are the causes of dyslexia? Decades of research reflect a determined search for a single cause where a common assumption is that dyslexia is a consequence of problems with converting phonological information into lexical codes. But reading is a highly complex activity requiring many well-functioning mechanisms, and several different visual problems have been documented in dyslexic readers. We critically review evidence from various sources for the role of visual factors in dyslexia, from magnocellular dysfunction through accounts based on abnormal eye movements and attentional processing, to recent proposals that problems with high-level vision contribute to dyslexia. We believe that the role of visual problems in dyslexia has been underestimated in the literature, to the detriment of the understanding and treatment of the disorder. We propose that rather than focusing on a single core cause, the role of visual factors in dyslexia fits well with risk and resilience models that assume that several variables interact throughout prenatal and postnatal development to either promote or hinder efficient reading.

Attentional modulation of neural sound tracking in children with and without dyslexia.

Auditory selective attention forms an important foundation of children's learning by enabling the prioritisation and encoding of relevant stimuli. It may also influence reading development, which relies on metalinguistic skills including the awareness of the sound structure of spoken language. Reports of attentional impairments and speech perception difficulties in noisy environments in dyslexic readers are also suggestive of the putative contribution of auditory attention to reading development. To date, it is unclear whether non-speech selective attention and its underlying neural mechanisms are impaired in children with dyslexia and to which extent these deficits relate to individual reading and speech perception abilities in suboptimal listening conditions. In this EEG study, we assessed non-speech sustained auditory selective attention in 106 7-to-12-year-old children with and without dyslexia. Children attended to one of two tone streams, detecting occasional sequence repeats in the attended stream, and performed a speech-in-speech perception task. Results show that when children directed their attention to one stream, inter-trial-phase-coherence at the attended rate increased in fronto-central sites; this, in turn, was associated with better target detection. Behavioural and neural indices of attention did not systematically differ as a function of dyslexia diagnosis. However, behavioural indices of attention did explain individual differences in reading fluency and speech-in-speech perception abilities: both these skills were impaired in dyslexic readers. Taken together, our results show that children with dyslexia do not show group-level auditory attention deficits but these deficits may represent a risk for developing reading impairments and problems with speech perception in complex acoustic environments. RESEARCH HIGHLIGHTS: Non-speech sustained auditory selective attention modulates EEG phase coherence in children with/without dyslexia Children with dyslexia show difficulties in speech-in-speech perception Attention relates to dyslexic readers' speech-in-speech perception and reading skills Dyslexia diagnosis is not linked to behavioural/EEG indices of auditory attention.

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.

Increased top-down semantic processing in natural speech linked to better reading in dyslexia

Early research proposed that individuals with developmental dyslexia use contextual information to facilitate lexical access and compensate for phonological deficits. Yet at present there is no corroborating neuro-cognitive evidence. We explored this with a novel combination of magnetoencephalography (MEG), neural encoding and grey matter volume analyses. We analysed MEG data from 41 adult native Spanish speakers (14 with dyslexic symptoms) who passively listened to naturalistic sentences. We used multivariate Temporal Response Function analysis to capture online cortical tracking of both auditory (speech envelope) and contextual information. To compute contextual information tracking we used word-level Semantic Surprisal derived using a Transformer Neural Network language model. We related online information tracking to participants’ reading scores and grey matter volumes within the reading-linked cortical network. We found that right hemisphere envelope tracking was related to better phonological decoding (pseudoword reading) for both groups, with dyslexic readers performing worse overall at this task. Consistently, grey matter volume in the superior temporal and bilateral inferior frontal areas increased with better envelope tracking abilities. Critically, for dyslexic readers only, stronger Semantic Surprisal tracking in the right hemisphere was related to better word reading. These findings further support the notion of a speech envelope tracking deficit in dyslexia and provide novel evidence for top-down semantic compensatory mechanisms.

The impact of phonological relatedness on semantic congruency judgements in readers with dyslexia: Evidence from behavioural judgements, event related potentials and pupillometry

Readers with developmental dyslexia are known to be impaired in representing and accessing phonology, but their ability to process meaning is generally considered to be intact. However, neurocognitive studies show evidence of a subtle semantic processing deficit in dyslexic readers, relative to their typically-developing peers. Here, we compared dyslexic and typical adult readers on their ability to judge semantic congruency (congruent vs. inconcongruent) in short, two-word phrases, which were further manipulated for phonological relatedness (alliterating vs. non-alliterating); “dazzling-diamond”; “sparkling-diamond”; “dangerous-diamond”; and “creepy-diamond”. At the level of behavioural judgement, all readers were less accurate when evaluating incongruent alliterating items compared with incongruent non-aliterating, suggesting that phonological patterning creates the illusion of semantic congruency (as per Egan et al., 2020). Dyslexic readers showed a similar propensity for this form-meaning relationship despite a phonological processing impairment as evidenced in the cognitive and literacy indicative assessments. Dyslexic readers also showed an overall reduction in the ability to accurately judge semantic congruency, suggestive of a subtle semantic impairment. Whilst no group differences emerged in the electrophysiological measures, our pupil dilation measurements revealed a global tendency for dyslexic readers to manifest a reduced attentional response to these word stimuli, compared with typical readers. Our results show a broad manifestation of neurocognitive differences in adult dyslexic and typical readers’ processing of print, at the level of autonomic arousal as well as in higher level semantic judgements.