Dyslexic Adults Research Articles

The Big Five Personality Traits in Dyslexic Adults: An Exploratory Study.

Dyslexia is a neurodevelopmental disorder that causes a pattern of learning difficulties that can be characterized by deficits in word reading accuracy, speed or fluency, and reading comprehension. Due to all this damage, emotional difficulties have been described in the literature mainly for childhood and adolescence. Within this emotional component, personality can be included. In Brazil, at the time of carrying out this research, no research had been found that investigated the personality of dyslexic adults. Thus, the present study aimed to investigate the personality of Brazilian adults with dyslexia. A semi-structured interview was administered and the Factorial Personality Battery, based on the Big Five personality traits. The sample was composed of two groups: one with dyslexia and another control. The first was formed by nine participants, aged between 18 and 47 (M = 31.7; standard deviation (SD) = 11.8), six of whom were women. The control group was formed by 60 participants, aged between 18 and 45 years (M = 26.4; SD = 8.8), 38 of whom were women. The data did not show significant differences between the groups in most of the analyzed factors and subfactors. Increased rates of "passivity/lack of energy" and lowered rates of "openness to new ideas" were identified in the group with dyslexia. These results could be useful for describing personality profiles in dyslexic adults, with these descriptions possibly providing clinical support for diagnoses and intervention procedures.

The Enduring Challenge of Literacy Issues in Adulthood: Investigating Spelling Deficits among Dyslexic Italian University Students.

The issue of literacy challenges among dyslexic adults remains a significant concern. This study investigates spelling deficits among highly educated adults with dyslexia learning a transparent orthography. Thirty-eight Italian dyslexic university students were examined and compared to a group of age- and education-matched typical readers. Firstly, we analyzed spelling performance using a Passage Dictation Test. Additionally, lists of words varying in length and word frequency were dictated under two experimental conditions: a normal condition (NC) and an articulatory suppression condition (ASC). The ASC assessed the participants' ability to spell with interference to the phonological (sublexical) spelling procedure, i.e., the most likely compensated spelling strategy of Italian dyslexic spellers. The results clearly indicated that, in spelling the meaningful passage, dyslexic participants underperformed compared to the controls, with a prevalence of lexical errors, despite the comparison with the normative reference data showing only mild spelling difficulties. In spelling isolated words in normal conditions, dyslexic participants performed within the reference norms and as accurately as control participants across all stimuli (short words, high- and low-frequency words), except for long words, where their spelling difficulties were evident. Articulatory suppression significantly impaired dyslexics' performance on short stimuli, reducing the usual sublexical advantage associated with them, and exacerbated misspellings on long words. Additionally, articulatory suppression disproportionately affected dyslexics' performance on high-frequency words, diminishing the typical lexical advantage associated with these words. Results are discussed in terms of their theoretical, clinical, and educational implications.

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.

Developing and validating an abbreviated adult reading history questionnaire in the Finnish and Dutch contexts

BackgroundThe adult reading history questionnaire (ARHQ) is frequently used in research on adult dyslexia and family risk for dyslexia. However, this measure is lengthy (23 items), reducing its applicability in studies with extensive assessment batteries.MethodsWe identified the best‐performing ARHQ items in a sample of 396 Finnish adults using exploratory factor analysis and item response theory. Consequently, we validated the brief questionnaire in independent Finnish and Dutch samples by comparing its performance with that of the complete questionnaire. We also evaluated how the scores on the questionnaires related to the scores on direct adult reading assessments in the Finnish samples. Finally, we tested how predictive parental questionnaires were of children's skills in the Dutch and one of the Finnish samples.ResultsFive items were selected to construct the short version of ARHQ. All of them relate to childhood/adolescent reading difficulties rather than current adult skills. The scores of the complete ARHQ significantly correlated with those of the abbreviated version in all samples. Moreover, in one of the samples, direct reading assessment scores had a stronger correlation with the short ARHQ than with the full version. Additionally, across all three samples parental scores on the short ARHQ were at least as predictive of children's reading skills as the complete ARHQ.ConclusionsThe short ARHQ proved to be on a par with the complete version in its usefulness for identifying adults with dyslexia. Future research should investigate whether the five selected items can effectively serve as a brief screening measure for adults with dyslexia in languages other than Finnish and Dutch.

Screening for Dyslexia in University Students: a Standardized Procedure Based on Conditional Inference Trees.

The focus of this study is on providing tools to enable researchers and practitioners to screen for dyslexia in adults entering university. The first aim is to validate and provide diagnostic properties for a set of seven tests including a 1-min word reading test, a 2-min pseudoword reading test, a phonemic awareness test, a spelling test, the Alouette reading fluency test, a connected-text reading fluency test, and the self-report Adult Reading History Questionnaire (ARHQ). The second, more general, aim of this study was to devise a standardized and confirmatory procedure for dyslexia screening from a subset of the initial seven tests. We used conditional inference tree analysis, a supervised machine learning approach to identify the most relevant tests, cut-off scores, and optimal order of test administration. A combined sample of 60 university students with dyslexia (clinical validation group) and 65 university students without dyslexia (normative group) provided data to determine the diagnostic properties of these tests including sensitivity, specificity, and cut-off scores. Results showed that combinations of four tests (ARHQ, text reading fluency, phonemic awareness, pseudoword reading) and their relative conditional cut-off scores optimize powerful discriminatory screening procedures for dyslexia, with an overall classification accuracy of approximately 90%. The novel use of the conditional inference tree methodology explored in the present study offered a way of moving toward a more efficient screening battery using only a subset of the seven tests examined. Both clinical and theoretical implications of these findings are discussed.

Domain-general but not speech-specific auditory duration perception predicts pseudoword reading in adults.

Associations between reading performance and duration perception have been found both for domain-general and speech-specific duration perception. However, research seems limited to children and, critically, the predictive value of the two duration perception modalities has not been compared so far. In the present study we compared the weight of domain-general (comparison of time intervals defined by beeps) vs. speech-specific duration perception (pre-attentive EEG responses to consonants with different durations) as statistical predictors of reading in a sample of 46 neurotypical adults (18-43 years old) with 13 years of schooling on average. Reading included word and pseudoword decoding, as well as reading comprehension. We ran one regression model with domain-general and speech-specific duration perception as predictors for each of the three reading skills. Pseudoword decoding was the only reading skill that was significantly predicted by duration perception, and this happened for domain-general duration perception only. A complementary analysis adding 26 typically developing and 24 dyslexic adults to the main sample (n = 96 in total) showed the same pattern of results in dyslexics, but not in added controls. Our findings strengthen the idea that duration perception is important to phonological encoding and its use in grapheme-to-phoneme conversion, given that only pseudoword decoding was predicted by the interval comparison task. The irrelevance of speech-specific duration perception tones down the possibility that accurately perceiving the length of speech sounds is crucial to skilled reading.

Improving non-native duration contrast with dichotic training in dyslexic and non-dyslexic individuals.

Perceiving and producing English phonemic vowel length contrasts is challenging for non-native speakers. According to multi-time resolution models, endogenous slow/fast rhythms contribute, respectively, in the right/left hemispheres, to long/short acoustic cue processing. This study introduced a perceptual training method implementing dichotic stimulation to improve /i:/-/ɪ/ processing by promoting hemispheric complementarity. Twenty non-dyslexic and 20 dyslexic French adults received 1 hr-training over 3 days. Productions were evaluated with pre-/post-tests. Training enhanced vowel duration contrast in word production by /i:/ lengthening and /ɪ/ shortening in both groups. Adults with dyslexia compensated fewer /i:/ lengthening by /ɪ/ shortening than did non-dyslexic adults. Transfer from perceptual training to production seems possible for foreign-language learning even in dyslexic adults. The extent to which dichotic presentation contributed to training effectiveness cannot be evaluated here, but the triggering of lengthening and shortening mechanisms suggests that lateralized complementary skills have been enhanced by dichotic stimulation.

Phoneme Representation and Articulatory Impairment: Insights from Adults with Comorbid Motor Coordination Disorder and Dyslexia.

Phonemic processing skills are impaired both in children and adults with dyslexia. Since phoneme representation development is based on articulatory gestures, it is likely that these gestures influence oral reading-related skills as assessed through phonemic awareness tasks. In our study, fifty-two young dyslexic adults, with and without motor impairment, and fifty-nine skilled readers performed reading, phonemic awareness, and articulatory tasks. The two dyslexic groups exhibited slower articulatory rates than skilled readers and the comorbid dyslexic group presenting with an additional difficulty in respiratory control (reduced speech proportion and increased pause duration). Two versions of the phoneme awareness task (PAT) with pseudoword strings were administered: a classical version under time pressure and a delayed version in which access to phonemic representations and articulatory programs was facilitated. The two groups with dyslexia were outperformed by the control group in both versions. Although the two groups with dyslexia performed equally well on the classical PAT, the comorbid group performed significantly less efficiently on the delayed PAT, suggesting an additional contribution of articulatory impairment in the task for this group. Overall, our results suggest that impaired phoneme representations in dyslexia may be explained, at least partially, by articulatory deficits affecting access to them.

Pragmatic competence in native German adults with and without Developmental Dyslexia

Abstract Developmental Dyslexia (DD) is a life-long deficit in reading and spelling with unclear causes. DD negatively impacts many language skills. Relatively little is known about whether skills of pragmatic competence are compromised in individuals with DD. Here, we assess DD symptomatology in a group of native German dyslexic adults. We first test for the presence of DD subtypes along the dimensions of phonological awareness and naming speed, two key deficits in DD. We then assess pragmatic competence in adults with DD compared to control participants without DD. We found that a subclassification of DD according to phonological awareness and naming speed only partially applies and that dyslexic participants show a lower pragmatic competence than control participants.

Forming New Orthographic Representations in Alzheimer’s Disease and Mild Cognitive Impairment

When we read the same word several times, we end up forming an orthographic representation of it that allows us to read it in a fluid way. Several investigations were aimed at how healthy people, children or dyslexic adults learn new words, but little is known on how this process works on patients with neurodegenerative diseases, for example Alzheimer’s disease (AD) and mild cognitive impairment (MCI). Hence, the aim of this project was to analyze the formation of new orthographic representations in these people. For that purpose, eight words of a very low frequency were selected, half of them short and half of them long, and were presented six times to the participants, 4 of them in a narrative context. The learning process was measured according to the elimination of the length effect that indicates the crossing from a sublexical reading to a lexical one. The results showed the disappearance of the length effect in the control group, as well as a reduction in RTs in MCI participants and AD patients, without a disappearance of length effect in these groups. All this indicates that learning was consolidated in the control group, whereas in the MCI and the AD group it cannot be said that a new representation has formed.

Event-related potential and lexical decision task in dyslexic adults: Lexical and lateralization effects.

Developmental dyslexia is a specific learning disorder that presents cognitive and neurobiological impairments related to different patterns of brain activation throughout development, continuing in adulthood. Lexical decision tasks, together with electroencephalography (EEG) measures that have great temporal precision, allow the capture of cognitive processes during the task, and can assist in the understanding of altered brain activation processes in adult dyslexics. High-density EEG allows the use of temporal analyses through event-related potentials (ERPs). The aim of this study was to compare and measure the pattern of ERPs in adults with developmental dyslexia and good readers, and to characterize and compare reading patterns between groups. Twenty university adults diagnosed with developmental dyslexia and 23 healthy adult readers paired with dyslexics participated in the study. The groups were assessed in tests of intelligence, phonological awareness, reading, and writing, as well as through the lexical decision test (LDT). During LDT, ERPs were recorded using a 128-channel EEG device. The ERPs P100 occipital, N170 occipito-temporal, N400 centro-parietal, and LPC centro-parietal were analyzed. The results showed a different cognitive profile between the groups in the reading, phonological awareness, and writing tests but not in the intelligence test. In addition, the brain activation pattern of the ERPs was different between the groups in terms of hemispheric lateralization, with higher amplitude of N170 in the dyslexia group in the right hemisphere and opposite pattern in the control group and specificities in relation to the items of the LDT, as the N400 were more negative in the Dyslexia group for words, while in the control group, this ERP was more pronounced in the pseudowords. These results are important for understanding different brain patterns in developmental dyslexia and can better guide future interventions according to the changes found in the profile.

"You Don't Look Dyslexic": Using the Job Demands-Resource Model of Burnout to Explore Employment Experiences of Australian Adults with Dyslexia.

Background: Employment and job security are key influences on health and wellbeing. In Australia, little is known about the employment lifecycle of adults with dyslexia. Materials and Methods: Using a qualitative research design, this study sought to explore the experiences faced by adults with dyslexia seeking and retaining employment. In-depth interviews were conducted with a cohort either currently or previously in the labour market. We used the Job Demands Resource Model of Burnout (JD-R Model) to explore links between workplace characteristics and employee wellbeing. Deductive content analysis attained condensed and broad descriptions of participants’ workplace experiences. Results: Dyslexic adults (n = 14) participated; majority employed part/full-time and experienced challenges throughout their employment; exhaustion and burnout at work were reported, also fear and indecision about disclosure of dyslexia. A minority reported receiving positive, useful support from team members following disclosure. Conclusion: The JD-R Model provided a guiding framework. We found participants experienced a myriad of challenges that included risk of mental exhaustion, discrimination, limited access to support and fatigue, leaving them vulnerable to job burn-out. Dyslexia does not have to be a major barrier to success in any occupation. Yet, when in supportive, informed workplace environments, employees with dyslexia thrive.

Parafoveal processing and transposed-letter effects in dyslexic reading.

During parafoveal processing, skilled readers encode letter identity independently of letter position (Johnson et al., 2007). In the current experiment, we examined orthographic parafoveal processing in readers with dyslexia. Specifically, the eye movements of skilled readers and adult readers with dyslexia were recorded during a boundary paradigm experiment (Rayner, 1975). Parafoveal previews were either identical to the target word (e.g., nearly), a transposed‐letter preview (e.g., enarly), or a substituted‐letter preview (e.g., acarly). Dyslexic and non‐dyslexic readers demonstrated orthographic parafoveal preview benefits during silent sentence reading and both reading groups encoded letter identity and letter position information parafoveally. However, dyslexic adults showed, that very early in lexical processing, during parafoveal preview, the positional information of a word's initial letters were encoded less flexibly compared to during skilled adult reading. We suggest that dyslexic readers are less able to benefit from correct letter identity information (i.e., in the letter transposition previews) due to the lack of direct mapping of orthography to phonology. The current findings demonstrate that dyslexic readers show consistent and dyslexic‐specific reading difficulties in foveal and parafoveal processing during silent sentence reading.

Dyslexia and Other Reading Difficulties in Adults: Where Are We Now and Where Are We Headed?

Dyslexia and Other Reading Difficulties in Adults: Where Are We Now and Where Are We Headed?

The Invisible Labor of Access in Academic Writing Practices: A Case Analysis with Dyslexic Adults

Writing is the currency of academia. Although technology-mediated writing has been studied extensively in CSCW, we know little about how writing practices unfold with disabled people, such as dyslexic writers whose neurodivergence shapes how they process language. Our qualitative analysis reveals how dyslexic professionals simultaneously identify how editing tools break down on academic language; develop workarounds that re-appropriate other tools as language sources; cultivate ad-hoc collaborations to compensate for technology's limitations; and navigate culturally ingrained ableist expectations for writing. We discuss how dyslexic writers' experiences with shouldering invisible work to participate in academic writing processes indicates that current tools and services do not support their needs. We then draw on our findings to inform design opportunities to make writing processes more accessible through changes to writing tools, institutional services, and peer review practices.

Neural sampling of the speech signal at different timescales by children with dyslexia

Phonological difficulties characterize individuals with dyslexia across languages. Currently debated is whether these difficulties arise from atypical neural sampling of (or entrainment to) auditory information in speech at slow rates (<10 Hz, related to speech rhythm), faster rates, or neither. MEG studies with adults suggest that atypical sampling in dyslexia affects faster modulations in the neurophysiological gamma band, related to phoneme-level representation. However, dyslexic adults have had years of reduced experience in converting graphemes to phonemes, which could itself cause atypical gamma-band activity. The present study was designed to identify specific linguistic timescales at which English children with dyslexia may show atypical entrainment. Adopting a developmental focus, we hypothesized that children with dyslexia would show atypical entrainment to the prosodic and syllable-level information that is exaggerated in infant-directed speech and carried primarily by amplitude modulations <10 Hz. MEG was recorded in a naturalistic story-listening paradigm. The modulation bands related to different types of linguistic information were derived directly from the speech materials, and lagged coherence at multiple temporal rates spanning 0.9–40 Hz was computed. Group differences in lagged speech-brain coherence between children with dyslexia and control children were most marked in neurophysiological bands corresponding to stress and syllable-level information (<5 Hz in our materials), and phoneme-level information (12–40 Hz). Functional connectivity analyses showed network differences between groups in both hemispheres, with dyslexic children showing significantly reduced global network efficiency. Global network efficiency correlated with dyslexic children's oral language development and with control children's reading development. These developmental data suggest that dyslexia is characterized by atypical neural sampling of auditory information at slower rates. They also throw new light on the nature of the gamma band temporal sampling differences reported in MEG dyslexia studies with adults.

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.

Graph Analysis of EEG Functional Connectivity Networks During a Letter-Speech Sound Binding Task in Adult Dyslexics

We performed an EEG graph analysis on data from 31 typical readers (22.27 ± 2.53 y/o) and 24 dyslexics (22.99 ± 2.29 y/o), recorded while they were engaged in an audiovisual task and during resting-state. The task simulates reading acquisition as participants learned new letter-sound mappings via feedback. EEG data was filtered for the delta (0.5–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), and beta (13–30 Hz) bands. We computed the Phase Lag Index (PLI) to provide an estimate of the functional connectivity between all pairs of electrodes per band. Then, networks were constructed using a Minimum Spanning Tree (MST), a unique sub-graph connecting all nodes (electrodes) without loops, aimed at minimizing bias in between groups and conditions comparisons. Both groups showed a comparable accuracy increase during task blocks, indicating that they correctly learned the new associations. The EEG results revealed lower task-specific theta connectivity, and lower theta degree correlation over both rest and task recordings, indicating less network integration in dyslexics compared to typical readers. This pattern suggests a role of theta oscillations in dyslexia and may reflect differences in task engagement between the groups, although robust correlations between MST metrics and performance indices were lacking.

The use of noninvasive brain stimulation techniques to improve reading difficulties in dyslexia: A systematic review.

Noninvasive brain stimulation (NIBS) allows to actively and noninvasively modulate brain function. Aside from inhibiting specific processes, NIBS may also enhance cognitive functions, which might be used for the prevention and intervention of learning disabilities such as dyslexia. However, despite the growing interest in modulating learning abilities, a comprehensive, up‐to‐date review synthesizing NIBS studies with dyslexics is missing. Here, we fill this gap and elucidate the potential of NIBS as treatment option in dyslexia. The findings of the 15 included studies suggest that repeated sessions of reading training combined with different NIBS protocols may induce long‐lasting improvements of reading performance in child and adult dyslexics, opening promising avenues for future research. In particular, the “classical” reading areas seem to be most successfully modulated through NIBS, and facilitatory protocols can improve various reading‐related subprocesses. Moreover, we emphasize the need to further explore the potential to modulate auditory cortex function as a preintervention and intervention approach for affected children, for example, to avoid the development of auditory and phonological difficulties at the core of dyslexia. Finally, we outline how future studies may increase our understanding of the neurobiological basis of NIBS‐induced improvements in dyslexia.

Audiovisual Learning in Dyslexic and Typical Adults: Modulating Influences of Location and Context Consistency.

Learning to read involves efficient binding of visual to auditory information. Aberrant cross-modal binding skill has been observed in both children and adults with developmental dyslexia. Here, we examine the contribution of episodic memory to acquisition of novel cross-modal bindings in typical and dyslexic adult readers. Participants gradually learned arbitrary associations between unfamiliar Mandarin Chinese characters and English-like pseudowords over multiple exposures, simulating the early stages of letter-to-letter sound mapping. The novel cross-modal bindings were presented in consistent or varied locations (i.e., screen positions), and within consistent or varied contexts (i.e., co-occurring distractor items). Our goal was to examine the contribution, if any, of these episodic memory cues (i.e., the contextual and spatial properties of the stimuli) to binding acquisition, and investigate the extent to which readers with and without dyslexia would differ in their reliance on episodic memory during the learning process. Participants were tested on their ability to recognize and recall the bindings both during training and then in post-training tasks. We tracked participants’ eye movements remotely with their personal webcams to assess whether they would re-fixate relevant empty screen locations upon hearing an auditory cue—indicative of episodic memory retrieval—and the extent to which the so-called “looking-at-nothing behavior” would modulate recognition of the novel bindings. Readers with dyslexia both recognized and recalled significantly fewer bindings than typical readers, providing further evidence of their persistent difficulties with cross-modal binding. Looking-at-nothing behavior was generally associated with higher recognition error rates for both groups, a pattern that was particularly more evident in later blocks for bindings encoded in the inconsistent location condition. Our findings also show that whilst readers with and without dyslexia are capable of using stimulus consistencies in the input—both location and context—to assist in audiovisual learning, readers with dyslexia appear particularly reliant on consistent contextual information. Taken together, our results suggest that whilst readers with dyslexia fail to efficiently learn audiovisual binding as a function of stimulus frequency, they are able to use stimulus consistency—aided by episodic recall—to assist in the learning process.