Exploring the Overlap Between Dyslexia and Speech Sound Production Deficits

Purpose Children with dyslexia have speech production deficits in a variety of spoken language contexts. In this article, we discuss the nature of speech production errors in children with dyslexia, including those who have a history of speech sound disorder and those who do not, to familiarize speech-language pathologists with speech production-specific risk factors that may help predict or identify dyslexia in young children. Method In this tutorial, we discuss the role of a phonological deficit in children with dyslexia and how this may manifest as speech production errors, sometimes in conjunction with a speech sound disorder but sometimes not. We also briefly review other factors outside the realm of phonology that may alert the speech-language pathologist to possible dyslexia. Results Speech-language pathologists possess unique knowledge that directly contributes to the identification and remediation of children with dyslexia. We present several clinical recommendations related to speech production deficits in children with dyslexia. We also review what is known about how and when children with speech sound disorder are most at risk for dyslexia. Conclusion Speech-language pathologists have a unique opportunity to assist in the identification of young children who are at risk for dyslexia

Evidence for the late MMN as a neurophysiological endophenotype for dyslexia.

Dyslexia affects 5-10% of school-aged children and is therefore one of the most common learning disorders. Research on auditory event related potentials (AERP), particularly the mismatch negativity (MMN) component, has revealed anomalies in individuals with dyslexia to speech stimuli. Furthermore, candidate genes for this disorder were found through molecular genetic studies. A current challenge for dyslexia research is to understand the interaction between molecular genetics and brain function, and to promote the identification of relevant endophenotypes for dyslexia. The present study examines MMN, a neurophysiological correlate of speech perception, and its potential as an endophenotype for dyslexia in three groups of children. The first group of children was clinically diagnosed with dyslexia, whereas the second group of children was comprised of their siblings who had average reading and spelling skills and were therefore "unaffected" despite having a genetic risk for dyslexia. The third group consisted of control children who were not related to the other groups and were also unaffected. In total, 225 children were included in the study. All children showed clear MMN activity to/da/-/ba/contrasts that could be separated into three distinct MMN components. Whilst the first two MMN components did not differentiate the groups, the late MMN component (300-700 ms) revealed significant group differences. The mean area of the late MMN was attenuated in both the dyslexic children and their unaffected siblings in comparison to the control children. This finding is indicative of analogous alterations of neurophysiological processes in children with dyslexia and those with a genetic risk for dyslexia, without a manifestation of the disorder. The present results therefore further suggest that the late MMN might be a potential endophenotype for dyslexia

More than Words: The Impact of Memory on How Undergraduates with Dyslexia Interact with Information

Despite the prevalence of dyslexia and the challenges it poses for seeking, assessing and using information, there has been relatively little research on the challenges people with dyslexia face when interacting with information. What existing research there is has mostly focused on the impact on information comprehension and spelling. However, people with dyslexia often face considerable memory impairment that can affect their learning. This paper reports findings from retrospective think-aloud (RTA) observations with 13 undergraduates with dyslexia, focusing on the memory-related barriers they face and the workarounds they use to overcome these barriers. An enhanced understanding of the full range of barriers faced by information-seekers with dyslexia can inform the design of dyslexia-aware digital information environments and information literacy programs. These can ‘level the information playing field’ by helping to break down barriers to information and, in turn, to knowledge creation

Metacognition for spelling in higher etudents with dyslexia: is there evidence for the dual burden hypothesis?

We examined whether academic and professional bachelor students with dyslexia are able to compensate for their spelling deficits with metacognitive experience. Previous research suggested that students with dyslexia may suffer from a dual burden. Not only do they perform worse on spelling but in addition they are not as fully aware of their difficulties as their peers without dyslexia. According to some authors, this is the result of a worse feeling of confidence, which can be considered as a form of metacognition (metacognitive experience). We tried to isolate this metacognitive experience by asking 100 students with dyslexia and 100 matched control students to rate their feeling of confidence in a word spelling task and a proofreading task. Next, we used Signal Detection Analysis to disentangle the effects of proficiency and criterion setting. We found that students with dyslexia showed lower proficiencies but not suboptimal response biases. They were as good at deciding when they could be confident or not as their peers without dyslexia. They just had more cases in which their spelling was wrong. We conclude that the feeling of confidence in our students with dyslexia is as good as in their peers without dyslexia. These findings go against the Dual Burden theory (Kruger & Dunning, 1999), which assumes that people with a skills problem suffer twice as a result of insufficiently developed metacognitive competence. As a result, there is no gain to be expected from extra training of this metacognitive experience in higher education students with dyslexia

Neural correlates of phonological, orthographic and semantic reading processing in dyslexia

Developmental dyslexia is one of the most prevalent learning disabilities, thought to be associated with dysfunction in the neural systems underlying typical reading acquisition. Neuroimaging research has shown that readers with dyslexia exhibit regional hypoactivation in left hemisphere reading nodes, relative to control counterparts. This evidence, however, comes from studies that have focused only on isolated aspects of reading. The present study aims to characterize left hemisphere regional hypoactivation in readers with dyslexia for the main processes involved in successful reading: phonological, orthographic and semantic. Forty-one participants performed a demanding reading task during MRI scanning. Results showed that readers with dyslexia exhibited hypoactivation associated with phonological processing in parietal regions; with orthographic processing in parietal regions, Broca's area, ventral occipitotemporal cortex and thalamus; and with semantic processing in angular gyrus and hippocampus. Stronger functional connectivity was observed for readers with dyslexia than for control readers 1) between the thalamus and the inferior parietal cortex/ventral occipitotemporal cortex during pseudoword reading; and, 2) between the hippocampus and the pars opercularis during word reading. These findings constitute the strongest evidence to date for the interplay between regional hypoactivation and functional connectivity in the main processes supporting reading in dyslexia. Keywords: Dyslexia, Reading, Hypoactivation, Functional connectivity, Thalamus, Hippocampu

A few remarks on the relationship between visuo-spatial attention deficits and dyslexia

Dyslexia and attentional problems are often comorbid. This raises the question whether reading deficits might etiologically follow from attentional difficulties, a hypothesis that has been proposed in regard to visuo-spatial attention deficits. This visuo-spatial attention deficit hypothesis would predict that attention deficits should be specific to dyslexia. However, it is here estimated that at the population level there are more non-dyslexic individuals than dyslexic individuals with visuo-spatial attention deficits. The reason for this is that in the overall population level there are far more individuals without dyslexia than with dyslexia. Thus, a relatively modest percentage presence of attention problems in the non-dyslexic population can result in a greater absolute number of on-dyslexic individuals with such problems. It is concluded that attention problems are unlikely to be specific to dyslexia

Neurobiology of dyslexia : A reinterpretation of the data

Theories of developmental dyslexia differ on how to best interpret the great variety of symptoms (linguistic, sensory, motor) observed in dyslexic individuals. One approach views dyslexia as a specific phonological deficit, which sometimes co-occurs with a more general sensorimotor syndrome. The present review of the neurobiology of dyslexia shows that neurobiological data are indeed consistent with this view, explaining both how a specific phonological deficit might arise, and why a sensorimotor syndrome should be significantly associated with it. This new conceptualisation of the aetiology of dyslexia may generalise to other neuro-developmental disorders, and may further explain heterogeneity within each disorder and co-morbidity between disorders

Speech and language difficulties in children with and without a family history of dyslexia

Comorbidity between SLI and dyslexia is well documented. Researchers have variously argued that dyslexia is a separate disorder from SLI, or that children with dyslexia show a subset of the difficulties shown in SLI. This study examines these hypotheses by assessing whether family history of dyslexia and speech and language difficulties are separable risk factors for literacy difficulties. Forty-six children with a family risk of dyslexia (FRD) and 36 children receiving speech therapy (SLT) were compared to 128 typically developing children. A substantial number (41.3%) of the children with FRD had received SLT. The nature of their difficulties did not differ in severity or form from those shown by the other children in SLT. However, both SLT and FRD were independent risk factors in predicting reading difficulties both concurrently and 6 months later. It is argued that the results are best explained in terms of Pennington's (2006) multiple deficits model

Spelling in adolescents with dyslexia: errors and modes of assessment

In this study we focused on the spelling of high-functioning students with dyslexia. We made a detailed classification of the errors in a word and sentence dictation task made by 100 students with dyslexia and 100 matched control students. All participants were in the first year of their bachelor’s studies and had Dutch as mother tongue. Three main error categories were distinguished: phonological, orthographic, and grammatical errors (on the basis of morphology and language-specific spelling rules). The results indicated that higher-education students with dyslexia made on average twice as many spelling errors as the controls, with effect sizes of d ≥ 2. When the errors were classified as phonological, orthographic, or grammatical, we found a slight dominance of phonological errors in students with dyslexia. Sentence dictation did not provide more information than word dictation in the correct classification of students with and without dyslexia

A PSYCHOLINGUISTIC ANALYSIS OF DYSLEXIA IN BACKWARDS: THE RIDDLE OF DYSLEXIA

This study is under a psycholinguistic umbrella. The aim of this study is to analyze linguistic phenomena of dyslexia suffered by Brian, the main character in Backwards: The Riddle of Dyslexia. This study has three objectives: (1) to identify and explain the types of linguistic errors experienced by the main character in Backwards: The Riddle of Dyslexia; (2) to examine the environmental factors which occur in the movie; and (3) to describe the kinds of teaching approaches used to recover the main character in the movie from dyslexia. This study employed a descriptive qualitative method since it emphasized on describing the phenomena of dyslexia in Backwards: The Riddle of Dyslexia. Moreover, the findings were presented in narrative or textual description. However, number was also used to support the analysis of the data. Some steps in analyzing the data were: identifying the raw data, classifying each datum into the categorization, analyzing each datum, interpreting each datum based on its contexts, reporting the findings, and drawing the conclusion. Finally, the data findings were triangulated by two linguistics students who were keen on psycholinguistics. This study reveals three findings. First, of eight types of miscues, only six types occur in Backwards: The Riddle of Dyslexia. They are substitution, hesitation, omission, non-response, addition, and self-corrections. Meanwhile, the absent types are repetition and reversal. Substitution is the most common error made by a dyslexic who has problems in extracting printed letters into sounds. Meanwhile, the other types have only small occurrences since they are not common errors made by a dyslexic. Second, all types of environmental factors occur in the movie, i.e. social interaction and communication, physical environment, cognitive modality preference, emotional motivation, and children’s behavior. Social interaction and communication as well as physical environment become the highest in rank because Brian works well with another and needs a suitable condition and situation to read. Finally, each type of environmental factors supports successful teaching approaches for a dyslexic. Third, types of teaching approaches which occur in the movie are language experience, teacher modeling, self-questioning, phonological approach, and engaging parents. Meanwhile, the absent types are creative writing and critical literacy. Those present types of teaching approaches have represented successful treatments for Brian to recover from dyslexia. Key words: psycholinguistics, dyslexia, Backwards: The Riddle of Dyslexi