Attention In Dyslexia Research Articles

Multiple Types of Developmental Dyslexias in a Shallow Orthography: Principles for Diagnostic Screening in Italian.

A new dyslexia screening test for Italian, Tiltan-IT, is presented. The test was developed based on an integrated dual-route model of reading, which describes in detail specific mechanisms underpinning early visual processes as well as the lexical and the sublexical routes. The principle according to which the test was developed is that each dyslexia type is manifested in different kinds of errors and in different kinds of stimuli, and we therefore included stimuli sensitive to each dyslexia type in the test. Tiltan-IT is a reading aloud test that includes word, nonword, and word pair lists. The test was administered to 618 Italian-speaking children (2nd-8th grade). Each error produced by the children was classified through the coding scheme developed to detect the different types of dyslexias described by the reading model. The Tiltan-IT was able to identify 110 children with dyslexia. The identified dyslexia types included letter position dyslexia, attentional dyslexia, letter identity dyslexia, surface dyslexia, vowel dyslexia, consonant conversion dyslexia, multi-letter phonological dyslexia, voicing dyslexia. The results confirm that the selection of items in the Tiltan-IT enabled the detection of the wide variety of dyslexias in Italian, some of them for the first time, adding evidence for the cross-linguistic validity of multiple types of developmental dyslexias and for the dual-route model of reading.

Characterizing different types of developmental dyslexias in French: The Malabi screener

ABSTRACT Reading is a complex process involving multiple stages. An impairment in any of these stages may cause distinct types of reading deficits– distinct types of dyslexia. We describe the Malabi, a screener to identify deficits in various orthographic, lexical, and sublexical components of the reading process in French. The Malabi utilizes stimuli that are sensitive to different forms of dyslexia, including “attentional dyslexia”, as it is traditionally refered to, characterized by letter-to-word binding impairments leading to letter migrations between words (e.g., “bar cat” misread as “bat car”), and “letter-position dyslexia”, resulting in letter transpositions within words (e.g., “destiny” misread as “density”). After collecting reading error norms from 138 French middle-school students, we analyzed error types of 16 students with developmental dyslexia. We identified three selective cases of attentional dyslexia and one case of letter-position dyslexia. Further tests confirmed our diagnosis and demonstrate, for the first time, how these dyslexias are manifested in French. These results underscore the significance of recognizing and discussing the existence of multiple dyslexias, both in research contexts when selecting participants for dyslexia studies, and in practical settings where educators and practitioners work with students to develop personalized support. The test and supporting materials are available on Open Science Framework (https://osf.io/3pgzb/).

Language, cognitive and neuroimaging determinants of Primary Progressive Aphasia in Hebrew Speakers, a case series

AbstractBackgroundPrimary progressive aphasias (PPA) are a group of neurocognitive disorders caused by neurodegenerative diseases and defined by progressive deterioration of language capabilities. PPA are traditionally classified into three predominant variants: nonfluent‐agrammatic, semantic, and logopenic. Emerging studies suggest an individual’s spoken language impacts the clinical presentation of PPA variants, potentially leading to misdiagnosis in languages underrepresented in research. We aimed at phenotyping PPA in native speakers of Hebrew, a Semitic language, with unique characteristics such as: under‐representation of vowels in the orthography, which makes it easier to detect various types of dyslexia, rich inflectional and derivational morphology, making it easier to identify morphosyntactic impairments, and, together with object case, making word order more flexible, enabling the examination of various syntactic deficits (e.g. in syntactic‐movement).MethodsFour native Hebrew speakers diagnosed with PPA (Mesulam 2001 criteria), aged 58‐68, complaint duration prior to assessment 10‐60 months, underwent assessment in Rabin Medical Center, Israel. Each participant underwent neurological evaluation, brain magnetic resonance imaging (MRI), and multi‐domain cognitive testing. Regional brain atrophy on T1 weighted MRI was rated with validated visual atrophy scales. All participants subsequently underwent Hebrew language evaluation using Norm‐referenced tests, assessing syntax, lexical retrieval, reading (including words and nonwords sensitive to various dyslexia types), semantic and conceptual abilities tasks, and phonology.ResultsParticipant’s presenting complaint was word finding difficulty (n = 3) and non‐fluent speech (n = 1). All participants exhibited deficits in the comprehension and production of syntactic movement including one participant with no other language deficits on formal testing and no brain atrophy. Three participants exhibited various dyslexias including morphological deficits,attentional dyslexia, vowel dyslexia, and surface dyslexia. As expected, poor scores on tests of lexical retrieval and syntax were observed in subjects with severe left anterior‐temporal and left fronto‐insular atrophy respectively.ConclusionTo our knowledge, this is the first case series of PPA in native Hebrew speakers. Errors in syntactic movement and various dyslexia types were common in all subjects suggesting they may be useful in early‐stage diagnosis. Full results (language, cognitive and neuroimaging), including additional eight cases will be presented in the AAIC conference.

Letter Migrations between Words in Reading Aloud Can Result either from an Impairment in Orthographic Input or in Phonological Output.

Letter migrations between words in reading aloud (e.g., reading "cane love" as "lane love" or "lane cove") are known to result from a deficit in the visual-orthographic analysis and characterize attentional dyslexia. In spontaneous speech, individuals with impairment in the phonological output buffer may show migrations of phonemes between words. The purpose of this study was to examine whether migrations between words in reading aloud can also result from a deficit in the phonological output buffer, to explore the characteristics of migrations resulting from orthographic input and from phonological output deficits, and to examine methods to distinguish these two sources. Using tasks of reading aloud of lists of 92-182 word pairs, we identified 18 adults and adolescents with developmental dyslexia who made between-word letter migrations in reading aloud, significantly more than age-matched controls (372 adults, 26 7th-graders and 44 4th-5th-graders). To distinguish between the orthographic input and phonological output sources for these migrations, we administered a test assessing orthographic input without spoken output (written semantic decision on 140 migratable word pairs) and a repetition test of 36 auditorily presented migratable word pairs, assessing spoken output without orthographic input (as well as nonword repetition and 3 span tests). These tests indicated that the migrations in reading aloud of 10 of the participants with dyslexia resulted from an orthographic input deficit-they made migrations not only in reading aloud but also in written word pair comprehension, but not in word pair repetition. For the other 8 participants, the migrations resulted from a phonological output deficit: they made migrations in reading aloud and in word pair repetition, but not in comprehension, and had limited spans and made errors in nonword repetition. We identified several differences between the two types of between-word errors: first, the individuals with attentional dyslexia made omissions of a letter that appeared in the same position in the two words, but the phonological output buffer group did not make such omissions. Second, the groups differed in the origin of migration: orthographic input migrations involve letters that are orthographically adjacent, whereas phonological output migrations involve phonologically adjacent phonemes: phonemes that have just been spoken or that are prepared together in the phonological buffer for production. Migrations from the line below and from 2 lines above the target occurred only in the orthographic input group. This study thus indicates that between-word migrations in reading aloud can result not only from attentional dyslexia, but also from a phonological output buffer deficit, and offers ways to distinguish between the two.

The role of visual attention in dyslexia: Behavioral and neurobiological evidence.

Poor phonological processing has typically been considered the main cause of dyslexia. However, visuo‐attentional processing abnormalities have been described as well. The goal of the present study was to determine the involvement of visual attention during fluent reading in children with dyslexia and typical readers. Here, 75 children (8–12 years old; 36 typical readers, 39 children with dyslexia) completed cognitive and reading assessments. Neuroimaging data were acquired while children performed a fluent reading task with (a) a condition where the text remained on the screen (Still) versus (b) a condition in which the letters were being deleted (Deleted). Cognitive assessment data analysis revealed that visual attention, executive functions, and phonological awareness significantly contributed to reading comprehension in both groups. A seed‐to‐voxel functional connectivity analysis was performed on the fluency functional magnetic resonance imaging task. Typical readers showed greater functional connectivity between the dorsal attention network and the left angular gyrus while performing the Still and Deleted reading tasks versus children with dyslexia. Higher connectivity values were associated with higher reading comprehension. The control group showed increased functional connectivity between the ventral attention network and the fronto‐parietal network during the Deleted text condition (compared with the Still condition). Children with dyslexia did not display this pattern. The results suggest that the synchronized activity of executive, visual attention, and reading‐related networks is a pattern of functional integration which children with dyslexia fail to achieve. The present evidence points toward a critical role of visual attention in dyslexia.

Chapter 19 - Rehabilitation of visual disorders

While there is a long history of rehabilitation for motor deficits following cerebral lesions, less is known about our ability to improve visual deficits. Vision therapy, prisms, occluders, and filters have been advocated for patients with mild traumatic brain injury, on the premise that some of their symptoms may reflect abnormal visual or ocular motor function, but the evidence for their efficacy is modest. For hemianopia, attempts to restore vision have had unimpressive results, though it appears possible to generate blindsight through training. Strategic approaches that train more efficient use of visual search in hemianopia have shown consistent benefit in visual function, while prism aids may help some patients. There are many varieties of alexia. Strategic adaptation of saccades can improve hemianopic alexia, but there has been less work and mixed results for pure alexia, neglect dyslexia, attentional dyslexia, and the central dyslexias. A number of approaches have been tried in prosopagnosia, with recent studies of small groups suggesting that face perception of prosopagnosic subjects can be enhanced through perceptual learning.

Eye vergence responses in children with and without reading difficulties during a word detection task

Vergence eye movements are movements of both eyes in opposite directions. Vergence is known to have a role in binocular vision. However recent studies link vergence eye movements also to attention and attention disorders. As attention may be involved in dyslexia, it is sensible to guess that the presence of reading difficulties can be associated with specific patterns in vergence responses. Data from school children performing a word-reading task have been analysed. In the task, children had to distinguish words from non-words (scrambled words or row of X’s), while their eye positions were recorded. Our findings show that after stimulus presentation eyes briefly converge. These vergence responses depend on the stimulus type and age of the child, and are different for children with reading difficulties. Our findings support the idea of a role of attention in word reading and offer an explanation of altered attention in dyslexia.

Cognitive Correlates of Japanese Language (Hiragana) Reading Abilities among School-Aged very Low Birth Weight Children

Previous studies have examined that the reading abilities of Very Low Birth Weight (VLBW) children are poorer than those of Normal Birth Weight (NBW) children. However, little is known about the cognitive functions that have been used to explain the reading problems in VLBW children. This study investigated that the effects of attention function on reading abilities in VLBW children. 23 VLBW children (mean age 9.1 years old) and 23 NBW children (mean age 9.2 years old) completed a reading test (containing word reading and non-word reading tasks), attention tasks, a phonological task and a naming task. The group differences were significant for the non-word reading task and attention tasks. Moreover, there were significant correlations between scores on the reading test and those on attention tasks. Multiple stepwise regression analysis suggested the reading scores were influenced by attention. These results of the present study suggest that attentional dyslexia is a characteristic of reading among VLBW children.

Acquired spatial dyslexia

Acquired spatial dyslexia is a reading disorder frequently occurring after left or right posterior brain lesions. This article describes several types of spatial dyslexia with an attentional approach. After right posterior lesions, patients show left neglect dyslexia with errors on the left side of text, words, and non-words. The deficit is frequently associated with left unilateral spatial neglect. Severe left neglect dyslexia can be detected with unlimited exposure duration of words or non-words. Minor neglect dyslexia is detected with brief presentation of bilateral words, one in the left and one in the right visual field (phenomenon of contralesional extinction). Neglect dyslexia can be explained as a difficulty in orienting attention to the left side of verbal stimuli. With left posterior lesions, spatial dyslexia is also frequent but multiform. Right neglect dyslexia is frequent, but right unilateral spatial neglect is rare. Attentional dyslexia represents difficulty in selecting a stimulus, letter or word among other similar stimuli; it is a deficit of attentional selection, and the left hemisphere plays a crucial role in selection. Two other types of spatial dyslexia can be found after left posterior lesions: paradoxical ipsilesional extinction and stimulus-centred neglect dyslexia. Disconnections between left or right parietal attentional areas and the left temporal visual word form area could explain these deficits. Overall, a model of attention dissociating modulation, selection control, and selection positioning can help in understanding these reading disorders.

Dissociations between developmental dyslexias and attention deficits.

We examine whether attention deficits underlie developmental dyslexia, or certain types of dyslexia, by presenting double dissociations between the two. We took into account the existence of distinct types of dyslexia and of attention deficits, and focused on dyslexias that may be thought to have an attentional basis: letter position dyslexia (LPD), in which letters migrate within words, attentional dyslexia (AD), in which letters migrate between words, neglect dyslexia, in which letters on one side of the word are omitted or substituted, and surface dyslexia, in which words are read via the sublexical route. We tested 110 children and adults with developmental dyslexia and/or attention deficits, using extensive batteries of reading and attention. For each participant, the existence of dyslexia and the dyslexia type were tested using reading tests that included stimuli sensitive to the various dyslexia types. Attention deficit and its type was established through attention tasks assessing sustained, selective, orienting, and executive attention functioning. Using this procedure, we identified 55 participants who showed a double dissociation between reading and attention: 28 had dyslexia with normal attention and 27 had attention deficits with normal reading. Importantly, each dyslexia with suspected attentional basis dissociated from attention: we found 21 individuals with LPD, 13 AD, 2 neglect dyslexia, and 12 surface dyslexia without attention deficits. Other dyslexia types (vowel dyslexia, phonological dyslexia, visual dyslexia) also dissociated from attention deficits. Examination of 55 additional individuals with both a specific dyslexia and a certain attention deficit found no attention function that was consistently linked with any dyslexia type. Specifically, LPD and AD dissociated from selective attention, neglect dyslexia dissociated from orienting, and surface dyslexia dissociated from sustained and executive attention. These results indicate that visuospatial attention deficits do not underlie these dyslexias.

On the use of cues to assess attention in dyslexia.

On the use of cues to assess attention in dyslexia.

Action Video Games Make Dyslexic Children Read Better

Learning to read is extremely difficult for about 10% of children; they are affected by a neurodevelopmental disorder called dyslexia [1, 2]. The neurocognitive causes of dyslexia are still hotly debated [3-12]. Dyslexia remediation is far from being fully achieved [13], and the current treatments demand high levels of resources [1]. Here, we demonstrate that only 12 hr of playing action video games-not involving any direct phonological or orthographic training-drastically improve the reading abilities of children with dyslexia. We tested reading, phonological, and attentional skills in two matched groups of children with dyslexia before and after they played action or nonaction video games for nine sessions of 80 min per day. We found that only playing action video games improved children's reading speed, without any cost in accuracy, more so than 1 year of spontaneous reading development and more than or equal to highly demanding traditional reading treatments. Attentional skills also improved during action video game training. It has been demonstrated that action video games efficiently improve attention abilities [14, 15]; our results showed that this attention improvement can directly translate into better reading abilities, providing a new, fast, fun remediation of dyslexia that has theoretical relevance in unveiling the causal role of attention in reading acquisition.

Dyslexia and the assessment of visual attention

AbstractVisual stream segregation has been proposed as a method to measure visual attention in dyslexia. Another task proposed to do this is the line-motion illusion. Both tasks, it is observed, can be carried out with spatially distributed stimuli. This, however, appears inconsistent with these tasks being linked speci?cally to attentional processes since this would require them to spatially focus cognitive resources. Also, both line-motion and visual stream segregation involve the perception of movement raising the possibility that what is actually measured by these tasks is not attention but some aspect of motion perception.

Induced letter migrations between words and what they reveal about the orthographic-visual analyzer

When skilled readers read briefly-presented word pairs, they produce between-word errors, in which letters migrate between neighboring words (e.g., mild wind can be misread as wild mind). Such errors are also produced by individuals with attentional dyslexia, even without time limitation. In this study, we tested several aspects of skilled reading of word pairs in short exposure, such as migrations between vertically and horizontally presented pairs, error types, position preservation, position sensitivity, and the effect of morphology. We compared the results to findings from developmental attentional dyslexia. Whereas both populations make between-word migrations, they crucially differ in the type and distribution of errors. In developmental attentional dyslexia, omission of identical letters that appear in the same position in the two words is prevalent, but it was rare in skilled reading. Other errors such as intrusions and buffer migrations also happened only in dyslexia but not in skilled reading. The different error patterns may suggest that different mechanisms underlie the incorrect reading in short exposure and the reading impairment in attentional dyslexia. Furthermore, the abundance of between-word migrations and the absence of letter position errors within words support that notion of two separate functions, one for letter-to-word binding, the other for letter position encoding.

Developmental attentional dyslexia

Attentional dyslexia is a reading deficit in which letters migrate between neighboring words, but are correctly identified and keep their correct relative position within the word. Thus, for example, fig tree can be read as fig free or even tie free. This study reports on 10 Hebrew-speaking individuals with developmental attentional dyslexia and explores in detail the characteristics of their between-word errors. Each participant read 2290 words, presented in word pairs: 845 horizontally presented word pairs, 240 vertically presented word pairs, and 60 nonword pairs. The main results are that almost all migrations preserve the relative position of the migrating letter within the word, indicating that the between-word position can be impaired while the within-word position encoding remains intact. This result is also supported by the finding that the participants did not make many letter position errors within words. Further analyses indicated that more errors occur in longer words, that most migrations occur in final letters (which are the leftmost letters in Hebrew), and that letters migrate both horizontally and vertically, and more frequently from the first to the second word in horizontal presentation. More migrations occurred when the result of migration was an existing word. Similarity between words in a pair did not increase error rates, and more migrations occurred when the words shared fewer letters. The between-word errors included the classic errors of migration of a letter between words, but also omission of one instance of a letter that appeared in the same position in the two words, an error that constituted a considerable percentage of the between-word errors, and intrusion of a letter from one word to the corresponding position in the neighboring word without erasing the original letter in the same position.

Abnormal auditory ERP N100 in children with dyslexia: comparison with their control siblings

BackgroundRecent research has implicated deficits of the working memory (WM) and attention in dyslexia. The N100 component of event-related potentials (ERP) is thought to reflect attention and working memory operation. However, previous studies showed controversial results concerning the N100 in dyslexia. Variability in this issue may be the result of inappropriate match up of the control sample, which is usually based exclusively on age and gender.MethodsIn order to address this question the present study aimed at investigating the auditory N100 component elicited during a WM test in 38 dyslexic children in comparison to those of 19 unaffected sibling controls. Both groups met the criteria of the International Classification of Diseases (ICD-10). ERP were evoked by two stimuli, a low (500 Hz) and a high (3000 Hz) frequency tone indicating forward and reverse digit span respectively.ResultsAs compared to their sibling controls, dyslexic children exhibited significantly reduced N100 amplitudes induced by both reverse and forward digit span at Fp1, F3, Fp2, Fz, C4, Cz and F4 and at Fp1, F3, C5, C3, Fz, F4, C6, P4 and Fp2 leads respectively. Memory performance of the dyslexics group was not significantly lower than that of the controls. However, enhanced memory performance in the control group is associated with increased N100 amplitude induced by high frequency stimuli at the C5, C3, C6 and P4 leads and increased N100 amplitude induced by low frequency stimuli at the P4 lead.ConclusionThe present findings are in support of the notion of weakened capture of auditory attention in dyslexia, allowing for a possible impairment in the dynamics that link attention with short memory, suggested by the anchoring-deficit hypothesis.

Letter position coding in attentional dyslexia

We report data from experiments on orthographic and phonological coding in two patients with attentional dyslexia following bilateral parietal damage. Two experiments required the patients to carry out lexical decisions and we varied whether the nonwords were orthographically or phonologically similar to real words. Experiment 1 showed that the patients were sensitive to the orthographic relations between nonwords and words, as they tended to accept as words nonwords whose letters could migrate within the string to form a word. There were no effects of phonological similarity between the nonwords and the words. Experiment 2 demonstrated that the patients were less likely to accept nonwords as words if the word had to be formed by transposing the first two letters in the string. The data suggest that attentional dyslexics are primarily sensitive to orthographic similarity between words and nonwords, and also that the first letters have privileged coding of their locations, despite the patients being poor at coding letter positions. The implications for theories of visual word recognition are discussed.

Patterns of Peripheral Paralexia: Pure Alexia and the Forgotten Visual Dyslexia?

The concept of visual dyslexia put forward by Marshall and Newcombe (1973) is assessed. After a long period of neglect it was resurrected in the late 1990s in a narrow form. In the current paper it is proposed that a wider form of the functional syndrome is useful to include amongst other conditions attentional dyslexia and neglect dyslexia. The variety of sub-forms would correspond to the behavioural effects of the different ways in which the orthographic processing systems can be impaired. What distinguishes the broader form from pure alexia is that the patient lacks the capacity to use a serial letter processing strategy, and so interpretation of visual dyslexia in terms of the impairment to the orthographic processing systems is not contaminated by the use of a compensatory strategy that results in processing operations which are qualitatively very different from the normal and highly opaque. The lack of a serial letter processing strategy makes visual dyslexia a much more transparent functional syndrome.

Auditory perceptual grouping and attention in dyslexia

Despite dyslexia affecting a large number of people, the mechanisms underlying the disorder remain undetermined. There are numerous theories about the origins of dyslexia. Many of these relate dyslexia to low-level, sensory temporal processing deficits. Another group of theories attributes dyslexia to language-specific impairments. Here, we show that dyslexics perform worse than controls on an auditory perceptual grouping task. The results show differences in performance between the groups that depend on sound frequency and not solely on parameters related to temporal processing. Performance on this task suggests that dyslexics' deficits may result from impaired attentional control mechanisms. Such deficits are neither modality nor language-specific and may help to reconcile differences between theories of dyslexia.

Presentation and task effects on migration errors in attentional dyslexia

We report a case study of a patient, FL, who shows symptoms of attentional dyslexia. He performs better at reading aloud single words than pairs of words, where he tends to make letter migration errors. These letter migrations are particularly prevalent from the word presented on the right into FL’s response to the word presented on the left. Performance on the word pair reading task is improved if the two words are presented in different cases or the space between them is increased. Further, FL performs better at reading a target word if he is only required to name the initial letter of a distractor word rather than read the whole word. However, single letter distractors then produce more interference than whole words. These findings are consistent with FL having poor letter location coding when attention is diffuse [Cognitive Neuropsychol. 18 (2001) 551; Cognitive Neuropsychol. 13 (1996) 205]. In addition, representations on the left side of his attentional space are particularly weak, and so vulnerable to stimuli on the right when FL adopts a wide spatial window for the task. The data point to a pre-categorical deficit in reading in this case.