The cognitive basis of dyslexia in school-aged children: A multiple case study in a transparent orthography.

This study focuses on the role of numerous cognitive skills such as phonological awareness (PA), rapid automatized naming (RAN), visual and selective attention, auditory skills, and implicit learning in developmental dyslexia. We examined the (co)existence of cognitive deficits in dyslexia and assessed cognitive skills' predictive value for reading. First, we compared school-aged children with severe reading impairment (n = 51) to typical readers (n = 71) to explore the individual patterns of deficits in dyslexia. Children with dyslexia, as a group, presented low PA and RAN scores, as well as limited implicit learning skills. However, we found no differences in the other domains. We found a phonological deficit in 51% and a RAN deficit in 26% of children with dyslexia. These deficits coexisted in 14% of the children. Deficits in other cognitive domains were uncommon and most often coexisted with phonological or RAN deficits. Despite having a severe reading impairment, 26% of children with dyslexia did not present any of the tested deficits. Second, in a group of children presenting a wide range of reading abilities (N = 211), we analysed the relationship between cognitive skills and reading level. PA and RAN were independently related to reading abilities. Other skills did not explain any additional variance. The impact of PA and RAN on reading skills differed. While RAN was a consistent predictor of reading, PA predicted reading abilities particularly well in average and good readers with a smaller impact in poorer readers.

Remote learning among students with and without reading difficulties during the initial stages of the COVID-19 pandemic.

This article presents the results of a survey on yet under-researched aspects of remote learning and learning difficulties in higher education during the initial stage (March - June 2020) of the COVID-19 pandemic. A total of 2182 students from University of Warsaw in Poland completed a two-part questionnaire regarding academic achievements in the academic year 2019/2020, living conditions and stress related to learning and pandemic, as well as basic demographic information, and Dyslexia Diagnosis Questionnaire (DDQ). The analyses were carried out in three sub-groups of students: who self-reported having a formal diagnosis of dyslexia (CDYS), self-reported reading difficulties, but had no formal diagnosis of dyslexia (SIDYS), and who reported no reading difficulties (CON). The results of the survey revealed that compared with the CON group, more students from CDYS and SIDYS groups did not pass at least one exam in the summer semester. CDYS and SIDYS groups experienced higher stress due to epidemiological restrictions, they had more difficulties than CON with the organisation of learning and obtaining credit during the COVID-19 pandemic. The results indicate a need for special consideration of additional support for students experiencing reading difficulties (whether or not they have a formal diagnosis).

Separating the influences of late talking and dyslexia on brain structure.

Being a late talker constitutes a risk factor for later neurodevelopmental disorders; however, its neurobiological basis remains unexplored. We aimed to determine the unique and mutual correlates of late talking and developmental dyslexia on brain structure and behavioral outcomes in a large sample of 8- to 10-year-old children in a between-groups design (N = 120). Brain structure was examined using voxel-based morphometry (to measure gray matter volume) and surface-based morphometry (to measure gray matter volume, cortical thickness, surface area, and curvature of the cortex). Behaviorally, late talking and dyslexia are independently connected to language and literacy skills, and late talkers have difficulties in grammar, phonological awareness, and reading accuracy. Children with dyslexia show impairments in all of the above, as well as in vocabulary, spelling, reading speed, and rapid automatized naming. Neuroanatomically, dyslexia is related to lower total intracranial volume and total surface area. Late talking is related to reduced cortical thickness in the left posterior cingulate gyrus and the right superior temporal gyrus, which are structures belonging to the dorsal speech articulatory-phonetic perception system. Finally, a cumulative effect of late talking and dyslexia was found on the left fusiform gray matter volume. This might explain inconsistencies in previous neuroanatomical studies of dyslexia. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Neural patterns of word processing differ in children with dyslexia and isolated spelling deficit.

There is an ongoing debate concerning the extent to which deficits in reading and spelling share cognitive components and whether they rely, in a similar fashion, on sublexical and lexical pathways of word processing. The present study investigates whether the neural substrates of word processing differ in children with various patterns of reading and spelling deficits. Using functional magnetic resonance imaging, we compared written and auditory processing in three groups of 9-13-year olds (N = 104): (1) with age-adequate reading and spelling skills; (2) with reading and spelling deficits (i.e., dyslexia); (3) with isolated spelling deficits but without reading deficits. In visual word processing, both deficit groups showed hypoactivations in the posterior superior temporal cortex compared to typical readers and spellers. Only children with dyslexia exhibited hypoactivations in the ventral occipito-temporal cortex compared to the two groups of typical readers. This is the result of an atypical pattern of higher activity in the occipito-temporal cortex for non-linguistic visual stimuli than for words, indicating lower selectivity. The print-speech convergence was reduced in the two deficit groups. Impairments in lexico-orthographic regions in a reading-based task were associated primarily with reading deficits, whereas alterations in the sublexical word processing route could be considered common for both reading and spelling deficits. These findings highlight the partly distinct alterations of the language network related to reading and spelling deficits.

Neural network for Braille reading and the speech-reading convergence in the blind: Similarities and differences to visual reading.

All writing systems represent units of spoken language. Studies on the neural correlates of reading in different languages show that this skill relies on access to brain areas dedicated to speech processing. Speech-reading convergence onto a common perisylvian network is therefore considered universal among different writing systems. Using fMRI, we test whether this holds true also for tactile Braille reading in the blind. The neural networks for Braille and visual reading overlapped in the left ventral occipitotemporal (vOT) cortex. Even though we showed similar perisylvian specialization for speech in both groups, blind subjects did not engage this speech system for reading. In contrast to the sighted, speech-reading convergence in the blind was absent in the perisylvian network. Instead, the blind engaged vOT not only in reading but also in speech processing. The involvement of the vOT in speech processing and its engagement in reading in the blind suggests that vOT is included in a modality independent language network in the blind, also evidenced by functional connectivity results. The analysis of individual speech-reading convergence suggests that there may be segregated neuronal populations in the vOT for speech processing and reading in the blind.

Reading and spelling skills are differentially related to phonological processing: Behavioral and fMRI study.

The manuscript reports a study on a large sample (N = 170) of Polish speaking 8-13 year old children, whose brain activation was measured in relation to tasks that require auditory phonological processing. We aimed to relate brain activation to individual differences in reading and spelling. We found that individual proficiency in both reading and spelling significantly correlated with activation of the left ventral occipito-temporal cortex encompassing the Visual Word Form Area which has been implicated in automatic orthographic activations. Reading but not spelling was found to correlate with activation in the left anterior dorsal stream (anterior supramarginal and postcentral gyri). Our results indicate that the level of both reading and spelling is related to activity in areas involved in the storage of fine-grained orthographic representations. However, only the reading level is uniquely related to activity of regions responsible for the articulation, motor planning and grapheme-to-phoneme correspondence, which form the basis for effective decoding skill.

Letter and Speech Sound Association in Emerging Readers With Familial Risk of Dyslexia.

In alphabetic scripts, learning letter-sound (LS) association (i.e., letter knowledge) is a strong predictor of later reading skills. LS integration is related to left superior temporal cortex (STC) activity and its disruption was previously observed in dyslexia (DYS). Whether disruption in LS association is a cause of reading impairment or a consequence of decreased exposure to print remains unclear. Using fMRI, we compared activation for letters, speech sounds and LS association in emerging readers with (FHD+, N = 50) and without (FHD-, N = 35) familial history of DYS, out of whom 17 developed DYS 2 years later. Despite having similar reading skills, FHD+ and FHD- groups showed opposite pattern of activation in left STC: In FHD- children activation was higher for incongruent compared to congruent, whereas in FHD+ it was higher for congruent LS pairs. Higher activation to congruent LS pairs was also characteristic of future DYS. The magnitude of incongruency effect in left STC was positively related to early reading skills, but only in FHD- children and (retrospectively) in typical readers. We show that alterations in brain activity during LS association can be detected at very early stages of reading acquisition, suggesting their causal involvement in later reading impairments. Increased response of left STC to incongruent LS pairs in FHD- group might reflect an early stage of automatizing LS associations, where the brain responds actively to conflicting pairs. The absence of such response in FHD+ children could lead to failures in suppressing incongruent information during reading acquisition, which could result in future reading problems.

Neither action nor phonological video games make dyslexic children read better.

The prevalence and long-term consequences of dyslexia make it crucial to look for effective and efficient ways of its therapy. Action video games (AVG) were implied as a possible remedy for difficulties in reading in Italian and English-speaking children. However, the studies examining the effectiveness of AVG application in dyslexia suffered from significant methodological weaknesses such as small sample sizes and lack of a control group with no intervention. In our study, we tested how two forms of training: based on AVG and on phonological non-action video games (PNAVG), affect reading in a group of fifty-four Polish children with dyslexia. Both speed and accuracy of reading increased in AVG as much as in PNAVG group. Moreover, both groups improved in phonological awareness, selective attention and rapid naming. Critically, the reading progress in the two groups did not differ from a dyslexic control group which did not participate in any training. Thus, the observed improvement in reading in AVG and PNAVG can be attributed either to the normal reading development related to schooling or to test practice effect. Overall, we failed to replicate previous studies: Neither AVG nor PNAVG remedy difficulties in reading in school children.