Figure - available via license: Creative Commons Attribution 2.0 Generic
Content may be subject to copyright.
Grey matter volume differences between the groups (in red decreased GMV; in blue increased GMV) together with contrast estimates for five significant clusters. Results are displayed at uncorrected p < 0.001
Source publication
The variety of different causal theories together with inconsistencies about the anatomical brain markers emphasize the heterogeneity of developmental dyslexia. Attempts were made to test on a behavioral level the existence of subtypes of dyslexia showing distinguishable cognitive deficits. Importantly, no research was directly devoted to the inves...
Similar publications
Citations
... It states that boys are more likely than girls to have dyslexia, with a rough estimated ratio of 4:1. [3]. A dyslexic child struggles with word recognition, decoding, and spelling. ...
The inability of standard linear research to clearly define the role of cognitive abilities in reading difficulties is most likely due to the fact that reading and the components that are related to reading are both part of a system of factors. There are numerous interrelated and mitigating elements that conventional statistical models are unable to deal effectively. This work aims to increase dyslexia prediction accuracy by introducing two stage non-linear methodology which incorporate both deep learning and uncertainty theory. In the first stage, the pattern of dyslexic symptoms is learned by introducing deep adaptive neural network. During the training phase, the hyperparameters weight and learning rate are optimized using a metaheuristic algorithm called the fruit fly optimization algorithm. This algorithm imitates the behavior of fruit flies to search for the best set of values. The acquired knowledge is infused in the uncertainty inference model known as intuitionistic inference classifier. Each characteristic that defines an instance as dyslexic or non-dyslexic is represented in tristate degrees to precisely address the inconsistent or vague instance which neither or nor exhibit dyslexic symptoms by introducing the hesitancy factor. The simulation results support the proposed intuitionistic fuzzy rules prominently improves the accuracy rate of dyslexia prediction compared to the other existing state of arts.
... In particular, individuals with DD demonstrate reduced grey matter volume in brain areas where they typically also show functional hypoactivation: A meta-analysis of studies investigating brain structure related to reading performance revealed a significant reduction of grey matter volume in the supramarginal gyrus/IPL, the STG, and the fusiform gyrus/VWFA (Linkersdörfer, Lonnemann, Lindberg, Hasselhorn, & Fiebach, 2012) when comparing poor readers to typical readers. In addition, the IFG has been found to show reduced grey matter volume in children with DD compared to typical-reading children (Jednoróg, Gawron, Marchewka, Heim, & Grabowska, 2014). In contrast, the PCG, which has been found to show functional hyperactivation in readers with DD, has been reported to demonstrate higher grey matter volume when comparing readers with DD to readers with typical reading skills (Jednoróg et al., 2015;Vinckenbosch, Robichon, & Eliez, 2005). ...
Structural covariance (SC) is a promising approach for investigating brain organization within the domain of literacy and developmental disorders as it thought to reflect both functional and structural information. This study presents a first-of-its-kind exploration of SC in reading- related brain regions across different ages and reading abilities.
Whole-brain SC analyses were conducted for six key regions of the reading network, including an anterior and posterior subdivision of the visual word form area (VWFA). We compared SC matrices of typically reading adults (N=134) and children (N=110), and between typically reading children and children with dyslexia (N=68).
Our results showed significant associations between reading-related brain regions in typically reading adults. We observed significant SC between the posterior VWFA and the left occipital cortex, and between the anterior VWFA and the left superior temporal gyrus and left inferior frontal gyrus. Typical-reading adults and children did not differ significantly in SC. However, typically reading children demonstrated significantly higher SC between the inferior parietal lobule (IPL) and other reading-related brain regions than children with dyslexia.
Our findings provide support for a functional and structural division of the VWFA and underscore the crucial role of the IPL in fluent reading.
... In addition, there is the problem that previous empirical studies, which investigated only one of the various hypotheses at a time, have led to heterogeneous findings [23]. Consequently, it is still unclear as to whether the various deficits might suggest that dyslexia should be divided into subgroups depending on the focus of the deficit [46,47] or whether these deficits are symptoms of a superordinate mechanism. Due to the heterogeneity of the findings of those "single deficits," successive studies were conducted, assessing various processing deficit theories in the same sample to investigate whether there is stronger evidence for one of the investigated disorder theories [23,[47][48][49][50][51]. ...
... In sum, the present individual profiles did not reveal predominant deficit profiles in children with dyslexia that would allow for the classification of subgroups [46,47] and speak more for an individual profile of performance deficits in children with dyslexia, as also described by others [18]. ...
Background:
The underlying mechanisms of dyslexia are still debated. The question remains as to whether there is evidence of a predominant type of deficit or whether it is a multideficit disorder with individual profiles. The assumptions of which mechanism causes the disorder influences the selection of the training approach.
Methods:
A sample of German neurotypical reading children (NT) and children with dyslexia (DYSL) was investigated with a comprehensive behavioral test battery assessing phonological, auditory, visual, and cerebellar performance, thus addressing performance described in three major theories in dyslexia.
Results:
In the present sample using the test battery of the present study, DYSL had the strongest impairment in phonological and auditory processing, accompanied by individual processing deficits in cerebellar performance, but only a few in the investigated visual domains. Phonological awareness and auditory performance were the only significant predictors for reading ability.
Conclusion:
These findings point out that those reading difficulties were associated with phonological as well as auditory processing deficits in the present sample. Future research should investigate individual deficit profiles longitudinally, with studies starting before literacy acquisition at as many processing domains as possible. These individual deficit profiles should then be used to select appropriate interventions to promote reading and spelling.
... This hypothesis fits well with our result showing an advantage for the AVG players on the localization of targets presented to the opposite side of a previous cue (invalid condition), resulting in faster RTs in the uncued location compared to the NAVG group. This attentional advantage shown in AVG players could be related to a general better attentional disengagement in spatial and temporal domain, which have both be related to more efficient reading and phonological processing skills Helenius, Uutela, & Hari, 1999;Jednoróg, Gawron, Marchewka, Heim, & Grabowska, 2014;Lallier et al., 2009;Lallier, Tainturier, et al., 2010;Lallier, Thierry, & Tainturier, 2013). Accordingly, the AVG players of the present study exhibited better performance on phonological and reading tasks. ...
Video games play a major role in the everyday life of children, teenagers, and adults. Several studies show that action video games (AVGs) improve visual attentional efficiency. AVGs also appear to improve reading speed and phonological skills in children with developmental dyslexia. These results have been linked to the intrinsic characteristics of AVGs, in which fast disengagement of multisensory attention allows for efficient extraction of relevant dynamic information, a skill that is crucially also involved in phonological and reading skills. We tested the hypothesis that AVG players demonstrate faster auditory attention disengagement in an auditory spatial cuing task, as well as better phonological and reading performance than non-players. We found that AVG players were faster in spatial localization of auditory targets and showed enhanced attentional disengagement as indexed by a smaller cuing effect. AVG players also showed better phonological decoding and working memory skills. Moreover, the beneficial effects of AVGs, as measured by faster attentional disengagement, were linked to better phonological and reading skills in adult AVG players. We suggest that a more efficient attentional disengagement - controlled by the posterior parietal cortex - induces enhanced multisensory processing in AVG players.
... In other words, dyslexia is not related to intellectual, sensory (vision, hearing) disorders (injuries), inappropriate teaching and learning or sociocultural environment. Also, dyslexia does not stand for temporal, passing learning difficulties or difficulties that occur due to neurological injuries (Jednoróg et al., 2014). ...
Straipsnyje pateikiama teorinė fonologinių gebėjimų apibrėžties ir struktūros analizė: atskleidžiama fonologinių gebėjimų samprata, jų grupės, sąsajos su skaitymo sutrikimu (disleksija). Taip pat šiame straipsnyje susitelkiama ties išsamiu fonologinių gebėjimų įvertinimo ypatumų tarptautiniu ir nacionaliniu mastu aptarimu.
Teoriniam fonologinių gebėjimų konceptui atskleisti atlikta Lietuvos bei užsienio autorių mokslinių publikacijų analizė. Atlikta koncepto analizė leidžia teigti, kad fonologiniai gebėjimai apima fonologinį suvokimą, trumpalaikę atmintį bei greitą vardijimą. Tai bene dažniausiai užsienio šalyse tyrinėjami fonologiniai procesai, susiję su skaitymu ir(ar) rašymu. Gausūs skirtingomis užsienio kalbomis atlikti tyrimai leido parodyti akivaizdžias fonologinių gebėjimų ir skaitymo sutrikimo (disleksijos) sąsajas. Nustatyta, jog asmenims, turintiems disleksiją, būdingi nepakankami šios srities gebėjimai. Tačiau apžvelgtų ilgalaikių tyrimų rezultatai rodo, jog skaitymo pasiekimus ikimokykliniame ar priešmokykliniame amžiuje geriausiai prognozuoja du rodikliai: fonologinis suvokimas ir greitas vardijimas. Panašaus pobūdžio mokslo darbai, kuriuose analizuojamos fonologinių gebėjimų ir skaitymo lietuvių kalba koreliacijos, kol kas gana reti. Todėl prieš pateikiant tvirtą, moksliniais įrodymais grįstą išvadą šiuo klausimu būtina sukaupti daugiau empirinių duomenų. Taip pat akivaizdus nacionalinių tyrimų apie vaikų, turinčių kalbėjimo ir kalbos sutrikimų, fonologinius gebėjimus, poreikis.
... As presented above, the right posterior part of the lobule VI, which could be responsible for phonological processing (Tan et al., 2005), is associated with dyslexic readers suffering from phonological deficits (van Ermingen-Marbach et al., 2013). In contrast, abnormalities in gray matter volume of left Crus I have been found in dyslexic readers with deficits in visual and phonological processing (Jednorog et al., 2014). ...
Extensive studies have reported significant activation of the cerebellum in reading and reading-related tasks. However, it has remained unclear how the cerebellum contributes to reading and how reading-related regions in the cerebrum are related to those in the cerebellum. In this review, by summarizing previous literature, we observe that multiple cerebellar areas are engaged in reading and vary in their contributions to reading. Moreover, the cerebellar reading-related areas are selectively connected with the cerebral areas with the same functional specificity. Abnormalities in the cerebro-cerebellar connection are also associated with reading impairments. We thus propose the cerebro-cerebellar mapping hypothesis, which suggests that the cerebellum could have another reading-related network rather than serving as a neural hub. This network maps to and collaborates with its functionally corresponding network in the cerebrum. This framework heightens the importance of the cerebellum to reading and provides new insights into the relationship between the cerebellum, cerebrum, and reading development.
... There are arguably many subtypes of reading disorders that could have multiple neural mechanisms underlying similar behavioral manifestations. 129,130 Nevertheless, differences between compensated readers and typical proficient readers have emerged from studying the neural substrates of compensated readers: namely, differences in asymmetry, 117,[131][132][133][134] and in the extent of topdown frontal engagement. 135,136 While there is significant support for irregular VWFA activity in dyslexic readers, 50,137 it is unclear whether VWFA activity in compensated readers bears a greater resemblance to that of typical proficient readers (i.e., strongly left lateralized) or dyslexics (i.e., bilateral). ...
Cross–writing system research in psychology and cognitive neuroscience has yielded important findings regarding how a writing system's structure can influence the cognitive challenges of learning to read and the neural underpinnings of literacy. The current paper reviews these differences and extends the findings to demonstrate diversity in how skilled reading is accomplished within a single writing system, English. We argue that broad clusters of behavioral and neural patterns found across writing systems can also be found within subpopulations who display atypical routes to skilled English reading, subpopulations including Chinese–English bilinguals, deaf native signers, compensated readers, and distortion‐sensitive readers. The patterns of interest include a tradeoff between the degree of reliance on phonological and morphological processing for skilled reading, a shift in attentional focus from smaller to larger orthographic units, and enhanced bilaterality of neural processing during word reading. Lastly, we consider how understanding atypical routes to reading may apply to other writing systems.
... If one embraces this view, our data can be taken as strongly supportive of the hypothesis of abnormal temporal sampling of speech at phrasal rate in the right hemisphere in dyslexia ( Goswami, 2011 ). In any case, the distinction between subgroups of dyslexia (in a broad sense) highlights the importance of factoring in the heterogeneity of the disorder ( McArthur et al., 2013 ), to better understand the neuronal correlates of its multiple etiology ( Jednoróg et al., 2014 ) and severity. The fact that most studies do not follow such an approach may explain discrepancies in the existing literature. ...
Dyslexia is a frequent developmental disorder in which reading acquisition is delayed and that is usually associated with difficulties understanding speech in noise. At the neuronal level, children with dyslexia were reported to display abnormal cortical tracking of speech (CTS) at phrasal rate. Here, we aimed to determine if abnormal tracking relates to reduced reading experience, and if it is modulated by the severity of dyslexia or the presence of acoustic noise.
We included 26 school-age children with dyslexia, 26 age-matched controls and 26 reading-level matched controls. All were native French speakers. Children's brain activity was recorded with magnetoencephalography while they listened to continuous speech in noiseless and multiple noise conditions. CTS values were compared between groups, conditions and hemispheres, and also within groups, between children with mild and severe dyslexia.
Syllabic CTS was significantly reduced in the right superior temporal gyrus in children with dyslexia compared with controls matched for age but not for reading level. Severe dyslexia was characterized by lower rapid automatized naming (RAN) abilities compared with mild dyslexia, and phrasal CTS lateralized to the right hemisphere in children with mild dyslexia and all control groups but not in children with severe dyslexia. Finally, an alteration in phrasal CTS was uncovered in children with dyslexia compared with age-matched controls in babble noise conditions but not in other less challenging listening conditions (non-speech noise or noiseless conditions); no such effect was seen in comparison with reading-level matched controls.
Overall, our results confirmed the finding of altered neuronal basis of speech perception in noiseless and babble noise conditions in dyslexia compared with age-matched peers. However, the absence of alteration in comparison with reading-level matched controls demonstrates that such alterations are associated with reduced reading level, suggesting they are merely driven by reduced reading experience rather than a cause of dyslexia. Finally, our result of altered hemispheric lateralization of phrasal CTS in relation with altered RAN abilities in severe dyslexia is in line with a temporal sampling deficit of speech at phrasal rate in dyslexia.
... However, dyslexic readers have reduced left-asymmetry in both brain structures and brain functions. Previous studies found reduced gray matter in the left fusiform gyrus (FG) (Linkersdörfer, Lonnemann, Lindberg, Hasselhorn, & Fiebach, 2012), left IFG (Eckert, Berninger, Vaden Jr, Gebregziabher, & Tsu, 2016;Jednoróg, Gawron, Marchewka, Heim, & Grabowska, 2014), left MFG (Siok et al., 2008), left superior temporal sulcus (Eckert, Berninger, Vaden, Gebregziabher, & Tsu, 2016;Richlan, 2020), and increased bilateral symmetry in the physical size of planum temporale for participants with RD (Bloom, Garcia-Barrera, Miller, Miller, & Hynd, 2013;Larsen, Høien, Lundberg, & Ødegaard, 1990;Morgan & Hynd, 1998, for review). Structural research on white matter suggested reduced leftlateralization in the structural integrity of inferior fronto-occipital fasciculus in children with RD, as well as increased right-lateralization in the second branch of the superior longitudinal fasciculus (Zhao, de Schotten, Altarelli, Dubois, & Ramus, 2016). ...
Using graph theory, we examined topological organization of the language network in Chinese children with poor reading during an auditory rhyming task and a visual spelling task, compared to reading-matched controls and age-matched controls. First, poor readers (PR) showed reduced clustering coefficient in the left inferior frontal gyrus (IFG) and higher nodal efficiency in the bilateral superior temporal gyri (STG) during the visual task, indicating a less functionally specialized cluster around the left IFG and stronger functional links between bilateral STGs and other regions. Furthermore, PR adopted additional right-hemispheric hubs in both tasks, which may explain increased global efficiency across both tasks and lower normalized characteristic shortest path length in the visual task for the PR. These results underscore deficits in the left IFG during visual word processing and conform previous findings about compensation in the right hemisphere in children with poor reading.
... Lately, Dohla et al. (2018) showed that auditory and visual magnocellular deficits, previously also implicated in dyslexia (Ramus et al. 2003) might be present in the spelling deficit. One study on neurocognitive subtypes of dyslexia (Jednoróg et al. 2014) showed grey matter volume differences between three dyslexia subtypes: with phonological awareness and magnocellular-dorsal skills, with impairments in rapid naming and auditory attention shifting and with a double deficit (phonological and rapid naming). However, further research on the neural basis of ISD subtypes are needed. ...
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.
