Project DyAdd: Implicit learning in adult dyslexia and ADHD

In this study of the project DyAdd, implicit learning was investigated through two paradigms in adults (18–55 years) with dyslexia (n?=?36) or with attention deficit/hyperactivity disorder (ADHD, n?=?22) and in controls (n?=?35). In the serial reaction time (SRT) task, there were no group differences in learning. However, those with ADHD exhibited faster RTs compared to other groups. In the artificial grammar learning (AGL) task, the groups did not differ from each other in their learning (i.e., grammaticality accuracy or similarity choices). Further, all three groups were sensitive to fragment overlap between learning and test-phase items (i.e., similarity choices were above chance). Grammaticality performance of control participants was above chance, but that of participants with dyslexia and participants with ADHD failed to differ from chance, indicating impaired grammaticality learning in these groups. While the main indices of AGL performance, grammaticality accuracy and similarity choices did not correlate with the neuropsychological variables that reflected dyslexia-related (phonological processing, reading, spelling, arithmetic) or ADHD-related characteristics (executive functions, attention), or intelligence, the explicit knowledge for the AGL grammar (i.e., ability to freely generate grammatical strings) correlated positively with the variables of phonological processing and reading. Further, SRT reaction times correlated positively with full scale intelligence quotient (FIQ). We conclude that, in AGL, learning difficulties of the underlying rule structure (as measured by grammaticality) are associated with dyslexia and ADHD. However, learning in AGL is not related to the defining neuropsychological features of dyslexia or ADHD. Instead, the resulting explicit knowledge relates to characteristics of dyslexia.     

Performance of children with developmental dyslexia on high and low topological entropy artificial grammar learning task

Graph complexity as measured by topological entropy has been previously shown to affect performance on artificial grammar learning tasks among typically developing children. The aim of this study was to examine the effect of graph complexity on implicit sequential learning among children with developmental dyslexia. Our goal was to determine whether children’s performance depends on the complexity level of the grammar system learned. We conducted two artificial grammar learning experiments that compared performance of children with developmental dyslexia with that of age- and reading level-matched controls. Experiment 1 was a high topological entropy artificial grammar learning task that aimed to establish implicit learning phenomena in children with developmental dyslexia using previously published experimental conditions. Experiment 2 is a lower topological entropy variant of that task. Results indicated that given a high topological entropy grammar system, children with developmental dyslexia who were similar to the reading age-matched control group had substantial difficulty in performing the task as compared to typically developing children, who exhibited intact implicit learning of the grammar. On the other hand, when tested on a lower topological entropy grammar system, all groups performed above chance level, indicating that children with developmental dyslexia were able to identify rules from a given grammar system. The results reinforced the significance of graph complexity when experimenting with artificial grammar learning tasks, particularly with dyslexic participants.     

The role of feedback in implicit and explicit artificial grammar learning: a comparison between dyslexic and non-dyslexic adults

The importance of feedback for learning has been firmly established over the past few decades. The question of whether feedback plays a significant role in the statistical learning abilities of adults with dyslexia, however, is currently unresolved. Here, we examined the role of feedback in grammaticality judgment, type of structural knowledge, and confidence rating in both typically developed and dyslexic adults. We implemented two artificial grammar learning experiments: implicit and explicit. The second experiment was directly analogous to the first experiment in all respects except training format: the standard memorization instruction was replaced with an explicit rule-search instruction. Each experiment was conducted with and without performance feedback. While both groups showed significantly improved learning in the feedback-based explicit artificial grammar learning task, only the typically developed adults demonstrated higher levels of conscious structural knowledge. The present study demonstrates that the basis for the grammaticality judgment of adults with dyslexia differs from that of typically developed adults, regardless of increase in the level of explicitness.     

Atypical predictive processing during visual statistical learning in children with developmental dyslexia: an event-related potential study

Previous research suggests that individuals with developmental dyslexia perform below typical readers on non-linguistic cognitive tasks involving the learning and encoding of statistical-sequential patterns. However, the neural mechanisms underlying such a deficit have not been well examined. The aim of the present study was to investigate the event-related potential (ERP) correlates of sequence processing in a sample of children diagnosed with dyslexia using a non-linguistic visual statistical learning paradigm. Whereas the response time data suggested that both typical and atypical readers learned the statistical patterns embedded in the task, the ERP data suggested otherwise. Specifically, ERPs of the typically developing children (n?=?12) showed a P300-like response indicative of learning, whereas the children diagnosed with a reading disorder (n?=?8) showed no such ERP effects. These results may be due to intact implicit motor learning in the children with dyslexia but delayed attention-dependent predictive processing. These findings are consistent with other evidence suggesting that differences in statistical learning ability might underlie some of the reading deficits observed in developmental dyslexia.     

Implicit sequence learning is preserved in dyslexic children

This study investigates the implicit sequence learning abilities of dyslexic children using an artificial grammar learning task with an extended exposure period. Twenty children with developmental dyslexia participated in the study and were matched with two control groups—one matched for age and other for reading skills. During 3 days, all participants performed an acquisition task, where they were exposed to colored geometrical forms sequences with an underlying grammatical structure. On the last day, after the acquisition task, participants were tested in a grammaticality classification task. Implicit sequence learning was present in dyslexic children, as well as in both control groups, and no differences between groups were observed. These results suggest that implicit learning deficits per se cannot explain the characteristic reading difficulties of the dyslexics.     

Sequential Implicit Learning Ability Predicts Growth in Reading Skills in Typical Readers and Children with Dyslexia

ABSTRACT

This study investigated in a longitudinal design how 74 Dutch children with dyslexia and 39 typically developing peers differed in sequential versus spatial implicit learning and overnight consolidation, and it examined whether implicit learning related to (pseudo)word reading development in Grades 5 and 6. The results showed that sequential, but not spatial, learning predicted growth in reading skills in children with and without dyslexia. Sequential implicit learning was also related to growth in pseudoword reading skills during an intervention in children with dyslexia, retrospectively. Furthermore, children with dyslexia had longer reaction times in general but did not differ from typical readers in how well or how quickly they learned either on an implicit learning task or in their overnight consolidation.     

Developmental dyslexia in an orthography of intermediate depth: the case of European Portuguese

Fifteen Portuguese children with dyslexia, aged 9–11 years, were compared with reading and chronological age controls with respect to five indicators related to the phonological deficit hypothesis: the effects of lexicality, regularity, and length, implicit and explicit phonological awareness, and rapid naming. The comparison between groups indicates that Portuguese children with dyslexia have a phonological impairment which is revealed by a developmental deficit in implicit phonological awareness and irregular word reading (where younger reading level controls performed better than dyslexics) and by a developmental delay in decoding ability and explicit phonological awareness (where dyslexics matched reading level controls). These results are discussed in relation to the idea that European Portuguese is written in an orthography of intermediate depth.     

Student teachers go online; the need for a focus on human agency and pedagogy in learning about ‘e-learning’ in initial teacher education (ITE)

This paper argues that student teachers’ developing pedagogical approaches achieve expression within the virtual classroom in much the same way as they would in the ‘real’ classroom; that is to say through language as the primary tool of mediation. Whilst the advent of new communications technologies affords new arenas in which learning can take place—Virtual Learning Environments (VLEs), online communities, Managed Learning Environments—the importance of human agency and the significance of language remains pivotal to the effective use of such technologies. As such it is argued that student teachers need opportunities to engage in authentic online dialogue with children as they endeavour to find their online pedagogical voice. The key findings emerge from a case study carried out with a group of Year 3 ICT specialists on an undergraduate initial teacher education (ITE) degree course in the UK, leading to qualified teacher status (QTS) in the primary and lower secondary phases of education. Funding from the University of Brighton, Community University Partnership Programme (CUPP), was used to design and resource a module, which facilitated opportunities for student teachers to engage in online learning dialogues with children from a local primary school, having initially met with the children face-to-face. Fourteen student teachers participated in the study. Interviews were carried out and their online dialogues with the children were analysed to establish both the issues and potential advantages of such a situated approach to learning about the educational use of new communications technologies with children.     

When diglossia meets dyslexia: The effect of diglossia on voweled and unvoweled word reading among native Arabic-speaking dyslexic children

Native Arabic speakers read in a language variety that is different from the one they use for everyday speech. The aim of the present study was: (1) to examine Spoken Arabic (SpA) and Standard Arabic (StA) voweled and unvoweled word reading among native-speaking sixth graders with developmental dyslexia; and (2) to determine whether SpA reading ability among children with dyslexia predicts StA reading fluency in the two orthographies: voweled and unvoweled. A comparison was made to three age groups of typically developing children: a group matched by chronological age, a group of children who are two years younger, and a group of children who are 4 years younger. Findings show that diglossia has a strong impact on reading ability in dyslexic children. Moreover, vowelization plays a pivotal role in the reading ability of Arabic-speaking children with dyslexia in both SpA and StA. This role is evident in the different performance patterns of dyslexic participants as compared with controls on word-reading accuracy and fluency for SpA versus StA. Finally, StA word-reading fluency appears to depend on and to be reliably and powerfully predicted by SpA word-level reading ability. These results underscore the role of diglossia and vowelization in the manifestation of dyslexia in Arabic-speaking children.     

内隐学习IQ独立性的研究

以65名智障中学生为被试，分别用色块串和色词串为材料，以限定状态语法组成学习规则，研究了智障学生颜色内隐和外显学习的特点。结果发现：指导语上不存在主效应，没有发生内隐和外显学习效应；反面证明内隐学习存在长时功效；非言语材料(色块)和言语材料(色词)均没有表现出内隐加工学习效应，但两学习成绩的范围及趋势不同，且材料与IQ之间没有交互作用。间接揭示内隐学习存在一定的“阈限”及IQ独立性在不同情况下表现出特异性。     

Do children with mathematics learning disability in Hong Kong perceive word problems differently?

The current study aimed at identifying the difficulties experienced by children with mathematics learning disability (MLD) in the problem representation phase of arithmetic word problem solving using a novel problem types identification task. An MLD group (n = 66) and a typically achieving control group (n = 139) were recruited for an assessment on problem type identification as well as some domain-general and mathematics-related cognitive abilities. Results from ANCOVA showed that the MLD group scored significantly lower than the typically achieving control group on this assessment, after controlling for the effect of cognitive correlates, reading achievement and arithmetic performance. Furthermore, this assessment significantly predicted MLD membership even after taking children's arithmetic competency into account. The current study confirmed the difficulties in problem representation of arithmetic word problems experienced by students with MLD and provided evidence for the need to introduce schema instructions in mathematics classes.     

The Home Literacy Environment as a Predictor of the Early Literacy Development of Children at Family-Risk of Dyslexia

The home literacy environment (HLE) predicts language and reading development in typically developing children; relatively little is known about its association with literacy development in children at family-risk of dyslexia. We assessed the HLE at age 4 years, precursor literacy skills at age 5, and literacy outcomes at age 6, in a sample of children at family-risk of dyslexia (n = 116) and children with no known risk (n = 72). Developmental relationships between the HLE and literacy were comparable between the groups; an additional effect of storybook exposure on phoneme awareness was observed in the family-risk group only. The effects of socioeconomic status on literacy were partially mediated by variations in the HLE; in turn, effects of the HLE on literacy were mediated by precursor skills (oral language, phoneme awareness, and emergent decoding) in both groups. Findings are discussed in terms of possible gene–environment correlation mechanisms underpinning atypical literacy development.     

Effect of chunk strength on the performance of children with developmental dyslexia on artificial grammar learning task may be related to complexity

There’s a long held view that chunks play a crucial role in artificial grammar learning performance. We compared chunk strength influences on performance, in high and low topological entropy (a measure of complexity) grammar systems, with dyslexic children, age-matched and reading-level-matched control participants. Findings show that age-matched control participants’ performance reflected equivalent influence of chunk strength in the two topological entropy conditions, as typically found in artificial grammar learning experiments. By contrast, dyslexic children and reading-level-matched controls’ performance reflected knowledge of chunk strength only under the low topological entropy condition. In the low topological entropy grammar system, they appeared completely unable to utilize chunk strength to make appropriate test item selections. In line with previous research, this study suggests that for typically developing children, it is the chunks that are attended during artificial grammar learning and create a foundation on which implicit associative learning mechanisms operate, and these chunks are unitized to different strengths. However, for children with dyslexia, it is complexity that may influence the subsequent memorability of chunks, independently of their strength.     

Computer-based learning of spelling skills in children with and without dyslexia

Our spelling training software recodes words into multisensory representations comprising visual and auditory codes. These codes represent information about letters and syllables of a word. An enhanced version, developed for this study, contains an additional phonological code and an improved word selection controller relying on a phoneme-based student model. We investigated the spelling behavior of children by means of learning curves based on log-file data of the previous and the enhanced software version. First, we compared the learning progress of children with dyslexia working either with the previous software (n = 28) or the adapted version (n = 37). Second, we investigated the spelling behavior of children with dyslexia (n = 37) and matched children without dyslexia (n = 25). To gain deeper insight into which factors are relevant for acquiring spelling skills, we analyzed the influence of cognitive abilities, such as attention functions and verbal memory skills, on the learning behavior. All investigations of the learning process are based on learning curve analyses of the collected log-file data. The results evidenced that those children with dyslexia benefit significantly from the additional phonological cue and the corresponding phoneme-based student model. Actually, children with dyslexia improve their spelling skills to the same extent as children without dyslexia and were able to memorize phoneme to grapheme correspondence when given the correct support and adequate training. In addition, children with low attention functions benefit from the structured learning environment. Generally, our data showed that memory sources are supportive cognitive functions for acquiring spelling skills and for using the information cues of a multi-modal learning environment.     

Statistical Learning of Orthographic Regularities in Chinese Children With and Without Dyslexia

This study examined distributional statistical learning of positional, phonetic, and semantic regularities of an artificial orthography in Chinese children aged 8–10 years: 29 with dyslexia, 29 age-matched controls, and 30 reading-level matched controls. Despite having positional regularity learning performance comparable to the controls, the children with dyslexia were poorer at learning left-right structured characters than top-bottom structured characters in high- and low-consistency conditions. Moreover, they showed difficulties in mapping a given sound or meaning to a specific character compared with the typically developing controls. These findings suggest that children with dyslexia have deficits in some, though not all, aspects of statistical learning of character orthography, which may reflect their difficulties in coping with distractors and inconsistency of orthographic input.     

Auditory Sensory Processing and Phonological Development in High IQ and Exceptional Readers,Typically Developing Readers,and Children With Dyslexia: A Longitudinal Study

Phonological difficulties characterize children with developmental dyslexia across languages, but whether impaired auditory processing underlies these phonological difficulties is debated. Here the causal question is addressed by exploring whether individual differences in sensory processing predict the development of phonological awareness in 86 English-speaking lower- and middle-class children aged 8 years in 2005 who had dyslexia, or were age-matched typically developing children, some with exceptional reading/high IQ. The predictive relations between auditory processing and phonological development are robust for this sample even when phonological awareness at Time 1 (the autoregressor) is controlled. High reading/IQ does not much impact these relations. The data suggest that basic sensory abilities are significant longitudinal predictors of growth in phonological awareness in children.     

Mixture growth models of RAN and RAS row by row: insight into the reading system at work over time

Children (n = 122) and adults (n = 200) with dyslexia completed rapid automatic naming (RAN) letters, rapid automatic switching (RAS) letters and numbers, executive function (inhibition, verbal fluency), and phonological working memory tasks. Typically developing 3rd (n = 117) and 5th (n = 103) graders completed the RAS task. Instead of analyzing RAN/RAS results the usual way (total time), growth mixture modeling assessed trajectories of successive times for naming 10 symbols in each of five rows. For all three samples and both RAN and RAS, two latent classes were identified. The “faster” class performed slowly on the first row and increased time by small increments on subsequent rows. The “slower” latent class performed more slowly on the first row, and children, but not adults, increased time by larger increments on subsequent rows. For children, both the initial row (automaticity index) and slope (sustained controlled processing index) of the trajectory differentiated the classes. For adults, only the initial row separated the classes. The longest time was on row 3 for RAN and row 4 for RAS. For the typically developing 5th graders, close in age to the children with dyslexia, the trajectories were flatter than for children with dyslexia and only the slower class (4%) showed the peak on row 4. For children with dyslexia, inhibition predicted RAN slope within the slower latent class and phonological working memory predicted RAS slope for both latent classes. For adults with dyslexia, inhibition and phonological working memory differentiated both latent classes on RAN intercept and RAS slope. Taken together, RAN, which may assess the phonological loop of working memory, and RAS, which may assess the central executive in working memory, may explain the timing deficit in dyslexia in sustaining coordinated orthographic-phonological processing over time. This research was supported by Grant Ns. P50 33812 and R01 HD25858 from the National Institute of Child Health and Human Development, Virginia W. Berninger, PI.     

Foreign language reading and spelling in gifted students with dyslexia in secondary education

A few studies suggest that gifted children with dyslexia have better literacy skills than averagely intelligent children with dyslexia. This finding aligns with the hypothesis that giftedness-related factors provide compensation for poor reading. The present study investigated whether, as in the native language (NL), the level of foreign language (FL) literacy of gifted students with dyslexia is higher than the literacy level of averagely intelligent students with dyslexia and whether this difference can be accounted for by the difference in their NL literacy level. The sample consisted of 148 Dutch native speaking secondary school students divided in four groups: dyslexia, gifted/dyslexia, typically developing (TD), and gifted. All students were assessed on word reading and orthographic knowledge in Dutch and English when they were in 7th or 8th grade. A subsample (n = 71) was (re)assessed on Dutch, English, French, and German literacy one year later. Results showed that Dutch gifted students with dyslexia have higher NL literacy levels than averagely intelligent students with dyslexia. As in the NL, a stepwise pattern of group differences was found for English word reading and spelling, i.e., dyslexia < gifted/dyslexia < TD < gifted. However, it was not found for French and German literacy performance. These results point towards compensation: the higher English literacy levels of gifted/dyslexic students compared to their averagely intelligent dyslexic peers result from mechanisms that are unique to English as a FL. Differences in results between FLs are discussed in terms of variation in orthographic transparency and exposure.     

Spelling in Children With Dyslexia: Analyses From the Treiman-Bourassa Early Spelling Test

We examined the oral and written spelling performance on the Treiman-Bourassa Early Spelling Test (Treiman & Bourassa, 2000a) of 30 children with serious reading and spelling problems and 30 spelling-level-matched younger children who were progressing normally in learning to read and spell. The 2 groups' spellings were equivalent on a composite measure of phonological and orthographic sophistication, representation of the phonological skeleton of the items, and orthographic legality. The groups showed a similar advantage for words over nonwords on the phonological skeleton and orthographic legality measures. The children with dyslexia and the comparison children also showed an equivalent advantage for written over oral spelling on the composite and phonological skeleton measures. Further analyses revealed that children with dyslexia made many of the same linguistically based errors as typically developing children but also pointed to some subtle differences between the groups. Overall, the spelling performance of children with dyslexia appears to be quite similar to that of normally progressing younger children.