Exploring How Initial Response to Instruction Predicts Morphology Outcomes Among Students With Decoding Difficulties.

Children with weak decoding skills often struggle to learn multisyllabic words during reading instruction. The primary purpose of this study was to investigate the extent to which initial response to morphological awareness instruction, along with specific language and cognitive variables (i.e., phonological awareness, rapid naming, orthographic knowledge/awareness, verbal comprehension, working memory), predicts responsiveness to morphological awareness instruction for third-grade students who were at risk for reading disabilities. Thirty-nine third-grade students with decoding deficits were assessed on five independent variables identified as critical predictors of future performance on morphological tasks. A series of regression analyses showed that initial response to instruction, compared to other cognitive and language variables, predicted the most variance in students' morphological skills with prefixes. Furthermore, two cognitive variables, verbal working memory and comprehension, were predictive of performance on morphological tasks after accounting for initial response to instruction. Findings from this study suggest that students with decoding deficits may benefit from morphological instruction and those who demonstrate low response to initial morphological instruction or have weak verbal comprehension and verbal working memory abilities could be risk for failing to acquire morphological instruction as expected.

The roles of cognitive and language abilities in predicting decoding and reading comprehension: comparisons of dyslexia and specific language impairment.

This study aimed to (a) explore the roles of cognitive and language variables in predicting reading abilities of two groups of individuals with reading disabilities (i.e., dyslexia and specific language impairment) and (b) examine which variable(s) is the most predictive in differentiating two groups. Inclusion/exclusion criteria applied to categorize the two groups yielded a total of 63 participants (n = 44 for the dyslexia; n = 19 for the specific language impairment). A stepwise multiple regression approach was conducted to examine which cognitive and/or language variables made the largest contribution to reading abilities (i.e., Phonetic Decoding Efficiency, Word Attack, Sight Word Efficiency, and Passage Comprehension). Results revealed that there were significant differences in which measures of cognitive and language ability predicted individuals with dyslexia and speech and language impairments reading ability, showing that the cognitive and language variables underlying their difficulty with reading abilities were not the same across the two groups. A discriminant function analysis showed that a measure of Verbal Comprehension, Phonological Awareness, and Phonetic Decoding Efficiency can be used to differentiate the two groups. These findings support the tenet that dyslexia and specific language impairment are two subgroups of reading disabilities and that thorough diagnostic evaluations are needed to differentiate between these two subgroups. Distinctions of this nature are central to determining the type and intensity of language-based interventions.

Investigating graph comprehension in students with dyslexia: an eye tracking study.

The purpose of this study was to examine graph comprehension in college students with developmental dyslexia. We investigated how graph types (line, vertical bar, and horizontal bar graphs), graphic patterns (single and double graphic patterns), and question types (point locating and comparison questions) differentially affect graph comprehension of students with and without dyslexia. Groups were compared for (1) reaction times for answering comprehension questions based on graphed data and (2) eye gaze times for specific graph subregions (x-axis, y-axis, pattern, legend, question, and answer). Dyslexic readers were significantly slower in their graph comprehension than their peers with group differences becoming more robust with the increasing complexity of graphs and tasks. In addition, dyslexic readers' initial eye gaze viewing times for linguistic subregions (question and answer) and total viewing times for both linguistic (question and answer) and nonlinguistic (pattern) subregions were significantly longer than their control peers' times. In spite of using elementary-level paragraphs for comprehension and simple graph forms, young adults with dyslexia needed more time to process linguistic and nonlinguistic stimuli. These findings are discussed relative to theories proposed to address fundamental processing deficits in individuals with dyslexia.

What do diagnostic test data tell us about differences in the profiles of children diagnosed with reading disability or language impairments?

UNLABELLED: A detailed evaluation of a child's strengths and weaknesses allows for a valid and reliable diagnosis of reading disability for the selection of optimal intervention practices. Using archival data from a clinic that specialized in the diagnosis of reading disabilities, we compared the performance of 60 children diagnosed with specific reading disability (SRD) and 31 children with language impairments and reading disability (LIRD) on measures of cognitive reasoning, verbal ability, phonological manipulation, rapid serial naming, and phonological memory. While the SRD and LIRD groups did not differ in their phonological processing, children with LIRD performed significantly below their peers with SRD on thinking ability and verbal ability measures. Rapid naming skills served as current predictors of text reading fluency and verbal ability skills served as concurrent predictors of reading comprehension in both groups. These findings highlight the need for reading diagnosticians to conduct comprehensive evaluations using a range of cognitive and language processes to ensure the most accurate and specific diagnoses of children with reading disabilities. LEARNING OUTCOMES: Readers will be able to (a) describe general characteristics of reading disabilities, (b) differentiate features of two learning disabilities, specific reading disability and language impairments and reading disability, and (c) identify key clinical issues and approaches for identification, diagnosis, and intervention of these two diagnostic profiles.

Relationships among cognitive deficits and component skills of reading in younger and older students with developmental dyslexia.

Processing speed deficits along with phonological awareness deficits have been identified as risk factors for dyslexia. This study was designed to examine the behavioral profiles of two groups, a younger (6-8 years) and an older (10-15 years) group of dyslexic children for the purposes of (1) evaluating the degree to which phonological awareness and processing speed deficits occur in the two developmental cohorts; (2) determining the strength of relationships between the groups' respective mean scores on cognitive tasks of phonological awareness and processing speed and their scores on component skills of reading; and (3) evaluating the degree to which phonological awareness and processing speed serve as concurrent predictors of component reading skills for each group. The mean scaled scores for both groups were similar on all but one processing speed task. The older group was significantly more depressed on a visual matching test of attention, scanning, and speed. Correlations between reading skills and the cognitive constructs were very similar for both age-groups. Neither of the two phonological awareness tasks correlated with either of the two processing speed tasks or with any of the three measures of reading. One of the two processing speed measures served as a concurrent predictor of word- and text-level reading in the younger, however, only the rapid naming measure functioned as a concurrent predictor of word reading in the older group. Conversely, phonological processing measures did not serve as concurrent predictors for word-level or text-level reading in either of the groups. Descriptive analyses of individual subjects' deficits in the domains of phonological awareness and processing speed revealed that (1) both linguistic and nonlinguistic processing speed deficits in the younger dyslexic children occurred at higher rates than deficits in phonological awareness and (2) cognitive deficits within and across these two domains were greater in the older dyslexic children. Our findings underscore the importance of using rapid naming measures when testing school-age children suspected of having a reading disability and suggest that processing speed measures that do not reply on verbal responses may serve as predictors of reading disability in young children prior to their development of naming automaticity.

Phonology matters: a comprehensive investigation of reading and spelling skills of school-age children with mild to moderate sensorineural hearing loss.

The investigators measured 7 literacy skills in a group of 21 school-age children with mild to moderate sensorineural hearing loss (MSNH group), and compared the scores to those of 2 age-matched groups: children with dyslexia (DYS group) and, as a control, typically developing hearing children (CA group). The MSNH group performed consistently below the CA group but better than the DYS group, an indication that differences in the groups' phonological processing profiles might be an important discriminating feature. Interestingly, the MSNH group showed a selective impairment in word reading accuracy only, whereas their reading rate was relatively unaffected. Children with MSNH who show weak phonological awareness skills seem to compensate by relying on orthographic recognition associated with rapid naming ability. To determine which children with MSNH are at high risk for depressed reading achievement, testing across a widerange of literacy skills should be considered.

A comparison of phonological processing skills of children with mild to moderate sensorineural hearing loss and children with dyslexia.

Using the comprehensive Test of Phonological Processes (Wagner, Torgesen, & Rashotte, 1999), the researchers compared strengths and weaknesses in phonological processing skills in three groups: 21 children with mild to moderate sensorineural hearing loss (MSNH group), 29 children with dyslexia, and 30 age-matched controls. The MSNH group showed phonological deficits that were restricted to phonological awareness tasks (elision/blending) and a phonological memory task (nonword repetition), yet exhibited unimpaired rapid naming ability. Children with dyslexia showed deficits in all 3 phonological constructs. Finally, both degree of hearing loss and age at which hearing loss was identified in the MSNH group were related to the children's phonological processing skills. Because of their deteriorated phonological skills, children with MSNH may be at risk of starting school with weaknesses in early literacy skills. Implications for practice aimed at improving phonological and literacy skills of these children are described.

Sentence comprehension in young adults with developmental dyslexia.

This study investigated the effects of syntactic complexity on written sentence comprehension in compensated adults with dyslexia. Because working memory (WM) plays a key role in processing complex sentences, and individuals with dyslexia often demonstrate persistent deficits in WM, we hypothesized that individuals with dyslexia would perform more poorly on tasks designed to assess the comprehension of syntactic structures that are especially taxing on WM (e.g., passives, sentences with relative clauses). Compared to their nondyslexic peers, individuals with dyslexia were significantly less accurate and marginally slower on passive sentences. For sentences containing relative clauses, the dyslexic group was also less accurate but did not differ in response times. Covarying WM and word reading in both analyses eliminated group differences showing that syntactic deficits in adults with dyslexia are constrained by both WM and word-reading ability. These findings support previous research showing that syntactic processing deficits are characteristic of dyslexia, even among high-achieving students.

Assessing the microstructure of written language using a retelling paradigm.

PURPOSE: The primary goal of this study was to document the progression of the microstructural elements of written language in children at 4 grade levels. The secondary purpose was to ascertain whether the variables selected for examination could be classified into valid categories that reflect the multidimensional nature of writing. METHOD: Written language samples were collected and transcribed from 120 children in Grades 3 through 6 using an expository text-retelling paradigm. Nine variables at various levels of language were analyzed. RESULTS: Using a text-retelling paradigm, measures of productivity (e.g., total number of words and ideas) improved steadily with age, whereas measures of complexity (e.g., mean length of T-unit) did not. Results for measures of accuracy (e.g., spelling and writing conventions) were mixed, with some showing improvement across grades. Grade 3 students showed consistently poorer performance than students in Grades 4, 5, and 6. Grade 4 students showed poorer performance than students in Grades 5 and 6. Exploratory factor analysis suggests that writing can be represented by 3 factors: Productivity, Complexity, and Accuracy. CONCLUSIONS: Clinicians can use this multidimensional scheme for examining writing skills using text-retelling formats with children from Grades 3 through 6. This empirically based framework for measuring microstructural variables of writing provides clinicians with a 3-prong conceptual framework for determining children's strengths and weaknesses within the translational stage of writing.

Manual and automated measures of superior temporal gyrus asymmetry: concordant structural predictors of verbal ability in children.

The planum temporale is a region on the posterior surface of the temporal lobe that exhibits robust leftward structural asymmetry, which has been linked to verbal ability in children and adults. Traditionally, structural asymmetry has been quantified with manual assessment of high resolution MRI scans. Such measures require subjective and frequently unreliable determination of highly variable anatomical boundaries. Methodological developments in automated image processing (voxel-based morphometry - VBM) offer the opportunity to obtain objective and reliable measures of structural variation. This study examined the extent to which a VBM measure of gray matter asymmetry in the posterior superior temporal gyrus (pSTG) characterized the same individual variation as a manual measure of planum temporale asymmetry in 99 healthy adults and 39 typically developing children. Planum temporale asymmetry was significantly correlated with pSTG gray matter asymmetry in the samples of adults and children. As a measure of validity we examined the extent to which the VBM measure of pSTG gray matter asymmetry predicted measures of verbal ability that were associated with the manual measure of planum temporale asymmetry in the same children. The two asymmetry measures predicted the same variance in verbal ability. The automated measure of pSTG gray matter asymmetry predicted additional significant variance in verbal ability, however. In addition, a posterior STS region was also identified that significantly predicted verbal ability. These results demonstrate significant advantages of an automated voxel-based measure over a manual measure of planum temporale asymmetry.

Sentence production in students with dyslexia.

BACKGROUND: While spoken language deficits have been identified in children with developmental dyslexia, microanalysis of sentence production proficiency in these children is a largely unexplored area. AIMS: The current study examines proficiency of syntactic production in children and young adults with dyslexia and typically developing age-matched controls on a constrained sentence production task targeting two advanced argument structures, theme-experiencer verbs and irregular past participles. METHODS & PROCEDURES: Participants aged between 8 and 22 years produced sentences that included three stimulus words, a proper name, an inanimate noun and a verb from one of three categories: control verbs (agent-patient verbs with regular morphology); theme-experiencer verbs, which require an inanimate subject in active sentences (e.g. The book bored Sarah); and irregular past participles, which require awareness of the syntactic requirements associated with the -en past participle ending, i.e. that this verb form cannot be used as a simple past tense (e.g. *Mary ___ hidden the candy). OUTCOMES & RESULTS: Students with dyslexia produced more dysfluent, ungrammatical and incomplete responses than normal readers; however, the developmental trajectories of the verb types varied between groups. Normal readers performed similarly with both experimental verb types, but those with dyslexia were particularly impaired using irregular past participles in sentences. CONCLUSIONS: The findings support a model of lexical representation in which development of grammar hinges on the acquisition of lexical knowledge. Furthermore, the data suggest that individuals with dyslexia may have difficulties with sentence formulation that persist into adulthood.

Subtyping of children with developmental dyslexia via bootstrap aggregated clustering and the gap statistic: comparison with the double-deficit hypothesis.

BACKGROUND: The marked degree of heterogeneity in persons with developmental dyslexia has motivated the investigation of possible subtypes. Attempts have proceeded both from theoretical models of reading and the application of unsupervised learning (clustering) methods. Previous cluster analyses of data obtained from persons with reading disabilities have suffered from the inherent limitations of unsupervised learning methods. Specifically, the reliability and stability of cluster solutions have proven difficult to determine. Recent developments in the clustering literature have addressed these concerns by permitting checks on the internal validity of the solution. Resampling methods produce consistent groupings of the data independent of initialization effects, while the gap statistic provides a confidence measure for the determination of the optimal number of clusters present in the data. Combining these methods produces a robust data-driven classification that can be compared with theoretically based subtypes to produce better-informed models of developmental dyslexia. AIMS: The present study is a novel application of resampling (bootstrap aggregating or bagging) methods and the gap statistic to the subtyping of children with developmental dyslexia. The specific aims of this study are: (1) to illustrate the use of bagging methods and the gap statistic in multivariate data obtained from children with developmental dyslexia; and (2) to compare the bagged clustering thresholded by the gap statistic against the predictions of the double-deficit hypothesis. The double-deficit hypothesis is a prominent theoretical model of developmental dyslexia, which predicts three subtypes: phonological, rate, and phonological-rate impaired readers. METHODS & PROCEDURES: Three simulated data sets with known cluster structure were created to check the validity and illustrate the utility of the bagged clustering with the gap statistic in data with known structure. Subsequently, a clinical database of standardized test data (eight tests) from 93 children with developmental dyslexia was clustered using these methods. This procedure was repeated on a database of 93 children without reading disability matched for gender and age as a control. Finally, the clustering was repeated on the entire database of 186 participants. Cluster solutions were obtained for an increasing number of clusters (1-10) and were tested against the null hypothesis that no subtypes were present, i.e. the data represented a single cluster. OUTCOMES & RESULTS: Four clusters were identified in the children with developmental dyslexia. There was no evidence of significant cluster structure in the children without dyslexia. Two clusters were identified when children with and without reading impairments were considered together. Among the participants with developmental dyslexia, there was evidence of a phonological-deficit cluster, a rapid-naming cluster, and a cluster showing both depressed phonological processing and rapid naming. These accounted for 73 of the 93 participants (78%). All three are predicted by the double-deficit hypothesis. The fourth cluster consisted of children with normal phonological and rapid naming ability incommensurate with their high verbal ability. An analysis of variance with post-hoc multiple comparisons demonstrated that the phonological, rapid-naming, and double deficit clusters did not differ significantly in age, but the fourth cluster was comprised of significantly older children. The mixed data set revealed two clusters. One cluster consisted almost entirely of the double-deficit and phonological subtypes. The other consisted of the participants without dyslexia and the children with dyslexia demonstrating either a single rapid naming deficit or standardized test scores in the normal range. A silhouette analysis indicated that the four-cluster solution for the children with developmental dyslexia was superior to the two-cluster solution obtained for the entire data set. CONCLUSIONS: The study provides support for the presence of distinct subtypes in children with developmental dyslexia and for the double-deficit hypothesis. Specifically, this study finds three subtypes predicted by the double-deficit hypothesis without the assumption of an a priori theoretical model of reading. Taken together, these subtypes account for 79% of the participants with dyslexia. Further, the percentages of children in each subtype are in good agreement with previous studies. The participants in the subtype not predicted by the double-deficit hypothesis were significantly older than the other three groups. Recent advances in unsupervised learning can be expected to aid the improvement and refinement of the definition of developmental dyslexia. If reliable and consistent subtypes can be identified among persons with developmental dyslexia, it is reasonable to assume that diagnostic and intervention efforts will be greatly improved.

Neuroanatomical and behavioral asymmetry in an adult compensated dyslexic.

Individual differences in cortical anatomy are readily observable, but their functional significance for behaviors such as reading is not well understood. Here, we report a case of an apparent compensated dyslexic who had attained high achievement in visuospatial mathematics. Data from a detailed background interview, psychometric testing, divided visual field tasks measuring basic word recognition (word naming, nonword naming, and lexical decision), and more controlled word retrieval (verb, category, and rhyme generation), and measurements of his atypical brain structure are described. The findings suggested that enhanced "top-down" processing could provide the means to compensate for deficient "bottom-up" word decoding skills in this case. Relative to controls, this individual also evidenced unusually large asymmetries on several divided visual field lexical tasks, an extreme leftward asymmetry of the planum temporale, and a rare form of Sylvian fissure morphology (Steinmetz type 4, [Steinmetz, H., Ebeling, U., Huang, Y., & Kahn, T. (1990). Sulcus topography of the parietal opercular region: An anatomic and MR study. Brain and Language, 38, 515-533.]). We suggest that certain forms of brain organization may be associated with successful behavioral compensation for dyslexia, and that anatomical variations in the right hemisphere may be important contributors to individual differences in reading acquisition and achievement.

Comorbid auditory processing disorder in developmental dyslexia.

OBJECTIVE: The primary objective of this study was to investigate the extent of comorbid auditory processing disorder (APD) in a group of adults with developmental dyslexia. An additional objective was to compare performance on auditory tasks to results from standardized tests of reading in an attempt to generate a clinically useful profile of developmental dyslexics with comorbid APD. DESIGN: A group of eleven persons with developmental dyslexia and 14 age- and intelligence-matched controls participated in the study. Behavioral audiograms, 226-Hz tympanograms, and word recognition scores were obtained binaurally from all subjects. Both groups were administered the frequency-pattern test (FPT) and duration-pattern test (DPT) monaurally (30 items per ear) in both the left and right ear. Gap detection results were obtained in both groups (binaural presentation) using narrowband noise centered at 1 kHz in an adaptive two-alternative forced-choice (2-AFC) paradigm. The FPT, DPT, and gap detection results were analyzed for interaural (where applicable), intergroup, and intragroup differences. Correlations between performance on the auditory tasks and the standardized tests of reading were examined. Additive logistic regression models were fit to the data to determine which auditory tests proved to be the best predictors of group membership. RESULTS: The persons with developmental dyslexia as a group performed significantly poorer than controls on both the FPT and DPT. Furthermore, the group differences were significant in both monaural conditions. On the FPT and DPT, five of the eleven participants with dyslexia performed below the widely used clinical criterion for APD of 70% correct in either ear. All five of these participants performed below criterion on the FPT, whereas four of the five additionally performed below 70% on the DPT. The data also were analyzed by fitting a series of stepwise logistic regression models, which indicated that gap detection did not significantly predict group membership, whereas the FPT and DPT were significant predictors. The addition of the FPT score after the DPT did not result in a significant change in the residual deviance. CONCLUSIONS: Approximately half of the participants with developmental dyslexia showed clinically significant diminished performance on the FPT and DPT indicative of APD. These results indicate that the percentage of persons with developmental dyslexia and comorbid APD may be substantial enough to warrant serious clinical considerations.

Anatomical risk factors that distinguish dyslexia from SLI predict reading skill in normal children.

UNLABELLED: These studies investigated whether anatomical measures could separate phonologically-based reading disability (PD) from nonphonologically-based learning disabilities such as specific language impairment (SLI). In a previous study. four brain measures (cerebral asymmetry. summed planum temporale and parietale asymmetry, anterior cerebellar asymmetry, and a duplicated left Heschl's gyrus) distinguished a group of PD adults from reading disabled adults without specific phonological deficits (URD). Study 1 found that these measures did not distinguish 14 reading disabled children from 21 children with SLI. Instead, differences were found in cerebral volume, planum temporale asymmetry, and the size of a single left Heschl's gyrus. Study 2 demonstrated that including all seven measures in a discriminant analysis separated the adults and children into two groups: one with 100% of the PD adults and 75% of the reading disabled children and the other with 72% of the SLI children and 75% of the URD adults. Study 3 demonstrated that an anatomical risk factor index (ARF7) generated from the discriminant function with seven brain measures predicted reading in normal children. Children with ARF7 near 0 (normal anatomy) had superior verbal ability and phonological decoding scores that improved with age. Normal children with negative ARF7 the relatively s mall symmetrical structures that characterize SLI)had deficits in verbal ability. Children with positive ARF7 (the asymmetrical structures that characterize PD) had phonological decoding scores that decreased with age. These results suggest that PD and SLI are qualitatively different disorders associated with anatomical deviations in opposite directions from the population mean. LEARNING OUTCOMES: As a result of this activity, the participant will be able to: (1) distinguish the neuroanatomical features that characterize PD and SLI; (2) recognize that PD is associated with large asymmetrical brain structures while SLI is associated with smaller symmetrical brain structures; (3) understand that children with moderate sized brains and whose anatomy is intermediate between symmetry and extreme asymmetry have an enhanced probability of developing good verbal ability; (4) understand that reading disabilities depend on the interaction of neurodevelopment and the environment.

Invented Spelling: Developmental Patterns in Kindergarten Children and Guidelines for Early Literacy Intervention.

Types and distributions of spelling patterns were identified in the invented spelling samples of 100 children in the second semester of their kindergarten year. Invented spellings were studied because they provide a valid measure of children's phonemic awareness in print-a skill that is highly correlated with reading success in the early stages of literacy acquisition. The subjects' spelling errors were used to develop a taxonomy of 10 invented spelling patterns and 21 response types that characterized the children's most frequently occurring spellings of graphemes targeted for analysis in 12 words. The acquisition of spelling patterns was examined by dividing the children into three groups based on the phonemic accuracy of their spellings on a pre-readirng instrument. A developmental ordering of spelling patterns is presented and relationships among phonological awareness, spelling, and reading are discussed as they are relevant to speech-language pathologists treating children who are at risk for reading disabilities.