Genetics can inform causation, but the concepts and language we use matters.

Madole & Harden describe how genetics can be used in a causal framework. We agree with many of their opinions but argue that comparing within-family designs to experiments is unnecessary and that the proposed influence of genetics on behavior can be better described as inus conditions.

Early Detection of Dyslexia Risk: Development of Brief, Teacher-Administered Screens.

Many states now mandate early screening for dyslexia, but vary in how they address these mandates. There is confusion about the nature of screening versus diagnostic assessments, risk versus diagnosis, concurrent versus predictive validity, and inattention to indices of classification accuracy as the basis for determining risk. To help define what constitutes a screening assessment, we summarize efforts to develop short (3-5 min), teacher-administered screens that used multivariate strategies for variable selection, item response theory to select items that are most discriminating at a threshold for predicting risk, and statistical decision theory. These methods optimize prediction and lower the burden on teachers by reducing the number of items needed to evaluate risk. A specific goal of these efforts was to minimize decision errors that would result in the failure to identify a child as at risk of dyslexia/reading problems (false negatives) despite the inevitable increase in identifications of children who eventually perform in the typical range (false positives). Five screens, developed for different periods during kindergarten, Grade 1, and Grade 2, predicted outcomes measured later in the same school year (Grade 2) or in the subsequent year (Grade 1). The results of this approach to development are applicable to other screening methods, especially those that attempt to predict those children at risk of dyslexia prior to the onset of reading instruction. Without reliable and valid early predictive screening measures that reduce the burden on teachers, early intervention and prevention of dyslexia and related reading problems will be difficult.

The Effects of ADHD Treatment and Reading Intervention on the Fluency and Comprehension of Children with ADHD and Word Reading Difficulties: A Randomized Clinical Trial.

Many students with reading difficulties and disabilities (RD) also have Attention Deficit/Hyperactivity Disorder (ADHD). This randomized clinical trial compared the effects of ADHD treatment alone (medication, parent training), intensive reading intervention alone, and their combination on the reading fluency and comprehension of students with both disorders. Students with ADHD and RD were randomly assigned to receive (a) Reading Intervention only (n=74), (b) ADHD Treatment only (n=78), or (c) simultaneous Combined ADHD and RD Treatment (n=70). For phonemic decoding fluency, the Reading Intervention group and the Combined Treatment group both had significantly better outcomes than the ADHD Treatment group, but did not differ from one another. For passage comprehension, the ADHD Treatment group had significantly better outcomes than the Reading Intervention group, while the other groups did not differ from one another. ADHD treatment may support passage comprehension in this population, while fluent decoding is best supported through intensive reading intervention.

Differential Co-Development of Vocabulary Knowledge and Reading Comprehension for Students with and without Learning Disabilities.

In this large-scale study of students from Title 1 schools (N = 14,773), we used multiple-group latent change score (LCS) modeling to investigate the developmental relations between vocabulary knowledge and reading comprehension in students with a school-identified learning disability (LD, n = 627) and typically developing students (n = 14,146). Students were tested for their vocabulary breadth and passage comprehension skills in Kindergarten through fourth grade. For typically developing students, there were bidirectional influences between their vocabulary knowledge and reading comprehension skills. There were no cross-lagged influences across constructs for students with an LD. We find evidence for a developmental delay, such that students with an LD had similar levels and gains in their vocabulary knowledge relative to typically developing students, but these students started much lower in their reading comprehension skills and did not catch up to their typically developing peers. We discuss the implications for children with learning disabilities and the development of their reading comprehension skills.

How the Science of Reading Informs 21st-Century Education.

The science of reading should be informed by an evolving evidence base built upon the scientific method. Decades of basic research and randomized controlled trials of interventions and instructional routines have formed a substantial evidence base to guide best practices in reading instruction, reading intervention, and the early identification of at-risk readers. The recent resurfacing of questions about what constitutes the science of reading is leading to misinformation in the public space that may be viewed by educational stakeholders as merely differences of opinion among scientists. Our goals in this paper are to revisit the science of reading through an epistemological lens to clarify what constitutes evidence in the science of reading and to offer a critical evaluation of the evidence provided by the science of reading. To this end, we summarize those things that we believe have compelling evidence, promising evidence, or a lack of compelling evidence. We conclude with a discussion of areas of focus that we believe will advance the science of reading to meet the needs of all children in the 21st century.

Genetic and environmental influences on early literacy skills across school grade contexts.

Recent research suggests that the etiology of reading achievement can differ across environmental contexts. In the US, schools are commonly assigned grades (e.g. 'A', 'B') often interpreted to indicate school quality. This study explored differences in the etiology of early literacy skills for students based on these school grades. Participants included twins drawn from the Florida Twin Project on Reading (n = 1313 pairs) aged 4 to 10 years during the 2006-07 school year. Early literacy skills were assessed with DIBELS subtests: Oral Reading Fluency (ORF), Nonsense Word Fluency (NWF), Initial Sound Fluency (ISF), Letter Naming Fluency (LNF), and Phoneme Segmentation Fluency (PSF). School grade data were retrieved from the Florida Department of Education. Multi-group analyses were conducted separately for subsamples defined by 'A' or 'non-A' schools, controlling for school-level socioeconomic status. Results indicated significant etiological differences on pre-reading skills (ISF, LNF, and PSF), but not word-level reading skills (ORF and NWF). There was a consistent trend of greater environmental influences on pre-reading skills in non-A schools, arguably representing 'poorer' environmental contexts than the A schools. Importantly, this is the case outside of resources linked with school-level SES, indicating that something about the direct environment on pre-reading skills in the non-A school context is more variable than for A schools.

Exploring the Co-Development of Reading Fluency and Reading Comprehension: A Twin Study.

This study explores the co-development of two related but separate reading skills, reading fluency and reading comprehension, across Grades 1-4. A bivariate biometric dual change score model was applied to longitudinal data collected from 1,784 twin pairs between the ages of 6 and 10 years. Grade 1 skills were influenced by highly overlapping genetic and environmental factors. Growth in both skills was influenced by highly overlapping shared environmental factors. Cross-lagged parameters indicated bidirectional effects, with stronger effects from fluency to comprehension change than from comprehension to fluency change.

Expanding the developmental models of writing: A direct and indirect effects model of developmental writing (DIEW).

We investigated direct and indirect effects of component skills on writing (DIEW) using data from 193 children in Grade 1. In this model, working memory was hypothesized to be a foundational cognitive ability for language and cognitive skills as well as transcription skills, which, in turn, contribute to writing. Foundational oral language skills (vocabulary and grammatical knowledge) and higher-order cognitive skills (inference and theory of mind) were hypothesized to be component skills of text generation (i.e., discourse-level oral language). Results from structural equation modeling largely supported a complete mediation model among four variations of the DIEW model. Discourse-level oral language, spelling, and handwriting fluency completely mediated the relations of higher-order cognitive skills, foundational oral language, and working memory to writing. Moreover, language and cognitive skills had both direct and indirect relations to discourse-level oral language. Total effects, including direct and indirect effects, were substantial for discourse-level oral language (.46), working memory (.43), and spelling (.37), followed by vocabulary (.19), handwriting (.17), theory of mind (.12), inference (.10), and grammatical knowledge (.10). The model explained approximately 67% of variance in writing quality. These results indicate that multiple language and cognitive skills make direct and indirect contributions, and it is important to consider both direct and indirect pathways of influences when considering skills that are important to writing.

Home Environmental and Behavioral Risk Indices for Reading Achievement.

The goal of this study was to identify home environmental and temperament/behavior variables that best predict standardized reading comprehension scores among school-aged children. Data from 269 children aged 9-16 (M = 12.08; SD = 1.62) were used in discriminant function analyses to create the Home and Behavior indices. Family income was controlled in each index. The final Home and Behavior models each classified around 75% of cases correctly (reading comprehension at grade level vs. not). Each index was then used to predict other outcomes related to reading. Results showed that Home and/or Behavior accounted for 4-7% of the variance in reading fluency and spelling and 20-35% of the variance in parent-rated problems in math, social anxiety, and other dimensions. These metrics show promise as environmental and temperament/behavior risk scores that could be used to predict and potentially screen for further assessment of reading related problems.

Using Simulations to Investigate the Longitudinal Stability of Alternative Schemes for Classifying and Identifying Children with Reading Disabilities.

The present study employed data simulation techniques to investigate the one-year stability of alternative classification schemes for identifying children with reading disabilities. Classification schemes investigated include low performance, unexpected low performance, dual-discrepancy, and a rudimentary form of constellation model of reading disabilities that included multiple criteria. Data from Spencer et al. (2014) were used to construct a growth model of reading development. The parameters estimated from this model were then used to construct three simulated datasets wherein the growth parameters were manipulated in one of three ways: A stable-growth pattern, a mastery learning pattern and a fan-spread pattern. Results indicated that overall the constellation model provided the most stable classifications across all conditions of the simulation, and that classification schemes were most stable in the fan-spread condition, and were the least stable under the mastery learning growth pattern. These results also demonstrate the utility of data simulations in reading research.

Intensive Reading Remediation in Grade 2 or 3: Are There Effects a Decade Later?

Despite data supporting the benefits of early reading interventions, there has been little evaluation of the long-term educational impact of these interventions, with most follow-up studies lasting less than two years (Suggate, 2010). This study evaluated reading outcomes more than a decade after the completion of an 8-month reading intervention using a randomized design with second and third graders selected on the basis of poor word-level skills (Blachman et al., 2004). Fifty-eight (84%) of the original 69 participants took part in the study. The treatment group demonstrated a moderate to small effect size advantage on reading and spelling measures over the comparison group. There were statistically significant differences with moderate effect sizes between treatment and comparison groups on standardized measures of word recognition (i.e., Woodcock Basic Skills Cluster, d = 0.53; Woodcock Word Identification, d = 0.62), the primary, but not exclusive, focus of the intervention. Statistical tests on other reading and spelling measures did not reach thresholds for statistical significance. Patterns in the data related to other educational outcomes, such as high school completion, favored the treatment participants, although differences were not significant.

Examining transactional influences between reading achievement and antisocially-behaving friends.

The association between poorer academic outcomes and having antisocial friends is reliably demonstrated yet not well understood. Genetically sensitive designs uniquely allow for measuring genetic vulnerabilities and/or environmental risk in the association of antisocial friend behavior and poor school achievement, allowing for a better understanding of the nature of the association. This study included 233 pairs of twins from the Florida Twin Project on Reading. First, the role of antisocial friends as an environmental moderator of reading comprehension was examined. Antisocial friends significantly moderated the nonshared environmental variance in reading comprehension, with increased variation at lower levels of association with antisocial friends, with niche-picking indicated. Second, the role of reading comprehension as an environmental moderator of antisocial friends was examined. Reading comprehension significantly moderated the nonshared environmental variance in associating with antisocial friends, with increased variance at lower levels of reading comprehension and indication that common genetic influences contributed to higher reading achievement and better-behaved friends. In total, these results suggested reciprocal influences between reading achievement and antisocially-behaving friends. The impact of antisocial friends appeared to be limited in the extent to which they can undermine reading achievement, and high reading achievement appeared to support less association with antisocial friends.

To Wait in Tier 1 or Intervene Immediately: A Randomized Experiment Examining First Grade Response to Intervention (RTI) in Reading.

This randomized controlled experiment compared the efficacy of two Response to Intervention (RTI) models - Typical RTI and Dynamic RTI - and included 34 first-grade classrooms (n = 522 students) across 10 socio-economically and culturally diverse schools. Typical RTI was designed to follow the two-stage RTI decision rules that wait to assess response to Tier 1 in many districts, whereas Dynamic RTI provided Tier 2 or Tier 3 interventions immediately according to students' initial screening results. Interventions were identical across conditions except for when intervention began. Reading assessments included letter-sound, word, and passage reading, and teacher-reported severity of reading difficulties. An intent-to-treat analysis using multi-level modeling indicated an overall effect favoring the Dynamic RTI condition (d = .36); growth curve analyses demonstrated that students in Dynamic RTI showed an immediate score advantage, and effects accumulated across the year. Analyses of standard score outcomes confirmed that students in the Dynamic condition who received Tier 2 and Tier 3 ended the study with significantly higher reading performance than students in the Typical condition. Implications for RTI implementation practice and for future research are discussed.

Incorporating RTI in a Hybrid Model of Reading Disability.

The present study seeks to evaluate a hybrid model of identification that incorporates response-to-intervention (RTI) as a one of the key symptoms of reading disability. The one-year stability of alternative operational definitions of reading disability was examined in a large scale sample of students who were followed longitudinally from first to second grade. The results confirmed previous findings of limited stability for single-criterion based operational definitions of reading disability. However, substantially greater stability was obtained for a hybrid model of reading disability that incorporates RTI with other common symptoms of reading disability.

Understanding Inadequate Response to First Grade Multi-Tier Intervention: Nomothetic and Idiographic Perspectives.

The purpose of this study was to use a mixed methods approach to learn about inadequate response to a year-long multi-tier RTI model that allowed first-grade students to move up and down tiers. Participants were 156 students who received supplemental intervention services during a larger multi-tier RTI study involving classrooms and 522 students across 10 schools. Findings from an all-subset regression indicate letter word reading, the fluency composite, and blending words explained the most variance (15%) in response among initial skills. Adding additional teacher ratings of behavior and academics, accounted for a small amount of additional variance (3%) in group membership. The ROC curve analysis indicated 87.5% of students were correctly classified, yielding a sensitivity of 85.3 and a specificity of 65.0. Findings from qualitative observations of intervention sessions suggest inadequate responders demonstrated physical and verbal task avoidance and displayed emotions of hopelessness and shame. Implications for practice are discussed.

A Community Data Sharing Resource: The LDbase Data Repository.

The purpose of this invited paper is to show the learning disabilities field what LDbase is, why it's important for the field, what it offers the field, and examples of how you can leverage LDbase in your own work.

Student Behavior Ratings and Response to Tier 1 Reading Intervention: Which Students Do Not Benefit?

Core reading instruction and interventions have differential effects based on student characteristics such as cognitive ability and pre-intervention skill level. Evidence for differential effect based on affective characteristics is scant and ambiguous; however, students with problem behavior are more often non-responsive to core reading instruction and intensive reading interventions. In this study, we estimated the range of students' behavior ratings in which a core reading instruction intervention was effective using a data set including 3,024 students in K-3. Data came from seven independent studies evaluating the Individualized Student Instruction (ISI) Tier 1 reading intervention and were pooled using integrative data analysis. We estimated Johnson-Neyman intervals of student behavior ratings that showed a treatment effect both at the within and between classroom level. ISI was effective in improving reading scores (b=0.51, p=.020, d = 0.08). However, students with very low or very high behavior ratings did not benefit from the approaches (range of behavior rating factor scores: -0.95 - 2.87). At the classroom level, students in classrooms with a higher average of problem behaviors did not benefit from ISI (average classroom behavior rating factor score: 0.05 - 4.25). Results suggest differentiating instruction alone is not enough for students with behavior problems to grow in reading ability.

Morphological Complexity in Writing: Implications for Writing Quality and Patterns of Change.

PURPOSE: The current study examined (a) the relation between morphologically complex word (MCW) use (words containing at least one derivational morpheme such as prefixes and suffixes) and teachers' ratings of writing quality, (b) average change in MCW use in writing across the school year, and (c) differential change in MCW among students with varying language abilities and linguistic backgrounds including students with developmental language disorders (DLDs) and multilingual learners (MLs). METHOD: Expository writing samples (writing for the purpose of explaining or educating) were collected in October and May from 824 fifth-grade students, including 109 with DLD and 170 who were MLs receiving English as a second language service. Students' written responses were coded for the use of MCW. Pearson product-moment correlations and two-level hierarchical linear models were employed to investigate the association between MCW usage and writing quality, as well as increases in MCW usage over the course of the academic year, taking into account the nested structure of students within classrooms. RESULTS: The relation between students' MCW use and teachers' writing quality ratings was moderately strong (r = .47). Student use of MCW in expository writing showed significant change from fall to spring across all students. However, the amount of change in MCW use across the school year was significantly lower for MLs (effect size [ES] = .09) and students identified with DLD (ES = .10). CONCLUSIONS: The relation between MCW use and teachers' writing quality ratings highlights the utility of MCW as a written language measure for progress monitoring or assessment. The presence of differential change and potential Matthew effects for MLs and students with DLD substantiates the need for further exploration of instructional components that support the increased use of complex vocabulary.

Rescuing impaired hippocampal-cortical interactions and spatial reorientation learning and memory during sleep in a mouse model of Alzheimer's disease using hippocampal 40 Hz stimulation.

In preclinical Alzheimer's disease (AD), spatial learning and memory is impaired. We reported similar impairments in 3xTg-AD mice on a virtual maze (VM) spatial-reorientation-task that requires using landmarks to navigate. Hippocampal (HPC)-cortical dysfunction during sleep (important for memory consolidation) is a potential mechanism for memory impairments in AD. We previously found deficits in HPC-cortical coordination during sleep coinciding with VM impairments the next day. Some forms of 40 Hz stimulation seem to clear AD pathology in mice, and improve functional connectivity in AD patients. Thus, we implanted a recording array targeting parietal cortex (PC) and HPC to assess HPC-PC coordination, and an optical fiber targeting HPC for 40 Hz or sham optogenetic stimulation in 3xTg/PV cre mice. We assessed PC delta waves (DW) and HPC sharp wave ripples (SWRs). In sham mice, SWR-DW cross-correlations were reduced, similar to 3xTg-AD mice. In 40 Hz mice, this phase-locking was rescued, as was performance on the VM. However, rescued HPC-PC coupling no longer predicted performance as in NonTg animals. Instead, DWs and SWRs independently predicted performance in 40 Hz mice. Thus, 40 Hz stimulation of HPC rescued functional interactions in the HPC-PC network, and rescued impairments in spatial navigation, but did not rescue the correlation between HPC-PC coordination during sleep and learning and memory. Together this pattern of results could inform AD treatment timing by suggesting that despite applying 40 Hz stimulation before significant tau and amyloid aggregation, pathophysiological processes led to brain changes that were not fully reversed even though cognition was recovered. Significance Statement: One of the earliest symptoms of Alzheimer's disease (AD) is getting lost in space or experiencing deficits in spatial navigation, which involve navigation computations as well as learning and memory. We investigated cross brain region interactions supporting memory formation as a potential causative factor of impaired spatial learning and memory in AD. To assess this relationship between AD pathophysiology, brain changes, and behavioral alterations, we used a targeted approach for clearing amyloid beta and tau to rescue functional interactions in the brain. This research strongly connects brain activity patterns during sleep to tau and amyloid accumulation, and will aid in understanding the mechanisms underlying cognitive dysfunction in AD. Furthermore, the results offer insight for improving early identification and treatment strategies.