Maureen W. Lovett

The second deficit: An investigation of the independence of phonological and naming-speed deficits in developmental dyslexia

An increasing body of dyslexia researchdemonstrates, in addition to phonologicaldeficits, a second core deficit in theprocesses underlying naming speed. Thehypothesized independence of phonologicalawareness and naming-speed variables inpredicting variance in three aspects of readingperformance was studied in a group of 144severely-impaired readers in Grades 2 and 3. Stepwise regression analyses were conducted onthese variables, controlling for the effects ofSES, age, and IQ. Results indicated thatphonological measures contribute more of thevariance to those aspects of reading skill thatinvolve decoding or word attack skills;naming-speed measures contribute more to skillsinvolved in word identification. Subtypeclassification findings were equally supportiveof the independence of the two deficits: 19%of the sample had single phonological deficits;15% had single naming-speed deficits; 60% had double-deficits; and 6% could not be classified. The implications of these findingsfor diagnosis and intervention are discussed.

Measuring Socioeconomic Status Reliability and Preliminary Validity for Different Approaches

This study investigated issues related to commonly used socioeconomic status (SES) measures in 140 participants from three cities (Atlanta, Boston, and Toronto) in two countries (United States and Canada). Measures of SES were two from the United States (four-factor Hollingshead scale, Nakao and Treas scale) and one from Canada (Blishen, Carroll, and Moore scale). Reliability was examined both within (interrater agreement) and across (intermeasure agreement) measures. Interrater reliability and classification agreement was high for the total sample (range r = .86 to .91), as were intermeasure correlations and classification agreement (range r = .81 to .88). The weakest agreement across measures was found when families had one wage earner who was female. Validity data for these SES measures with academic and intellectual measures also were obtained. Some support for a simplified approach to measuring SES was found. Implications of these findings for the use of SES in social and behavioral science research are discussed.

Treating the core deficits of developmental dyslexia: Evidence of transfer of learning after phonologically- and strategy-based reading training programs.

Individuals with dyslexia have difficulty generalizing from word identification training. This study compared 2 firls of word identification to promote transfer of learning by children with dyslexia. Sixty-two children were randomly assigned to one of the training programs or to a study skills control program. One program trained phonological analysis and blending skills and provided direct instruction of letter-sound correspondences; the other trained the acquisition, use, and monitoring of 4 metacognitive decoding strategies

Remediating the Core Deficits of Developmental Reading Disability A Double-Deficit Perspective

The double-deficit hypothesis (Wolf, 1997; Wolf & Bowers, 1999, this issue) contends that deficits in phonological awareness and deficits in visual naming speed represent two independent causal impediments to reading acquisition for children with developmental reading disabilities (RD). One hundred and sixty-six children with severe RD from 7 to 13 years of age were classified into three deficit subgroups according to a double-deficit framework. A total of 140 children with RD, 84% of the sample, were classified; 54% demonstrated a double deficit (DD), 22% a phonological deficit only (PHON), and 24% a visual-naming speed deficit only (VNS). Diagnostic test profiles highlighted the joint contributions of the two core deficits in depressing written language acquisition. The children in the DD group were more globally impaired than those in the other subgroups, and the VNS group children were the highest achieving and most selectively impaired readers. Following 35 hours of word identification training, sizable gains and significant generalization of training effects were achieved by all subgroups. A metacognitive phonics program resulted in greater generalized effects across the domain of real English words, and a phonological training program produced superior outcomes within the phonological processing domain. The greatest nonword reading gains were achieved by children with only phonological deficits.

Training the word recognition skills of reading disabled children: Treatment and transfer effects.

Fifty-four disabled readers were randomly assigned to one of two word recognition and spelling training programs or to a problem solving and study skills training program. One word-training program taught orthographically regular words by whole word methods alone; the other trained constituent grapheme-phoneme correspondences

Support for EKN1 as the susceptibility locus for dyslexia on 15q21.

Dyslexia has been linked to a number of chromosomal regions including 15q. Recently a gene, EKN1, with unknown function in the linked region, was identified via a translocation breakpoint. This gene was further supported as a susceptibility locus by association studies in a Finnish sample. We investigated the possibility of this locus as a susceptibility gene contributing to dyslexia, analyzed as a categorical trait, and analyzed key reading phenotypes as quantitative traits using six polymorphisms including the two previously reported to be associated with dyslexia. In our sample of 148 families identified through a proband with reading difficulties, we found significant evidence for an association to dyslexia analyzed as a categorical trait and found evidence of association to the reading and related processes of phonological awareness, word identification, decoding, rapid automatized naming, language ability, and verbal short-term memory. However, association was observed with different alleles and haplotypes than those reported to be associated in a Finnish sample. These findings provide support for EKN1 as a risk locus for dyslexia and as contributing to reading component processes and reading-related abilities. Based on these findings, further studies of this gene in independent samples are now required to determine the relationship of this gene to dyslexia.

The Effectiveness of Remedial Programs for Reading Disabled Children of Different Ages: Does the Benefit Decrease for Older Children?.

One hundred and twenty-two severely reading disabled children were randomly assigned to one of two word identification training programs or a study skills control program. One program remediated deficient phonological analysis and blending skills and provided direct instruction of letter-sound mappings. The other program taught children how to acquire, use, and monitor four metacognitive decoding strategies. The effectiveness of the remedial programs was evaluated for children in grades 2/3, 4, and 5/6 to determine whether programs were differentially effective at different grade levels. Both training approaches were associated with significant improvement in word identification and word attack skills and sizeable transfer-of-training effects. The phonological program resulted in greater transfer across the phonological processing domain, whereas the strategy training program produced broader transfer for real words of both regular and irregular orthography. Children at each grade level made equivalent gains with remediation. These results suggest that the phonological deficits associated with reading disability are amenable to focused and intensive remediation and that this effort is well directed across the elementary school years. From grades 2 through 6, there is no evidence of a developmental window beyond which phonological deficits cannot be effectively remediated with intensive phonological training.

Putting Struggling Readers on the PHAST Track A Program to Integrate Phonological and Strategy-Based Remedial Reading Instruction and Maximize Outcomes

PHAST (for Phonological and Strategy Training) is a research-based remedial reading program that attempts to capitalize upon current research on reading disabilities and their remediation. The focus of the program is on the primary obstacles to word identification learning and independent decoding that most disabled readers face and the steps necessary to help these children achieve independent reading skills. A framework of phonologically based remediation was used as a foundation upon which a set of flexible and effective word identification strategies were scaffolded in an integrated developmental sequence. The program uses a combination of direct instruction and dialogue-based metacognitive training, with the pedagogical emphasis shifting from an initial direct instruction, remedial focus to increasingly metacognitive-strategy-based methods. A continuum of intervention over 70 hours provides both (a) remediation of the basic phonological awareness and letter-sound-learning deficits of disabled readers and (b) specific training of five word identification strategies that offer different approaches to the decoding of unfamiliar words and exposure to different levels of subsyllabic segmentation. Explicit instruction in the application and monitoring of multiple word identification strategies and their application to text-reading activities continues throughout the PHAST Program. PHAST training provides the disabled reader with the opportunity to become a flexible reader who approaches new words in or out of context with multiple strategies and has the ability to evaluate the success of their application. The PHAST Program was developed following the controlled evaluation of its components in laboratory classroom settings and recent positive results from their sequential combination. PHAST represents a new integrated approach to programming in this area using instructional components that have already demonstrated their efficacy with children with severe reading disabilities.

Multiple-Component Remediation for Developmental Reading Disabilities IQ, Socioeconomic Status, and Race as Factors in Remedial Outcome

Results from a controlled evaluation of remedial reading interventions are reported: 279 young disabled readers were randomly assigned to a program according to a 2 × 2 × 2 factorial design (IQ, socioeconomic status [SES], and race). The effectiveness of two multiple-component intervention programs for children with reading disabilities (PHAB + RAVE-O; PHAB + WIST) was evaluated against alternate (CSS, MATH) and phonological control programs. Interventions were taught an hour daily for 70 days on a 1:4 ratio at three different sites. Multiple-component programs showed significant improvements relative to control programs on all basic reading skills after 70 hours and at 1-year follow-up. Equivalent gains were observed for different racial, SES, and IQ groups. These factors did not systematically interact with program. Differential outcomes for word identification, fluency, comprehension, and vocabulary were found between the multidimensional programs, although equivalent long-term outcomes and equal continued growth confirmed that different pathways exist to effective reading remediation.

A developmental perspective on reading dysfunction: Accuracy and rate criteria in the subtyping of dyslexic children☆

Children referred with specific reading dysfunction were subtyped as accuracy disabled or rate disabled according to criteria developed from an information processing model of reading skill. Multiple measures of oral and written language development were compared for two subtyped samples matched on age, sex, and IQ. The two samples were comparable in reading fluency, reading comprehension, word knowledge, and word retrieval functions. Accuracy disabled readers demonstrated inferior decoding and spelling skills. The accuracy disabled sample proved deficient in their understanding of oral language structure and in their ability to associate unfamiliar pseudowords and novel symbols in a task designed to simulate some of the learning involved in initial reading acquisition. It was suggested that these two samples of disabled readers may be best described with respect to their relative standing along a theoretical continuum of normal reading development.