Developmental dyslexia (DD) is a common reading disability, affecting 5% to 11% of children in North America. Children classified as having DD often have a history of early language delay (ELD) or language impairments. Nevertheless, studies have reported conflicting results as to the association between DD-ELD and the extent of current language…

This paper examines the effects of a morphological awareness intervention on the word reading and spelling skills of Grades 4 to 6 children with dyslexia. Sixteen children in eastern Ontario, Canada, received 20 hours of morphologically oriented instruction spread over 6 weeks and eight served as controls, and all received a battery of reading and…

Potential implicit orthographic learning deficits were investigated in adults with dyslexia. An artificial grammar learning paradigm served to assess dyslexic and typical readers' ability to exploit information about chunk frequency, letter-position patterns, and specific string similarity, all of which have analogous constructs in real…

The purpose of the present study was to identify and characterize surface and phonological subgroups of readers among college students with a prior diagnosis of developmental reading disability (RD). Using a speeded naming task derived from Castles and Coltheart's subtyping study, we identified subgroups of readers from among college students with…

Limited evidence supports the external validity of the distinction between developmental phonological and surface dyslexia. We previously identified children ages 8 to 13 meeting criteria for these subtypes (Peterson, Pennington, & Olson, 2013) and now report on their reading and related skills approximately 5 years later. Longitudinal…

Dyslexia and other learning disabilities are not being properly recognized and treated in our educational system or society at large. Unrecognized and untreated learning disabilities represent a serious social and economic problem, not only to the individual but to society as a whole. For example, antisocial behavior, as seen in prison populations…

Spatial attention performance was investigated in adults with dyslexia. Groups with and without dyslexia completed literacy/phonological tasks as well as two spatial cueing tasks, in which attention was oriented in response to a centrally presented pictorial (arrow) or alphabetic (letter) cue. Cued response times and orienting effects were largely…

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…

Some previous research has shown strong associations between spelling ability and rapid automatic naming (RAN) after controls for phonological processing and nonsense-word reading ability, consistent with the double-deficit hypothesis in reading and spelling. Previous studies did not, however, control for nonsense-word spelling ability before…

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…