Learning Disabilities: Links to Schools and Biology

This study is part of a larger project to investigate the biological and educational constraints operating in children with learning disabilities, with a focus on treatment and links between assessment and treatment. The project evaluates prevention and treatment of reading and writing disabilities, the genetic contribution to subtypes of dyslexia, the relationship between brain variables and dyslexia, and the brain's response to treatment for dyslexia. Genetic and brain imaging studies occur throughout the project.

During Year 1, at-risk readers in first grade were targeted for an intervention for mapping spoken words onto written words. These students were compared to a control group. During Year 2, the faster responders (those who reached grade level) and the slower responders (those who were not yet at grade level) from Year 1 were compared. Slower responders received additional treatment and comparisons were made again at the end of the year. The additional treatment was also studied in Spanish-speaking students in first grade. During Year 3, another group of at-risk, poor readers in second grade were randomized to either word decoding treatment, comprehension treatment, a combined word decoding and comprehension treatment, or a control treatment.

During Year 4, readers at risk for failing state standards in reading (decoding) participated in an extended day program providing comprehensive reading instruction. The students were compared to a control group. During Year 5, all students grades 4 to 9 took a battery of morphological, reading, and writing tests. The testing was administered throughout an entire school system.

During Year 6, older students with dyslexia were randomly assigned to phonological or morphological reading training. Students were then compared on pre- and post-test behavioral measures and brain activation results. During Year 7, students with dyslexia were randomly assigned to an orthographic or morphological treatment for spelling. Students underwent brain imaging before and after the intervention. Behavioral and brain activation measures were also assessed. During Year 8, students with dyslexia underwent attention or fluency training and writing training with and without attentional bridges. Only behavioral measures were collected.

Recruitment of families for the family genetics study is ongoing. Recruitment for the brain imaging-treatment studies will begin in 2004 when installation of new brain imaging equipment is complete.