| Abstract | Developmental Dyslexia (DD) is a heritable disorder that affects approximately 5-12% of children (Shaywitz et al, 1990) and persists in 4-6% of adults (Schulte-Korne & Remschmidt, 2003). In those with dyslexia, reading dysfunction is caused by phonological impairments that may result from neurological low-level sensory-processing mechanisms. Previous research suggests that rapid automized naming (RAN) deficits are the most reported deficit in adults with dyslexia (Araújo et al, 2019), however, it is unknown whether the RAN deficit is caused by general rapid processing deficits or a specific letter-sound binding problem. This experiment was designed to address this unknown question by measuring rapid visual processing deficits and their relation to reading skills in children with dyslexia. Children (N=103) were recruited during the COVID-19 pandemic as part of a larger study of rapid stimulus processing in dyslexia. Out of the 103 children screened, 77 qualified for the study (33 neurotypical, 33 dyslexia, and 11 compensated dyslexia). Children completed two visual processing tasks online. The first was a rapid serial visual perception task (RSVP; Amador-Campos et al, 2015) which evaluates the rapid stimulus processing of one or more symbols and letters. The second was a visuospatial working memory task (VSWM; Sander, Werkle-Bergner, & Lindenberger, 2011) that evaluates working memory and visual acuity at different speeds. Accuracy and reaction times were measured for each task. While we found no group differences on any task or condition, there were main effects of target number for RSVP accuracy and of set size and speed for VSWM. These results demonstrate that the tasks were adequately difficult but that those with dyslexia did not exhibit specific deficits on either task, even when the stimuli were printed letters. This suggests that RAN deficits in children with dyslexia may not originate from rapid visual perception deficits, but from some other neural mechanism. |
