Meta-Analysis of Visual-Spatial Deficits in Dyslexia
Year: 2014
Type: review
Study designs: Systematic Review, Meta-Analysis
Abstract: A number of studies have investigated visuo-spatial traits in dyslexia, and have reported mixed results. We undertook a systematic search of studies that examined visual-spatial deficits in dyslexia. The analysis involved comparisons of 324 students with dyslexia compared to 304 students without dyslexia from 12 studies. To address whether there was a difference between students with and without dyslexia (controls) on visual learning tasks, effect sizes were pooled and a weighted averaged effect size was computed using a fixed effects model. A significance test for the weighted average effect sizes was computed using an alpha level of .05.The weighted average effect size computed from these studies was found to be.72 (a medium effect size), which was statistically significant. Using a fixed-effects model, the mean effect size of our sample was .717+ .089, with a lower confidence mean effect size of .627 and an upper mean effect size of .806. The magnitude of deficits was, on average, moderate. Evidence for the visual attentional deficit was found to be robust to many variations in study design. The weighted average effect size for M(y)-cell abnormalities, was 1.0 (right eye) and 1.3 (left eye). However, moderate levels of heterogeneity were found between study-level effect sizes, Tau = .38771 (p=.092). These associations are discussed with respect to other findings that have demonstrated the existence of some specific visuo-spatial disorders in dyslexia.
Institution: Alzahra University
Language: English
Subfield: Developmental and Educational Psychology
Field: Psychology
Domain: Social Sciences
Open Access status: diamond
OpenAlex ID: W16868404