| This thesis examines the role of visual processes as they relate to reading disabilities in terms of the Double Deficit Hypothesis (Wolf and Bowers, 1999). 295 Grade Two children were screened for phonological deficits, naming-speed deficits and double deficits. Children chosen for the study (n = 81) were administered a battery of reading and visual processing measures. It was expected that this research would replicate previous research on the double deficit hypothesis, with single deficit groups demonstrating moderately poor performance on tests of reading compared to children having no deficits, and those children with double deficits showing the lowest scores on measures of reading. Results supported this hypothesis. It was also predicted that performance on visual processing tasks would be related to performance on timed reading measures, and that children with slow naming-speed would demonstrate more difficulty on visual processing tasks. Results showed that fast/slow naming-speed was associated with paper and pencil visual processing speed measures, the Quick Spell Test, reading speed, and reading accuracy. However, naming-speed was not consistently associated with measures of early visual processing as assessed by a Coherent Motion task (Talcott, 2000) or a Dot Counting task. Exploratory analysis found that, within this sample, Coherent Motion was highly related to reading skill in very poor readers. Results suggest that the Coherent Motion task is a good predictor of very poor reading ability. Moreover, performance on the Coherent Motion task did not share variance with other predictors, indicating that the Coherent Motion task may be measuring a separate aspect of reading disability. |
