DIFFERENCES IN VISUOSPATIAL JUDGMENT IN READING-DISABLED AND NORMAL-CHILDREN

Both visual and verbal impairments have been reported in two independe nt streams of research into the etiology of dyslexia or reading-disabi lity. To address the question of the presence of either abnormality in reading-disabled children, visuospatial and phonological ability were assessed and contrasted in 39 Normal and 26 Reading-disabled children . To assess whether these deficits are unique to dyslexia, scores were also compared to those of a group of 12 Poor Readers (''garden-variet y'' backward readers with low IQs). The Benton Judgement of Line Orien tation Test was used for its simplicity and clinical reliability: Read ing-disabled subjects performed significantly worse than Normal reader s (but similar to Poor Readers). Reading-disabled subjects performed w orse for lines in the left-hemifield compared to Normal subjects and a lso had a greater tendency to scan the task in reverse order (left-to- right) from the usual right-to-left scanning pattern observed in the N ormal group when performing this test. When both verbal and visuospati al variables were combined in a multiple regression analysis, 71% of r eading variance could be accounted for. These results suggest that Rea ding-disabled children not only have poor phonological awareness, but they also show visuospatial deficits. However, poor performance on bot h these tasks was also observed in the group of Poor Readers, suggesti ng that these deficits are nor unique to children with specific readin g disability. The results lend further evidence to the hypothesis that reading disability cannot solely be attributed to left-hemisphere dys function resulting in phonological impairment. There are other behavio ral deficits, possibly caused by a common mechanism, some of which, li ke visuospatial ability, can be measured by simple behavioral tests su ch as the Judgement of Line Orientation Test.