Research Projects Funded by IDA 

Summary: 

Dyslexia and Visual-Spatial Talents

Researchers have speculated that, along with underlying deficits, dyslexia may be associated with visual-spatial talents (e.g., Geschwind, 1982; Geschwind & Galaburda, 1987; Orton, 1925). While spatial populations have a higher than average incidence of dyslexia (Winner & Casey, 1993; Winner, Casey, DaSilva, & Hayes, 1991), the evidence that dyslexics as a group have higher than average spatial abilities is mixed. However, the disproportionate incidence of individuals with dyslexia in spatial fields cannot be ignored. The possibility that dyslexia is accompanied by visual spatial talents requires further investigation. We tested the hypotheses that dyslexia is associated with superior spatial skills and higher than average spatial interests; that relatives of dyslexics also have higher than average spatial interests; and that dyslexics and family members have above average rates of non-right-handedness and autoimmune disorders. We carried out 3 studies. In each study, we compared a group of dyslexics with a group of individuals without dyslexia on a wide range of visual-spatial tasks. Tasks included, for example, the Vandenberg Test of Mental Rotation, the Rey-Osterrieth Complex Figure Test, the Hidden Figures test, a visual matching test, and a test of the ability to recognize ?impossible? figures. Contrary to hypothesis, individuals with dyslexia performed either equivalently to or worse than the control participants on all but one of the spatial measures. On one measure, however, they were superior. They were significantly faster than were controls at recognizing an impossible figure as impossible. This task is a  “global” task because one must integrate the parts of the figure in order to determine that they conflict and that the figure could thus not exist in 3-D space. Modest support was found for the hypotheses that individuals with dyslexia have higher than average spatial interests, rates of non-right-handedness, and autoimmune disorders/allergies, but this support was not consistent across studies. Little support was found for the finding that family members of individuals with dyslexia have higher than average spatial interests, rates of non-right-handedness, and autoimmune disorders and allergies. With one exception, we failed to demonstrate spatial talents in dyslexia. This is surprising given the high frequency of individuals with dyslexia in spatial professions. To reconcile these two findings, we propose two hypotheses: the default hypothesis and the channeling hypothesis. We also suggest that further research is needed to replicate our finding that the ability to rapidly scan and integrate parts of a figure is a strength associated with dyslexia.