Abstract
80 male children between the ages of 8 and 10 yr. were divided into four groups on the basis of their reading ages. 20 words were tachistoscopically presented to the left and right visual half-fields to determine if incomplete hemispheric laterality is associated with all levels of reading deficiency or only with the more severe cases. The results support the hypothesis that incomplete hemispheric laterality is only associated with reading deficiency when the deficit exceeds 18 mo.