Abstract
Kosslyn's (1987) hypothesized cerebral hemispheric asymmetries for processing categorical and coordinate spatial relations were explored, using stimuli presented at varying degrees of retinal eccentricity. Thirty-three adult males performed hemifield reaction-time tasks requiring categorical or coordinate judgments. The hypothesized asymmetries were observed when stimuli were presented at 3° of visual angle, but not at 1 or 9°. Nevertheless, correlational analyses supported the existence of separate neural subsystems for categorical and coordinate processing. The results suggest that the model accurately predicts performance asymmetries only under specific conditions.