title: Judgments of relative position and distance on representations of spatial relations.
abstract: This article examines Kosslyn's (1987) hypothesis of the unequal capacity of cerebral hemispheres to process categorical and coordinate spatial relations. Experiment 1 comprised 4 different tasks and failed to support this hypothesis in normal Ss. With the same stimulus patterns as in Kosslyn's study, the results failed to confirm cerebral asymmetry for representing the 2 types of spatial relations, in normal (Experiment 2) and commissurotomized (Experiment 3) Ss. In Experiment 4, a reduction in stimulus luminance produced a partial confirmation of the hypothesis as the right hemisphere proved more adept than the left hemisphere at operating on coordinate representations, whereas both were equally competent at processing categorical spatial-relation representations. The results suggest that the 2 hemispheres can operate on both types of spatial relations, but their respective efficiency depends on the quality of the representations to be processed.
authors.affiliation: Montreal Neurological Institute, McGill University, Quebec, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Sergent
mesh_terms: D000328:Adult; D001288:Attention; D004215:Distance Perception; D004292:Dominance, Cerebral; D005260:Female; D006801:Humans; D008297:Male; D009949:Orientation; D011601:Psychophysics; D011930:Reaction Time; D013028:Space Perception