Within-modal and cross-modal consistency in the direction and magnitude of perceptual asymmetry

Three auditory and three visual tests of PA were administered to 45 healthy dextrals in order to evaluate within-modal and cross-modal consistency in the direction and magnitude of perceptual asymmetry (PA). Thirty-three subjects were retested after a 4-8 week interval to determine reliability of individual measures and stability of inter-test relationships. Pairs of visual and auditory tests consisted of exactly the same stimuli. Within-modal and cross-modal concordance in the direction of PA was high, providing additional empirical support for existing models of the neural basis of PA. Cross-modal correlations in the magnitude of PA were near zero despite highly significant within-modal correlations. Meaningfulness of the stimuli did not affect the magnitude of PA, although the presence of an orienting expression prior to each dichotic pair did. These three observations provide new information about the neural processes that determine the magnitude of PA.