Categorical and coordinate spatial task performance in inconsistent-handers versus consistent-right-handers: part II.

A previous study reported superior categorical and coordinate spatial task performance in inconsistent-versus consistent-right-handers (ICH versus CRH). Propper et al. used a three-dimensional (3D) computer-based task wherein individuals navigated to 21 locations within a realistic cityscape. During testing, participants were queried on their categorical and coordinate spatial knowledge of the map. In that study, the categorical and coordinate tasks may have inadvertently encouraged language coding of learned spatial information, potentially confounding spatial processing with recall ability for language-based information. Also, that study used a between-subjects design, which precludes examination of relationships between spatial knowledge as a function of handedness. The present study duplicated the learning task in Propper et al. using test stimuli that more faithfully represent spatial, and not language-based, information, as well as a within-subjects design. Results did not significantly replicate the previous study. Possible reasons for this finding are discussed.