Laterality effects, levels of processing, and stimulus properties.

Tested 2 hypotheses of hemispheric specialization which stressed (a) the importance of the kind of processing to which the stimulus is subjected and (b) the nature of the stimulus. Four experiments with 40 right-handed males were carried out. In Exp I verbal material was employed in a same–different classification task, and an overall right-visual-field superiority was found. Exp II, in which verbal stimuli were subjected to visuospatial transformations (i.e., mental rotations), yielded no laterality effect. In Exp III geometrical figures were employed in a classification task similar to that of Exp I, and an overall left-visual-field superiority was found. Exp IV employed both verbal and geometric stimuli and showed a significant interaction between field of presentation and nature of the stimulus but no interaction between field of presentation and level of processing. (38 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)