Hemispheric dominance and gender in the perception of an illusion.

Perception of geometric illusions is a visuo-spatial process. As such processes often have been found to be predominantly the domain of the right hemisphere, this hemisphere may be expected to perceive such illusions more readilly than the left hemisphere. Using the herringbone illusion in a reaction-test paradigm, we found that in right-handed males the right hemisphere was significantly more often deceived than the left, whereas no significant hemispheric difference was observed in females. This is the first demonstration of gender differences in the lateralized perception of an illusion.