Cortical activation during visual spatial processing: relation between hemispheric asymmetry of blood flow and performance.

Regional cerebral blood flow was studied in normal males and females during rest and three spatial tasks: counting of rectangular shapes, mental rotation, and cube analysis. Whereas gender caused no significant differences in performance scores or asymmetries, a highly significant relation was found between performance on the cube analysis task and right > left hemisphere flow asymmetry in the parietotemporooccipital border zone (PTO region) during cube analysis. This indicates that subjects utilizing a right hemisphere strategy when solving certain spatial tasks are superior to subjects with more bilateral involvement.