MULTITASK ANALYSIS OF CEREBRAL HEMISPHERE SPECIALIZATION IN MONOZYGOTIC TWINS DISCORDANT FOR HANDEDNESS

This study constitutes a multitask appraisal of cerebral hemisphere sp ecialization with 13 monozygotic (MZ) twin pairs discordant for handed ness. Tasks included dichotic listening, finger tapping with concurren t loads, two tachistoscopic visual half-field tests, and a free-vision face test. Overall, MZ twins showed similar performance asymmetries o n most tasks. Different asymmetries, however, were observed on the fin ger tapping with anagram load and visual half-field with chair stimuli . In these instances, asymmetries for left- and right-handed MZ twins were more similar to patterns reported in the literature for left- and right-handed singletons, respectively, than for opposite-handed co-tw ins.