MODULAR ORGANIZATION OF COGNITIVE SYSTEMS MASKED BY INTERHEMISPHERIC INTEGRATION

After resection of the corpus callosum, V.J., a left-handed woman with left-hemisphere dominance for spoken language, demonstrated a dissoci ation between spoken and written language. In the key experiment, word s flashed to V.J.'s dominant left hemisphere were easily spoken out lo ud, but could not be written. However, when the words were flashed to her right hemisphere, she could not speak them out loud, but could wri te them with her left hand. This marked dissociation supports the view that spoken and written language output can be controlled by independ ent hemispheres, even though before her hemispheric disconnection, the y appeared as inseparable cognitive entities.