The purpose of this protocol is to determine if the right hemisphere activation associated with perception of American Sign Language (ASL) in deaf subjects and in normal hearing individuals raised by deaf parents (who learned ASL before written English) is necessary for appropriate understanding of ASL.
Subject age between 18 and 65 years. Adult hearing offsprings of deaf parents. Congenitally deaf individuals. Intact hearing volunteers. No subjects with personal or family history of seizures or other neurological or demyelinating disorders. No pregnant women tested after urine pregnancy test. No subjects with severe coronary disease. No subjects with metal in the cranium except mouth. No subjects with intracardiac lines and implanted medication pumps. No subjects with increased intracranial pressure as evaluated by clinical means. No subjects with cardiac pacemakers. No subjects with an intake of neuroleptics.