to see if this process involves the cerebral cortex , the widths of the sylvian fissure , the interhemispheric fissure , and three cortical sulci were measured blindly on computerized tomography ( ct ) scans of 75 chronic psychiatric patients and 62 asymptomatic volunteers , all less than 50 years of age .
C0007776
cerebral cortex
C0228186
interhemispheric