Mental symptoms were more frequent in normal subjects than in mental patients except for the recall of forgotten experiences (noted in about 300f each group). . Somatic symptoms: the frequency of changes in heart rate, blood pressure, respiration and pupil reflexes and of facial reddening and sweating was identical in the two groups. . Changes which were more frequent in normal subjects than in mental patients were tremor, feeling of weakness, drowsiness, headache and gastro-intestinal disturbances. Mental factors were involved in these changes to a great extent.