History-taking in neurology is particularly favored by the fact that the disease processes occur at or in structures which underlie direct sensation and perception. No-one can so exactly report on disturbances of seeing, hearing, feeling, smelling, tasting, and equilibrium as the patient himself. But the personality of the observer is particularly involved: Is he minimizing, dramatizing, or are there changes in the cerebral cortex? For this reason the statements of relatives have special importance, particularly in convulsions and in the matter of personality changes.