We examined 2,029 volunteers 50 to 93 years of age in a cross-sectional study of nine bedside neurologic tests to determine the frequency of "abnormal" responses in uncomplicated aging (senescence). Rates of abnormal responses remained constant until age 70 years, after which they increased significantly. The number of abnormal signs per subject also increased, especially over 70 years of age. These results provide normative data against which these signs may be compared when applied as a clinical screening battery for diffuse cerebral dysfunction.