Temporal measures of human finger tapping: effects of age.

A computerized finger-tapping test was used in which nonclinical subjects were asked to tap a telegraph key with their index finger as rapidly as possible during five 10-s trials. Comparisons were made between young (mean age = 18 years) and aged (mean age = 75 years) subjects. Consistent with previous findings, aged subjects performed significantly fewer taps than younger subjects. Computerized analysis of finger-tapping patterns in the present study allowed for the determination of novel temporal parameters of tapping responses. Response initiation time was defined as the time from the offset of one finger tap until the onset of the next finger tap. Aged subjects had significant and substantially longer response initiation times than younger subjects. Response duration times also were measured: this parameter was defined as the time from the onset of one finger tap until the offset of the same finger tap. Although the magnitude of the effect was small, aged subjects had significantly longer response duration times than younger subjects. Thus, although the deficit in response rate of a voluntary repetitive response in aged subjects was largely due to impairments in response initiation times, the response duration also contributes to the overall deficit in responding. Using these methods it is possible that greater insight into aging or extrapyramidal motor disorders, such as parkinsonism, may be obtained; it is also possible that these data may be useful as a research tool to aid in drug development and evaluation.