The relationship between heart rate deceleration (HRD) and the contingent negative variation (CNV) was evaluated in 12 healthy, elderly men during performance of a signaled reaction time task. While amplitude of the CNV and HRD did parallel RT, CNV alone was found to be predictive of individual differences in speed of response indicating that phasic concordance of these physiological responses is probably not an important factor in age changes in RT. The results indicate the probable importance of central physiological indices such as the CNV over peripheral events such as HRD in the evaluation of RT performance in elderly individuals.