Objective
To investigate the correlation between age and P3 parameters of the latency, amplitude, and reaction time, and to assess the changes of parameters in heathy volunteers after the manual stimulation of an acupoint He-7 which is used to treat convulsive disorder, anxiety and insomnia, and of a non-acupuncture point.

Method
The P3 studies using an auditory paradigm and requiring a button press to infrequently occurring tones were performed in 36 healthy persons with age range from 21 to 72 years. The studies were repeated after the manual stimulation of an acupoint He-7 for 10 minutes and of a nonacupoint for 15 or 20 minutes afterwards.

Results
The mean P3 latency was 355.1⁑31.4 msec and reaction time was 691.4⁑139.7 msec. Significant correlations were seen between the age and P3 reaction time as well as latency. Considerable increase of P3 amplitude was observed after the stimulation of an acupoint He-7.

Conclusion
The results of this study suggest that the P3 latency and reaction time are sensitive to age and the reaction from an acupoint He-7 stimulation may be related to the neuromodulation of noradrenaline or endorphine.