The authors conducted a study of nocturnal penile tumescence (NPT) in 125 healthy males aged 3 to 79 by means of EEG recordings to provide normative data on how general the phenomenon is, its range of charateristics, and how it is related to man's sexual function. The results indicate that NPT occurs consistently in a healthy male population, that its expression is significantly affected by age, that it is related to stage of psychosexual development, and that it is worthy of further investigation. Clinical experience indicates that it is a useful, objective method of discriminating among various types of biogenic and psychogenic impotence.

1 Auditory awakening thresholds (AAT) and the back-to-sleep latency (BSL)