Differential control of puff duration and interpuff interval in cigarette smokers.

While subjects smoked cigarettes under naturalistic conditions, the duration of each puff progressively decreased as the cigarette was consumed, while the time between successive puffs progressively increased. Evidence obtained using modified half-length cigarettes indicates that puff duration, but not interpuff interval, is controlled by the distance from the burning tip (combustion zone) of the cigarette to the smoker's mouth. The results demonstrate that these two fundamental descriptors of cigarette smoking behavior are under differential control, and provide new insights into the pharmacological and behavioral variables that control cigarette smoking.