The Effects of Smoking and Urinary pH on a Detection Task

Abstract

Performance was measured in a detection task over a period of 50 min. Subjects were either non-smokers or smoked more than 15 cigarettes per day. No smoking was allowed during the task, but smokers were all asked to smoke a cigarette immediately before doing it. One hour previously, subjects had been given a double-blind dose of a substance which would shift the pH of their urine either upwards or downwards, by small amounts sufficient to affect the rate of renal excretion of nicotine in the smokers. The pH manipulation had no effect on the performance of the non-smokers, who improved steadily throughout the task. After some 40 min of performance, the deprived smokers showed less improvement than the non-smokers, and the smokers whose urine had been made acid improved less than those whose had been made alkaline. The results are interpreted as evidence for a phasic effect on performance of small degrees of nicotine deprivation, which has consequences for theories of nicotine dependence.