Effects of nicotine on finger tapping rate in non-smokers.

Five experiments were conducted investigating the effects of nicotine on finger tapping rate in non-smokers. In each experiment subjects tapped as fast as possible a fixed number of times with one finger on a conventional computer keyboard. In the first experiment tapping rate was increased by two 2 mg doses of a nasal nicotine solution (NNS) but not by an inactive solution. The second study was carried out double-blind and showed that a single 2 mg dose of NNS improved tapping performance by about 5% whereas a very low dose (0.15 mg) NNS and a placebo had no effect. The effect of the NNS was to bring about a sustained increase in tapping rate from the start of each trial. The third study found that the effect of nicotine on tapping was reduced by a single 2.5 mg dose of the central cholinergic blocking agent, mecamylamine, but not by a placebo. Experiment four followed tapping rate for one hour after a dose of two 2 mg NNS and showed that within a subject this behavioural measure can provide a very consistent and sensitive bio-assay of the time course of nicotine effects. The final experiment found that repeated dosing with one 2 mg NNS on an hourly schedule for six hours produced a reliable increase in tapping speed after each dose with no evidence of acute tolerance. The results indicate that nicotine can substantially improve performance by non-smokers on a simple motor task, probably via its action on cholinergic pathways. NNS provides for the first time an effective means of examining the effects of nicotine on non-smokers.