[Caffeine and smoking-induced changes in the behavior of car drivers].

The authors examined changes in the behaviour of car drivers under the effect of coffeini matrii benzoici in doses of 250 mg (125 mg pure caffeine) and 500 mg (250 mg pure caffeine) in a single experimental group who had been exposed, prior to that, to a zero control experiment. The behaviour changes were examined immediately after the smoking of 5 cigerettes in a row. The experimental subjects' reaction was investigated using the determination set, their attention--using a modified Block test. 125 mg pure caffeine proved to have an excitatory effect on most of the group, with an overall improvement in performance, brightening up of mental processes, with the rate of mistakes dropping, attention and reaction improving in comparison with the proceding zero experiment. A dose of 250 mg caffeine had an inhibitory effect on most of the probands with the overall quality of performance deteriorating in all of the group; the quality of attention was worse, too, while reaction showed a moderate degree of improvement as a result of transfer. The experiment involving smokers after a dose of 5 cigarettes showed a deterioration in the capacity for concentration and a higher rate of errors in the performance of sensorimotor task while the reaction capacity remained normal.