COMPARISON OF THE EFFECTS OF NICOTINE ON A FIXED RATE AND A SUBJECT-PACED VERSION OF THE RAPID INFORMATION-PROCESSING TASK

In a modified ''subject-paced'' rather than fixed rate version of a ra pid information processing (RIP) task, the presentation rate of the st imuli is continuously adapted to the individual performance level. Thu s, this modified task version probably assesses a continuous ''speed f unction'' rather than mere ''vigilance''. In order to compare the two task versions more directly, we carried out a study which assessed the effects of a regular nicotine cigarette and the nearly nicotine-free cigarette NEXT on both task versions under the same experimental condi tions. The dominant alpha frequency pointed to a greater arousal evoke d by the subject-paced RIP version compared with the fixed rate versio n. With the fixed rate version, smoking nicotine cigarettes reduced re action times, whereas with the subject-paced version, processing rate was improved. Additionally, smoking NEXT decreased craving less than s moking the regular cigarettes. It was concluded that the two task vers ions are sensitive to different cognitive functions. Whereas the subje ct-paced version was more sensitive to effects on the speed of process ing, the fixed rate version was more sensitive to effects on reaction time.