Smoking and vigilance. The effects of tobacco smoking on CFF as related to personality and smoking habits.

The effects of tobacco smoking on vigilance (Critical Flicker Fusion, CFF) measured by a computerized forced-choice interactive technique, was studied in a group of 28 male moderate smokers. Subjects participated in a Smoking (S) and a Non-Smoking (NS) condition each of 1 h duration. CFF performance was measured during fifteen 2-min trials in each condition. In the S condition subjects smoked three puffs during each of five pauses between five successive trials. Vigilance was significantly improved by smoking. An initial sharp increase in CFF performance was noticed with a maximum 8 min after the first puff. Performance was significantly higher in the S condition compared to the NS condition up to 20 min after the last puff. Two extreme groups, based on differences in CFF performance between the S and NS condition were compared by questionnaires on personality and smoking habits. The most improved group had significantly higher scores in an extraversion scale. Ratings of the effect of smoking on level of alertness indicated that the objective effect of increased vigilance had no counterpart on the subjective level.