SOME EFFECTS OF SMOKING WITHDRAWAL ON COMPLEX PERFORMANCE AND PHYSIOLOGICAL RESPONSES

The effects of smoking withdrawal on complex (time-shared) performance and physiological responses were studied at a simulated aircraft cabin altitude of 6,500 ft. Seventeen habitual smokers, nine women and eight men, served as subjects. Time-shared performance of monitoring, tracking, mental arithmetic and problem solving tasks was measured by the Civil Aeromedical Institute Multiple Task Performance Battery (MTPB) in two 4-hour test sessions, one in which smoking was permitted at 1/2-h intervals and a no-smoking session. Corollary physiological measurements involved urinary hormones (epinephrine, norepinephrine and 17-ketogenic steroids), carboxyhemoglobin levels and heart rate. Overall composite scores for MTPB performance revealed decrements during withdrawal which were statistically significant beginning at the third 1/2-h period of withdrawal sessions. The principal sources of the withdrawal effect were a significant decrement in tracking and a tendency toward longer reaction times in one monitoring task during withdrawal. These performance decrements were associated with significantly lower heart rate and lower ratings of attentiveness during withdrawal from smoking. These findings support a cautious approach to the prohibition of smoking on the flight deck for aircrew members.