Sexually dimorphic effect of an acute smoking manipulation on skin resistance but not on heart-rate during a cognitive verbal task.

In a two-day, two-session experiment where smokers male and female college-student subjects worked on a cognitive verbal task during either the first or second day, and on a cognitive spatial task on the second or first day, smoking was manipulated as an acute independent variable by requiring 10+ hours of pre-experimental abstention, and providing a cigarette during the 15-minute rest period between the two sessions. Non-smoker female and male subjects underwent the same experiment, and hence served as controls for the effects of this acute-smoking manipulation. Overall adaptation (decreased arousal) to the experiment was manifested in a significant increase in skin resistance level (SRL) in all subjects, but when this adaptation effect was statistically controlled, there was a significant smokers by sex interaction during the verbal task only, such that SRL was increased by the cigarette in males, but decreased in females. In contrast, the same analysis indicated only a marked increase in heart-rate (HR) due to smoking, which was unaffected either by sex or by whether the task was the verbal or the (easier) spatial one. We interpret the SRL results as reflecting a sex difference in the direction of transient psychological arousal, and discuss it in relation to evidence in the literature based on self reports, and to evidence (based on HR in this study and on blood pressure in other studies) on physiological (cardiovascular) arousal. Key Words: Electrodermal activity, heart-rate, psychological vs. physiological, verbal and spatial cognitive tasks.