EFFECTS OF TOBACCO SMOKING AND GENDER ON INTERHEMISPHERIC COGNITIVE FUNCTION - PERFORMANCE AND CONFIDENCE MEASURES

Cognitive function in tasks involving interhemispheric processing of v erbal and spatial information was studied in 31 college students in a 2X2 factorial design with chronic smoking status [smoker (10+ cigarett es per day) versus non-smoker (no history of smoking)] and gender as t he main between-subject factors. The subjects participated in two sess ions on two consecutive days. The same task was repeated within the sa me session with a IS min interval: smokers were tested before and afte r smoking whereas non-smokers rested during the interval. Dependent be havioral variables included those of performance (speed and accuracy) and confidence (low rate of non-responding), The verbal task yielded a n expected female advantage, and smoking had the gender-specific effec t of increasing both speed and accuracy more clearly in males. In addi tion, smoking decreased the rate of mon-responding (increase confidenc e) in women, thereby affecting preferred strategies for problem solvin g by shirting the female pattern towards the male pattern. The spatial task, which probably involved a more perceptual, rather than cognitiv e, level of functioning, produced no clear effects of smoking and gend er, and yielded some laterality effects. The acute within-subject smok ing manipulation wherein, among smokers, the first test mas preceded b y 10+ h of deprivation, whereas the second repeated task was preceded by the smoking of a cigarette (i.e. deprivation followed by partial re lease) did not affect the behavioral measures. In conclusion, smoking had a gender-specific effect on cognitive function: it improved the pe rformance of males in a verbal task and increased the subjective confi dence of females thereby affecting the preferred cognitive strategies for problem solving.