Acute effects of cigarettes in non-deprived smokers on memory, calculation and executive functions.

To determine whether smoking one or two cigarettes daily has effects on cognitive functions and the blood nicotine level, we examined 20 smokers and 20 nonsmokers as part of a normal daily smoking regimen using psychological tests for memory, calculation and association. Subjects underwent Buschke's selective reminding test, a mental arithmetic task (multiplication between two digits and one digit) and an association task (letter fluency); the duration of each task being 2 min under the condition of pre-smoking, one cigarette smoking and two cigarette smoking sessions, with an inter-session interval of 50 min. The total recall or correct responses were evaluated. The results showed that performance deteriorated in the later sessions in the memory task, whereas it improved in the later sessions in the calculation and association tasks, with no group (smoker-nonsmoker) difference, nor interaction between tasks and groups in each task. Plasma nicotine increased by 10 ng/ml immediately after smoking a cigarette, and 14 ng/ml immediately after smoking two cigarettes, but decreased to the pre-smoking level or slightly higher 10 min after smoking. These findings suggested that a daily dose of nicotine had little effect on the performance related to memory, calculation and mental association.