Effects of tobacco smoking on the topographic EEG-I.

1. The EEG and cardiovascular effects of smoking tobacco cigarettes of varying nicotine content were studied in Japanese chronic tobacco smokers. 2. Thirteen female and fifteen male adult normal volunteers were recruited for this study. 3. Each subject was asked to stop smoking the evening before coming to the laboratory the next morning, so they were approximately 10-12 hr deprived of cigarettes. 4. The objectives of this study were: a) To compare the mean differences in total activity in the alpha 1, alpha 2, beta, delta, and theta frequency bands before and after smoking a cigarette with 0, 0.27, 2.0, and 2.16 mg nicotine content in these 10-12 hr deprived tobacco smokers. b) To compare the topographic EEG patterns in such volunteers before and after smoking each of the above cigarettes. c) To compare the cardiovascular effects of smoking each of the above cigarettes in the same volunteers. 5. Smoking any of the four different types of cigarettes increased the total alpha EEG activity, although there were marked individual differences. Only after smoking nicotine containing cigarettes was there a mean decrease in alpha 1 (8.0-9.8 Hz) and an increase in alpha 2 (10-11.8 Hz) activity in the EEG, not only in the occipital areas but also more diffusely throughout the cerebral cortex. There were no consistent mean changes in EEG delta, theta, or beta activity. Individual differences were marked, irrespective of the nicotine content of the cigarette smoked. Baseline state, individual subject variation, and nicotine content of the cigarette smoked determine the EEG effects observed. Zero nicotine cigarette smoking also caused EEG changes, including an increase in alpha 1 and alpha 2 activity. 6. In contrast to smoking a zero nicotine cigarette, the cardiovascular effects of tobacco smoking include a slight increase in heart rate, systolic, and diastolic blood pressure.