Effects of tobacco smoking on the topographic EEG II.

1. Tobacco smokers are well aware of the long term hazards of tobacco smoking, yet they continue to smoke. Presumably people smoke because of short term gains due to nicotine. 2. The mechanism by which nicotine is a drug reinforcer still needs a great deal of study. The specific aim of the present study was to determine the effects of tobacco smoking on the topographic EEG of 12 hr deprived heavy tobacco smokers. 3. Seven normal adult tobacco smokers of mixed sex were recruited into the study and compared with six normal nonsmokers of similar age and sex. 4. A Grass Model 8-24D EEG and 16 different scalp monopolar electrodes were used to record the EEG using both ears as reference before and after smoking. EKG lead II was recorded on channel 17. Blood pressure was measured by auscultation. Exhaled CO was measured using a CO detector. Computer analysis of the EEG data was run of line on a Zenith 386/25 microcomputer using RHYTHM 7.1. The same system was used to store the EEG in digitized form. The maximum number of 4 sec artifact free epochs in a 3 min recording period with eyes open and then closed was used before and after low and high nicotine tobacco or sham smoking. 5. The hypothesis of this research was confirmed, i.e., that tobacco smoking of high nicotine cigarettes (about 2.0 mg/cigarette) would cause a shift in EEG alpha rhythm to higher frequencies in more diffuse midline cortical structures. In other studies an increase in alpha rhythm has been correlated with an awake relaxed behavioral state. 6. A heart rate increase was a more sensitive index of tobacco smoking than an increase in arterial blood pressure. Exhaled smoking CO levels correlated with the nicotine and tar content of the cigarette.