Quantitative EEG effects of nicotine replacement by cigarette smoking.

The effects of cigarette smoking on the central nervous system can be assessed directly using the electroencephalogram (EEG). Nicotine withdrawal and subsequent replacement have been studied, but have produced conflicting effects on brain electrical activity. We studied the effect of smoking 2 cigarettes at subjects' own pace in 20 subjects. EEG was recorded using the EEGSYS program in the eyes-closed awake state using a bipolar montage. Delta power decreased in central-posterior head regions. Theta power and power in the lower half of the alpha band decreased. Beta power and power in the upper half of the alpha band increased significantly over frontotemporal head regions. Examination of spectra underlying the usual frequency bands revealed that many effects of smoking on EEG power probably resulted from a shift of the overall power spectrum toward higher frequencies, rather than resulting from alterations in activity in specific frequency bands.

Olfactory thresholds for nicotine and menthol in smokers (abstinent and nonabstinent) and nonsmokers.

Nonsmokers and smokers were compared for olfactory sensitivity to two odors associated with cigarettes: nicotine and menthol. Smokers were tested twice--while nonabstinent, and after 16-20 h of smoking abstinence. Smokers showed a higher olfactory threshold for nicotine than did nonsmokers, but the same threshold for menthol. Furthermore, when the smokers were abstinent, they showed a lower olfactory threshold for nicotine than when they were nonabstinent, but again, the same threshold for menthol. These results suggest a nicotine specific olfactory deficit in smokers that is reduced during abstinence.

Enhanced lexical processing of smoking stimuli during smoking abstinence.

In a group of heavy smokers, overnight abstinence from smoking facilitated the perception of briefly presented smoking words. Subjects in the nicotine-abstinent condition accurately identified significantly more smoking-related words than food-related or neutral words. However, a group tested in a non-abstinent condition showed no significant differences in ability to identify the three different word types. Smokers deprived of cigarettes were also significantly better able to categorize smoking words than non-abstinent subjects. These results demonstrate an abstinence-based facilitation of processing smoking-related stimuli at the semantic level, consistent with the hypothesis that smoking-related concepts are activated, or primed, during deprivation from nicotine.

Menthol vs nonmenthol cigarettes: effects on smoking behavior.

OBJECTIVES: The purpose of this study was to examine intraindividual differences in smoking behavior between smoking regular and mentholated cigarettes. METHODS: Healthy male smokers (n = 29) smoked either a regular or a mentholated cigarette in two separate sessions 1 week apart. Commercial brands with comparable tar, nicotine, and CO content were used. Smoking behavior was constrained by fixed 15-second interpuff intervals, but puff volume and number of puffs were unconstrained. RESULTS: When smoking the non-mentholated brand of cigarettes, participants smoked 22% more puffs and had 13% higher mean volumes per puff than they did when smoking the mentholated brand of cigarettes. The aggregate 39% excess exposure to cigarette smoke in the regular-cigarette condition was not accompanied by commensurate excesses in expired carbon monoxide or in physiological measures normally correlated with nicotine exposure. CONCLUSIONS: These findings parallel differences in physiological correlates of exposure to nicotine found in cross-sectional comparisons of African-American and White smokers and are consistent with the results of emerging laboratory investigations.

Mentholated cigarettes decrease puff volume of smoke and increase carbon monoxide absorption.

The influence of mentholated vs. regular cigarettes on selected chemical and topographic parameters was measured in 20 smokers in a pulmonary function laboratory. Half the subjects were black and half were white; half were menthol and half regular smokers. All subjects smoked both types of cigarettes, one on each of 2 days. Compared to regular cigarettes, mentholated cigarettes produced a significantly greater boost in carbon monoxide measured as both blood carboxyhemoglobin and end-expired carbon monoxide, despite the fact that mentholated cigarettes decreased average and total cumulative puff volumes and increased mean puff flow rates of inhaled smoke. These chemical and topographic differences were independent of race. No significant differences in depth of inhalation of the smoke or in the amount of insoluble smoke particulates delivered to or retained in the respiratory tract were noted between the two types of cigarettes. Mentholation of cigarettes may decrease volume of smoke inhaled but appears to increase exposure of smokers to toxic effects of carbon monoxide.

Rapid smoking of menthol and nonmenthol cigarettes by black and white smokers.

White subjects took significantly more puffs of cigarette smoke before stopping than did black subjects in a modified, controlled-dose rapid smoking procedure. Paradoxically, however, no racial differences were detected for changes in carbon monoxide levels, or changes in cardiovascular variables (systolic and diastolic blood pressure, and heart rate). Due to the cooling and topical anesthetic properties of menthol, it was hypothesized that menthol and regular cigarette smokers would take more puffs from menthol cigarettes than from regular cigarettes before stopping in the controlled-dose rapid smoking procedure. However, no difference was observed for the number of puffs taken from regular as opposed to menthol cigarettes (cigarette type condition) and no differences were found for Cigarette Preference (regular smokers vs. menthol smokers).

Nicotine abstinence produces content-specific Stroop interference.

Adult, male smokers were randomly assigned to be nicotine abstinent for 12 h (n = 10) or to smoke normally for the same period of time (n = 10). Performance on a modified version of the Stroop (1935) color-naming task, where subjects named the color of ink in which each of a series of words was written, showed that abstinent smokers took significantly longer to color-name words related to cigarette smoking (e.g., Lighter) than to color-name neutral control words (e.g., Pennant). Non-abstinent smokers showed a significant difference in the opposite direction. These results suggest that nicotine abstinence decreases the ability to ignore the meaning of smoking-related information. This finding supports the hypothesis that abstinence produces a content-specific shift in attentional focus. The present pattern of results cannot be explained by a general decrease in cognitive function due to nicotine abstinence.