Tobacco smoking produces widespread dominant brain wave alpha frequency increases

Abstract

The major pharmacological ingredient in tobacco smoke is nicotine, a mild stimulant known to alter brain electrical activity. The objective of this study was to determine if tobacco smoking in humans produces localized or widespread neocortical dominant alpha electroencephalographic (EEG) frequency increases consistent with nicotine stimulation of the brainstem activating system in animals. Twenty-two male volunteer non-deprived tobacco smokers were studied. They were asked not to smoke for at least 1h before the experiment in mid-morning as part of their usual smoking schedule. In the laboratory, they sham smoked and then smoked their favorite tobacco cigarette. Two experimental sessions (#1 and #2) were conducted, separated by a one to two month interval. In both sessions, there were minor statistically significant increases in the dominant alpha frequencies after sham smoking. In both sessions, after the subjects smoked a favorite tobacco cigarette there was a significant generalized increase in dominant alpha EEG frequencies in most scalp recording sites. This study demonstrates that tobacco smoking produces widespread bilateral neocortical increases in dominant alpha EEG frequencies consistent with the stimulant effects of nicotine on the brainstem reticular activating system.

Fig 1

Effects of sham smoking on dominant EEG alpha frequency. In this and the subsequent figures, the scalp electrode placements are shown on the x-axis and the mean ± SE dominant alpha frequency (in Hz) on the y-axis. A. Data obtained from experiment 1. B. Data obtained from experiment 2. In this and subsequent figures: *p <.05, **p<.01, ***p<.001 indicated the significant alpha level that is produced by the two way ANOVA with repeated measures. Note that sham smoking increases selective right hemisphere neocortical dominant alpha frequencies. Slide file numbers are listed in the lower right hand corner.

Fig 2

Effects of smoking ones favorite brand cigarette on dominant EEG alpha frequency. Note that tobacco smoking increases dominant alpha frequencies in most neocortical areas in contrast to sham air smoking.