EEG power spectra and auditory P300 during free smoking and enforced smoking abstinence.

We investigated resting EEG and auditory P300 during free smoking and 36 h of enforced smoking abstinence in 12 healthy volunteers. Resting EEG was recorded on 19 scalp leads and auditory P300 was obtained by an oddball paradigm task. Spectral analysis of EEG (absolute and relative power, mean frequency), latency and amplitude of auditory P300 were considered for statistical analysis. EEG changes were not significant during free smoking but were significant during smoking abstinence. Theta absolute power increased by +57% (P<.001), whereas alpha and delta absolute power increased by +26% (P<.01) and +19% (P<.01), respectively; theta absolute power change was delayed and prolonged. Alpha mean frequency reduced by -0.31 Hz (P<.001), whereas delta, theta and beta1 mean frequency increased by +0.13 Hz (P<.05), +0.09 Hz (P<.05) and +0.23 Hz (P<.01), respectively. Auditory P300 amplitude and latency were unaffected by smoking abstinence. Resting EEG, but not auditory P300, was sufficiently sensitive to detect changes during enforced smoking abstinence, and EEG bands had different temporal changes.