Assessing the topographic EEG changes associated with aging and acute/long-term effects of smoking

As neuroelectric research into the smoking/nicotine habit has focused exclusively on young and middle-aged adults, this electroencephalographic (EEG) study was conducted to determine whether a long-term smoking history alters the aging brain and/or whether the aging brain demonstrates an altered sensitivity to acute smoking/nicotine. Forty healthy adults, 20 young, aged 18-39 years, and 20 elderly, aged 64-81 years, volunteered for participation. Half of the young and elderly were nonsmokers with no previous smoking history and the remaining half of the young and elderly were current smokers with average smoking histories of 9.3 and 52.0 years, respectively. Smokers attended the laboratory for two randomized test sessions during which multisite EEG recordings were collected pre and post sham and cigarette smoking. Nonsmokers attended the laboratory for one nonsmoking EEG recording session. Spectral power indices showed aging to be associated with significant reductions in absolute delta and theta power and increases in relative beta power and faster mean total band frequency. Aging effects varied with recording region but not with smoker versus nonsmoker status. Smokers did exhibit a faster mean beta frequency. Acute cigarette smoking decreased absolute delta power in young smokers and increased relative alpha 2, beta power and mean alpha frequency in both young and elderly smokers. Only the young smokers showed increase in mean theta and total frequency. The results are discussed in relation to cognition in normal and pathological aging.