Smoking History and Aging-Associated Cognitive Decline:An Event-Related Brain Potential Study

Abstract

Although cigarette smoking has been associated with reduced risk for dementia of the Alzheimer type, relatively little is known about the central impact of a lengthy smoking history, particularly with respect to the cognitive effects, on the normal aging brain. Given that elderly adults have been reported to exhibit poor short-term memory in conditions requiring divided attention, this study utilized behavioral performance and event-related potential (ERP) measures to compare groups (n = 10/group) of young (18–39 years) and elderly (64–81 years) adult smokers and nonsmokers during a continuous visual word recognition task carried out alone and concurrently with an auditory (oddball) tone discrimination task. Young and elderly adult smokers had average smoking histories of 9.3 and 52.0 years, respectively. Significant aging (young > elderly adults) and task (single-task > dual-task) effects were observed for performance accuracy and speed measures as well as for N400/P600 ERP waveform components elicited by ‘old/new’ word recognition and P300 ERP indices elicited by auditory target detection. The effects of smoking history were limited to the P600 component, which showed faster latencies in elderly smokers than elderly nonsmokers and young nonsmokers. Young smokers exhibited longer latencies than young nonsmokers. The results were discussed in relation to normal and pathological cognition in the elderly.