title: Effects of acute nicotine administration on behavioral and neural (EEG) correlates of working memory in non-smokers.
abstract: Enhancements in working memory (WM) performance have been previously reported following acute smoking/nicotine. Neuroimaging and behavioral assessments of nicotine's effects on WM have yielded inconsistent findings. Few studies, however, have examined the effects of nicotine on WM-related neural activity in non-smokers. The present study examined the effect of acute nicotine gum administration (6 mg) on electroencephalographic (EEG) activity (alpha(1), alpha(2) and theta bands) and performance on the parametrically manipulated N-back task of WM in 20 non-smoking adults. EEG activity varied with WM load (e.g. alpha(1) decreasing and theta increasing). Performance on the N-back was also load-sensitive, with slower reaction times and decreased accuracy associated with increasing memory load. Neither response speed nor accuracy measures were affected by nicotine but EEG was, with the effects varying by load and brain region. Nicotine-induced increases in alpha(2) and theta were observed under lower (0-, 1-back) memory load conditions Additionally, nicotine significantly reduced signal detection sensitivity values and altered response bias toward being more conservative at all levels of the N-back. Taken together, these findings suggest that while nicotine may boost WM neural processes at lower levels of WM load in non-smokers, it also may activate concurrent behavioral inhibition networks that negate any effects on behavioral performance. Additionally, nicotine appears to have no impact, or perhaps a negative impact, on these processes under more demanding (2-back, 3-back) conditions in non-smokers.
authors.affiliation: Department of Psychology, Carleton University, Ottawa, Ontario, Canada. derek.fisher@msvu.ca
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Fisher
authors.forename: Richelle
authors.initials: R
authors.lastname: Daniels
authors.forename: Natalia
authors.initials: N
authors.lastname: Jaworska
authors.forename: Amy
authors.initials: A
authors.lastname: Knobelsdorf
authors.forename: Verner J
authors.initials: VJ
authors.lastname: Knott
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000187:drug effects*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects*; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D011930:Reaction Time / Q000187:drug effects; D055815:Young Adult
chemical_list: D018722:Nicotinic Agonists; D009538:Nicotine