Effects of transdermal nicotine on lateralized identification and memory interference

Abstract

It has been proposed that nicotine may enhance performance on tasks requiring primarily left hemisphere (LH) resources while impairing right hemisphere (RH)-based performance. However, this hypothesis has not been directly tested using a lateralized cognitive task. The effects of transdermal nicotine administration on lateralized consonant identification and memory interference were examined in dependent smokers and never-smokers. In a double-blind placebo-controlled design, smokers (n = 24) and never-smokers (n = 24) were assigned to receive a nicotine or placebo patch. Subjects completed a lateralized letter identification task that required them to identify strings of three consonants presented in the left or right visual field while keeping a word in memory. A distinct right-visual-field (RVF) advantage was observed for consonant identification, but this effect was unaltered by nicotine or smoking status. However, nicotine decreased word memory errors on trials where consonants were presented in the RVF and increased errors on LVF trials. Nicotine may enhance LH-based cognitive performance by increasing LH cognitive resources or by reducing the influence of RVF distracting stimuli. These findings are consistent with a model of the lateralized effects of nicotine on cognitive performance.

Dose-Related Enhancement of Mood and Cognition in Smokers Administered Nicotine Nasal Spray

“…Although several studies have demonstrated that smoking or nicotine can improve working memory in tobacco-deprived or nondeprived smokers (Ernst et al, 2001;Grobe et al, 1998) and in nonsmokers (Kumari et al, 2003;McClernon et al, 2003), our results are in agreement with others who reported no nicotine-associated improvement in working memory (Kleykamp et al, 2005;Myers et al, 2004;Park et al, 2000).…”

“…In contrast, the effect of nicotine on working memory and computational skills is less clear. Some studies reported enhanced working memory following nicotine administration to nonsmokers (Foulds et al, 1996;Kumari et al, 2003;McClernon et al, 2003) and former smokers and abstinent smokers (Ernst et al, 2001). In contrast, other studies reported that nicotine either had no effect (Heishman et al, 1993;Kleykamp et al, 2005;Myers et al, 2004) or impaired working memory (Park et al, 2000).…”

Transdermal nicotine attenuates depression symptoms in nonsmokers: a double-blind, placebo-controlled trial

“…With regard to mood and affect, nonsmokers typically find nicotine aversive and acute administration typically results in increases in negative affect that diminish to some degree with repeated administrations (Heishman and Henningfield 2000). A great deal of research has sought to identify cognition-enhancing effects of acute nicotine in nonsmokers (Heishman 1998;Heishman et al 1994), although these effects have typically been small and difficult to replicate (Kleykamp et al 2005;McClernon et al 2003). In contrast, a number of studies have found acute nicotine to improve cognition in nonsmoking clinical samples including ADHD, Alzheimer, Parkinson, and schizophrenia (for a review, see Levin et al 2006).…”

Nicotinic effects on cognitive function: behavioral characterization, pharmacological specification, and anatomic localization

“…In a double-blind, placebo-controlled study, McClernon et al (2003) observed nicotine to decrease working memory errors in both smokers (14 or 21 mg) and nonsmokers (7 mg), but only when distracting stimuli were presented in the right visual field during rehearsal. Distractors presented in the left visual field worsened performance in the nicotine condition.…”