The effects of nicotine on novelty detection and memory for emotional, semantic, and perceptual oddballs in smokers and non-smokers

The ability to detect a potentially threatening stimulus enhances an organism's ability to survive. Likewise, detecting a potentially rewarding stimulus may afford an organism an opportunity to approach a situation that may sustain life. Prior research has found nicotine to modulate attention, affect, and memory in smokers. One line of research suggests that nicotine modulates lateralized neural networks, resulting in biasing attention towards positive and away from negative emotional information. Other research suggests nicotine may modulate attention by enhancing perceptual visual processing. Yet, other research suggests nicotine's most robust effects on attention may be during categorical or semantic processing. While most studies of nicotine's putative beneficial effects have frequently been assessed in habitual smokers, it remains unclear as to what extent these effects simply reflect the attenuation of nicotine withdrawal symptoms. It is important to disentangle the putative effects of acute nicotine, from nicotine's attenuation of withdrawal related cognitive deficits. Understanding how nicotine may enhance the detection and retrieval of novel emotional events may provide a greater understanding of the beneficial cognitive effects of smoking that tobacco users report. One goal of the current study was to investigate the effect of nicotine on novelty detection and memory for perceptual, semantic, and emotionally novel words. Another goal was to investigate how nicotine's effects on task performance is different for smokers (N=24)as compared to nonsmokers' (N=24). Based on prior research showing nicotine to increase cortical arousal and attention, it was hypothesized that nicotine would enhance novelty detection to all word types, and improve semantic and emotional memory in both groups. It was also hypothesized that nicotine, as compared to placebo, would benefit smokers more than nonsmokers on novelty detection and memory performance.;Nicotine enhanced novelty detection of emotional, perceptual, and semantic information in both smokers and nonsmokers. Benefits from nicotine included faster reaction times and significantly greater target detection. Nicotine also improved overall memory performance across tasks in both smokers and nonsmokers. While few differences in performance due to nicotine were found between smokers and nonsmoker, two contrasts were observed. First, nicotine improved positive emotional word memory performance for nonsmokers, but not smokers. This effect was driven by nicotine significantly reducing errors of false detection for positive words in nonsmokers. Secondly, nicotine improved semantic memory in nonsmokers by significantly reducing errors of false detections. Overall, nicotine improved novelty detection and memory across all tasks for both smokers and nonsmokers.