Effects of Nicotine on Emotional Distraction of Attentional Orienting

I was co-author on an article in collaboration with the Southern Illinois University Integrative Neuroscience Lab ( http://www.smokelab.siuc.edu/ ), submitted to the Journal of Nicotine & Tobacco Research - details and summary below:

Effects of Nicotine on Emotional Distraction of Attentional Orienting: Evidence of Possible Moderation by Dopamine Type 2 Receptor Genotype

David G. Gilbert, Adam Rzetelny, Jonathan Hammersley, Norka E. Rabinovich, Stacey L. Small, and Jodi I. Huggenvik
Southern Illinois University at Carbondale

Abstract
Introduction: Growing evidence suggests that attentional bias to and distraction by emotional stimuli moderate affective states and motivation for nicotine and other drug use.
Methods: The present study assessed the effects of nicotine and genotype on distraction by emotional picture stimuli during general attentional orienting in overnight-deprived 45 habitual smokers.
Results: Relative to placebo, 14 mg nicotine patch produced shorter reaction times (RTs) and individuals with two DRD2 A2 alleles exhibited the greatest RT benefit from nicotine following emotionally negative pictures after the longest delay (800 ms), but benefitted least from nicotine following positive pictures after the shortest delay (400 ms).  In contrast, at the shortest delay, A1 carriers did not benefit from nicotine following emotionally negative pictures but did following positive ones.
Conclusions: These genetic differences in the effects of nicotine on attention immediately following emotionally positive versus negative stimuli may reflect differential excitatory and inhibitory transmitter processes related to reward approach (reward) and avoidance (punishment) sensitivities of dopamine-related and other neural networks that support positive and negative affect.

In A2 individuals, nicotine’s ability to reduce distraction by negative, relative to positive and neutral stimuli, appears to rely on processes that develop between 600 and 800 ms after distractor offset. This finding in A2 individuals is consistent with other findings and theory (Gilbert, 1995; Gilbert, Rabinovich et al., 2008) suggesting that nicotine is effective in attenuating processing of negative affect when the negative stimulus is more temporally more distal and less proximal. For example, Gilbert, Rabinovich et al. (2008) found that nicotine reduced negative affect more during the distal periods (shortly after stressors) than during actual stressor exposure and reduced attentional bias (eye-gaze) toward negative pictures, relative to positive pictures, during the later but not earlier portions of picture presentations. Together, these findings suggest that in A2 individuals nicotine enhances distraction by (attention to) emotionally positive stimuli relative to neutral stimuli after brief delays (400 ms) but at 800 ms delays nicotine attenuates distraction by negative distractors (relative to both positive cues and to neutral distractors which no longer differ from each other).

Differential reward vs. threat sensitivity in nicotine-deprived A1 carriers appeared in the present study only at the earliest (400 ms) delay. An ability of nicotine to reduce impulsivity associated with nicotine abstinence state-dependent (and possibly temperamentally based) reward relative to punishment sensitivity could help explain the association of smoking with impulse-related disorders such as attention deficit hyperactivity disorder (Gilbert, 1995).

KEY WORDS:  nicotine, smokers, DRD2, genotype, attention, attentional orienting, distraction, emotion, prime