Influence of reinforcer magnitude and nicotine amount on smoking's acute reinforcement enhancing effects

Abstract

Background Nicotine’s acute effects on enhancing reinforcement from sensory rewards, shown in animal models, appear to occur with smoking in humans. These effects may vary due to reinforcer magnitude and amount of acute smoke intake (dose). Methods In a fully within-subjects design, dependent smokers (n=23) participated in 3 sessions. Each session followed overnight abstinence and involved 4 trials to assess responding via progressive ratio (PR50%) for sensory reinforcement from high, moderate, or low preference music, or no reward (counter-balanced, 30-sec/reinforcer). Sessions differed in smoking prior to each trial: 8 puffs on arrival and 2 puffs/trial (“8+2”), 2 puffs/trial only (“0+2”), or no smoking. Puffs were consumed via CReSS (Clinical Research Support System) to control topography, and smoking involved own brand to ensure palatability and increase generalizability of results. Results Reinforced responding was influenced by main effects of smoking condition (p<.05) and music reward type (p<.001). Compared to no smoking, responding for music was increased after smoking 8+2/trial puffs (p<.005), but not after 0+2/trial puffs. Smoking condition significantly increased reinforced responding only for the high preference music (p=.01), and not for moderate or low preference music, or for no reward. Withdrawal did not differ between the two smoking sessions, ruling out withdrawal relief as an explanation for differential reinforcement enhancement. Conclusions Our findings confirm that just one cigarette after abstinence is sufficient for reinforcement enhancing effects and suggest that such enhancement is greater as magnitude of a reward’s reinforcing efficacy increases.

Reinforcement enhancing effects of acute nicotine via electronic cigarettes

“…The former results are very consistent with, but the latter is contrary to, our prior studies of nicotine from cigarette smoking, which consistently showed enhancement of music reinforcement (Perkins and Karelitz, 2013a, 2013b, 2014), as in the ad lib smoking session of the current study (see Fig. 1).…”

“…Recent human studies have confirmed animal models showing acute effects of nicotine in enhancing reinforcement from rewards made available independent of nicotine intake (Perkins and Karelitz, 2013a, 2013b, 2014). However, nicotine dosing in this human research was manipulated via controlled tobacco smoking, and we are not aware of any human research examining reinforcement enhancing effects of nicotine administered via non-tobacco means.…”

“…Finally, we conducted similar analyses of reinforced responding between the nicotine e-cigarette session versus the preferred brand tobacco smoking session (i.e., “ad lib”, or no abstinence), to explore how much the effects due to acute nicotine intake from an e-cigarette after overnight abstinence differed from the non-abstinent, satiated condition (see Perkins and Karelitz, 2013b). Also, we assessed differences between the smoking and no e-cigarette conditions to replicate prior findings on effects of smoking abstinence vs. non-abstinence on reinforced responding by type of available reward (Perkins and Karelitz, 2013a; Perkins et al, 2013).…”

“…This session was added to explore the extent to which modest acute nicotine e-cigarette use after abstinence would match reinforced responding under typical non-abstinent smoking conditions. We recently found no such effects from minimal nicotine via smoking (one-half cigarette), despite significant enhancement of reinforcement from moderate nicotine (a full cigarette; Perkins and Karelitz, 2013b). This observation raises the question of what amount, in addition to what manner, of acute nicotine intake is needed to enhance reinforcement.…”

Expectancies for Cigarettes, E-Cigarettes, and Nicotine Replacement Therapies Among E-Cigarette Users (aka Vapers)

“…Satisfaction is generally one of the stronger effects found when nicotine is compared to placebo. 54,55 Given that nicotine is increasingly recognized as a secondary, rather than a primary reinforcer, [56][57][58][59] it may be that the unique flavorings associated with e-cigarettes are leading to the increased reports of satisfaction.…”