Extending the Role of Associative Learning Processes in Nicotine Addiction

Abstract

Compulsive smoking is a worldwide public health problem. Although research has confirmed the importance of associative learning processes in nicotine addiction, therapies targeting nicotine-associated cues still have a high relapse rate. Most theories conceptualize nicotine as an ‘outcome’ that reinforces behaviors and/or changes the affective value of stimuli. Albeit important, this view does not capture the complexity of associative processes involved in nicotine addiction. For example, nicotine serves as a conditional stimulus acquiring new appetitive/affective properties when paired with a non-drug reward. Also, nicotine functions as an occasion setter that participates in higher-order associative processes that likely permit a more pervasive influence of conditioned cues that are resistant to typically cue-exposure therapy techniques. Finally, nicotine appears to amplify the salience of other stimuli that have some incentive value resulting in enhanced nicotine selfadministration and conditioned reinforcement processes. Future smoking intervention strategies should take into consideration these additional associative learning processes.

Nicotine does not produce state-dependent effects on learning in a Pavlovian appetitive goal tracking task with rats

“…Until unambiguous evidence demonstrating the exclusive role of operant contingencies is available, we prefer to pursue this avenue of research from a Pavlovian conditioning framework for the mere utilitarian reason that this approach leads to novel and potentially important experiments that could elucidate factors contributing to drug addiction. That is, perhaps the abuse liability of nicotine-containing products could be affected by conditioned associations in which nicotine is an interoceptive cue for other appetitive USs [7,9,34]. Such evidence has been found in humans using diazepam [1] and ethanol [31] as the interoceptive cue.…”

“…Further, a 0.2 mg/kg dose of nicotine also served as an interoceptive CS using a fading procedure [7]. In that study, rats were first trained to discriminate 0.4 mg/kg nicotine from saline.…”

“…Recently, we have published several examples of a Pavlovian drug discrimination task in rats using the pharmacological effects of nicotine (0.4 mg base/kg) as the interoceptive CS and 4-sec access to liquid sucrose as the US [4,7,36]. In brief, on nicotine sessions rats have intermittent access to sucrose, whereas on saline sessions no sucrose occurs.…”

“…This acquired appetitive property of the nicotine cue comes to evoke an approach CR (goal tracking) to an area where sucrose has occurred in the past [7]. A statedependent learning account, in contrast, assumes the excitatory association is between the exteroceptive cues that compose the conditioning chamber (e.g., odors, rod floor, fan sound, etc.)…”

Effects of Nicotine on Olfactogustatory Incentives: Preference, Palatability, and Operant Choice Tests

“…The hypothesis that NIC amplifies the effects of incentive stimuli on behavior makes specific predictions about the role of associative and motivational processes in NIC self-administration and tobacco use (Bevins & Palmatier, 2004;Caggiula et al, 2009). For example, initiation of tobacco use may be facilitated if the effect of NIC coincides with stimuli that have acquired incentive properties.…”