Naqvi Nasir H, Bechara Antoine
Division of Cognitive Neuroscience, Department of Neurology, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, Iowa 52242, USA.
Int J Psychophysiol. 2006 Jul;61(1):77-86. doi: 10.1016/j.ijpsycho.2005.10.018. Epub 2006 Jan 5.
The airway sensations stimulated by smoking are an important source of hedonic impact (pleasure) for dependent smokers. The learning process by which these sensations become pleasurable is not well understood. The classical conditioning model predicts that airway sensory stimulation will elicit sympathetic arousal that is positively correlated with the hedonic impact that is elicited by airway sensory stimulation. To test this prediction, we measured skin conductance responses (SCRs) and subjective hedonic impact elicited by a series of individual puffs from nicotinized, denicotinized and unlit cigarettes. Nicotinized puffs elicited more subjective hedonic impact than denicotinized and unlit puffs partly as a result of the fact that they provided a greater level of airway sensory stimulation. We found that SCRs were not larger for nicotinized puffs than for denicotinized puffs, but that they were larger for both nicotinized and denicotinized puffs than for unlit puffs. We also found that the average SCR of a subject to denicotinized puffs was positively correlated with the average hedonic impact that a subject obtained from denicotinized puffs. Together, this suggests that SCR magnitude does not reflect within-subject variations in hedonic impact that are due to variations in the level of airway sensory stimulation, but that it does reflect individual differences in the amount of hedonic impact that is derived from a given level of airway sensory stimulation. The results of a post hoc correlation analysis suggest that these individual differences may have been due to variations in the prevailing urge to smoke. The implications of these findings for the classical conditioning model, as well as for other learning models, are discussed.
吸烟所刺激产生的气道感觉，是依赖吸烟者享乐影响（愉悦感）的一个重要来源。这些感觉变得令人愉悦的学习过程尚未得到充分理解。经典条件作用模型预测，气道感觉刺激将引发交感神经兴奋，而这种兴奋与气道感觉刺激所引发的享乐影响呈正相关。为了验证这一预测，我们测量了来自含尼古丁香烟、去尼古丁香烟和未点燃香烟的一系列单次抽吸所引发的皮肤电导反应（SCR）和主观享乐影响。含尼古丁的抽吸比去尼古丁和未点燃的抽吸引发了更多的主观享乐影响，部分原因是它们提供了更高水平的气道感觉刺激。我们发现，含尼古丁抽吸的SCR并不比去尼古丁抽吸的SCR大，但含尼古丁和去尼古丁抽吸的SCR都比未点燃抽吸的SCR大。我们还发现，受试者对去尼古丁抽吸的平均SCR与受试者从去尼古丁抽吸中获得的平均享乐影响呈正相关。综合来看，这表明SCR的大小并不能反映由于气道感觉刺激水平变化而导致的享乐影响在个体内部的差异，但它确实反映了从给定水平的气道感觉刺激中获得的享乐影响量的个体差异。事后相关分析的结果表明，这些个体差异可能是由于吸烟冲动的普遍差异所致。本文讨论了这些发现对经典条件作用模型以及其他学习模型的意义。
