Alpert Medical School of Brown University, Department of Psychiatry and Human Behavior, United States; University of South Florida, Department of Psychology, United States; Moffitt Cancer Center, Tobacco Research and Intervention Program, United States.
Int J Psychophysiol. 2013 Nov;90(2):258-64. doi: 10.1016/j.ijpsycho.2013.08.005. Epub 2013 Aug 16.
Drugs-of-abuse may increase the salience of drug cues by sensitizing the dopaminergic (DA) system (Robinson and Berridge, 1993), leading to differential attention to smoking stimuli. Event-related potentials (ERPs) have been used to assess attention to smoking cues but not using an ERP component associated with DA-mediated salience evaluation. In this study the DA-related P2a and the P3, were compared in smokers (N = 21) and non-smokers (N = 21) during an attention selection cue exposure task including both cigarette and neutral images. We predicted that both the P2a and P3 would be larger to targets than non-targets, but larger to non-target cigarette images than non-target neutral images only in the smokers, reflecting smokers' evaluation of smoking stimuli as relevant even when they were not targets. Results indicated that smokers showed behavioral cue reactivity, with more false alarms to cigarette images (responding to cigarette images when they were not targets) than non-smokers; however, both smokers and non-smokers had a larger P2a and P3 to cigarette images. Thus, while smokers showed behavioral evidence of differential salience evaluation of the cigarette images, this group difference was not reflected in differential brain activity. These findings may reflect characteristics of the ERPs (both ERP components were smaller in the smokers), the smoking sample (they were not more impulsive, i.e. reward sensitive, than the non-smokers, in contrast to prior studies) and the design (all participants were aware that the aim of the study was related to smoking).
药物滥用可能通过敏化多巴胺能（DA）系统增加药物线索的显著性（Robinson 和 Berridge，1993），从而导致对吸烟刺激的注意力不同。事件相关电位（ERP）已被用于评估对吸烟线索的注意力，但未使用与 DA 介导的显著性评估相关的 ERP 成分。在这项研究中，在包括香烟和中性图像的注意选择线索暴露任务中，比较了吸烟者（N=21）和非吸烟者（N=21）的与 DA 相关的 P2a 和 P3。我们预测，无论是 P2a 还是 P3，对于目标的反应都比对非目标的反应更大，但对于非目标香烟图像的反应比对非目标中性图像的反应更大，仅在吸烟者中，这反映了吸烟者即使不是目标也会将吸烟刺激评估为相关。结果表明，吸烟者表现出行为线索反应性，对香烟图像的假警报（在不是目标时对香烟图像做出反应）比非吸烟者更多；然而，吸烟者和非吸烟者对香烟图像都有更大的 P2a 和 P3。因此，尽管吸烟者对香烟图像的显著性评估表现出行为证据，但这种群体差异并未反映在大脑活动的差异上。这些发现可能反映了 ERPs 的特征（两个 ERP 成分在吸烟者中都较小）、吸烟样本（与先前的研究相反，他们的冲动性即奖励敏感性并不比非吸烟者高）和设计（所有参与者都知道研究的目的与吸烟有关）。
