Centre de recherche Fernand-Seguin, Institut Universitaire de Santé Mentale de Montréal, Montreal, Canada; Department of Psychiatry, Faculty of Medicine, University of Montreal, Montreal, Canada.
Centre de recherche Fernand-Seguin, Institut Universitaire de Santé Mentale de Montréal, Montreal, Canada; Department of Psychology, Bishop's University, Sherbrooke, Canada.
Prog Neuropsychopharmacol Biol Psychiatry. 2014 Apr 3;50:66-73. doi: 10.1016/j.pnpbp.2013.12.009. Epub 2013 Dec 18.
The addictive nature of smoking is characterized by responses to cigarette stimuli that significantly impede smoking cessation efforts. Studies have shown that smokers are roused by appetitive smoking-related stimuli, and their consumption tends to be unaffected by the negative value of smoking.
Using functional magnetic resonance imaging, the goal of this study was two-fold: to examine the brain reactivity of chronic smokers when processing the negative value of smoking using aversive smoking-related cues; to further characterize this response by comparing the latter to the processing of aversive nonsmoking-related and appetitive smoking-related cues.
Thirty chronic smokers passively viewed aversive smoking-related, aversive nonsmoking-related, appetitive smoking-related and neutral images presented in a block design while being scanned.
Aversive smoking-related stimuli elicited significantly greater activation in the medial prefrontal cortex, amygdala, inferior frontal gyrus and lateral orbitofrontal cortex than neutral stimuli. Aversive smoking-related stimuli elicited lower activation in the parahippocampal gyrus, insula and inferior frontal gyrus compared to the aversive nonsmoking-related condition, as well as lower activation in the posterior cingulate, precuneus and medial prefrontal cortices compared to appetitive smoking-related cues.
The brain activation pattern observed suggests that chronic smokers experience an aversive response when processing aversive smoking-related stimuli, however we argue that the latter triggers a weaker negative emotional and driving response than the aversive non-smoking-related and appetitive smoking-related cues respectively. These fMRI results highlight potentially important processes underlying the insensitivity to the negative value of smoking, an important characteristic of addiction.
本研究使用功能磁共振成像(fMRI),旨在从两个方面探究慢性吸烟者在处理吸烟负性价值时对厌恶吸烟相关线索的大脑反应:通过比较厌恶非吸烟相关线索和正性吸烟相关线索的处理,进一步描述这种反应。
30 名慢性吸烟者在被动观看厌恶吸烟相关、厌恶非吸烟相关、正性吸烟相关和中性图片时接受 fMRI 扫描。
与中性刺激相比,厌恶吸烟相关刺激在中前额皮质、杏仁核、下额回和外侧眶额皮质中引发了显著更大的激活。与厌恶非吸烟相关条件相比,厌恶吸烟相关刺激在海马旁回、岛叶和下额回中引发了更低的激活,与正性吸烟相关线索相比,在后扣带回、楔前叶和中前额皮质中引发了更低的激活。
观察到的大脑激活模式表明,慢性吸烟者在处理厌恶吸烟相关刺激时会产生厌恶反应,但我们认为,与厌恶非吸烟相关和正性吸烟相关线索相比,后者引发的负性情绪和驱动反应较弱。这些 fMRI 结果突出了吸烟负性价值不敏感的潜在重要过程,这是成瘾的一个重要特征。