Department of Psychiatry and Biobehavioral Sciences, University of California, 760 Westwood Plaza, Rm. 27-355, Los Angeles, CA, USA.
Appetite. 2012 Jun;58(3):964-70. doi: 10.1016/j.appet.2012.02.051. Epub 2012 Mar 2.
Binge eating is often preceded by reports of negative affect, but the mechanism by which affect may lead to binge eating is unclear. This study evaluated the effect of negative affect on neural response to anticipation and receipt of palatable food in women with bulimia nervosa (BN) versus healthy controls. We also evaluated connectivity between the amygdala and reward-related brain regions. Females with and without BN (n=26) underwent functional magnetic resonance imaging (fMRI) during receipt and anticipated receipt of chocolate milkshake and a tasteless solution. We measured negative affect just prior to the scan. Women with BN showed a positive correlation between negative affect and activity in the putamen, caudate, and pallidum during anticipated receipt of milkshake (versus tasteless solution). There were no significant relations between negative affect and receipt of milkshake. Connectivity analyses revealed a greater relation of amygdala activity to activation in the left putamen and insula during anticipated receipt of milkshake in the bulimia group relative to the control group. The opposite pattern was found for the taste of milkshake; the control group showed a greater relation of amygdala activity to activation in the left putamen and insula in response to milkshake receipt than the bulimia group. Results show that as negative affect increases, so does responsivity of reward regions to anticipated intake of palatable food, implying that negative affect may increase the reward value of food for individuals with bulimia nervosa or that negative affect has become a conditioned cue due to a history of binge eating in a negative mood.
暴食常伴有负性情绪的报告，但情绪如何导致暴食的机制尚不清楚。本研究评估了负性情绪对神经性贪食症（BN）女性和健康对照组在接受和预期接受美味食物时的神经反应的影响。我们还评估了杏仁核与奖励相关脑区之间的连接。有和没有 BN 的女性（n=26）在接受和预期接受巧克力奶昔和无味溶液时接受功能磁共振成像（fMRI）扫描。我们在扫描前测量了负性情绪。与接受无味溶液相比，BN 女性在预期接受奶昔时，负性情绪与纹状体、尾状核和苍白球的活动呈正相关。负性情绪与接受奶昔之间没有显著关系。连接分析显示，在预期接受奶昔时，与对照组相比，BN 组杏仁核的活动与左纹状体和岛叶的激活之间的关系更大。奶昔的味道则呈现出相反的模式；与 BN 组相比，对照组在接受奶昔时，杏仁核活动与左纹状体和岛叶的激活之间的关系更大。结果表明，随着负性情绪的增加，奖励区域对美味食物摄入的反应性也随之增加，这表明负性情绪可能会增加 BN 个体对食物的奖励价值，或者负性情绪由于在负面情绪下暴食的历史而成为一种条件性提示。
