Department of Psychiatry, University of Arizona, 1501 N., Campbell Ave., PO Box 245002, Room 7304B, Tucson, AZ, 85724-5002, USA.
Department of Psychiatry, McLean Hospital, Harvard Medical School, 115 Mill Street, Belmont, MA, USA.
Brain Imaging Behav. 2018 Jun;12(3):685-696. doi: 10.1007/s11682-017-9726-7.
Previous studies suggest obesity is associated with altered function within the insula and dorsomedial frontal cortex (including dorsal anterior cingulate cortex; DMFC/dACC), reflecting abnormal reward processing and reduced sensitivity to feelings of satiety. Given the proposed roles of DMFC/dACC in monitoring response conflict and reward-based decision making, the present study examined DMFC/dACC activation, and functional connectivity between the DMFC/dACC and the anterior insula (AI), during food-related decision-making. Twenty participants recruited from the general population (10 Female) performed a decision task while undergoing functional magnetic resonance imaging. They were instructed to "choose the healthier option" when simultaneously shown pairs of images of different foods. Significant DMFC/dACC activation was observed during food-related decision-making, and activation levels also positively correlated with self-reported cravings for high-fat foods (r = 0.57, p = 0.009) and self-reported desire to eat the high-fat foods depicted in the images (r = 0.48, p = 0.032). Negative functional connectivity estimates between the right AI and DMFC/dACC were also associated with self-reported control over eating (r = -0.50, p = 0.025). These results suggest that (1) more intense cravings for unhealthy foods are associated with greater response conflict when deciding between healthy and unhealthy food options, and (2) lack of eating-related control may involve a reduced influence of insula-mediated bodily signals on decision-making. This task may offer a neuroimaging-based probe for identifying individuals vulnerable to eating-related disorders and should be replicated in clinical populations.
先前的研究表明,肥胖与脑岛和背侧前额叶皮层(包括背侧前扣带皮层;DMFC/dACC)的功能改变有关,这反映了异常的奖励处理和对饱腹感的敏感性降低。鉴于 DMFC/dACC 在监测反应冲突和基于奖励的决策方面的作用,本研究在进行食物相关决策时检查了 DMFC/dACC 的激活以及 DMFC/dACC 与前脑岛(AI)之间的功能连接。从普通人群中招募了 20 名参与者(10 名女性),他们在进行功能磁共振成像的同时进行了决策任务。当同时显示不同食物的图像对时,他们被指示“选择更健康的选择”。在进行食物相关决策时观察到 DMFC/dACC 的显著激活,并且激活水平也与报告的高脂肪食物的渴望(r = 0.57,p = 0.009)和报告的想吃图像中描绘的高脂肪食物(r = 0.48,p = 0.032)呈正相关。右侧 AI 和 DMFC/dACC 之间的负功能连接估计也与报告的进食控制呈负相关(r = -0.50,p = 0.025)。这些结果表明:(1)在选择健康和不健康的食物之间时,对不健康食物的渴望越强烈,与反应冲突的关联越强烈,(2)缺乏与进食相关的控制可能涉及到脑岛介导的身体信号对决策的影响降低。该任务可能为识别易患进食相关障碍的个体提供基于神经影像学的探针,并且应该在临床人群中进行复制。