From the Department of Psychiatry (Donofry), University of Pittsburgh School of Medicine; Departments of Psychology (Donofry, Watt, Roecklein, Erickson) and Health and Physical Activity (Jakicic, Rogers), and Healthy Lifestyle Institute (Jakicic, Rogers), University of Pittsburgh; and The Center for the Neural Basis of Cognition (Roecklein, Erickson), Pittsburgh, Pennsylvania.
Psychosom Med. 2020 Apr;82(3):261-271. doi: 10.1097/PSY.0000000000000769.
Obesity is associated with differences in task-evoked and resting-state functional brain connectivity (FC). However, no studies have compared obesity-related differences in FC evoked by high-calorie food cues from that observed at rest. Such a comparison could improve our understanding of the neural mechanisms of reward valuation and decision making in the context of obesity.
The sample included 122 adults (78% female; mean age = 44.43 [8.67] years) with body mass index (BMI) in the overweight or obese range (mean = 31.28 [3.92] kg/m). Participants completed a functional magnetic resonance imaging scan that included a resting period followed by a visual food cue task. Whole-brain FC analyses examined seed-to-voxel signal covariation during the presentation of high-calorie food and at rest using seeds located in the left and right orbitofrontal cortex, left hippocampus, and left dorsomedial prefrontal cortex.
For all seeds examined, BMI was associated with stronger FC during the presentation of high-calorie food, but weaker FC at rest. Regions exhibiting BMI-related modulation of signal coherence in the presence of palatable food cues were largely located within the default mode network (z range = 2.34-4.91), whereas regions exhibiting BMI-related modulation of signal coherence at rest were located within the frontostriatal and default mode networks (z range = 3.05-4.11). All FC results exceeded a voxelwise threshold of p < .01 and cluster-defining familywise error threshold of p < .05.
These dissociable patterns of FC may suggest separate neural mechanisms contributing to variation in distinct cognitive, psychological, or behavioral domains that may be related to individual differences in risk for obesity.
肥胖与任务诱发和静息状态功能脑连接（FC）的差异有关。然而，目前尚无研究比较高卡路里食物线索诱发的肥胖相关 FC 差异与静息状态下观察到的差异。这种比较可以增进我们对肥胖背景下奖赏估值和决策的神经机制的理解。
该样本包括 122 名成年人（78%为女性；平均年龄=44.43[8.67]岁），体重指数（BMI）处于超重或肥胖范围（均值=31.28[3.92]kg/m2）。参与者完成了功能磁共振成像扫描，包括休息期和视觉食物线索任务。全脑 FC 分析使用位于左右眶额皮质、左海马体和左背内侧前额皮质的种子，检查了在呈现高热量食物和静息状态时种子之间的信号协变。
对于所有检查的种子，BMI 与高热量食物呈现时的 FC 增强有关，而与静息时的 FC 减弱有关。在存在美味食物线索时，表现出 BMI 相关的信号相干性调制的区域主要位于默认模式网络内（z 范围=2.34-4.91），而在静息时表现出 BMI 相关的信号相干性调制的区域位于额皮质-纹状体和默认模式网络内（z 范围=3.05-4.11）。所有 FC 结果均超过体素水平 p<0.01 和簇定义的家族性错误阈值 p<0.05。
这些可分离的 FC 模式可能表明，导致不同认知、心理或行为领域的个体差异的不同神经机制可能与肥胖风险的个体差异有关。
