Department of Psychology, University of Oregon, Eugene, OR 97403, USA.
Appetite. 2011 Aug;57(1):65-72. doi: 10.1016/j.appet.2011.03.017. Epub 2011 Apr 8.
We tested the hypothesis that obese individuals experience greater activation of the gustatory and somatosensory cortex, but weaker activation of the striatum, in response to intake and anticipated intake of high-fat chocolate milkshake versus an isocaloric milkshake labeled low-fat and a tasteless solution using functional magnetic resonance imaging (fMRI) with 17 obese and 17 lean young women. Obese relative to lean women showed greater activation in somatosensory (Rolandic operculum), gustatory (frontal operculum), and reward valuation regions (amgydala, ventralmedial prefrontal cortex (vmPFC) in response to intake and anticipated intake of milkshake versus tasteless solution, though there was little evidence of reduced striatal activation. Obese relative to lean women also showed greater activation in the Rolandic operculum, frontal operculum, and vmPFC in response to isocaloric milkshakes labeled regular versus low-fat. Results suggest that hyper-responsivity of somatosensory, gustatory, and reward valuation regions may be related to overeating and that top-down processing influence reward encoding, which could further contribute to weight gain.
我们通过功能磁共振成像（fMRI）技术检验了这样一个假设，即肥胖个体在摄入和预期摄入高脂巧克力奶昔与低脂奶昔和无味溶液时，味觉和躯体感觉皮层的激活程度更高，而纹状体的激活程度更低。研究共纳入 17 名肥胖女性和 17 名苗条女性。与苗条女性相比，肥胖女性在摄入和预期摄入奶昔与无味溶液时，躯体感觉（岛盖部）、味觉（额盖部）和奖赏评估区域（杏仁核、腹内侧前额叶皮层）的激活程度更高，尽管纹状体的激活程度较低。与苗条女性相比，肥胖女性在摄入和预期摄入常规和低脂奶昔时，在岛盖部、额盖部和腹内侧前额叶皮层的激活程度更高。结果表明，躯体感觉、味觉和奖赏评估区域的过度反应可能与暴食有关，而自上而下的加工过程影响奖赏编码，这可能进一步导致体重增加。
