Changes in brain activity related to eating chocolate - From pleasure to aversion
Changes in brain activity related to eating chocolate - From pleasure to aversion
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DOI：
10.1093/brain/124.9.1720
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发表时间：
2001-09-01
期刊：
影响因子：
14.5
通讯作者：
Jones-Gotman, M
中科院分区：
文献类型：
--
作者：
Small, DM;Zatorre, RJ;Jones-Gotman, M
我们对志愿者进行了连续的（H2O）-O-15-PET扫描，因为他们吃巧克力超过了饱腹感。因此，感官刺激和行为（进食）保持不变，而巧克力的奖励值和受试者进食的动机通过喂食来操纵。饱腹感的非特异性影响（如饱腹感和自主神经变化）也存在，可能有助于调节大脑活动。在吃完每一块巧克力后，受试者给出了巧克力有多令人愉快/不愉快以及他们有多想或不想再吃一块巧克力的评级。然后根据受试者的评分对局部脑血流量进行回归。根据受试者是否在吃巧克力时有高度的进食动机，并将巧克力评为非常愉快的[胼胝体下区域，尾内侧眶额皮质（OFC），小脑/盖，纹状体和中脑]，或者他们是否在吃饱的情况下吃巧克力（海马旁回，尾外侧OFC和前额区），选择性地招募了不同的结构组。正如预测的那样，调制观察皮质化学感受区，包括尾内侧和尾外侧眶额皮层，这表明食物的奖励价值是在这里表示。特别有趣的是，内侧和外侧尾侧眶额囊表现出相反的活动模式。这种活动模式表明，在这个区域内，奖励和惩罚的神经表征可能存在功能隔离。与中性条件相比，在阳性和阴性条件下唯一活跃的大脑区域是后扣带皮层。因此，这些结果支持的假设，有两个独立的动机系统：一个协调的方法和另一个回避行为。
We performed successive (H2O)-O-15-PET scans on volunteers as they ate chocolate to beyond satiety. Thus, the sensory stimulus and act (eating) were held constant while the reward value of the chocolate and motivation of the subject to eat were manipulated by feeding. Non-specific effects of satiety (such as feelings of fullness and autonomic changes) were also present and probably contributed to the modulation of brain activity. After eating each piece of chocolate, subjects gave ratings of how pleasant/ unpleasant the chocolate was and of how much they did or did not want another piece of chocolate. Regional cerebral blood flow was then regressed against subjects' ratings. Different groups of structures were recruited selectively depending on whether subjects were eating chocolate when they were highly motivated to eat and rated the chocolate as very pleasant [subcallosal region, caudomedial orbitofrontal cortex (OFC), insula/operculum, striatum and midbrain] or whether they ate chocolate despite being satiated (parahippocampal gyrus, caudolateral OFC and prefrontal regions). As predicted, modulation was observed in cortical chemosensory areas, including the insula and caudomedial and caudolateral OFC, suggesting that the reward value of food is represented here. Of particular interest, the medial and lateral caudal OFC showed opposite patterns of activity. This pattern of activity indicates that there may be a functional segregation of the neural representation of reward and punishment within this region. The only brain region that was active during both positive and negative compared with neutral conditions was the posterior cingulate cortex. Therefore, these results support the hypothesis that there are two separate motivational systems: one orchestrating approach and another avoidance behaviours.