Department of Computer Science, Oxford Centre for Computational Neuroscience, Oxford CV4 7AL, UK.
Proc Nutr Soc. 2012 Nov;71(4):488-501. doi: 10.1017/S0029665112000821. Epub 2012 Sep 19.
Complementary neuronal recordings and functional neuroimaging in human subjects show that the primary taste cortex in the anterior insula provides separate and combined representations of the taste, temperature and texture (including fat texture) of food in the mouth independently of hunger and thus of reward value and pleasantness. One synapse on, in the orbitofrontal cortex (OFC), these sensory inputs are for some neurons combined by learning with olfactory and visual inputs, and these neurons encode food reward in that they only respond to food when hungry, and in that activations correlate with subjective pleasantness. Cognitive factors, including word-level descriptions, and attention modulate the representation of the reward value of food in the OFC and a region to which it projects, the anterior cingulate cortex. Further, there are individual differences in the representation of the reward value of food in the OFC. It is argued that over-eating and obesity are related in many cases to an increased reward value of the sensory inputs produced by foods, and their modulation by cognition and attention that over-ride existing satiety signals. It is proposed that control of all rather than one or several of these factors that influence food reward and eating may be important in the prevention and treatment of overeating and obesity.
在人类受试者中，补充的神经元记录和功能神经影像学研究表明，位于前岛叶的主要味觉皮层独立于饥饿（因此也独立于奖励价值和愉悦感）提供了口中食物的味觉、温度和质地（包括脂肪质地）的单独和组合表示。在一个突触上，在眶额皮质（OFC）中，这些感觉输入通过学习与嗅觉和视觉输入相结合，这些神经元通过编码食物奖励来进行编码，即只有在饥饿时才对食物做出反应，并且激活与主观愉悦感相关。认知因素，包括词汇级别的描述和注意力，调节了 OFC 及其投射到的前扣带皮层中食物奖励价值的表示。此外，OFC 中食物奖励价值的表示存在个体差异。有人认为，在许多情况下，过度进食和肥胖与食物产生的感觉输入的奖励价值增加有关，以及认知和注意力对其的调节，这些调节会忽略现有的饱腹感信号。有人提出，控制所有这些影响食物奖励和进食的因素，而不是其中一个或几个因素，可能对预防和治疗过度进食和肥胖很重要。
