Yeomans Martin R, Leitch Margaret, Gould Natalie J, Mobini Sirous
Department of Psychology, University of Sussex, Brighton, United Kingdom.
Physiol Behav. 2008 Mar 18;93(4-5):798-806. doi: 10.1016/j.physbeh.2007.11.041. Epub 2007 Dec 4.
Flavor-flavor and flavor-nutrient associations can modify liking for a flavor CS, while flavor-flavor associations can also modify the sensory experience of the trained flavor. Less is known about how these associations modify behavioral responses to the trained CS. To test this, 60 participants classified as sweet likers were divided into five training conditions with a novel flavor CS. In the flavor-flavor only condition, participants consumed the target CS in a sweetened, low-energy form, with energy (maltodextrin) but no sweetness added in the flavor-nutrient only condition and both energy and sweetness (sucrose) in the combined flavor-flavor, flavor-nutrient condition. Comparison groups controlled for exposure to the CS, and repeat testing. Training was conducted in a hungry state on four non-consecutive days. To test for acquired changes in evaluation and intake, the flavor CS was processed into a low-energy sorbet, which was evaluated and consumed ad libitum on test days before and after training. Liking for the flavor CS increased only in the sucrose-sweetened condition, but intake increased significantly in both high-energy conditions. In contrast, rated sweetness of the sorbet increased in both sucrose-sweetened and aspartame-sweetened conditions. These findings suggest that liking changes were maximal when flavor-flavor and flavor-nutrient associations co-occurred, but that behavioral changes were specific to flavor-nutrient associations.
味道与味道以及味道与营养物质之间的关联可以改变对味道条件刺激（CS）的喜好，而味道与味道之间的关联也可以改变所训练味道的感官体验。关于这些关联如何改变对所训练的条件刺激的行为反应，人们了解得较少。为了对此进行测试，60名被归类为喜欢甜味的参与者被分为五个使用新味道条件刺激的训练组。在仅味道与味道的条件下，参与者以加甜的低能量形式食用目标条件刺激，在仅味道与营养物质的条件下添加了能量（麦芽糊精）但未添加甜味，而在味道与味道、味道与营养物质相结合的条件下同时添加了能量和甜味（蔗糖）。对照组控制了对条件刺激的接触以及重复测试。训练在饥饿状态下于四个非连续的日子进行。为了测试习得的评价和摄入量的变化，将味道条件刺激加工成低能量的冰沙，在训练前后的测试日让参与者随意对其进行评价和食用。对味道条件刺激的喜好仅在蔗糖加甜的条件下增加，但在两种高能量条件下摄入量均显著增加。相比之下，冰沙的甜度评分在蔗糖加甜和阿斯巴甜加甜的条件下均有所增加。这些发现表明，当味道与味道以及味道与营养物质的关联同时出现时，喜好变化最大，但行为变化特定于味道与营养物质的关联。
