Baeyens F, Vansteenwegen D, De Houwer J, Crombez G
University of Leuven, Belgium.
Appetite. 1996 Dec;27(3):235-50. doi: 10.1006/appe.1996.0049.
It has been suggested that the observation of a model consuming a food (CS) and facially expressing either to like or to dislike (US') the food, may be a sufficient condition to bring about a change in the valence of the food for the observer. Unfortunately, up to now this hypothesis has not been investigated in a straightforward manner. In this study, during acquisition, children consumed a series of evaluatively neutral colored and flavored drinks, while simultaneously they watched a videotaped model synchronically drinking identical drinks and facially expressing his evaluation (neutral or dislike) of the liquids. In one condition, the presence of a particular flavor in the drinks was designated to function as the CS+ or the CS-, whereas in the other condition it was the color of the drinks which was the critical CS+ or CS-. Next, the children evaluated a series of drinks containing the critical CSs. A clear evaluative learning effect was obtained when the flavor but not when the color of the drinks was systematically paired with the model's facial expression of dislike. Moreover, the flavor conditioning effect was dependent on the presence in the test drinks of the local context cues (c.q. the colors of the drinks) which were used during acquisition. Finally a double dissociation was observed between explicit beliefs and the "evaluative knowledge" expressed in the ratings of the drinks, in that none of the children in the CS = Flavor groups evidenced any explicit knowledge about the crucial CS-US' contingency but showed evaluative conditioning, whereas the majority of the children in CS = Color groups were aware of the CS-US' relation but failed to demonstrate an evaluative CS-/CS-differentiation.
有人提出，观察一个模型食用一种食物（条件刺激）并面部表现出喜欢或不喜欢（无条件刺激）这种食物，可能是使观察者对该食物的效价发生变化的充分条件。不幸的是，到目前为止，这个假设尚未以直接的方式进行研究。在本研究中，在习得阶段，儿童食用了一系列评价性中性的有色有味饮料，同时他们观看录像中的模型同步饮用相同的饮料，并面部表现出对这些液体的评价（中性或不喜欢）。在一种条件下，饮料中特定味道的存在被指定为条件刺激+或条件刺激-，而在另一种条件下，饮料的颜色是关键的条件刺激+或条件刺激-。接下来，儿童对一系列含有关键条件刺激的饮料进行评价。当饮料的味道而不是颜色与模型不喜欢的面部表情系统配对时，获得了明显的评价性学习效果。此外，味道条件作用效应取决于测试饮料中是否存在习得阶段使用的局部情境线索（即饮料的颜色）。最后，在明确信念和饮料评分中表达的“评价性知识”之间观察到了双重分离，即条件刺激=味道组的儿童均未表现出对关键条件刺激-无条件刺激偶联的任何明确知识，但表现出评价性条件作用，而条件刺激=颜色组的大多数儿童意识到了条件刺激-无条件刺激的关系，但未能表现出评价性条件刺激-/条件刺激-的区分。
