Studies of pleasantness and unpleasantness in olfaction

这个研究项目将研究我们的嗅觉和情绪之间的特殊关系。气味可以引起情绪变化，唤起充满感情的记忆。这个项目的主要目标是研究影响我们判断是否喜欢某种气味的几个因素，以及这些情绪判断是如何在我们的大脑中表现出来的。在第一个系列的研究中，由不同比例的愉快气味和不愉快气味组成的气味混合物将被用来确定我们对气味的生理反应（如皮肤电导）是否与它们的愉悦感相关，以及大脑结构对增加的气味愉悦感有何反应。在第二个系列中，我打算进一步探讨先前的发现，即我们不仅根据气味的物理特征，而且根据我们对气味来源的信念来判断和反应。例如，我们对气味的感知和生理反应会有很大的不同，这取决于我们认为它是来自胡萝卜汁还是发霉的蔬菜。这一现象的脑相关性将通过脑活动的电生理和血流测量来探索。最后，我们知道，当我们熟悉某些气味时，我们对它们的反应会减弱：令人愉快的气味变得不那么令人愉快，令人不愉快的气味变得不那么令人不愉快。在最后的一系列实验中，将探讨与此现象相关的几个问题：食物中的这种效果是否比非食物气味更强？效果持久吗？它发生在鼻子还是大脑？什么样的大脑结构与这种判断的转变有关？这个研究项目将帮助我们了解是什么因素导致了我们的情绪反应，以及这些反应是如何在我们的大脑中组织起来的。这些发现将推动心理学和神经生理学领域的发展，在健康参与者中获得的发现将在未来用于更好地了解患有不同类型情绪障碍（如抑郁症、焦虑症、精神分裂症和自闭症）的人如何对情绪挑衅性刺激作出反应。

This research program will examine the special relationship between our sense of smell and our emotions. Odours can elicit mood shifts and evoke emotionally loaded memories. The main goal of this program is to examine several factors that influence our judgments about whether or not we like certain smells and how these emotive judgments are represented in our brains. In the first series of studies, odour mixtures made of varying proportions of a pleasant and an unpleasant smell will be used to determine whether our physiological responses (such as skin conductance) to odours correlate with their pleasantness and also what brain structures respond to increasing odour pleasantness. In the second series, I intend to further explore previous findings that we judge and respond to odours based not only on their physical characteristics but also on our beliefs about their source. For example, our perception of and physiological response to an odour will be very different depending on whether we believe it emanates from carrot juice or mouldy vegetables. Brain correlates of this phenomenon will be explored using electrophysiological and blood flow measures of brain activity. Finally, we know that when we become familiar with certain odours, our reaction to them diminishes: pleasant odours become less pleasant and unpleasant odours become less unpleasant. In the last series of experiments, several questions related to this phenomenon will be explored: Is this effect stronger in food than non-food odours? Is the effect long-lasting? Does it occur in the nose or in the brain? What brain structures are associated with this shift in judgment? This research program will help us understand what factors contribute to our emotional responses and how these responses are organized in our brains. These discoveries will advance the fields of psychology and neurophysiology, and the findings obtained in healthy participants will be used in the future to better understand how people with different types of emotional disturbances, such as depression, anxiety disorders, schizophrenia and autism, respond to emotionally provocative stimuli.