MEntal Representation of ODors: from physical features to perceptual processing

到了世纪之交，认为文明人类可以不使用嗅觉的想法已经过时了：这种迄今为止被认为是认知多余的难以表达的感觉，本身就成了研究的焦点。它被诺贝尔奖确认为科学研究的对象;此外，社会变得更加享乐主义，因此更加关注气味的情感影响。气味是快乐和社会联系的来源;它们影响我们的性行为和与他人的关系，特别是与我们的孩子。它们有助于我们的情绪平衡：嗅觉损伤会破坏这种平衡。认知心理学中的一个重要问题是了解人类大脑如何表征气味对象。视觉对象的表征得到了更好的理解;我们知道视觉刺激的物理和感知属性是以分布式和分层的方式表示的，但仍然不清楚气味分子的化学性质和气味的感知方面是如何沿着人类嗅觉通路沿着表示的。在本项目中，我们假设气味的多维表征是一种神经机制的结果，该机制在嗅觉系统的各个阶段处理化学信息和感知信息的相似性。将进行三组嵌入3个任务中的实验，这些实验结合了德国团队（德累斯顿技术大学的Hummel实验室）和法国团队（里昂大学的Bensafi实验室和CNRS）的努力。在第一个任务中，我们将在法国和德国进行一系列广泛的心理物理学实验，在大样本的参与者中定义一组化学和感知特性不同的气味。该气味数据库将能够选择在德累斯顿和里昂进行的以下两个独立实验任务中使用的气味。在第二个实验任务中，中央嗅觉区（梨状皮质，杏仁核和眶额皮质）在提取气味和气味之间的化学和感知相似性方面的作用将在嗅觉新手（非专家）和专家（调香师，他们对气味有更高的辨别能力）中进行测试。在第三个任务中，将探索人类嗅球（气味信息的第一个中继）在提取气味的化学相似性中的作用。在第二个目标中，我们将根据该项目的原始发现，在公众和高等教育中促进嗅觉的科学文化和交流。因此，本项目旨在以原创目标在国际竞争中定位自己。它结合了人类嗅觉和认知心理学的专业知识。它旨在更好地理解气味的心理表征，从根本上解读其神经组织，并从教育的角度提供气味心理学领域的原创课程。

Around the turn of the century the idea that civilized human beings might do without olfaction became outdated: this inarticulate sense, hitherto considered superfluous to cognition, became a focus of study in its own right. It was acknowledged as an object of science by Nobel prizes; in addition, society ecame more hedonistic, and hence more attentive to the emotional effects of odors. Odors are sources of both pleasure and social bonding; they influence our sexuality and relations with others in general and with our children in particular. They contribute to our emotional balance: olfactory damage impairs this equilibrium. An important issue in cognitive psychology is to understand how the human brain represents odor objects. Representation of visual objects is far better understood; we know that physical and perceptual attributes of visual stimuli are represented in a distributed and hierarchical manner, but it is still unclear how chemical properties of odorant molecules and perceptual aspects of odors are represented along the human olfactory pathway. In the present project, we hypothesize that the multidimensional representation of odors is the result of a neural mechanism that processes similarities of chemical information and perceptual information at various stages of the olfactory system. Three sets of experiments embedded in 3 Tasks combining the efforts of a German team (Hummel lab at the Technical Unversity of Dresden) and a French team (Bensafi lab at the University of Lyon and CNRS) will be conducted. In the first Task, we shall realize a series of extensive psychophysical experiments in both France and Germany in a large sample of participants to define a set of odorants varying in chemical and perceptual properties. This odor database will enable selection of odors used in the two following, independent experimental tasks performed in Dresden and Lyon. In the second experimental Task, the role of central olfactory areas (piriform cortex, amygdala and orbitofrontal cortex) in extracting both chemical and perceptual similarities across odorants and odors will be tested in novices (non-experts) and experts in olfaction (perfumers, who have higher discrimination abilities about odors). In the third Task, the role of the human olfactory bulb (the first relay of odor information) in extracting chemical similarities across odorants will be explored. In a second aim, we will promote scientific culture and communication on olfaction in the general public and in higher education based on the original findings from the project. Thus, the present project aims to position itself in international competition with original objectives. It combines expertise in human olfaction and cognitive psychology. It aims to better understand mental representation of smells, in a fundamental perspective for deciphering their neural organization, and in an educational perspective for providing original courses i the field of psychology of smells.