Oral Somesthesis and Taste

这个项目的长期目标是了解躯体感觉和味觉系统如何共同作用，产生口腔感觉和风味。这个目标将通过利用最近的三个心理物理学发现来实现，这些发现提供了关于躯体感觉刺激如何影响味觉的新见解。首先，将进行研究以调查热味觉现象，其中味觉可以仅由温度诱导。特别感兴趣的是热味觉的个体和空间变化的来源，热味觉和化学味觉之间的相互作用，以及热味觉的空间和时间特征，因为它们与对温暖和寒冷的敏感性有关。其次，将研究由舌头前部的短暂冷刺激引起的“幻影”味觉的诱导和感知。这些冷诱导的幻觉（CIP）被认为是冷刺激后，而不是在冷刺激期间，并定位远离，而不是在冷却的网站。提出实验来测试的假设，CIP，可逆地模仿临床味觉障碍，出现时，假定的紧张性抑制内和之间的口腔感觉系统被冷块中断。第三，初步的观察表明，辣椒素，典型的“三叉神经”刺激物，可以引起显着的苦味在circumvallate区域的舌头，和感官刺激和温暖的感觉都比舌尖弱得多。实验将调查的可能性，一些舌咽神经元，有助于感知苦味是敏感的刺激物，更普遍的是，somesthesis和味觉之间的关系是不同的舌背，这两种刺激都是由舌咽神经介导的。总的来说，这些研究将促进我们对人类口腔感觉处理的理解，并提供有关感觉相互作用的数据，这些数据可能有助于理解某些类型的口腔感觉病理学的来源（例如，味觉障碍）。

The long-term goal of this project is to understand how the somesthetic and gustatory systems function together to produce oral sensations and flavors This goal will be pursued by taking advantage of three recent psychophysical findings that provide novel insights into how somatosensory stimulation can influence taste. First, studies will be conducted to investigate the phenomenon of thermal taste, in which tastes can be induced by temperature alone. Of particular interest are sources of individual and spatial variation in thermal taste, interactions between thermal taste and chemical taste, and the spatial and temporal characteristics of thermal tastes as they relate to the sensitivity to warmth and cold. Second, the induction and perception of 'phantom' tastes caused by brief bouts of cold stimulation on the front of the tongue will be investigated. These cold-induced phantoms (CIPs) are perceived after rather than during cold stimulation, and are localized away from rather than at the site of cooling. Experiments are proposed to test the hypothesis that CIPs, which reversibly mimic clinical dysgeusias, arise when putative tonic inhibition within and between oral sensory systems is interrupted by cold-block. Third, preliminary observations indicate that capsaicin, the prototypical "trigeminal" irritant, can evoke significant bitterness in the circumvallate region of the tongue, and that both sensory irritation and perception of warmth are much weaker there than on the tongue tip. Experiments will investigate the possibility that some glossopharyngeal neurons that contribute to perception of bitterness are sensitive to irritants, and more generally, that the relationship between somesthesis and taste is different on the back of the tongue, where both kinds of stimulation are mediated solely by the glossopharyngeal nerve. Overall, these studies will advance our understanding of oral sensory processing in humans as well as provide data on sensory interactions that may be helpful in understanding the source of certain types of oral sensory pathologies (e.g., dysgeusias).