Oral Somesthesis and Taste

描述（由申请人提供）：食物的选择和摄入主要取决于口腔的感觉模式。该项目的长期目标是了解躯体感觉和味觉系统如何协同工作以服务于这些重要功能。在当前资助期间获得的结果提供了关于这些系统之间存在或不存在的感知相互作用的新信息，以及构成这些系统的心理物理因素。从这些结果中产生的假设将在4个具体目标中进一步发展和测试。目的1将研究“主动”与“被动”品尝对味觉感知、口腔感知及其感知相互作用的影响。正常的味觉是在相关机械刺激的背景下发生的主动过程，但味觉感知几乎完全被研究为被动接受化学刺激。实验将检验一些假设，即感知某些味觉刺激（尤其是谷氨酸）、化学刺激（产生灼烧感或刺痛感的化学物质）和触觉刺激（粘性、涩味）的能力取决于品尝模式和口腔刺激发生的位置。基于新的发现，Aim 2将检验这一假设，即味觉感知的个体差异独立于体感感知的个体差异，并且味觉敏感性通过使用原型味觉刺激（如蔗糖）比广泛使用的苦味剂PROP更好地评估，因为许多个体都对其感到厌恶。Aim 3将根据最近的发现，对一个假设进行进一步的测试，即苦味和灼烧的“疼痛”具有密切的感知关系，这源于它们作为潜在有害刺激的感官信号的共同功能。最后，目标4将结合心理物理测量和功能磁共振成像来研究味觉和化学感觉的中枢神经处理。拟议的研究包括对苦味与化学感觉之间关系的特定假设的测试，以及中枢神经“增益”的存在，这种“增益”导致了味觉的个体差异，而不是躯体感觉。通过提供关于正常味觉、口腔感觉及其相互作用的感知特性和神经基础的新数据，拟议的研究有可能改善味觉和口腔感觉病理（例如“灼口综合征”）的临床评估，并为其可能的原因提供新的见解。

DESCRIPTION (provided by applicant): Food selection and ingestion depend critically upon the sensory modalities of the mouth. The long-term goal of this project is to understand how the somatosensory and gustatory systems work together to serve these vital functions. Results obtained during the current funding period have provided new information about the kinds of perceptual interactions that do and do not occur between these systems as well as the psychophysical factors that underlie them. Hypotheses generated from these results will be further developed and tested in 4 specific aims. Aim 1 will investigate the effect of "active" versus "passive" tasting on perception of taste, oral somesthesis, and their perceptual interactions. Normal tasting is an active process that occurs within the context of correlated mechanical stimulation, yet taste perception has been studied almost exclusively as a passive reception of chemical stimulation. Experiments will test hypotheses that the ability to perceive some taste stimuli (particularly glutamates), chemesthetic stimuli (chemicals that produce burning or stinging sensations) and tactile stimuli (viscosity, astringency) depends on the mode of tasting and where in the mouth stimulation occurs. Aim 2 will test the hypothesis, based on new findings, that individual differences in taste perception are independent of individual differences in somatosensory perception, and that taste sensitivity is better assessed by use of a prototype taste stimulus (e.g., sucrose) than by the widely used bitter tastant PROP, to which many individuals are aguesic. Aim 3 will provide further tests of a hypothesis, based on recent findings, that bitter taste and burning 'pain' have a close perceptual relationship that arises from their common function as sensory signals of potentially harmful stimuli. Finally, aim 4 will combine psychophysical measurements with fMRI to study the central neural processing of taste and chemesthesis. The proposed study includes tests of specific hypotheses about the relationship of bitter taste to chemesthesis and the presence of a central neural 'gain' that contributes to individual differences in taste but not somatosensation. By providing new data on the perceptual properties and neural basis of normal taste, oral somesthesis, and their interactions, the proposed studies have the potential to improve clinical assessment of gustatory and oral sensory pathologies (e.g., 'burning mouth syndrome') as well as to provide new insights into their possible causes.