Cognitive and affective influences on taste processing

描述（由申请人提供）：这是一个项目的申请，该项目将使用功能磁共振成像来研究人类大脑中味觉的中枢表征。有两个具体目标。具体目标I是评估任务的执行是否影响大脑对sapid刺激的反应。我们知道，在皮层味觉区中，预期神经元与味觉反应神经元之间存在着间隙，我们还知道，这些皮层味觉区参与情感决策。因此，很有可能的是，任务的执行，例如判断愉悦或检测味道的存在，会影响味觉神经元的反应或在味觉区域内引起可能阻碍或与对味道的反应的检测相互作用的反应。因此，很明显需要系统地研究判断味觉的感知属性如何与味觉反应相互作用。具体目标II是评估一般预测，质量特定的反应可以被隔离时，强度和情感值的控制，这样的反应可以根据生理意义的质量功能分组。尽管味觉质量编码问题在大鼠和灵长类动物味觉电生理工作中占据主导地位，但迄今为止，还没有研究在人类中解决这个问题。由于有可能是重叠的味觉强度，影响和质量编码的表示，我们建议检查大脑的味觉质量的反应，同时系统地操纵或控制的强度和情感值的刺激。由于情感价值可以是内在的刺激，或内部状态的变化的结果，我们将测试的假设，而内在的愉快的甜味可能会影响质量编码，质量编码应该是独立的短暂变化与饱腹感相关的愉快。我们将使用标准的功能磁共振成像以及2种新技术，功能磁共振成像适应和有效的连接分析，以检查质量是否表示为空间分离的反应（例如chemotopy），空间重叠，但不同的神经元群体反应或作为独特的模式内的互联网络的皮层味觉区。这项研究将提供有关人类味觉的基本信息，并将为肥胖和患有饮食，药物或酒精障碍的个人的味觉处理的未来研究提供重要的基线数据。

DESCRIPTION (provided by applicant): This is an application for a project that will use fMRI to investigate central representation of taste in the human brain. There are 2 specific aims. Specific aim I is to evaluate whether the performance of a task influences brain responses to sapid stimuli. We know that there are anticipatory neurons interspersed with taste-responsive neurons in the cortical gustatory areas and we know that these cortical taste regions participate in affective decision-making. Therefore, it is very likely that performance of a task, such as judging pleasantness or detecting the presence of a taste, affects the response of gustatory neurons or evokes a response within the gustatory areas that could hinder or interact with detection of the response to taste. Systematic investigation of how judging perceptual attributes of a taste interact with the gustatory response is therefore clearly needed. Specific aim II is to evaluate the general prediction that quality-specific responses can be isolated when intensity and affective value are controlled, and that such responses can be functionally grouped according the physiological meaning of the quality. Although the issue of taste-quality coding has dominated the rat and primate electrophysiological work in gustation, to date, no study has addressed this issue in humans. Since there is likely to be overlapping representation of taste intensity, affect, and quality coding, we propose to examine brain responses to taste quality while systematically manipulating or controlling for the intensity and affective value of the stimulus. Because affective value can be intrinsic to the stimulus, or the result of changes in internal state we will test the hypothesis that while the intrinsic pleasantness of a sweet taste may influence quality coding, quality coding should be independent from transient changes in pleasantness associated with satiety. We will use standard fMRI as well as 2 novel techniques, fMRI-adaptation, and effective connectivity analyses, to examine if quality is represented as spatially segregated responses (e.g. chemotopy), spatially overlapping but distinct neuronal population responses or as unique patterns of interconnectivity within a network of cortical gustatory areas. This research will provide fundamental information about human gustation and it will provide important baseline data for future studies of gustatory processing in the obese and individuals with an eating, drug or alcohol disorder.