Effects of Emotion on Neural Encoding of Sound

描述(申请人提供)：脑干的传统观点在将听觉信号传递到大脑的高级区域方面扮演着静态和被动的角色，但最近的证据表明，一个比之前认为的更具活力和可塑性的系统。在视觉系统中，有大量证据表明，人脸识别中存在平行的路径，大脑皮层中的高分辨率系统处理细粒度数据，而通往边缘系统的快速、进化的古老路径传递空间上粗糙但具有高度生物相关性的信息，如面部表情。在解剖学上，已知听觉脑干和边缘系统之间也有直接和广泛的联系，这些联系在解剖学上已经在啮齿动物和灵长类动物中表现出来。然而，这些联系还没有得到功能上的描述。我们的研究重点是了解声音的神经表征是如何在听觉加工的最早阶段受到情绪刺激(如情绪唤起图像)的影响，并确定这种相互作用在整个听觉通路中的增长和转化。我们感兴趣的是确定由情绪诱发的视觉刺激引起的听者的情绪状态如何影响听者对言语的生理反应。为了做到这一点，使用标准化的情感视觉刺激数据库中的图像，在听者中诱导出三种情绪状态(包括“中性”状态)后，测量对听觉语音的生理反应。远场和近场记录(分别为脑干和皮质反应)将评估皮质下和皮质过程对两种输入模式相互作用的相对贡献，并阐明相互作用的时间。我们的初步数据显示，不同情绪状态之间的差异具有统计学意义。我们目前知道，脑干的延展性比之前想象的要好得多，这为治疗疾病的潜在效果以及增强语言和音乐学习的潜力提供了希望，但这种延展性也有其他方面。众所周知，焦虑症与抑郁症有很高的共患率，情绪健康与一般心理健康有很大的互动关系。如果脑干在几个小时的时间尺度上是可塑性的，那么我们有理由相信，焦虑症不仅会影响一个人的情绪健康，它还会在非常基本的水平上对感觉处理产生不利影响。

DESCRIPTION (provided by applicant): Traditional views of the brainstem have assumed a static and passive role in relaying the auditory signal to higher regions of the brain, but recent evidence indicates a far more dynamic and malleable system than previously thought. In the visual system, there is a plethora of evidence pointing to parallel pathways in the recognition of faces, a high-resolution system in the cortex that processes fine-grained data, and a fast, evolutionary ancient pathway to the limbic system that relays spatially coarse but highly biologically relevant information like facial expression. Anatomically, there is known to be direct and widespread connections between the auditory brainstem and the limbic system as well, and these have been characterized, anatomically, in rodents and primates. However, these connections have not been functionally characterized. The focus of our research is to understand how the neural representation of sounds is affected by emotional stimuli, such as emotion-evoking images, at the earliest stages of the auditory processing stream and to define the growth and transformation of this interaction throughout the auditory pathway. We are interested in determining how a listener's emotional state, induced by emotion-evoking visual stimuli, influences the listener's physiological response to speech. To do this, physiological responses to auditory speech are measured after inducing three emotional states (including a "neutral" state) in the listener with the use of images from a standardized database of emotional visual stimuli. Far-field and near-field recordings (brainstem and cortical responses, respectively) will assess the relative contributions of subcortical and cortical processes to the interaction of the two input modes and illuminate timing of the interactions. Our preliminary data show statistically significant differences between emotional conditions. We currently know that the brainstem is far more malleable than previously thought, which gives promise to the potential effects of therapies for disorders as well as the potential to enhance the learning of language and music, but there are other aspects to this malleability as well. It is known that anxiety disorders have a high comorbidity with depression, and that emotional health is hugely interactive with general mental health. If the brainstem is malleable on the time-scale of hours, it is reasonable to believe that anxiety disorders not only influence one's emotional health, it can also adversely affect sensory processing at a very basic level.