Eye Position and the Neural Basis of Sound Localization

我们所看到的帮助我们理解我们所听到的。知道物体的位置似乎毫不费力，无论我们是看到物体、听到物体，还是两者兼而有之。每种感觉系统确定刺激位置的方式不同。例如，视网膜为大脑提供了一个类似快照的地图，显示物体相对于眼睛正在看的地方的位置。这是一个以眼睛为中心的参照系。相比之下，对声音位置的感知包括评估两只耳朵之间声音到达时间和音量的细微差异。这些差异使我们的大脑能够确定声音在空间中相对于头部和耳朵的位置--一个以头部为中心的参照系。这个项目研究的是视觉和听觉系统之间沟通和协调的神经机制。特别是，这些实验集中在从我们的眼睛和耳朵收集的空间信息上。当一个物体既可以看到又可以听到时，眼睛可以移动的事实给将物体的视觉和听觉成分联系起来带来了一个重大问题。发出声音的物体可能位于你鼻子的左侧，但如果你的眼睛凝视到更左侧，该物体的视觉图像将落在视网膜空间地图的右侧。为了协调和整合我们的眼睛和耳朵收集的信息，大脑必须使用关于凝视角度的信息来将视觉和听觉信息转换成一个共同的参照系。大脑是如何做到这一点的？以前的工作已经表明，听觉通路具有相当多的关于凝视角度的信息。眼位影响的具体特征尚不清楚，将在本项目中进行研究。具体地说，这个项目将通过记录清醒猴子听觉通路中神经元的电活动来解决这种眼睛位置信号的作用，这些神经元被训练成执行行为任务。我们将研究大脑的眼睛位置信号和观察声音位置的能力之间的关系，并确定眼睛位置信号的计算特征，以及眼睛位置和对声音的神经反应之间相互作用的性质。这些实验的结果将被用来建立一个详细的模型，说明视觉、听觉和眼动能力与人类相似的动物的大脑是如何结合视觉和听觉信息的。与这些研究目标相结合，该项目将促进对具有心理学背景的研究生和本科生进行高级计算机培训，将本科生和研究生带入实验室研究，并通过为报纸和杂志撰写关于这些和其他科学发现的文章，向广大非科学受众传播科学进步。

What we see helps us understand what we hear. Knowing the locations of objects seems effortless, regardless of whether we see the object, hear it, or both. Each sensory system determines stimulus location differently. For example, the retina provides the brain with a snapshot-like map of where objects are located with respect to where the eyes are looking. This is an eye-centered frame of reference. In contrast, the perception of sound location involves assessing subtle differences in sound arrival time and volume between the two ears. These differences allow our brains to determine where sounds are located in space with respect to the head and ears - a head-centered frame of reference. This project investigates the neural mechanisms that underlie the communication and coordination between our visual and auditory systems. In particular, the experiments focus on the spatial information gleaned from our eyes and ears. When an object can be both seen and heard, the fact that the eyes can move poses a major problem for relating the visual and auditory components of the object. An object making a sound might lie to the left of your nose, but if your eyes are gazing even farther to the left, the visual image of that object will land on the right side of the retina's map of space. To coordinate and integrate the information gathered by our eyes and ears, the brain must use information about the angle of gaze to translate visual and auditory information into a common frame of reference. How does the brain do this? Previous work has shown that the auditory pathway possesses considerable information about angle of gaze. The specific features of the eye position influence are poorly understood and will be investigated in this project. Specifically, this project will address the role of this eye position signal by recording electroical activity in neurons in the auditory pathways of awake monkeys trained to perform behavioral tasks. The relationship between the brain's eye position signal and the ability to look to the location of a sound will be investigated and the computational features of the eye position signal and the nature of the interaction between eye position and neural responses to sounds will be determined. The results of these experiments will be used to build a detailed model of how visual and auditory information are combined in the brain of an animal whose visual, auditory and oculomotor capacities are similar to those of humans.In tandem with these research objectives this project will foster advanced computer training of graduate and undergraduate students with psychology backgrounds, bring undergraduate and graduate students into laboratory research and disseminate scientific advances to the public by writing articles on these and other scientific findings for newspapers and magazines that reach a broad non-scientific audience.