Identifying Neurosensory Solutions to the Binding Problem in Animal Behavior

人类和动物的行为是由连续的、通常是复杂的感觉输入引导的。神经系统必须解析这个输入流，并将那些与环境中实际物体相对应的片段结合在一起。作为示例，考虑STOP命令。人类的视觉系统毫不费力地将一个带有红色的八角形结合成一个统一的视觉感知，从而引发停止行为。同样，在口语单词“stop”中，不同的声音也会被绑定到听觉感知中，从而引发停止行为。了解神经系统如何解决这些所谓的“结合问题”的努力推动了认知和计算神经科学领域的发展。相比之下，对于非人类动物如何产生与动物感兴趣的各种事物（如猎物、捕食者、配偶、交流信号）相对应的约束感知，我们知之甚少。因此，关于允许动物解决绑定问题的大脑机制，仍然存在重要的知识空白。该项目整合了行为和电生理实验，揭示了在嘈杂的社会环境中声音交流是成功繁殖的关键的动物模型中听觉感知结合的一般机制。这项研究很重要，因为神经感觉机制的基本知识使动物能够解决听觉绑定问题，可以通过帮助改善听力假肢和语音识别系统来造福社会，这些系统在嘈杂的声学场景中表现不佳。这项研究还将有助于回答有关神经系统如何影响交流行为进化的新问题。此外，该项目将为至少15名本科生创造研究经验，推进博士后学者的培养，并将研究和教学与针对大城市小学生的公共宣传相结合。该项目研究了绿色树蛙（Hyla cinerea）的听觉结合，这是一种著名的听觉和声音交流研究动物模型。目的1使用行为实验来识别促进听觉结合的线索。两个实验将验证这一假设，即同步起始/偏移、共同空间起源和谐波相关性将类似于人类元音共振峰的发声频谱的不同部分结合在一起。目的2涉及来自听觉中脑单个神经元的电生理记录，以识别听觉结合的神经相关。三个实验将验证这一假设，即对光谱组合敏感的神经元的反应变化与对Aim 1中听觉结合线索的操纵作出的行为决定的变化有关。

Human and animal behavior is guided by continuous and often complex sensory input. Nervous systems must parse this input stream and bind together those pieces corresponding to actual objects in the environment. As an illustration, consider the command to STOP. The human visual system effortlessly binds an octagonal shape with red coloration into a unified visual percept that elicits stopping behavior. Likewise, different sounds in the spoken word "stop" become bound into an auditory percept that also elicits stopping behavior. Efforts to understand how nervous systems solve these so-called "binding problems" have advanced the fields of cognitive and computational neuroscience. By comparison, much less is known about how nonhuman animals create bound percepts that correspond to the variety of things of interest to animals (e.g. prey, predators, mates, communication signals). Hence, important knowledge gaps remain concerning the brain mechanisms that allow animals to solve binding problems. This project integrates behavioral and electrophysiological experiments to uncover general mechanisms of auditory perceptual binding in an animal model for which vocal communication in noisy social environments is key to successful reproduction. This research is important because basic knowledge of neurosensory mechanisms that enable animals to solve auditory binding problems could benefit society by helping to improve hearing prosthetics and speech recognition systems, which perform poorly in noisy acoustic scenes. This research will also lead to answering new questions about how neural systems shape the evolution of communication behaviors. In addition, the project will create research experiences for a minimum of 15 undergraduates, advance the training of a postdoctoral scholar, and integrate research and teaching with public outreach aimed at elementary school kids in a large metropolitan area. The project investigates auditory binding in green treefrogs (Hyla cinerea), a well-known animal model in studies of hearing and sound communication. Aim 1 uses behavioral experiments to identify cues that promote auditory binding. Two experiments will test the hypothesis that synchronous onsets/offsets, common spatial origin, and harmonic relatedness function to bind together separate parts of the frequency spectrum of vocalizations analogous to formants in human vowel sounds. Aim 2 involves electrophysiological recordings from single neurons in the auditory midbrain to identify neural correlates of auditory binding. Three experiments will test the hypothesis that changes in the responses of neurons sensitive to spectral combinations correlate with changes in the behavioral decisions made in response to manipulations of the auditory binding cues from Aim 1.