Multiscale modeling of the cocktail party problem

项目摘要 在我们生活的每一个瞬间，不和谐的声音冲击着我们的耳朵，挑战着我们的大脑， 我们生活的复杂声学环境的感觉-一种被称为鸡尾酒会的现象 问题（CPP）。到目前为止，对这一现象的理解主要集中在声学线索在 形成大脑中听觉对象的感觉编码。但是，倾听并不等同于倾听。其接合 感官和认知过程，使大脑能够适应其计算原语和神经 对变化的音景进行编码，并转移需求以关注场景中的各种声音。当前 一项提案提出了一种听觉感知的自适应理论，它整合了感官和听觉的作用。 机制和认知控制在一个统一的多尺度理论，结合神经过程的水平， 单个神经元、神经群体和整个大脑区域。这一假设的核心是快速神经元的作用。 可塑性，重塑大脑对声音刺激的反应，根据统计结构的 声景，由记忆和注意力的反馈机制引导。研究计划将这一点 假设到一个统一的多尺度模型采用分布式推理架构（目标1）。该方案 采用分层动态系统，以不同的分辨率跟踪刺激的统计结构 和时间尺度，并根据记忆和注意力先验来调整他们的反应。这种架构 作为跳板，以预测在玩耍过程中感觉和认知机制之间的相互作用。 CPP。它还提供了一个通用的解决方案，现场分析的问题，将接口与现有的声音 技术（例如语音识别、医疗诊断、目标跟踪和监视）。这种计算 通过对人类受试者的实验数据（目标2）， 心理声学和脑电图;以及行为雪貂的单单位电生理学。这些实验 使用丰富的刺激操纵统计结构，以及 受试者（人/动物）的注意力焦点。最后的综合理论是在感性研究中提炼出来的， 年轻人和老年人，他们的感知受到复杂听觉音景的高度挑战（目标3）。这 努力产生可测试的预测失败的听觉感知在多个环境中，特别是 在老年人和精确定位可能的功能障碍，由于感官或认知因素。通过揭示 CPP过程中感觉和认知相互作用的功能原理和神经基础， 这项研究将对我们理解杂乱场景中的听觉感知产生重大影响。此外，本发明还提供了一种方法， 它与健康和幸福直接相关，特别是对于改善感官交流辅助工具， 受损和老龄化人口;以及为声音技术（例如语音）提供自适应处理 识别，音频分析），其大部分保持静态和硬连线。 1

Project summary At every instant of our lives, a cacophony of sounds impinges on our ears and challenges our brain to make sense of the complex acoustic environment in which we live – a phenomenon referred to as the cocktail party problem (CPP). Up till now, efforts to understand this phenomenon focused on the role of acoustic cues in shaping sensory encoding of auditory objects in the brain. Yet, listening is not the same as hearing. It engages both sensory and cognitive processes to enable the brain to adapt its computational primitives and neural encoding to the changing soundscape and shifting demands to attend to various sounds in the scene. The current proposal puts forth an adaptive theory of auditory perception which integrates the role of both sensory mechanisms and cognitive control in a unified multiscale theory that combines neural processes at the level of single neurons, neural populations and across brain areas. Central to this hypothesis is the role of rapid neural plasticity that reshapes brain responses to acoustic stimuli according to the statistical structure of the soundscape, guided by feedback mechanisms from memory and attention. The research plan translates this hypothesis into a unified multiscale model employing a distributed inference architecture (Aim 1). This scheme employs hierarchical dynamical systems that track the statistical structure of the stimulus at different resolutions and time-scales, and adapt their responses based on both memory and attentional priors. This architecture is used as springboard to predict the interaction between sensory and cognitive mechanisms at play during the CPP. It also affords a general solution to the scene analysis problem that will be interfaced with existing sound technologies (e.g. speech recognition, medical diagnosis, target tracking and surveillance). This computational effort is informed and validated with empirical data (Aim 2) from experiments in human subjects, using psychoacoustics and EEG; as well as single-unit electrophysiology in behaving ferrets. The experiments shed light of neural processes underlying the CPP using rich stimuli that manipulate the statistical structure as well as attentional focus of subjects (humans/animals). The final integrated theory is refined in perceptual studies in young and aging adults whose perception is highly challenged by complex listening soundscapes (Aim 3). This effort generates testable predictions about failures in auditory perception in multisource environments especially in aging adults and pinpoints possible malfunctions due to sensory or cognitive factors. By shedding light on the functional principles and neural underpinnings underlying the sensory and cognitive interaction during the CPP, the research will have a big impact on our understanding of auditory perception in cluttered scenes. In addition, it has direct relevance to health and wellbeing, particularly for improving communication aids for the sensory impaired and aging populations; as well as affording adaptive processing to sound technologies (e.g. speech recognition, audio analytics) which remain for the most part static and hard-wired. 1