Coincidence and continuity: uncovering the neural basis of auditory object perception

摘要 听觉对象是我们听觉感知世界的基本构件。听觉对象是 部分是由大脑从声学信号中提取和组织光谱和时间规律的能力形成的 环境。这种能力使人们能够在拥挤的餐厅的嘈杂声中听到朋友的声音。 在许多情况下，跨多个频率通道形成时间规律性。这个例子和几个 另一些人则认为，大脑可以跨多个频率跟踪这种时间相关的神经元活动 引导并使用这种活动作为形成听觉对象和组织听觉环境的手段。 尽管它对听觉很重要，但很少或根本没有直接证据支持 假设时间规律性被编码为时间相关的活动，并且该活动可以 引导行为。为了填补这一信息空白，我们将严格的心理物理学与高密度神经元相结合。 识别时间规律性与动态网络相互作用的记录和计算理论 结构和感知。因此，这项提议的总体目标是确定介观电路 学习环境的时间规律性--即重合和连续性--的听觉皮质层级 以及这些规则的神经元表示如何对听觉知觉的两个关键组成部分做出贡献： 图形背景分离和知觉不变性。在目标1中，我们假设图形-背景 通过动态印记到皮质回路的瞬时相关(即， 时间重合)跨声目标的频带。因此，我们测试音调是否带有 同步启动增加了皮质神经元的内在噪声相关性，这反过来又促进了 听者在嘈杂的地面刺激中听到图形刺激的能力。在目标2中，我们假设 刺激不变性是从光谱时间中的平滑(即，时间上连续的)变化中学习的 听觉刺激的结构。基于这一理论，我们假设大脑在时间上解释 作为潜在听觉对象的自然变换的听觉刺激的连续变化 推动对不变知觉表征的分层学习。无论是个人还是集体，这些目标 对听觉感知及其潜在的神经机制提供有价值的、定量的见解。这个 PIS是唯一有资格进行这项研究的人，他们在心理物理学、人口统计方面具有互补的专业知识 神经元记录和计算/理论神经科学。

SUMMARY Auditory objects are the foundational building blocks of our auditory-perceptual world. Auditory objects are formed, in part, by the brain’s ability to extract and organize spectral and temporal regularities from the acoustic environment. This ability allows a person to hear their friend’s voice amongst the noise of a crowded restaurant. In many cases, temporal regularities are formed across multiple frequency channels. This example and several others suggest that the brain can track this temporally correlated neuronal activity across multiple frequency channels and uses this activity as a means to form auditory objects and organize the auditory environment. Despite its clear importance to auditory perception, there is little to no direct evidence in support of the hypothesis that temporal regularities are encoded as temporally correlated activity and that this activity can guide behavior. To fill this information gap, we combine rigorous psychophysics with high-density neuronal recordings and computational theory to identify the interaction of temporal regularities with dynamic network structures and perception. Thus, the overall goal of this proposal is to identify the mesoscopic circuits of the auditory cortical hierarchy that learn temporal regularities –i.e., coincidence and continuity– of the environment and how neuronal representations of these regularities contribute to two key components of auditory perception: figure-ground segregation and to perceptual invariance, respectively. In Aim 1, we posit that figure-ground segregation is facilitated by the dynamic imprinting into cortical circuits of instantaneous correlations (i.e. temporal coincidence) across frequency bands of the acoustic target. Thus, we test whether tone bursts with synchronous onsets increase the intrinsic noise correlations of cortical neurons, which, in turn, facilitates a listener’s ability to hear a figure stimulus amongst a noisy ground stimulus. In Aim 2, we hypothesize that stimulus invariances are learned from smooth (i.e., temporally continuous) changes in the spectrotemporal structure of auditory stimuli. Based on this theory, we hypothesize that the brain interprets temporally continuous variations in an auditory stimulus as natural transformations of underlying auditory objects and drives hierarchical learning of invariant perceptual representations. Individually and collectively, the Aims provide valuable, quantitative insights into auditory perception and its underlying neuronal mechanisms. The PIs are uniquely qualified to conduct this research with complementary expertise in psychophysics, population neuronal recordings, and computational/theoretical neuroscience.