Behavioral and neural correlates of auditory-object integration and segregation

描述(申请人提供)：对象是我们听觉-感知世界的核心构件。然而，当我们目前对听觉物体处理的理解与处理听觉物体所需的假定步骤进行比较时，很明显，我们的知识中存在着关键的差距。最根本和最重要的差距是我们对听觉刺激的声学特征、神经活动和知觉之间的关系缺乏了解。事实上，我们所知道的这种关系在最基本的层面上是缺乏的：刺激被整合和分离成一个或多个知觉听觉对象的方式。这项提案的两项关键创新旨在填补我们理解上的这一空白。首先，PI直接测试听觉刺激的声学特征、单个神经元活动与受试者关于听觉-客体整合和分离的行为报告之间的关系。第二，PI记录并对比了初级听觉皮质和次级听觉皮质(即前外侧带)中听觉-物体加工的神经联系。目的1测试听觉皮质中的神经元是否编码(1)听觉刺激的声学特征，或(2)猴子听觉-客体整合和分离的行为报告。这一目的是通过评估这样一种假设来实现的，即初级听觉皮质中的神经活动可靠地受到听觉刺激的声学特征的调节，但不受受试者的行为报告的调节。相反，它还假设，次级听觉皮质(前外侧带)的神经活动可靠地受到受试者行为报告的调节，但不受听觉刺激的声学特征的调节。这两种假设都是通过记录听觉皮质神经元的细胞外信号来检验的，而猴子则参与了一项间隔一次、两种选择的强迫选择任务，要求它们听一听听觉刺激，并报告他们听到的是一个还是两个听觉物体。 公共卫生相关性：这一系列研究具有重要的临床意义。从这个提议中产生的数据中，将会出现对听觉对象处理基础的神经机制和过程的更大理解。这一增强的欣赏将为听力障碍和言语感知障碍提供重要的见解。最终，来自这些研究的见解将改进听力假体的设计、诊断分析和康复计划的开发。

DESCRIPTION (provided by applicant): Objects are the core building blocks of our auditory-perceptual world. However, when our current understanding of auditory-object processing is compared to the putative steps needed to process auditory objects, it is clear that there are key gaps in our knowledge. The most fundamental and important gap is our lack of understanding of the relationship between the acoustic features of an auditory stimulus, neural activity, and perception. Indeed, what we know of this relationship is lacking at the most fundamental level: the manner in which stimuli are integrated and segregated into one or more perceptual auditory objects. Two key innovations of this proposal are designed to fill this gap in our understanding. First, the PI directly tests the relationship between the acoustic features of auditory stimuli, single-neuron activity, and subjects' behavioral reports of auditory-object integration and segregation. Second, the PI records and contrasts neural correlate of auditory-object processing in both the primary auditory cortex and the secondary auditory cortex (i.e., the anterolateral belt). Aim #1 tests whether neurons in the auditory cortex code for (1) the acoustic features of an auditory stimulus, or (2) the monkeys' behavioral reports of auditory-object integration and segregation. This Aim is achieved by evaluating the hypothesis that neural activity in the primary auditory cortex is reliably modulated by the acoustic features of an auditory stimulus but is not modulated by the subjects' behavioral reports. In contrast, it is also hypothesized that neural activity in the secondary auditory cortex (the anterolateral belt) is reliably modulated by the subjects' behavioral reports but is not modulated by the acoustic features of an auditory stimulus. Both hypotheses are tested by recording extracellular from neurons in the auditory cortex while monkeys participate in a one-interval, two-alternative-forced-choice task that requires them to listen to an auditory stimulus and report whether they hear one or two auditory objects. PUBLIC HEALTH RELEVANCE: This line of research has important clinical ramifications. From the data that emerge from this proposal, a greater appreciation of the neural mechanisms and processes that underlie auditory-object processing will emerge. This enhanced appreciation will provide important insights into hearing dysfunction and disorders in speech perception. Ultimately, the insights from these studies will improve the design of hearing prosthetics, diagnostic assays, and the development of rehabilitation programs.