Behavioral and neural correlates of auditory-object integration and segregation

描述（由申请人提供）：物体是我们听觉感知世界的核心组成部分。然而，当我们目前对听觉对象处理的理解与处理听觉对象所需的假定步骤进行比较时，很明显，我们的知识中存在关键差距。最根本和最重要的差距是我们缺乏对听觉刺激的声学特征、神经活动和感知之间关系的理解。事实上，我们对这种关系的了解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感知听觉对象的方式。该提案的两个关键创新旨在填补我们理解中的这一空白。首先，PI直接测试了听觉刺激的声学特征、单个神经元活动与被试的听物整合和分离行为报告之间的关系。其次，PI记录并对比了初级听觉皮层和次级听觉皮层（即前外侧带）中听觉-物体处理的神经关联。目的1测试听觉皮层中的神经元是否编码(1)听觉刺激的声学特征，或(2)猴子的听觉-物体整合和分离的行为报告。这一目标是通过评估初级听觉皮层的神经活动被听觉刺激的声学特征可靠地调节，而不被受试者的行为报告调节的假设来实现的。相反，也有假设认为，次级听觉皮层（前外侧带）的神经活动是由受试者的行为报告可靠地调节的，而不是由听觉刺激的声学特征调节的。这两种假设都是通过记录听觉皮层神经元的细胞外细胞来测试的，同时猴子参与一个间隔两种选择的强迫选择任务，这个任务要求他们听一个听觉刺激，并报告他们是否听到了一个或两个听觉物体。

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.