Multi-scale study of auditory scene analysis in the ventral auditory pathway

描述（由申请人提供）：声音感知和听觉场景分析被认为是由腹侧听觉通路介导的，包括核心听觉皮层、听觉皮层内侧外侧和前外侧带区以及腹外侧前额叶皮层。相反，背侧听觉通路被认为介导空间和听运动行为，包括核心听觉皮层，听觉皮层的尾侧和尾侧带区域，以及顶叶和额叶皮层。我们目前关于这些通路在听觉场景分析和听觉感知中的作用的知识非常有限。本拨款提案的首要目标是确定系统级、电路级和层

DESCRIPTION (provided by applicant): Sound perception and auditory scene analysis are thought to be mediated by the ventral auditory pathway, including core auditory cortex, the medial lateral and anterolateral belt regions of auditory cortex, and the ventrolateral prefrontal cortex. The dorsal auditory pathway, in contrast, is thought to mediate spatial and audiomotor behaviors and includes core auditory cortex, the caudolateral and caudomedial belt regions of auditory cortex, and the parietal and frontal cortices. Our current knowledge regarding the roles of these pathways in auditory scene analysis and auditory perception is very limited. The overarching goal of this grant proposal is to identify the systems-level, circuit-level, and lamina specific properties of the auditory brain that contribute to sound perception and auditory scene analysis. To achieve this goal, monkeys will participate in a "sound-detection" task, which requires them to detect a "target" tone burst that is embedded within an auditory sequence comprised of other tone bursts. By systematically manipulating the spectral and spatial attributes of the sequence, we change the probability that the monkey can detect the target. This task provides an objective behavioral measure of auditory scene analysis because the target tone burst can only be detected when the sequence is segregated into two auditory streams. While the monkey is participating in this task, neural activity is recorded in one (in Specific Aim #1) or two simultaneously (in Specific Aim #2) brain regions using multi-contact, linear-array electrodes. Electrodes are inserted orthogonal to the cortical laminae to enable us to characterize the laminar distribution of neural activity in each brain region. For each cortical lamina and brain region, we test the correlation between neural activity (i.e., single-unit activit and neural-population responses [e.g., multi-unit activity]) and the monkey's behavioral performance. Specific Aim #1 identifies the neural circuitry in auditory cortex that mediates the integration of spatial information with spectral information to form perceptual representations of an auditory scene. Specific Aim #2 identifies the differential contributions of feedforward versus feedback connections between the prefrontal cortex and the auditory cortex to the neural mechanisms and computations underlying auditory scene analysis. Individually and collectively, the Specific Aims provide valuable, quantitative insights into neural bases of sound perception and auditory scene analysis.