Multisensory competition and spatial selection: Neural circuit and computational mechanisms

多感官竞争和空间选择：神经回路和计算机制

• 批准号: 10116391
• 负责人: Shreesh P Mysore
• 金额: $ 38.49万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-03-01 至 2022-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10116391
• 关键词: Adaptive Behaviors; Address; Affect; Algorithms; Animals; Attention; Attention deficit hyperactivity disorder; Auditory; Barn Owls; Behavior; Birds; Brain; Categories; Cell Nucleus; Clutterings; Collection; Complex; Computer Models; Data; Decision Making; Distant; Electrophysiology (science); Elements; Environment; Equilibrium; Exhibits; Exposure to; Floor; Head; Homologous Gene; Individual; Iontophoresis; Literature; Location; Logic; Mammals; Maps; Measures; Mediating; Mental disorders; Midbrain structure; Modality; Monkeys; Motor; Neurons; Noise; Pattern; Perception; Play; Process; Property; Resistance; Response Latencies; Role; Schizophrenia; Sensory; Services; Shapes; Signal Transduction; Site; Source; Stimulus; Tegmentum Mesencephali; Testing; Visual; Work; auditory stimulus; awake; cognitive ability; experimental study; extracellular; improved; in vivo; individual response; multisensory; neural circuit; neuromechanism; neurophysiology; predictive modeling; receptive field; relating to nervous system; response; sensory stimulus; simulation; superior colliculus Corpora quadrigemina; visual stimulus

Project Summary Animals are constantly exposed to a barrage of multisensory input from their stimulus-rich environments. They handle this informational complexity by having their behavior guided by the most physically salient (or more generally, the most important) stimulus source in the environment. The identification of the most physically salient stimulus occurs through neural mechanisms of stimulus competition, which must necessarily operate across sensory modalities and across spatial locations. Although the mechanisms of multisensory integration have been studied extensively, the circuit and computational principles underlying competition within and across sensory modalities are largely unknown. Recent evidence from behaving monkeys has revealed the midbrain superior colliculus (SC) as being critical for normal competitive stimulus selection. In parallel, our recent work in the barn owl optic tectum (OT, the avian homolog of the SC) has revealed special neural response properties, namely categorical signaling of the strongest stimulus, that can account for the SC's critical role in selection behavior. Inhibition from a GABAergic midbrain nucleus, the isthmi pars magnocellularis (Imc), is necessary to mediate these response properties. Nonetheless, the computational and mechanistic logic of Imc function in service of competitive stimulus selection remain unknown. Here, we propose to systematically unravel fundamental computations orchestrated by the Imc-OT network for multisensory competition, and to map their implementation explicitly onto circuit elements. Specifically, we first aim to elucidate how the reliable signaling of the strongest stimulus in the presence of noise, i.e, “robust” signaling, is implemented. Our hypothesis is that special donut-like patterns of spatial inhibition from the Imc to the OT play a central role. Second, we aim to understand if the Imc is an active computational locus for stimulus competition in the OT. Our hypothesis is that competitive interactions within the Imc control the accuracy and strength of categorization by the OT. Third, we ask how the OT resolves competition in cluttered sensory scenes that contain several stimuli. Our hypothesis is that a dynamic inhibitory balance among the multiple competing locations protects OTid responses from being driven to zero and permits network wide decoding of the strongest stimulus. We will test the hypotheses using in vivo electrophysiology and drug iontophoresis in awake, head-fixed barn owls together with computational modeling. In all cases, we will explicitly test whether the hypothesized mechanisms of competition generalize across sensory modalities. Preliminary data from the three aims support our hypotheses. They indicate that results from the proposed experiments have the power to reveal strategic principles of circuit organization for executing the sophisticated computations that subserve multisensory competition and stimulus selection.

项目摘要 动物经常暴露在来自刺激丰富的环境的多感官输入的弹幕中。他们 处理这种信息的复杂性，让他们的行为受到最明显的物理（或更多）的指导。 一般来说，最重要的）刺激源在环境中。最具物理意义的 显著刺激是通过刺激竞争的神经机制发生的，这种机制必然会起作用 跨越感官形态和空间位置。虽然多感觉整合的机制 已经被广泛研究，电路和计算原理的竞争， 在很大程度上是未知的。最近的证据表明， 中脑上级丘（SC）对于正常的竞争刺激选择至关重要。同时，我们的 最近对仓鸮视顶盖（OT，SC的鸟类同源物）的研究揭示了一种特殊的神经元， 反应特性，即最强刺激的分类信号，可以解释SC的 在选择行为中的重要作用。来自GABA能中脑核的抑制，峡部 magnocellularis（Imc）是介导这些响应特性所必需的。尽管如此，计算和 服务于竞争性刺激选择的Imc功能的机械逻辑仍然未知。这里我们 建议系统地解开由IMC-OT网络编排的基本计算， 多感官竞争，并明确映射到电路元件的实现。具体来说，我们首先 目的是阐明如何可靠的信号最强的刺激存在噪声，即“鲁棒” 信号，已实现。我们的假设是，特殊的甜甜圈样模式的空间抑制，从Imc到 OT发挥着核心作用。其次，我们的目标是了解IMC是否是一个活跃的计算轨迹， OT中的刺激竞争。我们的假设是，IMC内的竞争性相互作用控制了 OT分类的准确性和强度。第三，我们问OT如何解决混乱中的竞争。 包含多种刺激的感官场景。我们的假设是，一个动态的抑制平衡之间的 多个竞争位置保护OTid响应不被驱动为零， 最强刺激的解码我们将使用体内电生理学和药物来测试假设。 在清醒的，头部固定仓鸮离子电渗连同计算建模。在所有情况下，我们将 明确测试是否竞争的假设机制，普遍通过感官形式。 三个目标的初步数据支持我们的假设。他们指出，结果从拟议的 实验有能力揭示执行复杂任务的电路组织的战略原则。 有助于多感官竞争和刺激选择的计算。