Determining the contribution of relative timing of activities across neurons in coding behaviorally distinguishable percepts

准确的棘波计时在感觉编码中起着重要作用。尖峰可能会传达有关 外部世界中发生事件的时间，如动物需要迅速逃离捕食者。尖峰计时 可以携带有关外部世界的其他物理特征的信息；例如，耳间时间 差异是关于声源位置的信息。一般来说，感官信息可以 由时间代码携带，这意味着信息以时间尺度的尖峰序列表示， 比外部刺激的有意义的波动更快。然而，这些结论主要是基于 观察到感觉刺激和尖峰之间的相关性。感官信号的时序如何 与行为相关的问题仍然难以捉摸，主要是因为还没有适当精确的工具来 操纵感官表征的时间。 目前的项目将利用一种新的双光子全息刺激技术，它能够 在~10ms的时间尺度上，许多单个神经元的活动的扰动，这与感觉有关 表象和行为读数。这项技术在三种不同的感觉系统中的应用- 嗅觉、视觉和听力--结合新的统计和理论方法，将解决 关于神经编码的时间结构在行为中的作用的基本问题。 感觉信息可以由神经编码的多个时间特征来表示，例如多个时间特征 神经元的同步性，相对于其他棘波的棘波计时，或与全局神经动力学，如振荡。 然而，仅有信息的存在并不足以证明这些功能可用于 唤起人们的行为。目标1将研究动物可以使用感觉代码的哪些时间特征来指导 通过测量动物能够辨别哪些类别的时间信息来进行行为。目标2将 通过测量扰乱特定时间的行为后果来提供补充信息 神经元对自然刺激的反应。 尽管不同脑区的计时方法可能有所不同，但拟议的比较方法将揭示 感觉编码的一般原则，并确定神经网络如何针对特定的计算进行调整 感官信息处理的需求。

Precise spike timing plays an important role in sensory encoding. Spikes may convey information about the time of events in the external world, as when an animal needs to escape quickly from a predator. Spike timing may carry information about other physical characteristics of an external world; for example, interaural time differences are informative about a location of a sound source. And in general, sensory information can be carried by temporal codes, which means that information is represented in spike trains at time scales that are faster than meaningful fluctuations of the external stimuli. However, these conclusions are based mostly on observed correlations between sensory stimuli and spikes. The question of how the timing of sensory signals relates to behavior remains elusive, mostly because appropriately precise tools have not been available to manipulate the timing of sensory representations. The current project will capitalize on a novel technique of two-photon holographic stimulation, which enables the perturbation of activity in many individual neurons on time scales of ~10 ms, which is relevant for sensory representation and behavioral readout. Application of this technique in three different sensory systems — olfaction, vision, and audition — in combination with novel statistical and theoretical approaches, will address fundamental questions about the role of the temporal structure of neural codes in behavior. Sensory information may be represented by multiple temporal features of the neural code, such as multi- neuronal synchrony, spike timing relative to other spikes, or to global neural dynamics, such as oscillations. However, the presence of the information alone is not enough to prove that these features can be used to evoke behavior. Aim 1 will examine which temporal features of sensory code can be used by animals to guide behavior by measuring which classes of temporal information animals are capable of discriminating. Aim 2 will provide complementary information by measuring the behavioral consequences of perturbing specific temporal aspects of neuronal responses to natural stimuli. Although the use of timing may differ between brain areas, the proposed comparative approach will reveal general principles of sensory coding and establish how neural networks adjust for specific computational demands of sensory information processing.