Development and Neuroplasticity of Multisensory Integration

作为人类，我们处理感官信息的方式极大地影响着我们感知世界和与世界互动的方式。我们的感知所基于的感官信息本质上是多感官的，但我们对神经系统如何发展到跨感官整合信息知之甚少。这项工作旨在确定这一基本过程背后的基本神经机制和电路，这些神经机制是如何发展的，以及它们是如何随着经验而变化的。因此，拟议的工作将揭示塑造人类经验的一些最基本方面的神经机制，特别是我们如何感知和与环境互动。我们的环境本来就是嘈杂的，我们的感官不断受到信息的轰炸。考虑到这一点，我们必须能够确定哪些信号来自单一事件，因此必须整合到一个统一的感知中——这个过程被称为多感觉整合或感知绑定。我们的工作和其他实验室的工作已经表明，用来解决这个所谓的“绑定问题”的最重要的感官信息是感官输入之间的时间关系。具有相同时间结构的输入，特别是输入的开始，更有可能源自同一事件。感知系统反映了这些环境统计数据，并且更有可能整合在时间上紧密联系的感官输入。虽然我们之前的行为研究已经证明了多感官刺激的时间处理与个体结合听觉和视觉刺激的感知能力之间的紧密联系，但这种时间和整合之间的联系发生的神经机制相对未知，这一过程的发展和感官体验的影响也是如此。本提案的总体目标是了解(1)人类大脑如何支持视听时间整合，(2)这一过程如何发展，以及(3)感知经验如何影响整合。通过使用尖端的神经成像技术和优雅的实验设计，这项工作将提供神经网络发展的第一个解释，这个过程从根本上塑造了我们对周围世界的感知。这项工作的第一阶段将研究通过多感觉时间处理导致感觉信息知觉绑定的神经机制。第二阶段将使用横断面设计来研究这些神经网络如何随着童年、青春期和成年期的经历而发展。最后，我们将通过一个完善的感知学习范式探索与多感觉整合变化相关的潜在神经可塑性。

How we as humans process sensory information greatly impacts the manner with which we perceive and interact with the world. The sensory information upon which our perceptions are based is multisensory in nature yet we know surprisingly little about how neural systems develop to integrate information across senses. This work aims to determine basic neural mechanisms and circuitry that underlie this fundamental process, how these neural mechanisms develop, and how they change with experience. Thus, the proposed work will lay bare the neural mechanisms that shape some of the most fundamental aspects of the human experience, particularly how we perceive and interact with our environment. Our environments are inherently noisy, with the senses being consistently bombarded by information. Given this, we must be able to determine which signals originating from a single event, and thus must be integrated into a unified percept - a process known as multisensory integration or perceptual binding. Our work and the work of other labs have shown that the most salient piece of sensory information that is used to solve this so-called “binding problem” is the temporal relationship between sensory inputs. Inputs that share the same temporal structure, specifically the onset of input, are much more likely to originate from the same event. Perceptual systems reflect these environmental statistics and are more likely to integrate sensory inputs that are closely linked in time.Although our previous behavioural studies have demonstrated a strong link between temporal processing of multisensory stimuli and an individual's perceptual ability to bind auditory and visual stimuli, the neural mechanisms by which this link between timing and integration occurs is relatively unknown, as is the development of this process and the impact of sensory experience. The overarching goal of this proposal is to understand (1) how the human brain supports audiovisual temporal integration, (2) how this process develops, and (3) how perceptual experience influences integration. Through the use of cutting-edge neuroimaging techniques paired with elegant experimental designs, this work will provide the first account of the development of neural networks underlying this process that fundamentally shapes our perceptions of the world around us. The first stage of this work will investigate the neural mechanisms through which multisensory temporal processing leads to perceptual binding of sensory information. The second stage will use a cross-sectional design to investigate how these neural networks develop with experience from childhood, through adolescence, and into adulthood. Finally, we will explore the underlying neuroplasticity associated with changes in multisensory integration through a well-established perceptual learning paradigm.