Development and Neuroplasticity of Multisensory Integration

点击翻译按钮获取中文摘要

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.