Psychophysics & Neuroimaging Studies of the Multisensory Temporal Binding Window

描述（由申请人提供）：大脑将传入的听觉和视觉刺激结合起来的能力主要取决于这种多感官信息的时间结构。具体来说，存在一个视听整合的时间窗口，在这个窗口内，刺激被绑定并因此被处理为一个统一的感知事件。尽管先前的研究表明，这种多感官时间窗口在某种程度上是与任务和上下文相关的，但人们普遍认为，窗口的大小在几百毫秒左右。此外，最近的研究表明，通过重复呈现异步听觉-视觉配对可以改变其边界，该时间窗口具有延展性。虽然这项工作强调窗口可以及时改变以反映最近的感官体验，但没有研究检查窗口的大小是否可以改变。在目前的建议中，我们试图审查这个问题，它围绕两个具体目标。首先，使用感知训练范式，我们将寻求缩短多感官时间窗口的大小。其次，使用功能磁共振成像，我们将研究这种时间绑定过程的神经基础，以及已识别的网络如何随着窗口大小的变化而变化。为了实现这些目标，我们将使用视听同时性任务来描述时间窗口的大小。接下来，我们将开发一个同时性判断训练范式，其中每个判断都与其正确性的反馈配对。我们期望这种训练模式将导致时间绑定窗口的显着缩小，也许更重要的是，这些影响将扩展到多感官时间功能的其他测量（即，它们将普遍化）。我们已经收集了令人兴奋的初步数据，支持同时性判断的多感官时间绑定窗口的显著缩小。此外，这些影响似乎可以推广到其他任务，并且是持久的。更重要的是，在初步数据集中，我们强调了在多感官知觉训练后似乎被改变的大脑区域。这些研究将有助于更好地定义成人多感觉时间过程的可塑性及其神经基础，我们希望这些工作将为未来针对神经生物学障碍（例如，阅读障碍，自闭症）的修复计划奠定基础，其中有越来越多的证据表明多感觉时间功能被破坏。

DESCRIPTION (provided by applicant): The brain's ability to bind incoming auditory and visual stimuli depends critically on the temporal structure of this multisensory information. Specifically, there exists a temporal window of audiovisual integration within which stimuli are bound and consequently processed as a unitary perceptual event. Although previous work has shown that this multisensory temporal window is somewhat task-and context-dependent, there is general agreement that the size of the window is on the order of several hundred milliseconds. Furthermore, more recent work has demonstrated a malleability of this temporal window by showing that repeated presentations of asynchronous auditory-visual pairings can shift its boundaries. Although this work highlights that the window can be shifted in time to reflect recent sensory experience, no studies have examined whether the size of the window can be altered. In the current proposal, we seek to examine this issue, which is framed around two specific aims. First, using a perceptual training paradigm, we will seek to shorten the size of the multisensory temporal window. Second, using fMRI, we will examine the neural basis of this temporal binding process and how the identified networks change with changing window size. To accomplish these aims, we will use an audiovisual simultaneity task to delineate the size of the temporal window. Next, we will develop a simultaneity judgment training paradigm wherein each judgment is paired with feedback as to its correctness. It is our expectation that this training paradigm will result in a significant narrowing of the temporal binding window, and, perhaps more importantly, that these effects will extend to other measures of multisensory temporal function (i.e., they will generalize). We have already gathered exciting preliminary data in support of a significant narrowing of the multisensory temporal binding window for simultaneity judgments. In addition, these effects appear to generalize to other tasks and to be long-lasting. What's more, in a preliminary data set, we have highlighted brain areas that appear to be altered after multisensory perceptual training. These studies will help to better define the plastic capacity of multisensory temporal processes in adults and their neural underpinnings, work that we hope will form a foundation for future remediation programs targeted toward neurobiological disorders (e.g., dyslexia, autism) in which there is growing evidence of disruptions in multisensory temporal function.