Psychophysics & Neuroimaging Studies of the Multisensory Temporal Binding Window

描述(由申请人提供)：大脑结合传入的听觉和视觉刺激的能力严重依赖于这种多感官信息的时间结构。具体地说，存在视听整合的时间窗口，在该时间窗口内，刺激被绑定并因此被处理为单一感知事件。尽管以前的工作已经表明，这种多感觉的时间窗口在某种程度上是任务和上下文相关的，但人们普遍认为，窗口的大小约为几百毫秒。此外，最近的工作已经证明了这个时间窗口的可塑性，因为它表明了异步听觉-视觉配对的重复呈现可以改变其边界。尽管这项工作强调了窗口可以及时移动以反映最近的感官体验，但还没有研究检查窗口的大小是否可以改变。在目前的提案中，我们试图审查这一问题，该问题围绕两个具体目标展开。首先，使用知觉训练范式，我们将寻求缩短多感觉时间窗口的大小。其次，使用功能磁共振成像，我们将检查这种时间绑定过程的神经基础，以及所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，我们将使用视听同步任务来描绘时间窗口的大小。接下来，我们将开发一个同时判断训练范式，其中每个判断都与关于其正确性的反馈配对。我们期望，这种训练范式将导致时间约束窗口的显著缩小，也许更重要的是，这些影响将扩展到多感觉时间功能的其他测量(即，它们将得到推广)。我们已经收集了令人兴奋的初步数据，支持同时判断的多感觉时间结合窗口显著缩小。此外，这些影响似乎也适用于其他任务，而且是长期的。更重要的是，在初步数据集中，我们突出显示了在多感官知觉训练后似乎发生变化的大脑区域。这些研究将有助于更好地定义成年人多感觉时间进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(如阅读障碍、自闭症)的补救计划奠定基础，在这些疾病中，有越来越多的证据表明多感觉时间功能受到干扰。

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.