Multisensory perception: Audiovisual interactions under dynamic conditions

描述（由申请人提供）：本研究探讨听觉刺激对视觉感知影响的感觉间机制。来自单细胞神经生理学、事件相关脑电位和功能MRI的研究结果表明，曾经被认为是单感觉的皮层区域的神经元可以被多种方式的刺激驱动。此外，多感觉驱动活动的时间是这样的，它不太可能仅仅是由于解剖学上较晚的皮层区域的反馈。最近报道的一系列行为效应表明，信息不相关但同时呈现的听觉刺激可以增强视觉感知，这似乎是这些多感觉机制的表现。然而，到目前为止，这些影响还没有被理解为任何共同的感觉间机制。本研究检验了视听时间封装假说，该假说认为，突然的瞬态听觉刺激定义了一个时间窗口，在这个时间窗口内，出现在该时间窗口内的视觉刺激的表征与时间周围的视觉信息的相互作用是隔离的。这一假设可以解释上述所有的影响，并且它做出了新的预测，这是本提案的重点。值得注意的是，文献中报道的感觉间效应主要是伴随听觉刺激的视觉促进的例子。我们从视听时间封装假说中得出的新预测是伴随听觉刺激的视觉感知受损的例子，这使得它们特别有力地验证了这一假设。一般的想法是，如果视觉信息被伴随的听觉刺激封装，那么需要将封装的视觉信息与在不同时间采样的信息整合在一起的任务将受到损害。这一想法将在三个具体目标中得到检验。特异性目的1测试听觉刺激在视觉整合任务中的作用。具体目标2测试听觉刺激的影响，通过该过程可见的持久性运动刺激被积极抑制，称为运动去模糊。特异性目标3测试听觉刺激对眼球运动中视觉信息被抑制的过程的影响，即所谓的扫视抑制。如果得到证实，视听时间封装假说可以解释为什么人们在从事主要是视觉任务（例如，驾驶）时容易受到听觉分心的影响。此外，包封过程可能是一种在受损状态下由于药物、酒精或疾病而失效的机制。它也可能是一种随年龄增长而衰退的机制。

DESCRIPTION (provided by applicant): This research investigates intersensory mechanisms that underlie the influence of auditory stimuli on visual perception. Findings from single-cell neurophysiology, event-related brain potentials, and functional MRI indicate that neurons in cortical areas that were once thought to be unisensory can be driven by stimuli from multiple modalities. Moreover, the timing of multisensory-driven activity is such that it is unlikely to be due to just to feedback from anatomically later cortical areas. A set of recently reported behavioral effects showing the enhancement of visual perception from informationally unrelated but concomitantly presented auditory stimuli seem to be manifestations of these multisensory mechanisms. To date, however, these effects have not been understood in terms of any common intersensory mechanism. This research tests the audiovisual temporal-encapsulation hypothesis which states that an abrupt transient auditory stimulus defines a temporal window within which the representation of visual stimuli that appear in that time window are isolated from interaction with temporally surrounding visual information. This hypothesis can account for all of the effects reviewed above and it makes novel predictions beyond these, which are the focus of the present proposal. Significantly, the intersensory effects that have been reported in the literature are primarily examples of visual facilitation by concomitant auditory stimuli. The new predictions that we have derived from the audiovisual temporal encapsulation hypothesis are examples of impaired visual perception by concomitant auditory stimuli, which make them especially powerful for testing the hypothesis. The general idea is that if visual information is encapsulated by concomitant auditory stimuli, then it follows that tasks that require integration o that encapsulated visual information with information sampled at a different time will be impaired. This idea will be tested in three specific aims. Specific Aim 1 tests the effects of auditory stimuli in a visual integration task. Specific Aim 2 tests the effects of auditory stimulion the processes by which visible persistence for moving stimuli is actively suppressed known, as motion deblurring. Specific Aim 3 tests the effects of auditory stimuli on the processes by which visual information is suppressed during eye movements, known as saccadic suppression. If confirmed, the audiovisual temporal-encapsulation hypothesis could explain why people are susceptible to auditory distraction when engaged in what are primarily visual tasks (e.g., driving). Moreover, the encapsulation process might be a mechanism that is subject to failure in impaired states due to drugs, alcohol or disease. It may also be a mechanism that is subject to decline with age.