Krueger Fister Juliane, Stevenson Ryan A, Nidiffer Aaron R, Barnett Zachary P, Wallace Mark T
Neuroscience Graduate Program, Vanderbilt University Medical Center, United States; Vanderbilt Brain Institute, United States.
Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, United States; Vanderbilt Brain Institute, United States; Vanderbilt University Kennedy Center, United States; Department of Psychology, University of Toronto, Canada.
Neuropsychologia. 2016 Jul 29;88:92-100. doi: 10.1016/j.neuropsychologia.2016.02.016. Epub 2016 Feb 23.
One of the more challenging feats that multisensory systems must perform is to determine which sensory signals originate from the same external event, and thus should be integrated or "bound" into a singular perceptual object or event, and which signals should be segregated. Two important stimulus properties impacting this process are the timing and effectiveness of the paired stimuli. It has been well established that the more temporally aligned two stimuli are, the greater the degree to which they influence one another's processing. In addition, the less effective the individual unisensory stimuli are in eliciting a response, the greater the benefit when they are combined. However, the interaction between stimulus timing and stimulus effectiveness in driving multisensory-mediated behaviors has never been explored - which was the purpose of the current study. Participants were presented with either high- or low-intensity audiovisual stimuli in which stimulus onset asynchronies (SOAs) were parametrically varied, and were asked to report on the perceived synchrony/asynchrony of the paired stimuli. Our results revealed an interaction between the temporal relationship (SOA) and intensity of the stimuli. Specifically, individuals were more tolerant of larger temporal offsets (i.e., more likely to call them synchronous) when the paired stimuli were less effective. This interaction was also seen in response time (RT) distributions. Behavioral gains in RTs were seen with synchronous relative to asynchronous presentations, but this effect was more pronounced with high-intensity stimuli. These data suggest that stimulus effectiveness plays an underappreciated role in the perception of the timing of multisensory events, and reinforces the interdependency of the principles of multisensory integration in determining behavior and shaping perception.
多感官系统必须执行的一项更具挑战性的任务是确定哪些感官信号源自同一外部事件，因此应整合或“绑定”到单个感知对象或事件中，以及哪些信号应被分离。影响这一过程的两个重要刺激属性是配对刺激的时间和有效性。已经充分证实，两个刺激在时间上的对齐程度越高，它们对彼此处理的影响程度就越大。此外，单个单感官刺激引发反应的效果越差，它们组合时的益处就越大。然而，刺激时间和刺激有效性在驱动多感官介导行为方面的相互作用从未被探索过——这就是本研究的目的。向参与者呈现高强度或低强度的视听刺激，其中刺激起始异步性（SOA）参数化变化，并要求他们报告配对刺激的感知同步/异步情况。我们的结果揭示了刺激的时间关系（SOA）和强度之间的相互作用。具体而言，当配对刺激效果较差时，个体对较大的时间偏移更宽容（即更有可能称它们为同步）。这种相互作用在反应时间（RT）分布中也可见。与异步呈现相比，同步呈现时RTs有行为增益，但这种效应在高强度刺激下更明显。这些数据表明，刺激有效性在多感官事件时间感知中起着未被充分认识的作用，并强化了多感官整合原则在决定行为和塑造感知方面的相互依存关系。
