The sound-induced flash illusion (SIFI) occurs when a rapidly presented visual stimulus is accompanied by two auditory stimuli, creating the illusory percept of two visual stimuli. While much research has focused on how the temporal proximity of the audiovisual stimuli impacts susceptibility to the illusion, comparatively less research has focused on the impact of spatial manipulations. Here, we aimed to assess whether manipulating the eccentricity of visual flash stimuli altered the properties of the temporal binding window associated with the SIFI. Twenty participants were required to report whether they perceived one or two flashes that were concurrently presented with one or two beeps. Visual stimuli were presented at one of four different retinal eccentricities (2.5, 5, 7.5, or 10 degrees below fixation) and audiovisual stimuli were separated by one of eight stimulus-onset asynchronies. In keeping with previous findings, increasing stimulus-onset asynchrony between the auditory and visual stimuli led to a marked decrease in susceptibility to the illusion allowing us to estimate the width and amplitude of the temporal binding window. However, varying the eccentricity of the visual stimulus had no effect on either the width or the peak amplitude of the temporal binding window, with a similar pattern of results observed for both the “fission” and “fusion” variants of the illusion. Thus, spatial manipulations of the audiovisual stimuli used to elicit the SIFI appear to have a weaker effect on the integration of sensory signals than temporal manipulations, a finding which has implications for neuroanatomical models of multisensory integration.

当一个快速呈现的视觉刺激伴随着两个听觉刺激时，就会发生声音诱发的闪光错觉（SIFI），从而产生两个视觉刺激的幻觉。虽然很多研究都集中在视听刺激的时间接近性如何影响对错觉的敏感性，但相对较少的研究集中在空间操作的影响上。在这里，我们旨在评估操纵视觉闪光刺激的离心率是否会改变与 SIFI 相关的时间绑定窗口的属性。二十名参与者被要求报告他们是否感知到一两次闪光，同时发出一两声哔哔声。视觉刺激呈现在四种不同的视网膜偏心率（2.5、5、7.5、或低于注视 10 度）和视听刺激被八种刺激开始异步中的一种分开。与之前的研究结果一致，增加听觉和视觉刺激之间的刺激开始不同步导致对错觉的敏感性显着降低，从而使我们能够估计时间结合窗口的宽度和幅度。然而，改变视觉刺激的偏心率对时间结合窗口的宽度或峰值幅度没有影响，对于错觉的“裂变”和“融合”变体都观察到类似的结果模式。因此，用于引发 SIFI 的视听刺激的空间操作似乎比时间操作对感觉信号的整合有更弱的影响，