Bruchmann Maximilian, Thaler Kathrin, Vorberg Dirk
Institute of Medical Psychology and Systems Neuroscience, University of Münster, Münster, Germany.
Institute for Biomagnetism and Biosignalanalysis, University of Münster, Münster, Germany.
PLoS One. 2015 Sep 8;10(9):e0137091. doi: 10.1371/journal.pone.0137091. eCollection 2015.
Visible persistence refers to the continuation of visual perception after the physical termination of a stimulus. We studied an extreme case of visible persistence by presenting two matrices of randomly distributed black and white pixels in succession. On the transition from one matrix to the second, the luminance polarity of all pixels within a disk- or annulus-shaped area reversed, physically creating a single second-order transient signal. This transient signal produces the percept of a disk or an annulus with an abrupt onset and a gradual offset. To study the nature of this fading percept we varied spatial parameters, such as the inner and the outer diameter of annuli (Experiment I) and the radius and eccentricity of disks (Experiment III), and measured the duration of visible persistence by having subjects adjust the synchrony of the onset of a reference stimulus with the onset or the offset of the fading percept. We validated this method by comparing two modalities of the reference stimuli (Experiment I) and by comparing the judgments of fading percepts with the judgments of stimuli that actually fade in luminance contrast (Experiment II). The results show that (i) irrespective of the reference modality, participants are able to precisely judge the on- and the offsets of the fading percepts, (ii) auditory reference stimuli lead to higher visible persistence durations than visual ones, (iii) visible persistence duration increases with the thickness of annuli and the diameter of disks, but decreases with the diameter of annuli, irrespective of stimulus eccentricity. These effects cannot be explained by stimulus energy, which suggests that more complex processing mechanisms are involved. Seemingly contradictory effects of disk and annulus diameter can be unified by assuming an abstract filling-in mechanism that speeds up with the strength of the edge signal and takes more time the larger the stimulus area is.
可见持续性是指在刺激的物理终止后视觉感知的延续。我们通过连续呈现两个随机分布的黑白像素矩阵来研究可见持续性的一个极端情况。在从一个矩阵过渡到第二个矩阵时，圆盘或环形区域内所有像素的亮度极性反转，从物理上产生了一个单一的二阶瞬态信号。这个瞬态信号产生了一个具有突然 onset 和逐渐 offset 的圆盘或环形的感知。为了研究这种渐隐感知的本质，我们改变了空间参数，如环形的内径和外径（实验 I）以及圆盘的半径和偏心率（实验 III），并通过让受试者调整参考刺激的 onset 与渐隐感知的 onset 或 offset 的同步性来测量可见持续性的持续时间。我们通过比较参考刺激的两种模态（实验 I）以及通过比较渐隐感知的判断与实际亮度对比度渐隐的刺激的判断来验证这种方法。结果表明：（i）无论参考模态如何，参与者都能够精确判断渐隐感知的 onset 和 offset；（ii）听觉参考刺激导致的可见持续性持续时间比视觉参考刺激更长；（iii）可见持续性持续时间随着环形的厚度和圆盘的直径增加，但随着环形的直径减小，与刺激偏心率无关。这些效应不能用刺激能量来解释，这表明涉及更复杂的处理机制。圆盘和环形直径看似矛盾的效应可以通过假设一种抽象的填充机制来统一，该机制随着边缘信号强度的增加而加速，并且刺激区域越大所需时间越长。
Zotero 插件
