Perceived duration of brief visual events is mediated by timing mechanisms at the global stages of visual processing.
Perceived duration of brief visual events is mediated by timing mechanisms at the global stages of visual processing.
复制标题
DOI：
10.1098/rsos.160928
复制
发表时间：
2017-03
影响因子：
3.5
通讯作者：
Hibbard PB
中科院分区：
文献类型：
--
作者：
Beattie L;Curran W;Benton CP;Harris JM;Hibbard PB
有越来越多的证据表明，存在特定于模态的计时机制来编码亚秒持续时间。例如，持续时间压缩效应描述了对动态视觉刺激的先前适应如何导致参与者低估亚秒级测试刺激在适应位置处呈现时的持续时间。有大量的证据表明，皮质和前皮质视觉计时机制的存在，但是，鲜为人知的是，在处理层次的皮质机制可能位于。我们进行了一系列的实验，以确定是否定时机制被发现在全球处理水平。我们让参与者适应随机的点图案，这些图案在运动连贯性上各不相同，从而使我们能够在运动整合的水平上探索视觉系统。我们的第一个实验揭示了适配器刺激的运动连贯性水平和持续时间压缩幅度之间的正线性关系。然而，增加刺激中的运动相干性水平也会导致全局速度的增加。为了测试持续时间压缩效果是否由全局速度或全局运动驱动，我们重复了实验，但保持全局速度固定，同时改变运动相干性水平。持续时间压缩持续存在，但与运动连贯性的线性关系不存在，这表明该效果是由适应全局速度机制驱动的。我们的研究结果支持以前的说法，视觉计时机制坚持在全球处理的水平。
There is a growing body of evidence pointing to the existence of modality-specific timing mechanisms for encoding sub-second durations. For example, the duration compression effect describes how prior adaptation to a dynamic visual stimulus results in participants underestimating the duration of a sub-second test stimulus when it is presented at the adapted location. There is substantial evidence for the existence of both cortical and pre-cortical visual timing mechanisms; however, little is known about where in the processing hierarchy the cortical mechanisms are likely to be located. We carried out a series of experiments to determine whether or not timing mechanisms are to be found at the global processing level. We had participants adapt to random dot patterns that varied in their motion coherence, thus allowing us to probe the visual system at the level of motion integration. Our first experiment revealed a positive linear relationship between the motion coherence level of the adaptor stimulus and duration compression magnitude. However, increasing the motion coherence level in a stimulus also results in an increase in global speed. To test whether duration compression effects were driven by global speed or global motion, we repeated the experiment, but kept global speed fixed while varying motion coherence levels. The duration compression persisted, but the linear relationship with motion coherence was absent, suggesting that the effect was driven by adapting global speed mechanisms. Our results support previous claims that visual timing mechanisms persist at the level of global processing.