Perceived Duration Increases with Contrast, but Only a Little
Perceived Duration Increases with Contrast, but Only a Little
复制标题
DOI：
10.3389/fpsyg.2016.01950
复制
发表时间：
2016-12-15
影响因子：
3.8
通讯作者：
Redfern, Annabelle S.
中科院分区：
文献类型：
--
作者：
Benton, Christopher P.;Redfern, Annabelle S.
最近的适应性研究提供了证据，早期视觉领域发挥作用的持续知觉。对于适应中常见的明显持续时间压缩的一种解释是，它反映了适应驱动的早期视觉区域神经活动的刺激特异性减少。如果这种水平的刺激相关的神经活动确实驱动持续时间，那么我们可以预期对比度对感知持续时间的强烈影响，因为电生理研究表明早期视觉区域的神经活动与对比度密切相关。我们采用了空间各向同性的噪声刺激，其中每个噪声元素的亮度是独立的正弦调制在4 Hz。参与者将高（0.9）或低（0.1）对比度刺激的感知持续时间与先前提供的标准刺激（600 ms，对比度= 0.3）相匹配。为了实现感知上相同的持续时间，低对比度刺激的呈现时间必须比高对比度刺激更长。这发生在我们控制刺激大小和调整感知时间频率的个体差异时。此外，我们发现，这种效果不能解释的变化，感知的起始和偏移，是不是一个简单的对比度驱动的反应偏差解释。我们的研究结果显然与神经活动水平决定持续时间的观点一致。然而，效果的大小（类似于对比度降低0.9-0.1的10%持续时间差异）与重复抑制和古怪效应中发现的较大持续时间失真形成鲜明对比;特别是当这些可能与神经活动的差异比我们的对比度差异预期的更小时。两者合计，这些结果表明，刺激相关的神经活动在早期视觉领域的水平是不可能提供一个一般的机制来解释感知持续时间的差异。
Recent adaptation studies provide evidence for early visual areas playing a role in duration perception. One explanation for the pronounced duration compression commonly found with adaptation is that it reflects adaptation-driven stimulus-specific reduction in neural activity in early visual areas. If this level of stimulus-associated neural activity does drive duration, then we would expect a strong effect of contrast on perceived duration as electrophysiological studies shows neural activity in early visual areas to be strongly related to contrast. We employed a spatially isotropic noise stimulus where the luminance of each noise element was independently sinusoidally modulated at 4 Hz. Participants matched the perceived duration of a high (0.9) or low (0.1) contrast stimulus to a previously presented standard stimulus (600 ms, contrast = 0.3). To achieve perceptually equivalent durations, the low contrast stimulus had to be presented for longer than the high contrast stimulus. This occurred when we controlled for stimulus size and when we adjusted for individual differences in perceived temporal frequency. Further, we show that the effect cannot be explained by shifts in perceived onset and offset and is not explained by a simple contrast-driven response bias. The direction of our results is clearly consistent with the idea that level of neural activity drives duration. However, the magnitude of the effect (similar to 10% duration difference over a 0.9-0.1 contrast reduction) is in marked contrast to the larger duration distortions that can be found with repetition suppression and the oddball effect; particularly when these may be associated with smaller differences in neural activity than that expected from our contrast difference. Taken together, these results indicate that level of stimulus-related neural activity in early visual areas is unlikely to provide a general mechanism for explaining differences in perceived duration.