Functional Brain Mapping Laboratory, Department of Fundamental Neuroscience, University of Geneva Geneva, Switzerland.
Front Psychol. 2012 Dec 17;3:564. doi: 10.3389/fpsyg.2012.00564. eCollection 2012.
Perceived duration of a sensory event often exceeds its actual duration. This phenomenon is called time dilation. The distortion may occur because sensory systems are optimized for perception within their respective modalities and not for perception of time. We investigated how the dilation of visual events depends on the duration and content of events. Observers compared the durations of two successive visual stimuli while the luminance of one of the stimuli was modulated at different temporal frequencies. Time dilation correlated with the frequency of modulation and the duration of the stimulus: the faster the modulation and the longer the stimulus duration, the larger the dilation. Notably, time dilation was also accompanied by a decreased sensitivity to stimulus duration. We show that these results are consistent with the notion that stimulus duration is estimated using measurement intervals of the lengths that depend on stimulus frequency content. Estimation of temporal frequency content is more precise using longer measurement intervals, whereas estimation of temporal location is more precise using shorter ones. As a result, visual perception will benefit from using longer intervals when the stimulus is modulated so that its frequency content is measured more precisely. A side effect of using longer temporal intervals is a larger uncertainty about the timing of stimulus offset (temporal location), ensuing time dilation and the reduction of sensitivity to duration. Our findings support the view that time dilation follows from basic principles of measurement and from the notion that visual systems are optimized for visual perception rather than for perception of time.
人们感知到的一个事件的持续时间往往会超过其实际持续时间。这种现象被称为时间膨胀。这种扭曲可能是因为感觉系统是针对其各自的模式进行感知优化的，而不是针对时间感知进行优化的。我们研究了视觉事件的膨胀是如何依赖于事件的持续时间和内容的。当一个刺激的亮度以不同的时间频率调制时，观察者比较了两个连续视觉刺激的持续时间。时间膨胀与调制频率和刺激持续时间相关：调制越快，刺激持续时间越长，膨胀越大。值得注意的是，时间膨胀还伴随着对刺激持续时间的敏感性降低。我们表明，这些结果与这样一种观点是一致的，即刺激持续时间是使用依赖于刺激频率内容的长度的测量间隔来估计的。使用较长的测量间隔可以更精确地估计时间频率内容，而使用较短的测量间隔可以更精确地估计时间位置。因此，当刺激被调制时，使用较长的间隔将有利于视觉感知，从而更精确地测量其频率内容。使用较长时间间隔的一个副作用是，对刺激结束（时间位置）的时间的不确定性更大，从而导致时间膨胀和对持续时间的敏感性降低。我们的发现支持这样一种观点，即时间膨胀是由测量的基本原理以及视觉系统针对视觉感知而不是针对时间感知进行优化的观点所导致的。
