Uncomfortable images generally have a particular spatial structure, which deviates from a reciprocal relationship between amplitude and spatial frequency (f) in the Fourier domain (1/f). Although flickering patterns with similar temporal structure also appear uncomfortable, the discomfort is affected by not only the amplitude spectrum but also the phase spectrum. Here we examined how discomfort from flicker with differing temporal profiles also varies as a function of the mean light level and luminance contrast of the stimulus. Participants were asked to rate discomfort for a 17° flickering uniform field at different light levels from scotopic to photopic. The flicker waveform was varied with a square wave or random phase spectrum and filtered by modulating the slope of the amplitude spectrum relative to 1/f. At photopic levels, the 1/f square wave flicker appeared most comfortable, whereas the discomfort from the random flicker increased monotonically as the slope of the amplitude spectrum decreased. This special status for the 1/f square wave condition was limited to photopic light levels. At the lower mesopic or scotopic levels, the effect of phase spectrum on the discomfort was diminished, with both phase spectra showing a monotonic change with the slope of the amplitude spectrum. We show that these changes cannot be accounted for by changes in the effective luminance contrast of the stimuli or by the responses from a linear model based on the temporal impulse responses under different light levels. However, discomfort from flicker is robustly correlated with judgments of the perceived naturalness of flicker across different contrasts and mean luminance levels.

不舒服的图像通常具有特定的空间结构，其从幅度和空间频率（之间的相互关系偏离˚F在傅里叶域中）（1 / ˚F）。虽然具有相似时间结构的闪烁模式也显得不舒服，但这种不舒服不仅受幅度谱的影响，还受相位谱的影响。在这里，我们研究了具有不同时间分布的闪烁引起的不适如何作为刺激的平均光级和亮度对比度的函数而变化。参与者被要求对从暗到明的不同光照水平下 17° 闪烁均匀场的不适程度进行评分。闪烁波形随方波或随机相位谱变化，并通过调制相对于 1/ f的幅度谱的斜率进行滤波。在明视水平，1/ f方波闪烁看起来最舒服，而随机闪烁的不适感随着振幅谱斜率的降低而单调增加。这种特殊状态为 1/ f方波条件仅限于明视光级。在较低的中间或暗视水平，相位谱对不适的影响减弱，两个相位谱都显示出随振幅谱斜率的单调变化。我们表明，这些变化不能通过刺激的有效亮度对比度的变化来解释，也不能通过基于不同光照水平下的时间脉冲响应的线性模型的响应来解释。然而，闪烁带来的不适感与对不同对比度和平均亮度级别的闪烁感知自然度的判断密切相关。