Induced fading of natural scenes

Prolonged fixation leads to fading of a peripheral target (Troxler, 1804). Moreover, fading can be induced more rapidly in other contexts: yellow disks disappear when presented against dynamic background elements (Bonneh et al., 2001), colored circles disappear as a function of attentional modulation (Lou, 1999), and display transients near a target induce fading (Kanai & Kamitani, 2003). We have found that full-color, low-pass filtered photographs of natural scenes fade to a uniform hue and luminance in less than 30 seconds when observers maintain fixation. Moreover, fading is more complete and more rapid when transient high-contrast splotches flashed repeatedly on the display. Here we show that perceived fading of scenes is induced by the offset of high-contrast splotches superimposed on the scene but not by the onset of such splotches. Given that the appearance of splotches does not induce fading, our results are not readily explained by transient-induced fading. Because the fading can be induced nearly instantaneously in some conditions, it does not appear to reflect a slow adaptation process such as Troxler fading. Finally, we find that the presence of static splotches does not facilitate fading, suggesting that the results are not readily attributable to contrast gain-control settings. Instead, building on May et al (2003), we argue that the fading of entire scenes can be induced by a contrast decrement. Most of our induced scene fading effects are sufficiently robust that they can be experienced in a single trial.