Change in feature space is not necessary for the flash-lag effect

To achieve perceptual match between a flashed target and a gradually changing one, the flashed target should have the feature value corresponding to the value to be obtained by the gradually changing target only later. Flashed target should be positioned ahead of the continuously moving one in order to be perceived as aligned (Nijhawan (1994). Nature, 370, 256-257); with continuously changing colour, spatial frequency, pattern entropy or luminance, the flashed target should have feature value which changing target obtains only later (Sheth, Nijhawan, & Shimojo (2000). Nature Neuroscience, 3, 489-495). It was found that flash-lag effect is present even if the continuously accumulating pre- and post-target input consists in spatially and featurally invariant stimulation. The perceptual precedence of the target in stream over its synchronous single-flashed replica may result from perceptual acceleration where newly arriving visual signals are facilitated by the locally preceding stimulation.