Purchase this article with an account.
Andrew Stockman, Hannah Smithson, Jonathan Aboshiha, Peter West, Caterina Ripamonti; Chromatic appearance depends on the rate of change of the colour signal (the “slew” rate). Journal of Vision 2008;8(6):1098. doi: 10.1167/8.6.1098.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
At low to moderate flicker frequencies (6 to 13 Hz), the overall mean colour appearances of M- and L-cone-isolating sawtooth stimuli depend on whether the direction of the sawtooth is rapid-on (slowly-off) or rapid-off (slowly-on). Rapid-on-L-cone and rapid-off-M-cone sawtooth stimuli appear greener, while rapid-off-L-cone and rapid-on-M-cone sawtooth stimuli appear redder, even though they have the same mean chromaticities. These changes can be explained by supposing that chromatic mechanisms are better able to track the slowly changing part of the sawtooth than its quickly changing part. Thus, their mean output will always be skewed in the direction of the slow change. By investigating how chromatic detection and discrimination depends on the slopes and amplitudes of the sawtooth waveforms, we can understand more about the temporal properties of the underlying chromatic mechanisms. Our findings are inconsistent with models of red-green opponent colour processing that incorporate only simple filters or nonlinearities. However, they are broadly consistent with models that are limited by a maximum rate of change in the colour signal from red to green or vice versa (i.e., the colour change is “slew-rate-limited”) preceded by a stage of temporal integration.
This PDF is available to Subscribers Only