Chromatic induction with remote chromatic contrast varied in magnitude, spatial frequency, and chromaticity.

Chromatic induction from a surround is attenuated by chromatic contrast within a remote region outside of the surround (Shevell & Wei, 1998, Vision Research, 38, 1561-1566). The present study reports hue-cancellation measurements that show the attenuation depends on the magnitude, spatial frequency and chromaticity of remote chromatic contrast. Spatial-frequency tuning is shown by maximal attenuation of induction with remote contrast elements of the same size as the test. Experiments with various chromaticities of remote contrast show that S-cone stimulation within the remote region has a much weaker effect than L-/M-cone chromatic contrast, and does not depend on whether the S-cone stimulation is uniform or uneven across the region. Overall, the results show that remote L/M contrast affects classical chromatic induction, with its effect depending on the spatial frequency and magnitude of contrast. The influence of remote S-cone stimulation, on the other hand, is relatively weak and depends on only the S-cone spatial average, at least when S-cone stimulation by the test and its immediate surround is minimal (as in all experiments here).