Key points are not available for this paper at this time.
When measured with small, sharp-edged targets, sinusoidal-grating thresholds are biased by two types of artifacts related to Weber’s and Ricco’s laws. These artifacts depend on both the nominal frequency of the grating and the phase at its edge: the effect of truncating a low-frequency grating at a given phase is just opposite from the effect of truncating a high-frequency grating at the same phase. These edge effects are predicted by spatial-frequency analyses of the targets, and confirmed by appropriate modulation-threshold measurements, with both rectilinear and circular gratings.
D. H. Kelly (Thu,) studied this question.