Figure 4.

Memory matching data, Experiment 1. The plots show the basic results for two observers (S2 left panel; S3 right panel) for the Absence contextual condition. The CIELAB a* b* coordinates of the reference colors are indicated by x’s. Filled circles show the mean memory matches for the D65 reference background condition. Deviations between x’s and filled circles indicate an effect of memory, with no illuminant change. Open circles show the mean memory matches for the CIE illuminant A reference background condition. Thus the blue arrows indicate the effect of changing reference illumination, once the shift introduced by memory has been accounted for. For comparison, the dashed black arrows show how the data would shift for a color constant system. These shifts were computed from the reference color coordinates, as described in Methods, and scaled to 1/5 the vector length of the shift that would be shown by a color constant system. To ease comparison with the data, the shifts are plotted with their origins at the match for the D65 background, rather than at the reference color itself. The error bars show +/− 1 SEM, taken over replications.