Surface color similarity may cause the perceptual grouping of uniform achromatic surfaces on an achromatic background both when the background is homogeneous and when the background contains achromatic context surfaces. Empirical results reported here show that the grouping response due to the similarity in color of test surfaces is also affected by context surfaces. It is proposed that this response bias results from interference of the grouping response caused by the similarity in color of test surfaces with an implicit grouping response caused by the similarity in color between context surfaces and test surfaces.
Perceptual grouping; achromatic color similarity; context effects; response bias
