Relationship between facilitation at threshold and suprathreshold contour integration

We reevaluate the facilitation at threshold previously reported between aligned micropatterns and assess the role of such lateral spatial interactions in suprathreshold contour integration tasks. Contrary to previous claims, we show that these interactions are phase dependent. Furthermore, they are clearly evident only for foveal viewing, are not evident for curved alignments (>20 degrees), and do not produce any suprathreshold consequence for contrast perception. Such findings question their usefulness for contour integration of smoothly curved suprathreshold paths. (C) 1998 Optical Society of America.