Do McCollough effects provide evidence for global pattern processing?

Abstract

Contingent color aftereffects (CAEs, or McCollough effects) were induced using two pairs of orthogonally related patterns (horizontal/vertical and concentric/radial) to determine whether the CAEs of the four patterns are independent. Tests using composite test patterns (like those employed by Emerson, Humphrey, & Dodwell, 1985) suggested independent aftereffects. However, tests using unitary patterns indicated additive or competing effects of the four patterns in regions where line orientations were similar, and tests isolating such regions showed clear interactions between the pattern aftereffects. The results fail to support the claim that global (rather than local) features of the patterns control these CAEs.