More on the Associative Interpretation of the Indirect McCollough Effect

Following an induction procedure in which a coloured pattern (e.g. spokes) is alternated with a complementarily coloured, homogeneous, patternless circle, subjects report colour after effects on both the pattern presented during induction (i.e. spokes) and on an orthogonal non-induced pattern (i.e. concentric circles). The after effect reported on the induced pattern is the McCollough effect (ME), and the aftereffect reported on the non-induced orthogonal pattern has been labelled the indirect McCollough effect (IME). The results of the present experiments show that the colour aftereffect reported on the non-induced pattern is not indirect but is elicited by elements of the patternless circle that alternated with the patterned stimulus during induction. These data provide further support for the associative account of the IME proposed by Eissenberg, Allan, Siegel, and Petrov (1995).