Conditioning and Perception: The McCollough Effect and the Indirect McCollough Effect

Abstract

<p>According to a conditioning analysis of the orientation-contingent colour aftereffect (McCollough effect, ME), orientation stimuli (grids) become associated with colour. Challenges to this interpretation include the suggestion that specific patterned stimuli are required to elicit the effect, that the effect is not influenced by manipulations of the grid-colour correlation, and that some colour aftereffects appear to be elicited by stimuli that are never paired with colour (i.e. the indirect ME). The present results indicate: (a) nonpatterned stimuli--the lightness of a frame surrounding a coloured area--can contingently elicit colour aftereffects; (b) this frame lightness contingent-colour aftereffect can be used to demonstrate that correlational manipulations affect the ME; and (c) that the indirect ME is elicited by form and frame stimuli that have been previously paired with colour. Thus the present results support a conditioning analysis of both the ME and the indirect ME.</p>