Checkerboard-specific color aftereffects: A failure to find effects of perceptual organization

Abstract

Two experiments investigated the effects of differing perceptual organizations of reversible figures on McCollough aftereffects. Experiment 1 used colored checkerboard inducing stimuli and achromatic grating test stimuli. While some subjects tended to organize the checkerboards into rows and/or columns and others to organize them into obliques, these variations did not result in differences in aftereffect direction or magnitude. Experiment 2 induced an aftereffect with colored gratings and tested with checkerboards, gratings, and a reversible concentric octagon pattern. Perceptual organization had no effect on results for checkerboards, but was related to aftereffect strength for the octagon pattern. Indirect evidence suggests that, in the latter case, differences in aftereffect strength may have influenced the perceived organization, rather than vice versa. Finally, regardless of the specific organization perceived, spontaneous viewing of all test stimuli produced stronger aftereffects than were found when subjects reorganized the pattern. This may have resulted from a viewing strategy associated with reorganization, since similarly small aftereffects were found when subjects concentrated their attention on a single pattern element.The McCollough effect can be elicited by exposing subjects to chromatic grating patterns. The color aftereffects are contingent upon the orientation of achromatic test gratings and are roughly complementary to the adapting color (McCollough, 1965;Skowbo, Timney, Gentry, & Morant, 1975;Stromeyer, 1978).Most attempts to account for these aftereffects have proposed the adaptation of neural analyzers that are specific to both color and orientation (McCollough, 1965) and, in some cases, to other features, such as movement direction (Hepler, 1968), curvature (Riggs, 1973), and spatial frequency (Stromeyer, 1972). These explanations are based on relatively low-level, involuntary mechanisms. Such interpretations are enticing, because, in most cases, the effects are associated with retinal stimulus properties rather than the properties as perceived by the subject (Harris, 1970;Stromeyer, 1978 (1977) found strong color aftereffects when subjects organized their concentric-square test pattern into four triangular sections of stripes. But little or no aftereffect was observed when the test pattern was organized as concentric squares. These results have important implications for our understanding of McCollough aftereffects. They suggest that the effects may not be as inflexible or as dependent on the physical stimulus properties as neural analyzer explanations would predict. Instead, they argue that higher order cognitive factors must be included for a complete explanation.However, conclusions from the results of previous studies with reversible figures must be tentative for several reasons. The first has to do with the distinction between the empirical results obtained and the internal condition of the subjects that is inferred from them.Both Jenkins and Ross (1977) and Uhlarik et al. (1977) ...

Making ambiguous displays unambiguous: The influence of real colors and colored aftereffects on perceptual alternation

“…The data reported by Milewski et al (1980) are complex and somewhat difficult to interpret. For example, observers who were unable to switch their perceptual organization, or who experienced great difficulty in doing so, were still required to give a subjective CAE rating for the alternative perceptual organization.…”

“…Despite these problems, the data provide support for the idea that adaptation influences both the color appearance and perceptual organization of an ambiguous test display. However, the procedures used by Milewski et al (1980) do not address this issue directly. They also introduce a new set of problems concerning the ability of observers to reorganize ambiguous figures at will, and to rate both the effort required in this task and the appearance of the new organization.…”

“…Using an entirely different procedure, Milewski et al (1980) induced CAEs in the normal manner and asked observers to rate CAE strength (on an ll-point scale) while inspecting (1) orthogonal gratings (i.e., a standard CAE test pattern), (2) two checkerboard patterns, and (3) a set ofconcentric octagons (which could be perceived either as a set of concentric octagons or as a set of eight triangular wedges). In addition, observers were asked to rate (on a 4-point scale) the ease with which they could switch consciously from the organization perceived spontaneously in the test display to the alternative organization.…”

Color aftereffect contingent on text

“…There have been reports that a color aftereffect contingent on orientation can be induced when homogeneous colored fields are presented and the subject is instructed to project imagined bar patterns of a particular orientation onto the colored field (Finke, 1981;Finke & Schmidt, 1977, 1978Kaufman, May, & Kunen, 1981;Kunen & May, 1980, 1981. It has also been reported that when perceptually ambiguous patterns are used as test figures, the perceived color depends upon how the pattern is organized (Jenkins & Ross, 1977;Jordan & Uhlarik, 1983;Meyer & Phillips, 1980;Milewski, Iaccino, & Smith, 1980;Uhlarik, Pringle, & Brigell, 1977). Such demonstrations are controversial, and some investigators have failed to obtain color aftereffects based on imagined grids (Broerse & Crassini, 1980, 1981b, 1984 or pattern organization (Broerse & Crassini, 1981a, 1986.…”

Comments on the use of perceptually ambiguous figures as McCollough-effect stimuli

“…One such approach is based on the use of perceptually ambiguous figures (see Figure 1) as test stimuli following adaptation to typical McCollough-effect inspection patterns. For example, Jenkins and Ross (1977), Meyer and Phillips (1980), and Uhlarik, Pringle, and Brigell (1977) report correlations between fluctuations in the alternative subjective organizations of ambiguous test figures and fluctuations in the strength of CAEs (see also Meyer & Sherman, 1981;Milewski, Iaccino, & Smith, 1980). Despite their correlational nature, however, these data are interpreted as reflecting a causal relationship between the higher order, cognitive processes assumed to determine subjective perceptual organization and the mechanisms assumed to account for CABs.…”