The influence of imagery ability on color aftereffects produced by physically present and imagined induction stimuli

Abstract

Two methods of induction were used to produce orientation-contingent color aftereffects for observers assigned to one of three groups (high, medium, and low) on the basis of self-rated imagery ability. In Experiment 1, observers were required to make magnitude estimates of color aftereffects following inspection of stimulus patterns normally used to produce McCollough effects (e.g., red vertical contours, green horizontal contours). Experiment 2 was a partial replication of Experiment 1, with additional induction conditions in which observers were required to imagine the presence of appropriately oriented contours when particular homogeneous color patches were presented. The results indicated that self-rated imagery ability was not a significant factor in differentiating between observers' performance when orthodox induction procedures were used (Experiment 1). In addition, there were no reliable indications (Experiment 2) that imagined stimulus attributes can be effectively substituted for real stimulus attributes in order to produce orientation-contingent color aftereffects. The results are discussed in terms of their implications for the use of imagery-induced perceptual phenomena as a paradigm for investigating the possibility of common neural mechanisms in perception and imagination; in addition, the general implications of the results for understanding the functional significance of self-reported imagery ability are examined.Current empirical investigation of,and theoretical speculation about, the phenomenon of imagery is focused on two closely related issues. The first is concerned with the nature of the mental representations underlying imagery and incorporates the debate between those who argue that "visual imagery is encoded in terms of properties that are quite spatial and modality specific" and others who consider that "imagery is encoded in an abstract propositional format and that this same format is used to encode verbal information" (Anderson, 1978, pp. 249-250; see also Kosslyn & Pomerantz, 1977). The second issue involves the relationship between perception and imagination; Hebb (1968), for example, proposed that common neural mechanisms are involved in

Is visual imagery really visual? Overlooked evidence from neuropsychology.

“…The difficulty of replicating many of the more impressive findings of image-percept equivalence (Broerse & Crassini, 1980, 1981Intons-Peterson & White, 1981) has led some psychologists to consider the role of experimenter expectancy effects in imagery research. For example, Intons-Peterson (1983) has contended that the experimental paradigms used to study the visual properties of imagery are sufficiently vulnerable to experimenter expectancy that much, if not all, of the data showing visual properties of images could be artifactual.…”

The VVIQ and imagery-induced McCollough effects: An alternative analysis

“…Hoen (1978) found a low, but significant, positive correlation between scores on the VVIQ and Form C of the Stanford Hypnotic Susceptibility Scale. On this view, one would expect an "experimenter effect" in studies of lIMEs, which may be one of the reasons why Broerse and Crassini (1980) failed to find them.…”

“…In view of the recent discussion (Broerse & Crassini, 1980Finke, 1981) of the relationship between self-ratings of vividness of visual imagery and imagery-induced McCollough effects (Finke & Schmidt, 1977, 1978Kunen & May, 1980;Kaufman, May, & Kunen, 1981), it seemed worthwhile to look again at the original data (Finke & Schmidt, 1978, Table I) and examine how unequivocally they support the conclusion that subjects with visual imagery self-rated as more vivid report stronger imageryinduced McCollough effects (lIMEs). The reanalysis suggests an alternative view of the data, and of other effects which follow adaptation to partially imaginary stimuli.…”

Interpretations of imagery-induced McCollough effects

“…I would like to comment on two articles, recently published in this journal (Broerse & Crassini, 1980;Kunen & May, 1980),which explored the finding that mental images can be used to establish the McCollough effect, reported by M. J. Schmidt and myself several years ago (Finke & Schmidt, 1977, 1978. In particular, I would like to examine the evidence provided in these recent studies pertaining to the proposal that imagined and observed patterns are functionally equivalent.…”