Abstract
Unconscious perceptual effects remain controversial because it is hard to rule out alternative conscious perception explanations for them. We present a novel methodological framework, stressing the centrality of specifying the single-process conscious perception model (i.e., the null hypothesis). Various considerations, including those of SDT (Macmillan & Creelman, 1991), suggest that conscious perception functions hierarchically, in such a way that higher level effects (e.g., semantic priming) should not be possible without lower level discrimination (i.e., detection and identification). Relatedly, alternative conscious perception accounts (as well as the exhaustiveness, null sensitivity, and exclusiveness problems—Reingold & Merikle, 1988, 1990) predict positive relationships between direct and indirect measures. Contrariwise, our review suggests that negative and/or nonmonotonic relationships are found, providing strong evidence for unconscious perception and further suggesting that conscious and unconscious perceptual influences are functionally exclusive (cf. Jones, 1987), in such a way that the former typically override the latter when both are present. Consequently, unconscious perceptual effects manifest reliably only when conscious perception is completely absent, which occurs at the objective detection (butnot identification) threshold.
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This research was undertaken as part of a research program on conscious and unconscious processes in the Ormond and Hazel Hunt Memorial Laboratory, directed by Howard Shevrin and supported by gifts from Robert Berry.
Note—This article was accepted by the previous editorial team, headed by Neil Macmillan.
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Snodgrass, M., Bernat, E. & Shevrin, H. Unconscious perception: A model-based approach to method and evidence. Perception & Psychophysics 66, 846–867 (2004). https://doi.org/10.3758/BF03194978
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DOI: https://doi.org/10.3758/BF03194978