The scope of unconscious processing remains hotly debated, driven by diverse methods for manipulating and measuring perceptual awareness. Through dialogue among researchers with varied theoretical backgrounds, ten recommendations and nine outstanding issues are provided for designing experimental paradigms, analyzing data, and reporting results. These guidelines aim to evoke discussion about norms in studying unconscious processes and help researchers make informed decisions. While some recommendations may not align with existing approaches and will likely evolve, they are intended to foster a more convergent understanding of the extent and limits of unconscious processing.
A common method for studying unconscious processing compares participants' ability to consciously detect a stimulus with an indirect measure of processing, such as reaction time or brain activity. If the direct measure shows no awareness but the indirect measure shows a significant effect, researchers conclude the stimulus was processed unconsciously. However, this reasoning rests on a statistical fallacy: the sensitivities of the two measures are never directly compared. Reanalyzing 80 experimental conditions from 16 fMRI studies, only eight provided evidence for unconscious processing when sensitivities were properly compared. This suggests that the scope of unconscious processing—both its capacity and the brain areas involved—has been overestimated.