Unconscious semantic processing: Insights from metaphorical priming

The limits of unconscious processing in the semantic domain are highly debated. While prior research presents polarized views on whether word representations are accessible when presented subliminally, this work proposes a more fine-grained investigation into which aspects of word meaning can be accessed unconsciously. Specifically, we explore the conditions under which high-level semantic information, such as metaphorical relations, can be processed subliminally. We rely on space-time and space-number metaphorical mappings, which have been observed in many experiments as well as in spontaneous behavior, such as the association of the past (or subtraction) and the future (or addition) with "left" and "right", respectively. We exploited the fact that some of these conceptual associations (i.e., sagittal or vertical mappings) are also present in language (e.g., "you have a bright future in front of you"; "taxes are going down"), whereas others (i.e., lateral mapping) are not (e.g., "you have a bright future on your right"; "taxes are going left"). In two experiments, space-time and space-number semantic priming consistent with canonical metaphorical mappings emerged when both prime (e.g., "right") and target (e.g., "tomorrow") were consciously perceived, confirming their conceptual association. However, with masked priming, only language-encoded associations were activated. These results suggest that consciousness is necessary to process even ubiquitous and overlearned metaphorical associations and that putatively unconscious semantic priming, when present, may be lexical in nature.