Subliminal Semantic Processing of Grasping Actions: Evidence from ERP Measures of Action-Verb Priming

Abstract

Human interaction with manipulable objects relies heavily on the ability to perceive and execute grasping actions, yet it remains unclear whether the semantics of these actions are processed without conscious awareness. While previous work has identified bottom-up influences on grasp recognition, direct evidence for subliminal semantic processing of grasping actions is limited. Grounded in embodied cognition theory—which posits overlapping neural mechanisms for action language and action execution—the present study examined whether grasp-related verbs can elicit subliminal priming effects on grasping-action recognition. Using a masked priming paradigm, participants classified objects requiring either precision or power grasps while subliminal Chinese action verbs served as primes. Behavioral measures revealed faster responses for semantically congruent cue–target pairs. ERP analyses further demonstrated congruency effects in the N400 and P600 components, reflecting semantic integration and conflict monitoring, as well as modulation of the P300 associated with action-related evaluation. Both grasp types showed evidence of unconscious semantic processing, though precision- and power-grasping actions produced distinct neural patterns. These findings provide direct experimental support for subthreshold semantic activation of grasping actions and confirm the viewpoint of action-language-embodied processing. The study advances the theoretical understanding of unconscious-action semantics and offers a framework for investigating how manipulative-action meaning is accessed below the threshold of awareness.